// MassBuilderSaveTool
// Copyright (C) 2021-2022 Guillaume Jacquemin
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

#ifdef SAVETOOL_DEBUG_BUILD
#include <iostream>
#else
#include <fstream>
#endif
#include <mutex>

#include <Corrade/Containers/GrowableArray.h>
#include <Corrade/Utility/Debug.h>

#include <Magnum/Types.h>

#include "Logger.h"

using Containers::Array;
using Utility::Debug;
using Utility::Warning;
using Utility::Error;

using namespace Magnum;

namespace MassBuilderSaveTool { namespace Logger {

#ifndef SAVETOOL_DEBUG_BUILD
static std::ofstream log_file{"SaveToolLog.txt", std::ios::trunc};
#endif

static UnsignedInt _indentLevel = 0;

static std::mutex _logMutex;

static Array<LogEntry> _entries;

inline Debug&
operator<<(Debug& out, const LogEntry& entry) {
    using namespace Containers::Literals;

    out << "["_s << Debug::nospace << entry.timestamp << Debug::nospace << "]"_s;

#ifdef SAVETOOL_DEBUG_BUILD
#define COLOUR(col) << Debug::color(Debug::Color::col)
#else
#define COLOUR(col)
#endif

    switch(entry.type) {
        case EntryType::Info:
            out << "[INFO]"_s COLOUR(Default);
            break;
        case EntryType::Success:
            out << "[SUCCESS]"_s COLOUR(Green);
            break;
        case EntryType::Warning:
            out << "[WARNING]"_s COLOUR(Yellow);
            break;
        case EntryType::Error:
            out << "[ERROR]"_s COLOUR(Red);
            break;
    }

#undef DEBUG_COLOUR

    for(UnsignedInt i = 0; i < _indentLevel; i++) {
        out << Debug::nospace << "    "_s << Debug::nospace;
    }

    out << entry.message << Debug::resetColor;

    return out;
}

void
initialise() {
    arrayReserve(_entries, 100);
}

void
indent() {
    _indentLevel++;
}

void
unindent() {
    if(_indentLevel > 0) {
        _indentLevel--;
    }
}

void
addEntry(EntryType type, StringView message) {
    auto time = std::time(nullptr);

    static char formatted_time[20] = {'\0'};
    std::strftime(&formatted_time[0], sizeof(formatted_time)/sizeof(formatted_time[0]),
                  "%Y-%m-%d %H:%M:%S", // Because MSVCRT (which is the CRT I target by default) is not C99-compliant,
                                       // I can't use "%F %T" as the format string.
                  std::localtime(&time));

    LogEntry entry{
        formatted_time, type,
        (message.back() == '\n') ? String{message.exceptSuffix(1)} : String{message}
    };

    Debug{
#ifndef SAVETOOL_DEBUG_BUILD
        &log_file
#else
        &std::cout
#endif
    } << entry;

    arrayAppend(_entries, std::move(entry));
}

ArrayView<const LogEntry>
entries() {
    return _entries;
}

void
lockMutex() {
    _logMutex.lock();
}

void
unlockMutex() {
    _logMutex.unlock();
}

bool
tryLockMutex() {
    return _logMutex.try_lock();
}

} // Logger

} // MassBuilderSaveTool