// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package kv contains function to translate name value pairs into
// attribute.KeyValue.
package kv // import "go.opentelemetry.io/contrib/otelconf/internal/kv"

import (
        "fmt"
        "strconv"

        "go.opentelemetry.io/otel/attribute"
)

func FromNameValue(k string, v any) attribute.KeyValue {
        switch val := v.(type) {
        case bool:
                return attribute.Bool(k, val)
        case int64:
                return attribute.Int64(k, val)
        case uint64:
                return attribute.String(k, strconv.FormatUint(val, 10))
        case float64:
                return attribute.Float64(k, val)
        case int8:
                return attribute.Int64(k, int64(val))
        case uint8:
                return attribute.Int64(k, int64(val))
        case int16:
                return attribute.Int64(k, int64(val))
        case uint16:
                return attribute.Int64(k, int64(val))
        case int32:
                return attribute.Int64(k, int64(val))
        case uint32:
                return attribute.Int64(k, int64(val))
        case float32:
                return attribute.Float64(k, float64(val))
        case int:
                return attribute.Int(k, val)
        case uint:
                return attribute.String(k, strconv.FormatUint(uint64(val), 10))
        case string:
                return attribute.String(k, val)
        default:
                return attribute.String(k, fmt.Sprint(v))
        }
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package provider contains various providers
// used to replace variables in configuration files.
package provider // import "go.opentelemetry.io/contrib/otelconf/internal/provider"

import (
        "fmt"
        "os"
        "regexp"
        "strings"
        "time"

        "go.yaml.in/yaml/v3"
)

const validationPattern = `^[a-zA-Z_][a-zA-Z0-9_]*$`

var (
        validationRegexp        = regexp.MustCompile(validationPattern)
        doubleDollarSignsRegexp = regexp.MustCompile(`\$\$([^{$])`)
        envVarRegexp            = regexp.MustCompile(`([$]*)\{([a-zA-Z_][a-zA-Z0-9_]*-?[^}]*)\}`)
)

func ReplaceEnvVars(input []byte) ([]byte, error) {
        // start by replacing all $$ that are not followed by a {

        out := doubleDollarSignsRegexp.ReplaceAllFunc(input, func(s []byte) []byte {
                return append([]byte("$"), doubleDollarSignsRegexp.FindSubmatch(s)[1]...)
        })

        var err error

        out = envVarRegexp.ReplaceAllFunc(out, func(s []byte) []byte {
                match := envVarRegexp.FindSubmatch(s)
                var data []byte

                // check if we have an odd number of $, which indicates that
                // env var replacement should be done
                dollarSigns := match[1]
                if len(match) > 2 && (len(dollarSigns)%2 == 1) {
                        data, err = replaceEnvVar(string(match[2]))
                        if err != nil {
                                return data
                        }
                        if len(dollarSigns) > 1 {
                                data = append(dollarSigns[0:(len(dollarSigns)/2)], data...)
                        }
                } else {
                        // need to expand any default value env var to support the case $${STRING_VALUE:-${STRING_VALUE}}
                        _, defaultValue := parseEnvVar(string(match[2]))
                        if !defaultValue.valid || !strings.Contains(defaultValue.data, "$") {
                                return fmt.Appendf(dollarSigns[0:(len(dollarSigns)/2)], "{%s}", match[2])
                        }
                        // expand the default value
                        data, err = ReplaceEnvVars(append(match[2], byte('}')))
                        if err != nil {
                                return data
                        }
                        data = fmt.Appendf(dollarSigns[0:(len(dollarSigns)/2)], "{%s", data)
                }
                return data
        })
        if err != nil {
                return nil, err
        }
        return out, nil
}

func replaceEnvVar(in string) ([]byte, error) {
        envVarName, defaultValue := parseEnvVar(in)
        if strings.Contains(envVarName, ":") {
                return nil, fmt.Errorf("invalid environment variable name: %s", envVarName)
        }
        if !validationRegexp.MatchString(envVarName) {
                return nil, fmt.Errorf("invalid environment variable name: %s", envVarName)
        }

        val := os.Getenv(envVarName)
        if val == "" && defaultValue.valid {
                val = strings.ReplaceAll(defaultValue.data, "$$", "$")
        }
        if val == "" {
                return nil, nil
        }

        out := []byte(val)
        if err := checkRawConfType(out); err != nil {
                return nil, fmt.Errorf("invalid value type: %w", err)
        }

        return out, nil
}

type defaultValue struct {
        data  string
        valid bool
}

func parseEnvVar(in string) (string, defaultValue) {
        in = strings.TrimPrefix(in, "env:")
        const sep = ":-"
        if i := strings.Index(in, sep); i >= 0 {
                return in[:i], defaultValue{data: in[i+len(sep):], valid: true}
        }
        return in, defaultValue{}
}

func checkRawConfType(val []byte) error {
        var rawConf any
        err := yaml.Unmarshal(val, &rawConf)
        if err != nil {
                return err
        }

        switch rawConf.(type) {
        case int, int32, int64, float32, float64, bool, string, time.Time:
                return nil
        default:
                return fmt.Errorf(
                        "unsupported type=%T for retrieved config,"+
                                " ensure that values are wrapped in quotes", rawConf)
        }
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package tls provides functionality to translate configuration options into tls.Config.
package tls // import "go.opentelemetry.io/contrib/otelconf/internal/tls"

import (
        "crypto/tls"
        "crypto/x509"
        "errors"
        "fmt"
        "os"
)

// CreateConfig creates a tls.Config from certificate files.
func CreateConfig(caCertFile, clientCertFile, clientKeyFile *string) (*tls.Config, error) {
        tlsConfig := &tls.Config{}
        if caCertFile != nil {
                caText, err := os.ReadFile(*caCertFile)
                if err != nil {
                        return nil, err
                }
                certPool := x509.NewCertPool()
                if !certPool.AppendCertsFromPEM(caText) {
                        return nil, errors.New("could not create certificate authority chain from certificate")
                }
                tlsConfig.RootCAs = certPool
        }
        if clientCertFile != nil {
                if clientKeyFile == nil {
                        return nil, errors.New("client certificate was provided but no client key was provided")
                }
                clientCert, err := tls.LoadX509KeyPair(*clientCertFile, *clientKeyFile)
                if err != nil {
                        return nil, fmt.Errorf("could not use client certificate: %w", err)
                }
                tlsConfig.Certificates = []tls.Certificate{clientCert}
        }
        return tlsConfig, nil
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package otelconf provides an OpenTelemetry declarative configuration SDK.
package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "context"
        "errors"
        "fmt"

        "go.opentelemetry.io/otel/baggage"
        "go.opentelemetry.io/otel/log"
        nooplog "go.opentelemetry.io/otel/log/noop"
        "go.opentelemetry.io/otel/metric"
        noopmetric "go.opentelemetry.io/otel/metric/noop"
        sdklog "go.opentelemetry.io/otel/sdk/log"
        sdkmetric "go.opentelemetry.io/otel/sdk/metric"
        sdktrace "go.opentelemetry.io/otel/sdk/trace"
        "go.opentelemetry.io/otel/trace"
        nooptrace "go.opentelemetry.io/otel/trace/noop"
        yaml "go.yaml.in/yaml/v3"

