#include "core/Logger.h"
#include <QDateTime>
#include <QFileInfo>
#include <QDir>

Logger* Logger::s_instance = nullptr;

Logger* Logger::instance()
{
    if (!s_instance) {
        s_instance = new Logger();
    }
    return s_instance;
}

Logger::Logger(QObject *parent)
    : QObject(parent)
    , m_maxLines(100000)  // 保留最新10000行
    , m_currentLines(0)
{
}

Logger::~Logger()
{
}

void Logger::setLogFile(const QString &filePath)
{
    QMutexLocker locker(&m_mutex);
    m_logFilePath = filePath;
    
    // Count existing lines
    QFile file(m_logFilePath);
    if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        m_currentLines = 0;
        while (!file.atEnd()) {
            file.readLine();
            m_currentLines++;
        }
        file.close();
    }
}

void Logger::setMaxLines(int maxLines)
{
    QMutexLocker locker(&m_mutex);
    m_maxLines = maxLines;
}

void Logger::log(const QString &message)
{
    writeLog("LOG", message);
}

void Logger::debug(const QString &message)
{
    writeLog("DEBUG", message);
}

void Logger::info(const QString &message)
{
    writeLog("INFO", message);
}

void Logger::warning(const QString &message)
{
    writeLog("WARN", message);
}

void Logger::error(const QString &message)
{
    writeLog("ERROR", message);
}

void Logger::writeLog(const QString &level, const QString &message)
{
    QMutexLocker locker(&m_mutex);
    
    if (m_logFilePath.isEmpty()) {
        return;
    }

    QString timestamp = QDateTime::currentDateTime().toString("[yyyy-MM-dd hh:mm:ss.zzz]");
    QString logLine = QString("%1 [%2] %3\n").arg(timestamp).arg(level).arg(message);

    QFile file(m_logFilePath);
    if (file.open(QIODevice::Append | QIODevice::Text)) {
        QTextStream out(&file);
        out << logLine;
        file.close();
        
        m_currentLines++;
        
        // Check if we need to trim the log
        if (m_currentLines > m_maxLines) {
            checkAndTrimLog();
        }
    }
}

void Logger::checkAndTrimLog()
{
    // Read all lines
    QFile file(m_logFilePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        return;
    }

    QStringList lines;
    QTextStream in(&file);
    while (!in.atEnd()) {
        lines.append(in.readLine());
    }
    file.close();

    // Keep only the last m_maxLines
    if (lines.size() > m_maxLines) {
        lines = lines.mid(lines.size() - m_maxLines);
    }

    // Write back
    if (file.open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate)) {
        QTextStream out(&file);
        for (const QString &line : lines) {
            out << line << "\n";
        }
        file.close();
        m_currentLines = lines.size();
    }
}