// Copyright 2023 The Abseil Authors

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "absl/status/internal/status_internal.h"

#include <atomic>

#include <cassert>

#include <cstddef>

#include <cstdint>

#include <cstdio>

#include <cstring>

#include <memory>

#include <string>

#include <utility>

#include "absl/base/attributes.h"

#include "absl/base/config.h"

#include "absl/base/macros.h"

#include "absl/base/nullability.h"

#include "absl/debugging/stacktrace.h"

#include "absl/debugging/symbolize.h"

#include "absl/memory/memory.h"

#include "absl/status/status.h"

#include "absl/status/status_payload_printer.h"

#include "absl/strings/cord.h"

#include "absl/strings/escaping.h"

#include "absl/strings/str_cat.h"

#include "absl/strings/str_format.h"

#include "absl/strings/str_split.h"

#include "absl/strings/string_view.h"

#include "absl/types/optional.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

namespace status_internal {

void StatusRep::Unref() const {

  // Fast path: if ref==1, there is no need for a RefCountDec (since

  // this is the only reference and therefore no other thread is

  // allowed to be mucking with r).

  if (ref_.load(std::memory_order_acquire) == 1 ||

      ref_.fetch_sub(1, std::memory_order_acq_rel) - 1 == 0) {

    delete this;

  }

}

static absl::optional<size_t> FindPayloadIndexByUrl(

    const Payloads* payloads, absl::string_view type_url) {

  if (payloads == nullptr) return absl::nullopt;

  for (size_t i = 0; i < payloads->size(); ++i) {

    if ((*payloads)[i].type_url == type_url) return i;

  }

  return absl::nullopt;

}

absl::optional<absl::Cord> StatusRep::GetPayload(

    absl::string_view type_url) const {

  absl::optional<size_t> index =

      status_internal::FindPayloadIndexByUrl(payloads_.get(), type_url);

  if (index.has_value()) return (*payloads_)[index.value()].payload;

  return absl::nullopt;

}

void StatusRep::SetPayload(absl::string_view type_url, absl::Cord payload) {

  if (payloads_ == nullptr) {

    payloads_ = absl::make_unique<status_internal::Payloads>();

  }

  absl::optional<size_t> index =

      status_internal::FindPayloadIndexByUrl(payloads_.get(), type_url);

  if (index.has_value()) {

    (*payloads_)[index.value()].payload = std::move(payload);

    return;

  }

  payloads_->push_back({std::string(type_url), std::move(payload)});

}

StatusRep::EraseResult StatusRep::ErasePayload(absl::string_view type_url) {

  absl::optional<size_t> index =

      status_internal::FindPayloadIndexByUrl(payloads_.get(), type_url);

  if (!index.has_value()) return {false, Status::PointerToRep(this)};

  payloads_->erase(payloads_->begin() + index.value());

  if (payloads_->empty() && message_.empty()) {

    // Special case: If this can be represented inlined, it MUST be inlined

    // (== depends on this behavior).

    EraseResult result = {true, Status::CodeToInlinedRep(code_)};

    Unref();

    return result;

  }

  return {true, Status::PointerToRep(this)};

}

void StatusRep::ForEachPayload(

    absl::FunctionRef<void(absl::string_view, const absl::Cord&)> visitor)

    const {

  if (auto* payloads = payloads_.get()) {

    bool in_reverse =

        payloads->size() > 1 && reinterpret_cast<uintptr_t>(payloads) % 13 > 6;

    for (size_t index = 0; index < payloads->size(); ++index) {

      const auto& elem =

          (*payloads)[in_reverse ? payloads->size() - 1 - index : index];

#ifdef NDEBUG

      visitor(elem.type_url, elem.payload);

#else

      // In debug mode invalidate the type url to prevent users from relying on

      // this string lifetime.