        "go.opentelemetry.io/contrib/otelconf/internal/provider"
)

const (
        protocolProtobufHTTP = "http/protobuf"
        protocolProtobufGRPC = "grpc"

        compressionGzip = "gzip"
        compressionNone = "none"
)

type configOptions struct {
        ctx                   context.Context
        opentelemetryConfig   OpenTelemetryConfiguration
        loggerProviderOptions []sdklog.LoggerProviderOption
        meterProviderOptions  []sdkmetric.Option
        tracerProviderOptions []sdktrace.TracerProviderOption
}

type shutdownFunc func(context.Context) error

func noopShutdown(context.Context) error {
        return nil
}

// SDK is a struct that contains all the providers
// configured via the configuration model.
type SDK struct {
        meterProvider  metric.MeterProvider
        tracerProvider trace.TracerProvider
        loggerProvider log.LoggerProvider
        shutdown       shutdownFunc
}

// TracerProvider returns a configured trace.TracerProvider.
func (s *SDK) TracerProvider() trace.TracerProvider {
        return s.tracerProvider
}

// MeterProvider returns a configured metric.MeterProvider.
func (s *SDK) MeterProvider() metric.MeterProvider {
        return s.meterProvider
}

// LoggerProvider returns a configured log.LoggerProvider.
func (s *SDK) LoggerProvider() log.LoggerProvider {
        return s.loggerProvider
}

// Shutdown calls shutdown on all configured providers.
func (s *SDK) Shutdown(ctx context.Context) error {
        return s.shutdown(ctx)
}

var noopSDK = SDK{
        loggerProvider: nooplog.LoggerProvider{},
        meterProvider:  noopmetric.MeterProvider{},
        tracerProvider: nooptrace.TracerProvider{},
        shutdown:       func(context.Context) error { return nil },
}

// NewSDK creates SDK providers based on the configuration model.
func NewSDK(opts ...ConfigurationOption) (SDK, error) {
        o := configOptions{
                ctx: context.Background(),
        }
        for _, opt := range opts {
                o = opt.apply(o)
        }
        if o.opentelemetryConfig.Disabled != nil && *o.opentelemetryConfig.Disabled {
                return noopSDK, nil
        }

        r := newResource(o.opentelemetryConfig.Resource)

        mp, mpShutdown, err := meterProvider(o, r)
        if err != nil {
                return noopSDK, err
        }

        tp, tpShutdown, err := tracerProvider(o, r)
        if err != nil {
                return noopSDK, err
        }

        lp, lpShutdown, err := loggerProvider(o, r)
        if err != nil {
                return noopSDK, err
        }

        return SDK{
                meterProvider:  mp,
                tracerProvider: tp,
                loggerProvider: lp,
                shutdown: func(ctx context.Context) error {
                        return errors.Join(mpShutdown(ctx), tpShutdown(ctx), lpShutdown(ctx))
                },
        }, nil
}

// ConfigurationOption configures options for providers.
type ConfigurationOption interface {
        apply(configOptions) configOptions
}

type configurationOptionFunc func(configOptions) configOptions

func (fn configurationOptionFunc) apply(cfg configOptions) configOptions {
        return fn(cfg)
}

// WithContext sets the context.Context for the SDK.
func WithContext(ctx context.Context) ConfigurationOption {
        return configurationOptionFunc(func(c configOptions) configOptions {
                c.ctx = ctx
                return c
        })
}

// WithOpenTelemetryConfiguration sets the OpenTelemetryConfiguration used
// to produce the SDK.
func WithOpenTelemetryConfiguration(cfg OpenTelemetryConfiguration) ConfigurationOption {
        return configurationOptionFunc(func(c configOptions) configOptions {
                c.opentelemetryConfig = cfg
                return c
        })
}

// WithLoggerProviderOptions appends LoggerProviderOptions used for constructing
// the LoggerProvider. OpenTelemetryConfiguration takes precedence over these options.
func WithLoggerProviderOptions(opts ...sdklog.LoggerProviderOption) ConfigurationOption {
        return configurationOptionFunc(func(c configOptions) configOptions {
                c.loggerProviderOptions = append(c.loggerProviderOptions, opts...)
                return c
        })
}

// WithMeterProviderOptions appends metric.Options used for constructing the
// MeterProvider. OpenTelemetryConfiguration takes precedence over these options.
func WithMeterProviderOptions(opts ...sdkmetric.Option) ConfigurationOption {
        return configurationOptionFunc(func(c configOptions) configOptions {
                c.meterProviderOptions = append(c.meterProviderOptions, opts...)
                return c
        })
}

// WithTracerProviderOptions appends TracerProviderOptions used for constructing
// the TracerProvider. OpenTelemetryConfiguration takes precedence over these options.
func WithTracerProviderOptions(opts ...sdktrace.TracerProviderOption) ConfigurationOption {
        return configurationOptionFunc(func(c configOptions) configOptions {
                c.tracerProviderOptions = append(c.tracerProviderOptions, opts...)
                return c
        })
}

// ParseYAML parses a YAML configuration file into an OpenTelemetryConfiguration.
func ParseYAML(file []byte) (*OpenTelemetryConfiguration, error) {
        file, err := provider.ReplaceEnvVars(file)
        if err != nil {
                return nil, err
        }

        var cfg OpenTelemetryConfiguration
        err = yaml.Unmarshal(file, &cfg)
        if err != nil {
                return nil, err
        }

        return &cfg, nil
}

// createHeadersConfig combines the two header config fields. Headers take precedence over headersList.
func createHeadersConfig(headers []NameStringValuePair, headersList *string) (map[string]string, error) {
        result := make(map[string]string)
        if headersList != nil {
                // Parsing follows https://github.com/open-telemetry/opentelemetry-configuration/blob/568e5080816d40d75792eb754fc96bde09654159/schema/type_descriptions.yaml#L584.
                headerslist, err := baggage.Parse(*headersList)
                if err != nil {
                        return nil, fmt.Errorf("invalid headers list: %w", err)
                }
                for _, kv := range headerslist.Members() {
                        result[kv.Key()] = kv.Value()
                }
        }
        // Headers take precedence over HeadersList, so this has to be after HeadersList is processed
        if len(headers) > 0 {
                for _, kv := range headers {
                        if kv.Value != nil {
                                result[kv.Name] = *kv.Value
                        }
                }
        }
        return result, nil
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "encoding/json"
        "errors"
        "fmt"
        "reflect"
)

// MarshalJSON implements json.Marshaler.
func (j *AttributeNameValueType) MarshalJSON() ([]byte, error) {
        return json.Marshal(j.Value)
}

var enumValuesAttributeNameValueType = []any{
        nil,
        "string",
        "bool",
        "int",
        "double",
        "string_array",
        "bool_array",
        "int_array",
        "double_array",
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *AttributeNameValueType) UnmarshalJSON(b []byte) error {
        var v struct {
                Value any
        }
        if err := json.Unmarshal(b, &v.Value); err != nil {
                return err
        }
        var ok bool
        for _, expected := range enumValuesAttributeNameValueType {
                if reflect.DeepEqual(v.Value, expected) {
                        ok = true
                        break
                }
        }
        if !ok {
                return fmt.Errorf("invalid value (expected one of %#v): %#v", enumValuesAttributeNameValueType, v.Value)
        }
        *j = AttributeNameValueType(v)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *BatchLogRecordProcessor) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in BatchLogRecordProcessor: required")
        }
        type Plain BatchLogRecordProcessor
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = BatchLogRecordProcessor(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *BatchSpanProcessor) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in BatchSpanProcessor: required")
        }
        type Plain BatchSpanProcessor
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = BatchSpanProcessor(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *GeneralInstrumentationPeerServiceMappingElem) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["peer"]; raw != nil && !ok {
                return errors.New("field peer in GeneralInstrumentationPeerServiceMappingElem: required")
        }
        if _, ok := raw["service"]; raw != nil && !ok {
                return errors.New("field service in GeneralInstrumentationPeerServiceMappingElem: required")
        }
        type Plain GeneralInstrumentationPeerServiceMappingElem
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = GeneralInstrumentationPeerServiceMappingElem(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *NameStringValuePair) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["name"]; !ok {
                return errors.New("json: cannot unmarshal field name in NameStringValuePair required")
        }
        if _, ok := raw["value"]; !ok {
                return errors.New("json: cannot unmarshal field value in NameStringValuePair required")
        }
        var name, value string
        var ok bool
        if name, ok = raw["name"].(string); !ok {
                return errors.New("yaml: cannot unmarshal field name in NameStringValuePair must be string")
        }
        if value, ok = raw["value"].(string); !ok {
                return errors.New("yaml: cannot unmarshal field value in NameStringValuePair must be string")
        }

