#pragma once

#include <filesystem>
#include <string>
#include <vector>

#include <cstddef>

#include <QDateTime>
#include <QFile>
#include <QMessageLogger>
#include <QString>
#include <QTextStream>

static inline void rotateLog(const std::filesystem::path& logFileName, int numRotatingLogs)
{
    const auto generateRotateNames = [&]() {
        std::vector<QString> rotateFileNames = {QString().fromStdString(logFileName.string())};

        for(size_t i = 1; i < numRotatingLogs; ++i) {
            auto rotateName = logFileName.stem();
            rotateName += std::string(".") + std::to_string(i);
            rotateName += logFileName.extension();
            rotateFileNames.push_back(QString().fromStdString(rotateName.string()));
        }

        return rotateFileNames;
    };

    const auto rotateFileNames = generateRotateNames();

    for(auto i = static_cast<int>(rotateFileNames.size()) - 2; i >= 0; --i) {
        QFile file(rotateFileNames[i]);
        QFile newFile(rotateFileNames[i + 1]);
        if(file.exists()) {
            newFile.remove();
            file.rename(rotateFileNames[i + 1]);
        }
    }
}

void logToFile(QtMsgType msgType, [[maybe_unused]] const QMessageLogContext& msgContext, const QString& msg)
{
    constexpr auto MAX_LOG_FILE_SIZE = 4 /*MiB*/ * 1024 * 1024;
    constexpr auto NUM_ROTATING_LOGS = 4;

    const auto logFileName = std::filesystem::path{"AdaptiveBrightness.log"};

    const auto dateTime = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss.zzz");
    QString formattedMsg = QString("[%1] ").arg(dateTime);

    switch(msgType) {
    case QtDebugMsg:
        formattedMsg += "[Debug] ";
        break;
    case QtWarningMsg:
        formattedMsg += "[Warning] ";
        break;
    case QtCriticalMsg:
        formattedMsg += "[Critical] ";
        break;
    case QtFatalMsg:
        formattedMsg += "[Fatal] ";
        break;
    case QtInfoMsg:
        formattedMsg += "[Info] ";
        break;
    }

#ifdef LOG_SOURCE_LOCATION
    const auto msgFromFile = QString(msgContext.file);
    const auto msgFromLine = (msgContext.line == 0) ? QString("") : QString("%1").arg(msgContext.line);
    if(!msgFromFile.isEmpty() && !msgFromLine.isEmpty()) {
        formattedMsg += QString("[%1:%2] ").arg(msgContext.file).arg(msgContext.line);
    }
#endif

#ifdef LOG_FUNCTION_LOCATION
    const auto msgFromFunction = QString(msgContext.function);
    if(!msgFromFunction.isEmpty()) {
        formattedMsg += QString("[%1] ").arg(msgContext.function);
    }
#endif

    formattedMsg += QString("%1").arg(msg);

    QFile logFile(QString().fromStdString(logFileName.string()));
    logFile.open(QIODevice::WriteOnly | QIODevice::Append);

    if(logFile.size() > MAX_LOG_FILE_SIZE) {
        logFile.close();
        rotateLog(logFileName, NUM_ROTATING_LOGS);
        logFile.open(QIODevice::WriteOnly | QIODevice::Append);
    }

#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
    constexpr auto qtEndl = Qt::endl;
#else
    constexpr auto qtEndl = ::endl;
#endif

    QTextStream textStream(&logFile);
    textStream << formattedMsg << qtEndl;
}