#include <limits>

#include <numeric>

#include "envoy/annotations/deprecation.pb.h"

#include "envoy/protobuf/message_validator.h"

#include "envoy/type/v3/percent.pb.h"

#include "source/common/common/assert.h"

#include "source/common/common/documentation_url.h"

#include "source/common/common/fmt.h"

#include "source/common/protobuf/message_validator_impl.h"

#include "source/common/protobuf/protobuf.h"

#include "source/common/protobuf/utility.h"

#include "source/common/protobuf/visitor.h"

#include "source/common/runtime/runtime_features.h"

#include "absl/strings/match.h"

#include "udpa/annotations/sensitive.pb.h"

#include "udpa/annotations/status.pb.h"

#include "utf8_validity.h"

#include "validate/validate.h"

#include "xds/annotations/v3/status.pb.h"

#include "yaml-cpp/yaml.h"

using namespace std::chrono_literals;

namespace Envoy {

namespace {

void blockFormat(YAML::Node node) {

  node.SetStyle(YAML::EmitterStyle::Block);

  if (node.Type() == YAML::NodeType::Sequence) {

    for (const auto& it : node) {

      blockFormat(it);

    }

  }

  if (node.Type() == YAML::NodeType::Map) {

    for (const auto& it : node) {

      blockFormat(it.second);

    }

  }

}

ProtobufWkt::Value parseYamlNode(const YAML::Node& node) {

  ProtobufWkt::Value value;

  switch (node.Type()) {

  case YAML::NodeType::Null:

    value.set_null_value(ProtobufWkt::NULL_VALUE);

    break;

  case YAML::NodeType::Scalar: {

    if (node.Tag() == "!") {

      value.set_string_value(node.as<std::string>());

      break;

    }

    bool bool_value;

    if (YAML::convert<bool>::decode(node, bool_value)) {

      value.set_bool_value(bool_value);

      break;

    }

    int64_t int_value;

    if (YAML::convert<int64_t>::decode(node, int_value)) {

      if (std::numeric_limits<int32_t>::min() <= int_value &&

          std::numeric_limits<int32_t>::max() >= int_value) {

        // We could convert all integer values to string but it will break some stuff relying on

        // ProtobufWkt::Struct itself, only convert small numbers into number_value here.

        value.set_number_value(int_value);

      } else {

        // Proto3 JSON mapping allows use string for integer, this still has to be converted from

        // int_value to support hexadecimal and octal literals.

        value.set_string_value(std::to_string(int_value));

      }

      break;

    }

    // Fall back on string, including float/double case. When protobuf parse the JSON into a message

    // it will convert based on the type in the message definition.

    value.set_string_value(node.as<std::string>());

    break;

  }

  case YAML::NodeType::Sequence: {

    auto& list_values = *value.mutable_list_value()->mutable_values();

    for (const auto& it : node) {

      *list_values.Add() = parseYamlNode(it);

    }

    break;

  }

  case YAML::NodeType::Map: {

    auto& struct_fields = *value.mutable_struct_value()->mutable_fields();

    for (const auto& it : node) {

      if (it.first.Tag() != "!ignore") {

        struct_fields[it.first.as<std::string>()] = parseYamlNode(it.second);

      }

    }

    break;

  }

  case YAML::NodeType::Undefined:

    throw EnvoyException("Undefined YAML value");

  }

  return value;

}

void jsonConvertInternal(const Protobuf::Message& source,

                         ProtobufMessage::ValidationVisitor& validation_visitor,

                         Protobuf::Message& dest) {

  Protobuf::util::JsonPrintOptions json_options;

  json_options.preserve_proto_field_names = true;

  std::string json;

  const auto status = Protobuf::util::MessageToJsonString(source, &json, json_options);

  if (!status.ok()) {

    throw EnvoyException(fmt::format("Unable to convert protobuf message to JSON string: {} {}",

                                     status.ToString(), source.DebugString()));

  }

  MessageUtil::loadFromJson(json, dest, validation_visitor);

}

} // namespace

void MessageUtil::loadFromJson(const std::string& json, Protobuf::Message& message,

                               ProtobufMessage::ValidationVisitor& validation_visitor) {

  bool has_unknown_field;

  auto load_status = loadFromJsonNoThrow(json, message, has_unknown_field);

  if (load_status.ok()) {

    return;

  }

  if (has_unknown_field) {

    // If the parsing failure is caused by the unknown fields.