        *j = NameStringValuePair{
                Name:  name,
                Value: &value,
        }
        return nil
}

var enumValuesOTLPMetricDefaultHistogramAggregation = []any{
        "explicit_bucket_histogram",
        "base2_exponential_bucket_histogram",
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *OTLPMetricDefaultHistogramAggregation) UnmarshalJSON(b []byte) error {
        var v string
        if err := json.Unmarshal(b, &v); err != nil {
                return err
        }
        var ok bool
        for _, expected := range enumValuesOTLPMetricDefaultHistogramAggregation {
                if reflect.DeepEqual(v, expected) {
                        ok = true
                        break
                }
        }
        if !ok {
                return fmt.Errorf("invalid value (expected one of %#v): %#v", enumValuesOTLPMetricDefaultHistogramAggregation, v)
        }
        *j = OTLPMetricDefaultHistogramAggregation(v)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *OTLPMetric) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["endpoint"]; raw != nil && !ok {
                return errors.New("field endpoint in OTLPMetric: required")
        }
        if _, ok := raw["protocol"]; raw != nil && !ok {
                return errors.New("field protocol in OTLPMetric: required")
        }
        type Plain OTLPMetric
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = OTLPMetric(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *OTLP) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["endpoint"]; raw != nil && !ok {
                return errors.New("field endpoint in OTLP: required")
        }
        if _, ok := raw["protocol"]; raw != nil && !ok {
                return errors.New("field protocol in OTLP: required")
        }
        type Plain OTLP
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = OTLP(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *OpenTelemetryConfiguration) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["file_format"]; raw != nil && !ok {
                return errors.New("field file_format in OpenTelemetryConfiguration: required")
        }
        type Plain OpenTelemetryConfiguration
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = OpenTelemetryConfiguration(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *PeriodicMetricReader) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in PeriodicMetricReader: required")
        }
        type Plain PeriodicMetricReader
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = PeriodicMetricReader(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *PullMetricReader) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in PullMetricReader: required")
        }
        type Plain PullMetricReader
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = PullMetricReader(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *SimpleLogRecordProcessor) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in SimpleLogRecordProcessor: required")
        }
        type Plain SimpleLogRecordProcessor
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = SimpleLogRecordProcessor(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *SimpleSpanProcessor) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["exporter"]; raw != nil && !ok {
                return errors.New("field exporter in SimpleSpanProcessor: required")
        }
        type Plain SimpleSpanProcessor
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = SimpleSpanProcessor(plain)
        return nil
}

var enumValuesViewSelectorInstrumentType = []any{
        "counter",
        "histogram",
        "observable_counter",
        "observable_gauge",
        "observable_up_down_counter",
        "up_down_counter",
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *ViewSelectorInstrumentType) UnmarshalJSON(b []byte) error {
        var v string
        if err := json.Unmarshal(b, &v); err != nil {
                return err
        }
        var ok bool
        for _, expected := range enumValuesViewSelectorInstrumentType {
                if reflect.DeepEqual(v, expected) {
                        ok = true
                        break
                }
        }
        if !ok {
                return fmt.Errorf("invalid value (expected one of %#v): %#v", enumValuesViewSelectorInstrumentType, v)
        }
        *j = ViewSelectorInstrumentType(v)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *Zipkin) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["endpoint"]; raw != nil && !ok {
                return errors.New("field endpoint in Zipkin: required")
        }
        type Plain Zipkin
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        *j = Zipkin(plain)
        return nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (j *AttributeNameValue) UnmarshalJSON(b []byte) error {
        var raw map[string]any
        if err := json.Unmarshal(b, &raw); err != nil {
                return err
        }
        if _, ok := raw["name"]; raw != nil && !ok {
                return errors.New("field name in AttributeNameValue: required")
        }
        if _, ok := raw["value"]; raw != nil && !ok {
                return errors.New("field value in AttributeNameValue: required")
        }
        type Plain AttributeNameValue
        var plain Plain
        if err := json.Unmarshal(b, &plain); err != nil {
                return err
        }
        if plain.Type != nil && plain.Type.Value == "int" {
                val, ok := plain.Value.(float64)
                if ok {
                        plain.Value = int(val)
                }
        }
        if plain.Type != nil && plain.Type.Value == "int_array" {
                m, ok := plain.Value.([]any)
                if ok {
                        var vals []any
                        for _, v := range m {
                                val, ok := v.(float64)
                                if ok {
                                        vals = append(vals, int(val))
                                } else {
                                        vals = append(vals, val)
                                }
                        }
                        plain.Value = vals
                }
        }

        *j = AttributeNameValue(plain)
        return nil
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "errors"
        "fmt"
        "reflect"
)

// UnmarshalYAML implements yaml.Unmarshaler.
func (j *AttributeNameValueType) UnmarshalYAML(unmarshal func(any) error) error {
        var v struct {
                Value any
        }
        if err := unmarshal(&v.Value); err != nil {
                return err
        }
        var ok bool
        for _, expected := range enumValuesAttributeNameValueType {
                if reflect.DeepEqual(v.Value, expected) {
                        ok = true
                        break
                }
        }
        if !ok {
                return fmt.Errorf("invalid value (expected one of %#v): %#v", enumValuesAttributeNameValueType, v.Value)
        }
        *j = AttributeNameValueType(v)
        return nil
}

// UnmarshalYAML implements yaml.Unmarshaler.
func (j *NameStringValuePair) UnmarshalYAML(unmarshal func(any) error) error {
        var raw map[string]any
        if err := unmarshal(&raw); err != nil {
                return err
        }
        if _, ok := raw["name"]; !ok {
                return errors.New("yaml: cannot unmarshal field name in NameStringValuePair required")
        }
        if _, ok := raw["value"]; !ok {
                return errors.New("yaml: cannot unmarshal field value in NameStringValuePair required")
        }
        var name, value string
        var ok bool
        if name, ok = raw["name"].(string); !ok {
                return errors.New("yaml: cannot unmarshal field name in NameStringValuePair must be string")
        }
        if value, ok = raw["value"].(string); !ok {
                return errors.New("yaml: cannot unmarshal field value in NameStringValuePair must be string")
        }
        *j = NameStringValuePair{
                Name:  name,
                Value: &value,
        }
        return nil
}

// UnmarshalYAML implements yaml.Unmarshaler.
func (j *LanguageSpecificInstrumentation) UnmarshalYAML(unmarshal func(any) error) error {
        var raw map[string]any
        if err := unmarshal(&raw); err != nil {
                return err
        }

        *j = raw
        return nil
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "context"
        "errors"
        "fmt"
        "net/url"
        "time"

