#ifndef MYLOG_H
#define MYLOG_H

#include <iostream>
#include <QDateTime>
#include <QMutexLocker>
#include <QDir>
#include <QTimer>
#include <QTextStream>


//最大保存文件大小
const int g_logLimitSize = 5;

class MyLog
{
public:
    MyLog();
    ~MyLog();

    static MyLog* getInstance();

    //消息處理函數(shù)
    static void messageHandler(QtMsgType type,
                                   const QMessageLogContext& context,
                                   const QString& msg);
public:
    //打開并備份之前的日志文件
    void openAndBackupLogFile();
    void checkLogFiles();
    void autoDeleteLog();
    //安裝消息處理函數(shù)
    void installMessageHandler();

    //卸載消息處理函數(shù)，并釋放資源
    void uninstallMessageHandler();
private:
    //日志文件夾目錄
    QDir logDir;
    //重命名日志文件使用的定時(shí)器
    QTimer renameLogFileTimer;
    //刷新輸出到日志文件的定時(shí)器
    QTimer flushLogFileTimer;
    //日志文件的創(chuàng)建時(shí)間
    QDate logFileCreateDate;

    //日志文件
    static QFile* logFile;
    //輸出日志
    static QTextStream* logOut;
    //日志鎖
    static QMutex logMutex;
    static QScopedPointer<MyLog> self;
};

#endif // MYLOG_H

#include "mylog.h"
#include<QDebug>
#include<QTextCodec>

#define LOG 1
//初始化靜態(tài)變量
QMutex MyLog::logMutex;
QFile* MyLog::logFile = NULL;
QTextStream* MyLog::logOut = NULL;
QScopedPointer<MyLog> MyLog::self;

//定義單例模式
MyLog* MyLog::getInstance()
{
    //還沒(méi)有創(chuàng)建實(shí)例
    if(self.isNull())
    {
        //加把鎖,只能有一個(gè)線程訪問(wèn)
        static QMutex mutex;
        //自動(dòng)加解鎖
        QMutexLocker locker(&mutex);
        //再次判斷有沒(méi)有實(shí)例，防止等待的時(shí)間中有線程獲取到實(shí)例了
        if(self.isNull())
        {
            self.reset(new MyLog);
        }
    }
    return self.data();

}

MyLog::MyLog()
{
    //設(shè)置日志文件夾的路徑，./exe
    logDir.setPath("log");
    //獲取日志的絕對(duì)路徑
    QString logPath = logDir.absoluteFilePath("today.log");

    //獲取日志文件創(chuàng)建的時(shí)間
    //保存日志文件最后的修改時(shí)間
    logFileCreateDate = QFileInfo(logPath).lastModified().date();

    //打開并備份日志文件
    openAndBackupLogFile();

    //每10分鐘檢查一次日志文件創(chuàng)建的時(shí)間
    renameLogFileTimer.setInterval(1000 * 60 *1000);
    renameLogFileTimer.start();

    //處理超時(shí)事件，10分鐘重復(fù)一次
    QObject::connect(&renameLogFileTimer,&QTimer::timeout,[this](){
        QMutexLocker locker(&MyLog::logMutex);
        openAndBackupLogFile();
        checkLogFiles();
        autoDeleteLog();
    });

    //定時(shí)刷新日志輸出到日志文件，1秒1刷新
    flushLogFileTimer.setInterval(1000);
    flushLogFileTimer.start();

    QObject::connect(&flushLogFileTimer,&QTimer::timeout,[](){
#if LOG
        // 測(cè)試不停地寫入當(dāng)前時(shí)間到日志文件
        qDebug() << QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss");
#endif
        //刷新
        QMutexLocker locker(&MyLog::logMutex);
        if(NULL != logOut)
        {
            logOut->flush();
        }
    });
}

MyLog::~MyLog()
{
    if(NULL != logFile)
    {
        logFile->flush();
        logFile->close();
        logOut = NULL;
        logFile = NULL;
    }
}

//打開并備份之前的日志文件
void MyLog::openAndBackupLogFile()
{
    //有可能一天多次打開日志文件，使用追加的方式打開
    //目錄不存在，創(chuàng)建目錄
    if(!logDir.exists())
    {
        logDir.mkpath(".");
    }
    //log.txt的路徑
    QString logPath = logDir.absoluteFilePath("today.log");

    //程序啟動(dòng)的時(shí)候，logfile為空
    if(logFile == NULL)
    {
        //創(chuàng)建新的
        logFile = new QFile(logPath);
        //只寫，追加的方式打開日志文件
        //成功，創(chuàng)建文本流對(duì)象與日志文件關(guān)聯(lián)，向日志文件寫內(nèi)容
        logOut = (logFile->open(QIODevice::WriteOnly | QIODevice::Text |QIODevice::Append)) ? new QTextStream(logFile) : NULL;

        if(logOut != NULL)
        {
            //設(shè)置編碼格式
            logOut->setCodec("UTF-8");
        }