    THROW_IF_NOT_OK(validation_visitor.onUnknownField("type " + message.GetTypeName() + " reason " +

                                                      load_status.ToString()));

  } else {

    // If the error has nothing to do with unknown field.

    throw EnvoyException("Unable to parse JSON as proto (" + load_status.ToString() + "): " + json);

  }

}

absl::Status MessageUtil::loadFromJsonNoThrow(const std::string& json, Protobuf::Message& message,

                                              bool& has_unknown_fileld) {

  has_unknown_fileld = false;

  Protobuf::util::JsonParseOptions options;

  options.case_insensitive_enum_parsing = true;

  // Let's first try and get a clean parse when checking for unknown fields;

  // this should be the common case.

  options.ignore_unknown_fields = false;

  // Clear existing values (if any) from the destination message before serialization.

  message.Clear();

  const auto strict_status = Protobuf::util::JsonStringToMessage(json, &message, options);

  if (strict_status.ok()) {

    // Success, no need to do any extra work.

    return strict_status;

  }

  // If we fail, we see if we get a clean parse when allowing unknown fields.

  // This is essentially a workaround

  // for https://github.com/protocolbuffers/protobuf/issues/5967.

  // TODO(htuch): clean this up when protobuf supports JSON/YAML unknown field

  // detection directly.

  options.ignore_unknown_fields = true;

  const auto relaxed_status = Protobuf::util::JsonStringToMessage(json, &message, options);

  // If we still fail with relaxed unknown field checking, the error has nothing

  // to do with unknown fields.

  if (relaxed_status.ok()) {

    has_unknown_fileld = true;

    return strict_status;

  }

  return relaxed_status;

}

void MessageUtil::loadFromJson(const std::string& json, ProtobufWkt::Struct& message) {

  // No need to validate if converting to a Struct, since there are no unknown

  // fields possible.

  loadFromJson(json, message, ProtobufMessage::getNullValidationVisitor());

}

void MessageUtil::loadFromYaml(const std::string& yaml, Protobuf::Message& message,

                               ProtobufMessage::ValidationVisitor& validation_visitor) {

  ProtobufWkt::Value value = ValueUtil::loadFromYaml(yaml);

  if (value.kind_case() == ProtobufWkt::Value::kStructValue ||

      value.kind_case() == ProtobufWkt::Value::kListValue) {

    jsonConvertInternal(value, validation_visitor, message);

    return;

  }

  throw EnvoyException("Unable to convert YAML as JSON: " + yaml);

}

std::string MessageUtil::getYamlStringFromMessage(const Protobuf::Message& message,

                                                  const bool block_print,

                                                  const bool always_print_primitive_fields) {

  auto json_or_error = getJsonStringFromMessage(message, false, always_print_primitive_fields);

  if (!json_or_error.ok()) {

    throw EnvoyException(json_or_error.status().ToString());

  }

  YAML::Node node;

  TRY_ASSERT_MAIN_THREAD { node = YAML::Load(json_or_error.value()); }

  END_TRY

  catch (YAML::ParserException& e) {

    throw EnvoyException(e.what());

  }

  catch (YAML::BadConversion& e) {

    throw EnvoyException(e.what());

  }

  catch (std::exception& e) {

    // Catch unknown YAML parsing exceptions.

    throw EnvoyException(fmt::format("Unexpected YAML exception: {}", +e.what()));

  }

  if (block_print) {

    blockFormat(node);

  }

  YAML::Emitter out;

  out << node;

  return out.c_str();

}

absl::StatusOr<std::string>

MessageUtil::getJsonStringFromMessage(const Protobuf::Message& message, const bool pretty_print,

                                      const bool always_print_primitive_fields) {

  Protobuf::util::JsonPrintOptions json_options;

  // By default, proto field names are converted to camelCase when the message is converted to JSON.