        "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc"
        "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp"
        "go.opentelemetry.io/otel/exporters/stdout/stdoutlog"
        "go.opentelemetry.io/otel/log"
        "go.opentelemetry.io/otel/log/noop"
        sdklog "go.opentelemetry.io/otel/sdk/log"
        "go.opentelemetry.io/otel/sdk/resource"
        "google.golang.org/grpc/credentials"

        "go.opentelemetry.io/contrib/otelconf/internal/tls"
)

func loggerProvider(cfg configOptions, res *resource.Resource) (log.LoggerProvider, shutdownFunc, error) {
        if cfg.opentelemetryConfig.LoggerProvider == nil {
                return noop.NewLoggerProvider(), noopShutdown, nil
        }
        opts := append(cfg.loggerProviderOptions, sdklog.WithResource(res))

        var errs []error
        for _, processor := range cfg.opentelemetryConfig.LoggerProvider.Processors {
                sp, err := logProcessor(cfg.ctx, processor)
                if err == nil {
                        opts = append(opts, sdklog.WithProcessor(sp))
                } else {
                        errs = append(errs, err)
                }
        }

        if len(errs) > 0 {
                return noop.NewLoggerProvider(), noopShutdown, errors.Join(errs...)
        }

        lp := sdklog.NewLoggerProvider(opts...)
        return lp, lp.Shutdown, nil
}

func logProcessor(ctx context.Context, processor LogRecordProcessor) (sdklog.Processor, error) {
        if processor.Batch != nil && processor.Simple != nil {
                return nil, errors.New("must not specify multiple log processor type")
        }
        if processor.Batch != nil {
                exp, err := logExporter(ctx, processor.Batch.Exporter)
                if err != nil {
                        return nil, err
                }
                return batchLogProcessor(processor.Batch, exp)
        }
        if processor.Simple != nil {
                exp, err := logExporter(ctx, processor.Simple.Exporter)
                if err != nil {
                        return nil, err
                }
                return sdklog.NewSimpleProcessor(exp), nil
        }
        return nil, errors.New("unsupported log processor type, must be one of simple or batch")
}

func logExporter(ctx context.Context, exporter LogRecordExporter) (sdklog.Exporter, error) {
        if exporter.Console != nil && exporter.OTLP != nil {
                return nil, errors.New("must not specify multiple exporters")
        }

        if exporter.Console != nil {
                return stdoutlog.New(
                        stdoutlog.WithPrettyPrint(),
                )
        }

        if exporter.OTLP != nil && exporter.OTLP.Protocol != nil {
                switch *exporter.OTLP.Protocol {
                case protocolProtobufHTTP:
                        return otlpHTTPLogExporter(ctx, exporter.OTLP)
                case protocolProtobufGRPC:
                        return otlpGRPCLogExporter(ctx, exporter.OTLP)
                default:
                        return nil, fmt.Errorf("unsupported protocol %q", *exporter.OTLP.Protocol)
                }
        }
        return nil, errors.New("no valid log exporter")
}

func batchLogProcessor(blp *BatchLogRecordProcessor, exp sdklog.Exporter) (*sdklog.BatchProcessor, error) {
        var opts []sdklog.BatchProcessorOption
        if blp.ExportTimeout != nil {
                if *blp.ExportTimeout < 0 {
                        return nil, fmt.Errorf("invalid export timeout %d", *blp.ExportTimeout)
                }
                opts = append(opts, sdklog.WithExportTimeout(time.Millisecond*time.Duration(*blp.ExportTimeout)))
        }
        if blp.MaxExportBatchSize != nil {
                if *blp.MaxExportBatchSize < 0 {
                        return nil, fmt.Errorf("invalid batch size %d", *blp.MaxExportBatchSize)
                }
                opts = append(opts, sdklog.WithExportMaxBatchSize(*blp.MaxExportBatchSize))
        }
        if blp.MaxQueueSize != nil {
                if *blp.MaxQueueSize < 0 {
                        return nil, fmt.Errorf("invalid queue size %d", *blp.MaxQueueSize)
                }
                opts = append(opts, sdklog.WithMaxQueueSize(*blp.MaxQueueSize))
        }

        if blp.ScheduleDelay != nil {
                if *blp.ScheduleDelay < 0 {
                        return nil, fmt.Errorf("invalid schedule delay %d", *blp.ScheduleDelay)
                }
                opts = append(opts, sdklog.WithExportInterval(time.Millisecond*time.Duration(*blp.ScheduleDelay)))
        }

        return sdklog.NewBatchProcessor(exp, opts...), nil
}

func otlpHTTPLogExporter(ctx context.Context, otlpConfig *OTLP) (sdklog.Exporter, error) {
        var opts []otlploghttp.Option

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlploghttp.WithEndpoint(u.Host))

                if u.Scheme == "http" {
                        opts = append(opts, otlploghttp.WithInsecure())
                }
                if u.Path != "" {
                        opts = append(opts, otlploghttp.WithURLPath(u.Path))
                }
        }
        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlploghttp.WithCompression(otlploghttp.GzipCompression))
                case compressionNone:
                        opts = append(opts, otlploghttp.WithCompression(otlploghttp.NoCompression))
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil && *otlpConfig.Timeout > 0 {
                opts = append(opts, otlploghttp.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlploghttp.WithHeaders(headersConfig))
        }

        tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
        if err != nil {
                return nil, err
        }
        opts = append(opts, otlploghttp.WithTLSClientConfig(tlsConfig))

        return otlploghttp.New(ctx, opts...)
}

func otlpGRPCLogExporter(ctx context.Context, otlpConfig *OTLP) (sdklog.Exporter, error) {
        var opts []otlploggrpc.Option

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                // ParseRequestURI leaves the Host field empty when no
                // scheme is specified (i.e. localhost:4317). This check is
                // here to support the case where a user may not specify a
                // scheme. The code does its best effort here by using
                // otlpConfig.Endpoint as-is in that case
                if u.Host != "" {
                        opts = append(opts, otlploggrpc.WithEndpoint(u.Host))
                } else {
                        opts = append(opts, otlploggrpc.WithEndpoint(*otlpConfig.Endpoint))
                }
                if u.Scheme == "http" || (u.Scheme != "https" && otlpConfig.Insecure != nil && *otlpConfig.Insecure) {
                        opts = append(opts, otlploggrpc.WithInsecure())
                }
        }
        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlploggrpc.WithCompressor(*otlpConfig.Compression))
                case compressionNone:
                        // none requires no options
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil && *otlpConfig.Timeout > 0 {
                opts = append(opts, otlploggrpc.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlploggrpc.WithHeaders(headersConfig))
        }

        if otlpConfig.Certificate != nil || otlpConfig.ClientCertificate != nil || otlpConfig.ClientKey != nil {
                tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlploggrpc.WithTLSCredentials(credentials.NewTLS(tlsConfig)))
        }

        return otlploggrpc.New(ctx, opts...)
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "context"
        "encoding/json"
        "errors"
        "fmt"
        "math"
        "net"
        "net/http"
        "net/url"
        "os"
        "strconv"
        "time"

        "github.com/prometheus/client_golang/prometheus"
        "github.com/prometheus/client_golang/prometheus/promhttp"
        "go.opentelemetry.io/otel"
        "go.opentelemetry.io/otel/attribute"
        "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
        "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
        otelprom "go.opentelemetry.io/otel/exporters/prometheus"
        "go.opentelemetry.io/otel/exporters/stdout/stdoutmetric"
        "go.opentelemetry.io/otel/metric"
        "go.opentelemetry.io/otel/metric/noop"
        "go.opentelemetry.io/otel/sdk/instrumentation"
        sdkmetric "go.opentelemetry.io/otel/sdk/metric"
        "go.opentelemetry.io/otel/sdk/metric/metricdata"
        "go.opentelemetry.io/otel/sdk/resource"
        "google.golang.org/grpc/credentials"

