// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: Copyright The WasmEdge Authors

// BUILTIN-PLUGIN: Temporarily move the wasi-logging plugin sources here until

// the new plugin architecture is ready in 0.15.0.

#pragma once

#include "common/hexstr.h"

#include "common/spdlog.h"

#include <spdlog/sinks/basic_file_sink.h>

#include <spdlog/sinks/stdout_color_sinks.h>

#include <spdlog/spdlog.h>

#include <limits>

#include <memory>

#include <mutex>

#include <random>

#include <string>

#include <string_view>

#include <unordered_set>

namespace WasmEdge {

namespace Host {

namespace WASILogging {

class LogEnv {

public:

  LogEnv() noexcept {

    using namespace std::literals;

    // Get the stdout and stderr logger.

    StdoutLogger = spdlog::get("wasi_logging_stdout"s);

    if (!StdoutLogger) {

      StdoutLogger = spdlog::stdout_color_mt("wasi_logging_stdout"s);

      StdoutLogger->set_level(spdlog::level::trace);

      StdoutLogger->set_pattern(DefFormat);

    }

    StderrLogger = spdlog::get("wasi_logging_stderr"s);

    if (!StderrLogger) {

      StderrLogger = spdlog::stderr_color_mt("wasi_logging_stderr"s);

      StderrLogger->set_level(spdlog::level::trace);

      StderrLogger->set_pattern(DefFormat);

    }

    std::random_device RandDev;

    std::mt19937 RandGen(RandDev());

    std::uniform_int_distribution<uint64_t> RandDist(

        0, std::numeric_limits<uint64_t>::max());

    std::unique_lock Lock(Mutex);

    do {

      InstanceID = RandDist(RandGen);

    } while (RegisteredID.find(InstanceID) != RegisteredID.cend());

    LogRegName = "wasi_logging_file_" + convertUIntToHexStr(InstanceID);

    RegisteredID.insert(InstanceID);

  }

  ~LogEnv() noexcept {

    std::unique_lock Lock(Mutex);

    // Drop the file logger by its registered name; never LogFileName, which is

    // empty until a file is set and would reset the unnamed default logger.

    if (FileLogger) {

      spdlog::drop(LogRegName);

    }

    RegisteredID.erase(InstanceID);

  }

  std::string_view getLogFileName() const noexcept { return LogFileName; }

  void setLogFileName(std::string_view Name) noexcept {

    LogFileName = std::string(Name);

  }

  const std::string &getLogRegName() const noexcept { return LogRegName; }

  uint64_t getInstanceID() const noexcept { return InstanceID; }

  static std::mutex Mutex;

  static std::unordered_set<uint64_t> RegisteredID;

  static const std::string DefFormat;

  std::shared_ptr<spdlog::logger> StdoutLogger;

  std::shared_ptr<spdlog::logger> StderrLogger;

  std::shared_ptr<spdlog::logger> FileLogger;

private:

  std::string LogFileName;

  std::string LogRegName;

  uint64_t InstanceID;

};

} // namespace WASILogging

} // namespace Host

} // namespace WasmEdge