        //日志文件第一次創(chuàng)建，創(chuàng)建日期無(wú)效，設(shè)置為修改日期
        if(logFileCreateDate.isNull())
        {
            logFileCreateDate = QDate::currentDate();
        }
    }

    //程序運(yùn)行的時(shí)候，創(chuàng)建日期不是當(dāng)前日期，更新日期，重命名，備份老的并生成新的log.txt
    if(logFileCreateDate != QDate::currentDate())
    {
        //先刷新緩沖區(qū)，確保內(nèi)容先輸出到文件里
        logFile->flush();
        logFile->close();

        //更新日期到備份文件
        QString backUpLogPath = logDir.absoluteFilePath(logFileCreateDate.toString("yyyy-MM-dd.log"));;
        //備份原來(lái)的日志
        QFile::copy(logPath,backUpLogPath);
        //刪除原來(lái)的日志文件
        QFile::remove(logPath);

        //創(chuàng)建新的log.txt，進(jìn)行更新
        //只寫，截?cái)嗟姆绞酱蜷_日志
        logFile = new QFile(logPath);
        logOut = (logFile->open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate)) ? new QTextStream(logFile) : NULL;
        //更新為修改時(shí)間
        logFileCreateDate = QDate::currentDate();
        if(logOut != NULL)
        {
            logOut->setCodec("UTF-8");
        }
    }
}

//檢查文件大小
void MyLog::checkLogFiles()
{
    //日志文件大小超過(guò)5m，備份并重新創(chuàng)建日志文件
    if(logFile->size() > 1024* g_logLimitSize)
    {
        //清空緩沖
        logFile->flush();
        logFile->close();

        QString logPath = logDir.absoluteFilePath("today.log");
        //備份老的日志文件
        QString backUplogPath = logDir.absoluteFilePath(logFileCreateDate.toString("yyyy-MM-dd.log"));
        QFile::copy(logPath,backUplogPath);
        QFile::remove(logPath);

        //創(chuàng)建新的日志文件
        logFile = new QFile(logPath);
        logOut = (logFile->open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate)) ? new QTextStream(logFile) :NULL;
        logFileCreateDate = QDate::currentDate();
        if(logOut != NULL)
        {
            logOut->setCodec("UTF-8");
        }
    }
}

//自動(dòng)刪除超過(guò)時(shí)間的日志文件
void MyLog::autoDeleteLog()
{
    //當(dāng)前時(shí)間
    QDateTime now = QDateTime::currentDateTime();

    //基準(zhǔn)，30天前
    QDateTime dateTime1 = now.addDays(-30);
    QDateTime dateTime2;

    QString logPath = logDir.absoluteFilePath("today.log");
    //打開日志目錄
    QDir dir(logPath);
    //獲取目錄下的所有文件信息列表
    QFileInfoList fileList = dir.entryInfoList();
    foreach(QFileInfo f, fileList)
    {
        //跳過(guò)文件名為空的文件
        if(f.baseName() == "")
        {
            continue;
        }

        //將文件名解析為日期對(duì)象
        dateTime2 = QDateTime::fromString(f.baseName(),"yyyy-MM-dd");
        //大于30天，刪除
        if(dateTime2 < dateTime1)
        {
            dir.remove(f.absoluteFilePath());
        }
    }
}


//定義消息處理函數(shù)
void MyLog::messageHandler(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
    QMutexLocker locker(&MyLog::logMutex);
        QString level;

        switch (type) {
        case QtDebugMsg:
            level = "DEBUG";
            break;
        case QtInfoMsg:
            level = "INFO";
            break;
        case QtWarningMsg:
            level = "WARN";
            break;
        case QtCriticalMsg:
            level = "ERROR";
            break;
        case QtFatalMsg:
            level = "FATAL";
            break;
        default:
            break;
        }

#if defined (Q_OS_WIN)
        QByteArray localMsg = QTextCodec::codecForName("GB2312")->fromUnicode(msg);
#else
        QByteArray localMsg = msg.toLocal8Bit();
#endif

        //輸出到控制臺(tái)
        std::cout << std::string(localMsg) << std::endl;
        if(NULL == MyLog::logOut)
        {
            return;
        }

        //輸出到日志文件
        //獲取文件名，去掉路徑
        QString fileName = context.file;
        int index = fileName.lastIndexOf(QDir::separator());
        fileName = fileName.mid(index + 1);

        //寫入日志信息
        (*MyLog::logOut) << QString("%1 - [%2] (%3:%4, %5): %6\n")
                                        .arg(QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss"))
                                        .arg(level)
                                        .arg(fileName)
                                        .arg(context.line)
                                        .arg(context.function)
                                        .arg(msg);
}

//安裝
void MyLog::installMessageHandler()
{
    qInstallMessageHandler(MyLog::messageHandler);
}

//卸載
void MyLog::uninstallMessageHandler()
{
    qInstallMessageHandler(NULL);
}