        "go.opentelemetry.io/contrib/otelconf/internal/tls"
)

var zeroScope instrumentation.Scope

const instrumentKindUndefined = sdkmetric.InstrumentKind(0)

func meterProvider(cfg configOptions, res *resource.Resource) (metric.MeterProvider, shutdownFunc, error) {
        if cfg.opentelemetryConfig.MeterProvider == nil {
                return noop.NewMeterProvider(), noopShutdown, nil
        }
        opts := append(cfg.meterProviderOptions, sdkmetric.WithResource(res))

        var errs []error
        for _, reader := range cfg.opentelemetryConfig.MeterProvider.Readers {
                r, err := metricReader(cfg.ctx, reader)
                if err == nil {
                        opts = append(opts, sdkmetric.WithReader(r))
                } else {
                        errs = append(errs, err)
                }
        }
        for _, vw := range cfg.opentelemetryConfig.MeterProvider.Views {
                v, err := view(vw)
                if err == nil {
                        opts = append(opts, sdkmetric.WithView(v))
                } else {
                        errs = append(errs, err)
                }
        }

        if len(errs) > 0 {
                return noop.NewMeterProvider(), noopShutdown, errors.Join(errs...)
        }

        mp := sdkmetric.NewMeterProvider(opts...)
        return mp, mp.Shutdown, nil
}

func metricReader(ctx context.Context, r MetricReader) (sdkmetric.Reader, error) {
        if r.Periodic != nil && r.Pull != nil {
                return nil, errors.New("must not specify multiple metric reader type")
        }

        if r.Periodic != nil {
                var opts []sdkmetric.PeriodicReaderOption
                if r.Periodic.Interval != nil {
                        opts = append(opts, sdkmetric.WithInterval(time.Duration(*r.Periodic.Interval)*time.Millisecond))
                }

                if r.Periodic.Timeout != nil {
                        opts = append(opts, sdkmetric.WithTimeout(time.Duration(*r.Periodic.Timeout)*time.Millisecond))
                }
                return periodicExporter(ctx, r.Periodic.Exporter, opts...)
        }

        if r.Pull != nil {
                return pullReader(ctx, r.Pull.Exporter)
        }
        return nil, errors.New("no valid metric reader")
}

func pullReader(ctx context.Context, exporter PullMetricExporter) (sdkmetric.Reader, error) {
        if exporter.Prometheus != nil {
                return prometheusReader(ctx, exporter.Prometheus)
        }
        return nil, errors.New("no valid metric exporter")
}

func periodicExporter(ctx context.Context, exporter PushMetricExporter, opts ...sdkmetric.PeriodicReaderOption) (sdkmetric.Reader, error) {
        if exporter.Console != nil && exporter.OTLP != nil {
                return nil, errors.New("must not specify multiple exporters")
        }
        if exporter.Console != nil {
                enc := json.NewEncoder(os.Stdout)
                enc.SetIndent("", "  ")

                exp, err := stdoutmetric.New(
                        stdoutmetric.WithEncoder(enc),
                )
                if err != nil {
                        return nil, err
                }
                return sdkmetric.NewPeriodicReader(exp, opts...), nil
        }
        if exporter.OTLP != nil && exporter.OTLP.Protocol != nil {
                var err error
                var exp sdkmetric.Exporter
                switch *exporter.OTLP.Protocol {
                case protocolProtobufHTTP:
                        exp, err = otlpHTTPMetricExporter(ctx, exporter.OTLP)
                case protocolProtobufGRPC:
                        exp, err = otlpGRPCMetricExporter(ctx, exporter.OTLP)
                default:
                        return nil, fmt.Errorf("unsupported protocol %q", *exporter.OTLP.Protocol)
                }
                if err != nil {
                        return nil, err
                }
                return sdkmetric.NewPeriodicReader(exp, opts...), nil
        }
        return nil, errors.New("no valid metric exporter")
}

func otlpHTTPMetricExporter(ctx context.Context, otlpConfig *OTLPMetric) (sdkmetric.Exporter, error) {
        opts := []otlpmetrichttp.Option{}

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlpmetrichttp.WithEndpoint(u.Host))

                if u.Scheme == "http" {
                        opts = append(opts, otlpmetrichttp.WithInsecure())
                }
                if u.Path != "" {
                        opts = append(opts, otlpmetrichttp.WithURLPath(u.Path))
                }
        }
        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlpmetrichttp.WithCompression(otlpmetrichttp.GzipCompression))
                case compressionNone:
                        opts = append(opts, otlpmetrichttp.WithCompression(otlpmetrichttp.NoCompression))
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil {
                opts = append(opts, otlpmetrichttp.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlpmetrichttp.WithHeaders(headersConfig))
        }
        if otlpConfig.TemporalityPreference != nil {
                switch *otlpConfig.TemporalityPreference {
                case "delta":
                        opts = append(opts, otlpmetrichttp.WithTemporalitySelector(deltaTemporality))
                case "cumulative":
                        opts = append(opts, otlpmetrichttp.WithTemporalitySelector(cumulativeTemporality))
                case "lowmemory":
                        opts = append(opts, otlpmetrichttp.WithTemporalitySelector(lowMemory))
                default:
                        return nil, fmt.Errorf("unsupported temporality preference %q", *otlpConfig.TemporalityPreference)
                }
        }

        tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
        if err != nil {
                return nil, err
        }
        opts = append(opts, otlpmetrichttp.WithTLSClientConfig(tlsConfig))

        return otlpmetrichttp.New(ctx, opts...)
}

func otlpGRPCMetricExporter(ctx context.Context, otlpConfig *OTLPMetric) (sdkmetric.Exporter, error) {
        var opts []otlpmetricgrpc.Option

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                // ParseRequestURI leaves the Host field empty when no
                // scheme is specified (i.e. localhost:4317). This check is
                // here to support the case where a user may not specify a
                // scheme. The code does its best effort here by using
                // otlpConfig.Endpoint as-is in that case
                if u.Host != "" {
                        opts = append(opts, otlpmetricgrpc.WithEndpoint(u.Host))
                } else {
                        opts = append(opts, otlpmetricgrpc.WithEndpoint(*otlpConfig.Endpoint))
                }
                if u.Scheme == "http" || (u.Scheme != "https" && otlpConfig.Insecure != nil && *otlpConfig.Insecure) {
                        opts = append(opts, otlpmetricgrpc.WithInsecure())
                }
        }