  // Setting this option makes debugging easier because it keeps field names consistent in JSON

  // printouts.

  json_options.preserve_proto_field_names = true;

  if (pretty_print) {

    json_options.add_whitespace = true;

  }

  // Primitive types such as int32s and enums will not be serialized if they have the default value.

  // This flag disables that behavior.

  if (always_print_primitive_fields) {

    json_options.always_print_fields_with_no_presence = true;

  }

  std::string json;

  if (auto status = Protobuf::util::MessageToJsonString(message, &json, json_options);

      !status.ok()) {

    return status;

  }

  return json;

}

std::string MessageUtil::getJsonStringFromMessageOrError(const Protobuf::Message& message,

                                                         bool pretty_print,

                                                         bool always_print_primitive_fields) {

  auto json_or_error =

      getJsonStringFromMessage(message, pretty_print, always_print_primitive_fields);

  return json_or_error.ok() ? std::move(json_or_error).value()

                            : fmt::format("Failed to convert protobuf message to JSON string: {}",

                                          json_or_error.status().ToString());

}

void MessageUtil::jsonConvert(const Protobuf::Message& source, Protobuf::Message& dest) {

  jsonConvertInternal(source, ProtobufMessage::getNullValidationVisitor(), dest);

}

void MessageUtil::jsonConvert(const Protobuf::Message& source, ProtobufWkt::Struct& dest) {

  // Any proto3 message can be transformed to Struct, so there is no need to check for unknown

  // fields. There is one catch; Duration/Timestamp etc. which have non-object canonical JSON

  // representations don't work.

  jsonConvertInternal(source, ProtobufMessage::getNullValidationVisitor(), dest);

}

void MessageUtil::jsonConvert(const ProtobufWkt::Struct& source,

                              ProtobufMessage::ValidationVisitor& validation_visitor,

                              Protobuf::Message& dest) {

  jsonConvertInternal(source, validation_visitor, dest);

}

bool MessageUtil::jsonConvertValue(const Protobuf::Message& source, ProtobufWkt::Value& dest) {

  Protobuf::util::JsonPrintOptions json_options;

  json_options.preserve_proto_field_names = true;

  std::string json;

  auto status = Protobuf::util::MessageToJsonString(source, &json, json_options);

  if (!status.ok()) {

    return false;

  }

  bool has_unknow_field;

  status = MessageUtil::loadFromJsonNoThrow(json, dest, has_unknow_field);

  if (status.ok() || has_unknow_field) {

    return true;

  }

  return false;

}

ProtobufWkt::Value ValueUtil::loadFromYaml(const std::string& yaml) {

  TRY_ASSERT_MAIN_THREAD { return parseYamlNode(YAML::Load(yaml)); }

  END_TRY

  catch (YAML::ParserException& e) {

    throw EnvoyException(e.what());

  }

  catch (YAML::BadConversion& e) {

    throw EnvoyException(e.what());

  }

  catch (std::exception& e) {

    // There is a potentially wide space of exceptions thrown by the YAML parser,

    // and enumerating them all may be difficult. Envoy doesn't work well with

    // unhandled exceptions, so we capture them and record the exception name in

    // the Envoy Exception text.

    throw EnvoyException(fmt::format("Unexpected YAML exception: {}", +e.what()));

  }

}

namespace {

// This is a modified copy of the UTF8CoerceToStructurallyValid from the protobuf code.

// A copy was needed after if was removed from the protobuf.

std::string utf8CoerceToStructurallyValid(absl::string_view str, const char replace_char) {

  std::string result(str);

  auto replace_pos = result.begin();

  while (!str.empty()) {

    size_t n_valid_bytes = utf8_range::SpanStructurallyValid(str);

    if (n_valid_bytes == str.size()) {

      break;

    }

    replace_pos += n_valid_bytes;

    *replace_pos++ = replace_char; // replace one bad byte

    str.remove_prefix(n_valid_bytes + 1);

  }

  return result;

}

} // namespace

std::string MessageUtil::sanitizeUtf8String(absl::string_view input) {

  // The choice of '!' is somewhat arbitrary, but we wanted to avoid any character that has

  // special semantic meaning in URLs or similar.

  return utf8CoerceToStructurallyValid(input, '!');

}

} // namespace Envoy