      // NOLINTNEXTLINE intentional extra conversion to force temporary.

      visitor(std::string(elem.type_url), elem.payload);

#endif  // NDEBUG

    }

  }

}

std::string StatusRep::ToString(StatusToStringMode mode) const {

  std::string text;

  absl::StrAppend(&text, absl::StatusCodeToString(code()), ": ", message());

  const bool with_payload = (mode & StatusToStringMode::kWithPayload) ==

                            StatusToStringMode::kWithPayload;

  if (with_payload) {

    status_internal::StatusPayloadPrinter printer =

        status_internal::GetStatusPayloadPrinter();

    this->ForEachPayload([&](absl::string_view type_url,

                             const absl::Cord& payload) {

      absl::optional<std::string> result;

      if (printer) result = printer(type_url, payload);

      absl::StrAppend(

          &text, " [", type_url, "='",

          result.has_value() ? *result : absl::CHexEscape(std::string(payload)),

          "']");

    });

  }

  return text;

}

bool StatusRep::operator==(const StatusRep& other) const {

  assert(this != &other);

  if (code_ != other.code_) return false;

  if (message_ != other.message_) return false;

  const status_internal::Payloads* this_payloads = payloads_.get();

  const status_internal::Payloads* other_payloads = other.payloads_.get();

  const status_internal::Payloads no_payloads;

  const status_internal::Payloads* larger_payloads =

      this_payloads ? this_payloads : &no_payloads;

  const status_internal::Payloads* smaller_payloads =

      other_payloads ? other_payloads : &no_payloads;

  if (larger_payloads->size() < smaller_payloads->size()) {

    std::swap(larger_payloads, smaller_payloads);

  }

  if ((larger_payloads->size() - smaller_payloads->size()) > 1) return false;

  // Payloads can be ordered differently, so we can't just compare payload

  // vectors.

  for (const auto& payload : *larger_payloads) {

    bool found = false;

    for (const auto& other_payload : *smaller_payloads) {

      if (payload.type_url == other_payload.type_url) {

        if (payload.payload != other_payload.payload) {

          return false;

        }

        found = true;

        break;

      }

    }

    if (!found) return false;

  }

  return true;

}

absl::Nonnull<StatusRep*> StatusRep::CloneAndUnref() const {

  // Optimization: no need to create a clone if we already have a refcount of 1.

  if (ref_.load(std::memory_order_acquire) == 1) {

    // All StatusRep instances are heap allocated and mutable, therefore this

    // const_cast will never cast away const from a stack instance.

    //

    // CloneAndUnref is the only method that doesn't involve an external cast to

    // get a mutable StatusRep* from the uintptr_t rep stored in Status.

    return const_cast<StatusRep*>(this);

  }

  std::unique_ptr<status_internal::Payloads> payloads;

  if (payloads_) {

    payloads = absl::make_unique<status_internal::Payloads>(*payloads_);

  }

  auto* new_rep = new StatusRep(code_, message_, std::move(payloads));

  Unref();

  return new_rep;

}

// Convert canonical code to a value known to this binary.

absl::StatusCode MapToLocalCode(int value) {

  absl::StatusCode code = static_cast<absl::StatusCode>(value);

  switch (code) {

    case absl::StatusCode::kOk:

    case absl::StatusCode::kCancelled:

    case absl::StatusCode::kUnknown:

    case absl::StatusCode::kInvalidArgument:

    case absl::StatusCode::kDeadlineExceeded:

    case absl::StatusCode::kNotFound:

    case absl::StatusCode::kAlreadyExists:

    case absl::StatusCode::kPermissionDenied:

    case absl::StatusCode::kResourceExhausted:

    case absl::StatusCode::kFailedPrecondition:

    case absl::StatusCode::kAborted:

    case absl::StatusCode::kOutOfRange:

    case absl::StatusCode::kUnimplemented:

    case absl::StatusCode::kInternal:

    case absl::StatusCode::kUnavailable:

    case absl::StatusCode::kDataLoss:

    case absl::StatusCode::kUnauthenticated:

      return code;

    default:

      return absl::StatusCode::kUnknown;

  }

}

absl::Nonnull<std::string*> MakeCheckFailString(

    absl::Nonnull<const absl::Status*> status,

    absl::Nonnull<const char*> prefix) {

  return new std::string(

      absl::StrCat(prefix, " (",

                   status->ToString(StatusToStringMode::kWithEverything), ")"));

}

}  // namespace status_internal

ABSL_NAMESPACE_END

}  // namespace absl