        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlpmetricgrpc.WithCompressor(*otlpConfig.Compression))
                case compressionNone:
                        // none requires no options
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil && *otlpConfig.Timeout > 0 {
                opts = append(opts, otlpmetricgrpc.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlpmetricgrpc.WithHeaders(headersConfig))
        }
        if otlpConfig.TemporalityPreference != nil {
                switch *otlpConfig.TemporalityPreference {
                case "delta":
                        opts = append(opts, otlpmetricgrpc.WithTemporalitySelector(deltaTemporality))
                case "cumulative":
                        opts = append(opts, otlpmetricgrpc.WithTemporalitySelector(cumulativeTemporality))
                case "lowmemory":
                        opts = append(opts, otlpmetricgrpc.WithTemporalitySelector(lowMemory))
                default:
                        return nil, fmt.Errorf("unsupported temporality preference %q", *otlpConfig.TemporalityPreference)
                }
        }

        if otlpConfig.Certificate != nil || otlpConfig.ClientCertificate != nil || otlpConfig.ClientKey != nil {
                tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlpmetricgrpc.WithTLSCredentials(credentials.NewTLS(tlsConfig)))
        }

        return otlpmetricgrpc.New(ctx, opts...)
}

func cumulativeTemporality(sdkmetric.InstrumentKind) metricdata.Temporality {
        return metricdata.CumulativeTemporality
}

func deltaTemporality(ik sdkmetric.InstrumentKind) metricdata.Temporality {
        switch ik {
        case sdkmetric.InstrumentKindCounter, sdkmetric.InstrumentKindHistogram, sdkmetric.InstrumentKindObservableCounter:
                return metricdata.DeltaTemporality
        default:
                return metricdata.CumulativeTemporality
        }
}

func lowMemory(ik sdkmetric.InstrumentKind) metricdata.Temporality {
        switch ik {
        case sdkmetric.InstrumentKindCounter, sdkmetric.InstrumentKindHistogram:
                return metricdata.DeltaTemporality
        default:
                return metricdata.CumulativeTemporality
        }
}

// newIncludeExcludeFilter returns a Filter that includes attributes
// in the include list and excludes attributes in the excludes list.
// It returns an error if an attribute is in both lists
//
// If IncludeExclude is empty a include-all filter is returned.
func newIncludeExcludeFilter(lists *IncludeExclude) (attribute.Filter, error) {
        if lists == nil {
                return func(attribute.KeyValue) bool { return true }, nil
        }

        included := make(map[attribute.Key]struct{})
        for _, k := range lists.Included {
                included[attribute.Key(k)] = struct{}{}
        }
        excluded := make(map[attribute.Key]struct{})
        for _, k := range lists.Excluded {
                if _, ok := included[attribute.Key(k)]; ok {
                        return nil, fmt.Errorf("attribute cannot be in both include and exclude list: %s", k)
                }
                excluded[attribute.Key(k)] = struct{}{}
        }
        return func(kv attribute.KeyValue) bool {
                // check if a value is excluded first
                if _, ok := excluded[kv.Key]; ok {
                        return false
                }

                if len(included) == 0 {
                        return true
                }

                _, ok := included[kv.Key]
                return ok
        }, nil
}

func prometheusReader(ctx context.Context, prometheusConfig *Prometheus) (sdkmetric.Reader, error) {
        if prometheusConfig.Host == nil {
                return nil, errors.New("host must be specified")
        }
        if prometheusConfig.Port == nil {
                return nil, errors.New("port must be specified")
        }

        opts, err := prometheusReaderOpts(prometheusConfig)
        if err != nil {
                return nil, err
        }

        reg := prometheus.NewRegistry()
        opts = append(opts, otelprom.WithRegisterer(reg))

        reader, err := otelprom.New(opts...)
        if err != nil {
                return nil, fmt.Errorf("error creating otel prometheus exporter: %w", err)
        }

        mux := http.NewServeMux()
        mux.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))
        server := http.Server{
                // Timeouts are necessary to make a server resilient to attacks.
                // We use values from this example: https://blog.cloudflare.com/exposing-go-on-the-internet/#:~:text=There%20are%20three%20main%20timeouts
                ReadTimeout:  5 * time.Second,
                WriteTimeout: 10 * time.Second,
                IdleTimeout:  120 * time.Second,
                Handler:      mux,
        }

        // Remove surrounding "[]" from the host definition to allow users to define the host as "[::1]" or "::1".
        host := *prometheusConfig.Host
        if len(host) > 2 && host[0] == '[' && host[len(host)-1] == ']' {
                host = host[1 : len(host)-1]
        }

        addr := net.JoinHostPort(host, strconv.Itoa(*prometheusConfig.Port))
        lis, err := net.Listen("tcp", addr)
        if err != nil {
                return nil, errors.Join(
                        fmt.Errorf("binding address %s for Prometheus exporter: %w", addr, err),
                        reader.Shutdown(ctx),
                )
        }

        // Only for testing reasons, add the address to the http Server, will not be used.
        server.Addr = lis.Addr().String()

        go func() {
                if err := server.Serve(lis); err != nil && !errors.Is(err, http.ErrServerClosed) {
                        otel.Handle(fmt.Errorf("the Prometheus HTTP server exited unexpectedly: %w", err))
                }
        }()

        return readerWithServer{reader, &server}, nil
}

func prometheusReaderOpts(prometheusConfig *Prometheus) ([]otelprom.Option, error) {
        var opts []otelprom.Option
        if prometheusConfig.WithoutScopeInfo != nil && *prometheusConfig.WithoutScopeInfo {
                opts = append(opts, otelprom.WithoutScopeInfo())
        }
        if prometheusConfig.WithoutTypeSuffix != nil && *prometheusConfig.WithoutTypeSuffix {
                opts = append(opts, otelprom.WithoutCounterSuffixes()) //nolint:staticcheck // WithouTypeSuffix is deprecated, but we still need it for backwards compatibility.
        }
        if prometheusConfig.WithoutUnits != nil && *prometheusConfig.WithoutUnits {
                opts = append(opts, otelprom.WithoutUnits()) //nolint:staticcheck // WithouTypeSuffix is deprecated, but we still need it for backwards compatibility.
        }
        if prometheusConfig.WithResourceConstantLabels != nil {
                f, err := newIncludeExcludeFilter(prometheusConfig.WithResourceConstantLabels)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otelprom.WithResourceAsConstantLabels(f))
        }

        return opts, nil
}

type readerWithServer struct {
        sdkmetric.Reader
        server *http.Server
}

func (rws readerWithServer) Shutdown(ctx context.Context) error {
        return errors.Join(
                rws.Reader.Shutdown(ctx),
                rws.server.Shutdown(ctx),
        )
}

func view(v View) (sdkmetric.View, error) {
        if v.Selector == nil {
                return nil, errors.New("view: no selector provided")
        }

        inst, err := instrument(*v.Selector)
        if err != nil {
                return nil, err
        }

        s, err := stream(v.Stream)
        if err != nil {
                return nil, err
        }
        return sdkmetric.NewView(inst, s), nil
}

func instrument(vs ViewSelector) (sdkmetric.Instrument, error) {
        kind, err := instrumentKind(vs.InstrumentType)
        if err != nil {
                return sdkmetric.Instrument{}, fmt.Errorf("view_selector: %w", err)
        }
        inst := sdkmetric.Instrument{
                Name: strOrEmpty(vs.InstrumentName),
                Unit: strOrEmpty(vs.Unit),
                Kind: kind,
                Scope: instrumentation.Scope{
                        Name:      strOrEmpty(vs.MeterName),
                        Version:   strOrEmpty(vs.MeterVersion),
                        SchemaURL: strOrEmpty(vs.MeterSchemaUrl),
                },
        }

        if instrumentIsEmpty(inst) {
                return sdkmetric.Instrument{}, errors.New("view_selector: empty selector not supporter")
        }
        return inst, nil
}

func stream(vs *ViewStream) (sdkmetric.Stream, error) {
        if vs == nil {
                return sdkmetric.Stream{}, nil
        }

        f, err := newIncludeExcludeFilter(vs.AttributeKeys)
        if err != nil {
                return sdkmetric.Stream{}, err
        }
        return sdkmetric.Stream{
                Name:            strOrEmpty(vs.Name),
                Description:     strOrEmpty(vs.Description),
                Aggregation:     aggregation(vs.Aggregation),
                AttributeFilter: f,
        }, nil
}

