//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2022, the clio developers.

    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#include "util/log/Logger.h"

#include "util/SourceLocation.h"
#include "util/config/Config.h"

#include <boost/algorithm/string/predicate.hpp>
#include <boost/date_time/posix_time/posix_time_duration.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/json/conversion.hpp>
#include <boost/json/value.hpp>
#include <boost/log/core/core.hpp>
#include <boost/log/expressions/predicates/channel_severity_filter.hpp>
#include <boost/log/keywords/auto_flush.hpp>
#include <boost/log/keywords/file_name.hpp>
#include <boost/log/keywords/format.hpp>
#include <boost/log/keywords/max_size.hpp>
#include <boost/log/keywords/open_mode.hpp>
#include <boost/log/keywords/rotation_size.hpp>
#include <boost/log/keywords/target.hpp>
#include <boost/log/keywords/target_file_name.hpp>
#include <boost/log/keywords/time_based_rotation.hpp>
#include <boost/log/sinks/text_file_backend.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/utility/setup/console.hpp>
#include <boost/log/utility/setup/file.hpp>
#include <boost/log/utility/setup/formatter_parser.hpp>

#include <algorithm>
#include <array>
#include <cstddef>
#include <cstdint>
#include <ios>
#include <iostream>
#include <ostream>
#include <stdexcept>
#include <string>

namespace util {

Logger LogService::general_log_ = Logger{"General"};
Logger LogService::alert_log_ = Logger{"Alert"};

std::ostream&
operator<<(std::ostream& stream, Severity sev)
{
    static constexpr std::array<char const*, 6> labels = {
        "TRC",
        "DBG",
        "NFO",
        "WRN",
        "ERR",
        "FTL",
    };

    return stream << labels.at(static_cast<int>(sev));
}

Severity
tag_invoke(boost::json::value_to_tag<Severity>, boost::json::value const& value)
{
    if (not value.is_string())
        throw std::runtime_error("`log_level` must be a string");
    auto const& logLevel = value.as_string();

    if (boost::iequals(logLevel, "trace"))
        return Severity::TRC;
    if (boost::iequals(logLevel, "debug"))
        return Severity::DBG;
    if (boost::iequals(logLevel, "info"))
        return Severity::NFO;
    if (boost::iequals(logLevel, "warning") || boost::iequals(logLevel, "warn"))
        return Severity::WRN;
    if (boost::iequals(logLevel, "error"))
        return Severity::ERR;
    if (boost::iequals(logLevel, "fatal"))
        return Severity::FTL;

    throw std::runtime_error(
        "Could not parse `log_level`: expected `trace`, `debug`, `info`, `warning`, `error` or `fatal`"
    );
}

void
LogService::init(util::Config const& config)
{
    namespace keywords = boost::log::keywords;
    namespace sinks = boost::log::sinks;

    boost::log::add_common_attributes();
    boost::log::register_simple_formatter_factory<Severity, char>("Severity");
    auto const defaultFormat = "%TimeStamp% (%SourceLocation%) [%ThreadID%] %Channel%:%Severity% %Message%";
    std::string format = config.valueOr<std::string>("log_format", defaultFormat);

    if (config.valueOr("log_to_console", false)) {
        boost::log::add_console_log(std::cout, keywords::format = format);
    }

    if (auto logDir = config.maybeValue<std::string>("log_directory"); logDir) {
        boost::filesystem::path dirPath{logDir.value()};
        if (!boost::filesystem::exists(dirPath))
            boost::filesystem::create_directories(dirPath);
        auto const rotationSize = config.valueOr<uint64_t>("log_rotation_size", 2048u) * 1024u * 1024u;
        auto const rotationPeriod = config.valueOr<uint32_t>("log_rotation_hour_interval", 12u);
        auto const dirSize = config.valueOr<uint64_t>("log_directory_max_size", 50u * 1024u) * 1024u * 1024u;
        auto fileSink = boost::log::add_file_log(
            keywords::file_name = dirPath / "clio.log",
            keywords::target_file_name = dirPath / "clio_%Y-%m-%d_%H-%M-%S.log",
            keywords::auto_flush = true,
            keywords::format = format,
            keywords::open_mode = std::ios_base::app,
            keywords::rotation_size = rotationSize,
            keywords::time_based_rotation =
                sinks::file::rotation_at_time_interval(boost::posix_time::hours(rotationPeriod))
        );
        fileSink->locked_backend()->set_file_collector(
            sinks::file::make_collector(keywords::target = dirPath, keywords::max_size = dirSize)
        );
        fileSink->locked_backend()->scan_for_files();
    }

    // get default severity, can be overridden per channel using the `log_channels` array
    auto defaultSeverity = config.valueOr<Severity>("log_level", Severity::NFO);
    static constexpr std::array<char const*, 7> channels = {
        "General",
        "WebServer",
        "Backend",
        "RPC",
        "ETL",
        "Subscriptions",
        "Performance",
    };

    auto core = boost::log::core::get();
    auto min_severity = boost::log::expressions::channel_severity_filter(log_channel, log_severity);

    for (auto const& channel : channels)
        min_severity[channel] = defaultSeverity;
    min_severity["Alert"] = Severity::WRN;  // Channel for alerts, always warning severity

    for (auto const overrides = config.arrayOr("log_channels", {}); auto const& cfg : overrides) {
        auto name = cfg.valueOrThrow<std::string>("channel", "Channel name is required");
        if (std::count(std::begin(channels), std::end(channels), name) == 0)
            throw std::runtime_error("Can't override settings for log channel " + name + ": invalid channel");

        min_severity[name] = cfg.valueOr<Severity>("log_level", defaultSeverity);
    }

    core->set_filter(min_severity);
    LOG(LogService::info()) << "Default log level = " << defaultSeverity;
}

Logger::Pump
Logger::trace(SourceLocationType const& loc) const
{
    return {logger_, Severity::TRC, loc};
};
Logger::Pump
Logger::debug(SourceLocationType const& loc) const
{
    return {logger_, Severity::DBG, loc};
};
Logger::Pump
Logger::info(SourceLocationType const& loc) const
{
    return {logger_, Severity::NFO, loc};
};
Logger::Pump
Logger::warn(SourceLocationType const& loc) const
{
    return {logger_, Severity::WRN, loc};
};
Logger::Pump
Logger::error(SourceLocationType const& loc) const
{
    return {logger_, Severity::ERR, loc};
};
Logger::Pump
Logger::fatal(SourceLocationType const& loc) const
{
    return {logger_, Severity::FTL, loc};
};

std::string
Logger::Pump::pretty_path(SourceLocationType const& loc, size_t max_depth)
{
    auto const file_path = std::string{loc.file_name()};
    auto idx = file_path.size();
    while (max_depth-- > 0) {
        idx = file_path.rfind('/', idx - 1);
        if (idx == std::string::npos || idx == 0)
            break;
    }
    return file_path.substr(idx == std::string::npos ? 0 : idx + 1) + ':' + std::to_string(loc.line());
}

}  // namespace util