// Taken from here: http://www.drdobbs.com/cpp/logging-in-c/201804215
// Original author: Petru Marginean <petru.marginean@gmail.com>
// Modified by: Czarek Tomczak <czarek.tomczak@gmail.com>

// Usage:
//   LOG_DEBUG << "Browser: someVar = " << someVar;
// Warning:
//   Log is written when ~Log() destructor is called, which
//   occurs when outside of scope. This could result in log
//   not being written if program crashes before code goes
//   outside of current scope. You could embrace LOG_DEBUG
//   statements with braces {} to guarantee the log to be
//   written immediately.

#ifndef __LOG_DEBUG_H__
#define __LOG_DEBUG_H__

#include <sstream>
#include <string>
#include <stdio.h>
#include "DebugLog.h"

inline std::string NowTime();

enum TLogLevel {logERROR, logWARNING, logINFO, logDEBUG, 
                logDEBUG1, logDEBUG2, logDEBUG3, logDEBUG4};

template <typename T>
class Log
{
public:
    Log();
    virtual ~Log();
    std::ostringstream& Get(TLogLevel level = logINFO);
public:
    static TLogLevel& ReportingLevel();
    static std::string ToString(TLogLevel level);
    static TLogLevel FromString(const std::string& level);
protected:
    std::ostringstream os;
private:
    Log(const Log&);
    Log& operator =(const Log&);
};

template <typename T>
Log<T>::Log()
{
}

template <typename T>
std::ostringstream& Log<T>::Get(TLogLevel level)
{
    // os << "- " << NowTime();
    // os << " " << ToString(level) << ": ";
    // os << std::string(level > logDEBUG ? level - logDEBUG : 0, '\t');
    return os;
}

template <typename T>
Log<T>::~Log()
{
    os << std::endl;
    /*
    if (T::Stream() != stderr) {
        fprintf(stderr, "%s", os.str().c_str());
        fflush(stderr);
    }
    T::Output(os.str());
    */
    DebugLog(os.str().c_str());
}

template <typename T>
TLogLevel& Log<T>::ReportingLevel()
{
    static TLogLevel reportingLevel = logDEBUG4;
    return reportingLevel;
}

template <typename T>
std::string Log<T>::ToString(TLogLevel level)
{
	static const char* const buffer[] = {"ERROR", "WARNING", "INFO", "DEBUG",
            "DEBUG1", "DEBUG2", "DEBUG3", "DEBUG4"};
    return buffer[level];
}

template <typename T>
TLogLevel Log<T>::FromString(const std::string& level)
{
    if (level == "DEBUG4")
        return logDEBUG4;
    if (level == "DEBUG3")
        return logDEBUG3;
    if (level == "DEBUG2")
        return logDEBUG2;
    if (level == "DEBUG1")
        return logDEBUG1;
    if (level == "DEBUG")
        return logDEBUG;
    if (level == "INFO")
        return logINFO;
    if (level == "WARNING")
        return logWARNING;
    if (level == "ERROR")
        return logERROR;
    Log<T>().Get(logWARNING) << "Unknown logging level '" << level 
                             << "'. Using INFO level as default.";
    return logINFO;
}

class Output2FILE
{
public:
    static FILE*& Stream();
    static void Output(const std::string& msg);
};

inline FILE*& Output2FILE::Stream()
{
    static FILE* pStream = stderr;
    return pStream;
}

inline void Output2FILE::Output(const std::string& msg)
{
    /*
    FILE* pStream = Stream();
    if (!pStream)
        return;
    fprintf(pStream, "%s", msg.c_str());
    fflush(pStream);
    */
}

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
#   if defined (BUILDING_FILELOG_DLL)
#       define FILELOG_DECLSPEC   __declspec (dllexport)
#   elif defined (USING_FILELOG_DLL)
#       define FILELOG_DECLSPEC   __declspec (dllimport)
#   else
#       define FILELOG_DECLSPEC
#   endif // BUILDING_DBSIMPLE_DLL
#else
#   define FILELOG_DECLSPEC
#endif // _WIN32

class FILELOG_DECLSPEC FILELog : public Log<Output2FILE> {};
//typedef Log<Output2FILE> FILELog;

#ifndef FILELOG_MAX_LEVEL
#define FILELOG_MAX_LEVEL logDEBUG4
#endif

// Name conflits with cef_logging.h, see:
// https://bitbucket.org/chromiumembedded/cef/issues/1830
// LOG, LOG_ERROR, LOG_WARNING and LOG_INFO are already defined
// in cef_logging.h and must not be used here. So far we've only
// used LOG_DEBUG in code.

#define CEFPYTHON_LOG(level) \
    if (level > FILELOG_MAX_LEVEL) ;\
    else if (level > FILELog::ReportingLevel() || !Output2FILE::Stream()) ; \
    else FILELog().Get(level) \

// #define LOG_ERROR LOG(logERROR)
// #define LOG_WARNING LOG(logWARNING)
// #define LOG_INFO LOG(logINFO)
#define LOG_DEBUG CEFPYTHON_LOG(logDEBUG)

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)

#include <windows.h>

inline std::string NowTime()
{
    const int MAX_LEN = 200;
    char buffer[MAX_LEN];
    if (GetTimeFormatA(LOCALE_USER_DEFAULT, 0, 0, 
            "HH':'mm':'ss", buffer, MAX_LEN) == 0)
        return "Error in NowTime()";

    char result[100] = {0};
    static DWORD first = GetTickCount();
    #pragma warning(suppress: 4996)
    sprintf(result, "%s.%03ld", buffer, (long)(GetTickCount() - first) % 1000); 
    return result;
}

#else

#include <sys/time.h>

inline std::string NowTime()
{
    char buffer[11];
    time_t t;
    time(&t);
    tm r = {0};
    strftime(buffer, sizeof(buffer), "%X", localtime_r(&t, &r));
    struct timeval tv;
    gettimeofday(&tv, 0);
    char result[100] = {0};
    sprintf(result, "%s.%03ld", buffer, (long)tv.tv_usec / 1000); 
    return result;
}

#endif //WIN32

#endif //__LOG_DEBUG_H__