func aggregation(aggr *ViewStreamAggregation) sdkmetric.Aggregation {
        if aggr == nil {
                return nil
        }

        if aggr.Base2ExponentialBucketHistogram != nil {
                return sdkmetric.AggregationBase2ExponentialHistogram{
                        MaxSize:  int32OrZero(aggr.Base2ExponentialBucketHistogram.MaxSize),
                        MaxScale: int32OrZero(aggr.Base2ExponentialBucketHistogram.MaxScale),
                        // Need to negate because config has the positive action RecordMinMax.
                        NoMinMax: !boolOrFalse(aggr.Base2ExponentialBucketHistogram.RecordMinMax),
                }
        }
        if aggr.Default != nil {
                // TODO: Understand what to set here.
                return nil
        }
        if aggr.Drop != nil {
                return sdkmetric.AggregationDrop{}
        }
        if aggr.ExplicitBucketHistogram != nil {
                return sdkmetric.AggregationExplicitBucketHistogram{
                        Boundaries: aggr.ExplicitBucketHistogram.Boundaries,
                        // Need to negate because config has the positive action RecordMinMax.
                        NoMinMax: !boolOrFalse(aggr.ExplicitBucketHistogram.RecordMinMax),
                }
        }
        if aggr.LastValue != nil {
                return sdkmetric.AggregationLastValue{}
        }
        if aggr.Sum != nil {
                return sdkmetric.AggregationSum{}
        }
        return nil
}

func instrumentKind(vsit *ViewSelectorInstrumentType) (sdkmetric.InstrumentKind, error) {
        if vsit == nil {
                // Equivalent to instrumentKindUndefined.
                return instrumentKindUndefined, nil
        }

        switch *vsit {
        case ViewSelectorInstrumentTypeCounter:
                return sdkmetric.InstrumentKindCounter, nil
        case ViewSelectorInstrumentTypeUpDownCounter:
                return sdkmetric.InstrumentKindUpDownCounter, nil
        case ViewSelectorInstrumentTypeHistogram:
                return sdkmetric.InstrumentKindHistogram, nil
        case ViewSelectorInstrumentTypeObservableCounter:
                return sdkmetric.InstrumentKindObservableCounter, nil
        case ViewSelectorInstrumentTypeObservableUpDownCounter:
                return sdkmetric.InstrumentKindObservableUpDownCounter, nil
        case ViewSelectorInstrumentTypeObservableGauge:
                return sdkmetric.InstrumentKindObservableGauge, nil
        }

        return instrumentKindUndefined, errors.New("instrument_type: invalid value")
}

func instrumentIsEmpty(i sdkmetric.Instrument) bool {
        return i.Name == "" &&
                i.Description == "" &&
                i.Kind == instrumentKindUndefined &&
                i.Unit == "" &&
                i.Scope == zeroScope
}

func boolOrFalse(pBool *bool) bool {
        if pBool == nil {
                return false
        }
        return *pBool
}

func int32OrZero(pInt *int) int32 {
        if pInt == nil {
                return 0
        }
        i := *pInt
        if i > math.MaxInt32 {
                return math.MaxInt32
        }
        if i < math.MinInt32 {
                return math.MinInt32
        }
        return int32(i)
}

func strOrEmpty(pStr *string) string {
        if pStr == nil {
                return ""
        }
        return *pStr
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "go.opentelemetry.io/otel/attribute"
        "go.opentelemetry.io/otel/sdk/resource"

        "go.opentelemetry.io/contrib/otelconf/internal/kv"
)

func newResource(res *Resource) *resource.Resource {
        if res == nil {
                return resource.Default()
        }

        var attrs []attribute.KeyValue
        for _, v := range res.Attributes {
                attrs = append(attrs, kv.FromNameValue(v.Name, v.Value))
        }

        if res.SchemaUrl == nil {
                return resource.NewSchemaless(attrs...)
        }
        return resource.NewWithAttributes(*res.SchemaUrl, attrs...)
}

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"

import (
        "context"
        "errors"
        "fmt"
        "net/url"
        "time"

        "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
        "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
        "go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
        "go.opentelemetry.io/otel/sdk/resource"
        sdktrace "go.opentelemetry.io/otel/sdk/trace"
        "go.opentelemetry.io/otel/trace"
        "go.opentelemetry.io/otel/trace/noop"
        "google.golang.org/grpc/credentials"

        "go.opentelemetry.io/contrib/otelconf/internal/tls"
)

var errInvalidSamplerConfiguration = errors.New("invalid sampler configuration")

func tracerProvider(cfg configOptions, res *resource.Resource) (trace.TracerProvider, shutdownFunc, error) {
        if cfg.opentelemetryConfig.TracerProvider == nil {
                return noop.NewTracerProvider(), noopShutdown, nil
        }
        opts := append(cfg.tracerProviderOptions, sdktrace.WithResource(res))

        var errs []error
        for _, processor := range cfg.opentelemetryConfig.TracerProvider.Processors {
                sp, err := spanProcessor(cfg.ctx, processor)
                if err == nil {
                        opts = append(opts, sdktrace.WithSpanProcessor(sp))
                } else {
                        errs = append(errs, err)
                }
        }
        if s, err := sampler(cfg.opentelemetryConfig.TracerProvider.Sampler); err == nil {
                opts = append(opts, sdktrace.WithSampler(s))
        } else {
                errs = append(errs, err)
        }
        if len(errs) > 0 {
                return noop.NewTracerProvider(), noopShutdown, errors.Join(errs...)
        }
        tp := sdktrace.NewTracerProvider(opts...)
        return tp, tp.Shutdown, nil
}

func parentBasedSampler(s *SamplerParentBased) (sdktrace.Sampler, error) {
        var rootSampler sdktrace.Sampler
        var opts []sdktrace.ParentBasedSamplerOption
        var errs []error
        var err error

        if s.Root == nil {
                rootSampler = sdktrace.AlwaysSample()
        } else {
                rootSampler, err = sampler(s.Root)
                if err != nil {
                        errs = append(errs, err)
                }
        }
        if s.RemoteParentSampled != nil {
                remoteParentSampler, err := sampler(s.RemoteParentSampled)
                if err != nil {
                        errs = append(errs, err)
                } else {
                        opts = append(opts, sdktrace.WithRemoteParentSampled(remoteParentSampler))
                }
        }
        if s.RemoteParentNotSampled != nil {
                remoteParentNotSampler, err := sampler(s.RemoteParentNotSampled)
                if err != nil {
                        errs = append(errs, err)
                } else {
                        opts = append(opts, sdktrace.WithRemoteParentNotSampled(remoteParentNotSampler))
                }
        }
        if s.LocalParentSampled != nil {
                localParentSampler, err := sampler(s.LocalParentSampled)
                if err != nil {
                        errs = append(errs, err)
                } else {
                        opts = append(opts, sdktrace.WithLocalParentSampled(localParentSampler))
                }
        }
        if s.LocalParentNotSampled != nil {
                localParentNotSampler, err := sampler(s.LocalParentNotSampled)
                if err != nil {
                        errs = append(errs, err)
                } else {
                        opts = append(opts, sdktrace.WithLocalParentNotSampled(localParentNotSampler))
                }
        }
        if len(errs) > 0 {
                return nil, errors.Join(errs...)
        }
        return sdktrace.ParentBased(rootSampler, opts...), nil
}

func sampler(s *Sampler) (sdktrace.Sampler, error) {
        if s == nil {
                // If omitted, parent based sampler with a root of always_on is used.
                return sdktrace.ParentBased(sdktrace.AlwaysSample()), nil
        }
        if s.ParentBased != nil {
                return parentBasedSampler(s.ParentBased)
        }
        if s.AlwaysOff != nil {
                return sdktrace.NeverSample(), nil
        }
        if s.AlwaysOn != nil {
                return sdktrace.AlwaysSample(), nil
        }
        if s.TraceIDRatioBased != nil {
                if s.TraceIDRatioBased.Ratio == nil {
                        return sdktrace.TraceIDRatioBased(1), nil
                }
                return sdktrace.TraceIDRatioBased(*s.TraceIDRatioBased.Ratio), nil
        }
        return nil, errInvalidSamplerConfiguration
}

func spanExporter(ctx context.Context, exporter SpanExporter) (sdktrace.SpanExporter, error) {
        if exporter.Console != nil && exporter.OTLP != nil {
                return nil, errors.New("must not specify multiple exporters")
        }

        if exporter.Console != nil {
                return stdouttrace.New(
                        stdouttrace.WithPrettyPrint(),
                )
        }
        if exporter.OTLP != nil && exporter.OTLP.Protocol != nil {
                switch *exporter.OTLP.Protocol {
                case protocolProtobufHTTP:
                        return otlpHTTPSpanExporter(ctx, exporter.OTLP)
                case protocolProtobufGRPC:
                        return otlpGRPCSpanExporter(ctx, exporter.OTLP)
                default:
                        return nil, fmt.Errorf("unsupported protocol %q", *exporter.OTLP.Protocol)
                }
        }
        return nil, errors.New("no valid span exporter")
}

func spanProcessor(ctx context.Context, processor SpanProcessor) (sdktrace.SpanProcessor, error) {
        if processor.Batch != nil && processor.Simple != nil {
                return nil, errors.New("must not specify multiple span processor type")
        }
        if processor.Batch != nil {
                exp, err := spanExporter(ctx, processor.Batch.Exporter)
                if err != nil {
                        return nil, err
                }
                return batchSpanProcessor(processor.Batch, exp)
        }
        if processor.Simple != nil {
                exp, err := spanExporter(ctx, processor.Simple.Exporter)
                if err != nil {
                        return nil, err
                }
                return sdktrace.NewSimpleSpanProcessor(exp), nil
        }
        return nil, errors.New("unsupported span processor type, must be one of simple or batch")
}

func otlpGRPCSpanExporter(ctx context.Context, otlpConfig *OTLP) (sdktrace.SpanExporter, error) {
        var opts []otlptracegrpc.Option

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                // ParseRequestURI leaves the Host field empty when no
                // scheme is specified (i.e. localhost:4317). This check is
                // here to support the case where a user may not specify a
                // scheme. The code does its best effort here by using
                // otlpConfig.Endpoint as-is in that case.
                if u.Host != "" {
                        opts = append(opts, otlptracegrpc.WithEndpoint(u.Host))
                } else {
                        opts = append(opts, otlptracegrpc.WithEndpoint(*otlpConfig.Endpoint))
                }

                if u.Scheme == "http" || (u.Scheme != "https" && otlpConfig.Insecure != nil && *otlpConfig.Insecure) {
                        opts = append(opts, otlptracegrpc.WithInsecure())
                }
        }

        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlptracegrpc.WithCompressor(*otlpConfig.Compression))
                case compressionNone:
                        // none requires no options
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil && *otlpConfig.Timeout > 0 {
                opts = append(opts, otlptracegrpc.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlptracegrpc.WithHeaders(headersConfig))
        }

        if otlpConfig.Certificate != nil || otlpConfig.ClientCertificate != nil || otlpConfig.ClientKey != nil {
                tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlptracegrpc.WithTLSCredentials(credentials.NewTLS(tlsConfig)))
        }

        return otlptracegrpc.New(ctx, opts...)
}

func otlpHTTPSpanExporter(ctx context.Context, otlpConfig *OTLP) (sdktrace.SpanExporter, error) {
        var opts []otlptracehttp.Option

        if otlpConfig.Endpoint != nil {
                u, err := url.ParseRequestURI(*otlpConfig.Endpoint)
                if err != nil {
                        return nil, err
                }
                opts = append(opts, otlptracehttp.WithEndpoint(u.Host))

                if u.Scheme == "http" {
                        opts = append(opts, otlptracehttp.WithInsecure())
                }
                if u.Path != "" {
                        opts = append(opts, otlptracehttp.WithURLPath(u.Path))
                }
        }
        if otlpConfig.Compression != nil {
                switch *otlpConfig.Compression {
                case compressionGzip:
                        opts = append(opts, otlptracehttp.WithCompression(otlptracehttp.GzipCompression))
                case compressionNone:
                        opts = append(opts, otlptracehttp.WithCompression(otlptracehttp.NoCompression))
                default:
                        return nil, fmt.Errorf("unsupported compression %q", *otlpConfig.Compression)
                }
        }
        if otlpConfig.Timeout != nil && *otlpConfig.Timeout > 0 {
                opts = append(opts, otlptracehttp.WithTimeout(time.Millisecond*time.Duration(*otlpConfig.Timeout)))
        }
        headersConfig, err := createHeadersConfig(otlpConfig.Headers, otlpConfig.HeadersList)
        if err != nil {
                return nil, err
        }
        if len(headersConfig) > 0 {
                opts = append(opts, otlptracehttp.WithHeaders(headersConfig))
        }

        tlsConfig, err := tls.CreateConfig(otlpConfig.Certificate, otlpConfig.ClientCertificate, otlpConfig.ClientKey)
        if err != nil {
                return nil, err
        }
        opts = append(opts, otlptracehttp.WithTLSClientConfig(tlsConfig))

        return otlptracehttp.New(ctx, opts...)
}

func batchSpanProcessor(bsp *BatchSpanProcessor, exp sdktrace.SpanExporter) (sdktrace.SpanProcessor, error) {
        var opts []sdktrace.BatchSpanProcessorOption
        if bsp.ExportTimeout != nil {
                if *bsp.ExportTimeout < 0 {
                        return nil, fmt.Errorf("invalid export timeout %d", *bsp.ExportTimeout)
                }
                opts = append(opts, sdktrace.WithExportTimeout(time.Millisecond*time.Duration(*bsp.ExportTimeout)))
        }
        if bsp.MaxExportBatchSize != nil {
                if *bsp.MaxExportBatchSize < 0 {
                        return nil, fmt.Errorf("invalid batch size %d", *bsp.MaxExportBatchSize)
                }
                opts = append(opts, sdktrace.WithMaxExportBatchSize(*bsp.MaxExportBatchSize))
        }
        if bsp.MaxQueueSize != nil {
                if *bsp.MaxQueueSize < 0 {
                        return nil, fmt.Errorf("invalid queue size %d", *bsp.MaxQueueSize)
                }
                opts = append(opts, sdktrace.WithMaxQueueSize(*bsp.MaxQueueSize))
        }
        if bsp.ScheduleDelay != nil {
                if *bsp.ScheduleDelay < 0 {
                        return nil, fmt.Errorf("invalid schedule delay %d", *bsp.ScheduleDelay)
                }
                opts = append(opts, sdktrace.WithBatchTimeout(time.Millisecond*time.Duration(*bsp.ScheduleDelay)))
        }
        return sdktrace.NewBatchSpanProcessor(exp, opts...), nil
}