#include <pthread.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include "logfile.h"
#include "fileutil.h"

/////////////////////////////////////////////////////////////////////////////

CLogfile::CLogfile(void) :	m_pf(NULL),
							m_bAttached(false),
							m_bClose(false),
							m_vb(VB_Off),
							m_nFileSize(0),
							m_nMaxFileSize(0),
							m_nMaxBackupFiles(0)
{
	m_lsync = PTHREAD_MUTEX_INITIALIZER;
}

CLogfile::CLogfile(FILE *pf, bool bClose, int verb) :	m_pf(pf),
														m_bAttached(false),
														m_bClose(false),
														m_vb(VB_Off),
														m_nFileSize(0),
														m_nMaxFileSize(0),
														m_nMaxBackupFiles(0)
{
	m_lsync = PTHREAD_MUTEX_INITIALIZER;

	if(!Attach(pf, bClose, verb))
	{
		StdErr("CLogfile::Attach failed!\n");
		throw EINVAL;
	}
}

CLogfile::CLogfile(const char *pszFilename, bool bAppend, int verb, size_t nMaxFileSize, unsigned int nMaxBackupFiles) :	m_pf(NULL),
																															m_bAttached(false),
																															m_bClose(false),
																															m_vb(VB_Off),
																															m_nFileSize(0),
																															m_nMaxFileSize(0),
																															m_nMaxBackupFiles(0)
{
	m_lsync = PTHREAD_MUTEX_INITIALIZER;

	if(!Open(pszFilename, bAppend, verb, nMaxFileSize, nMaxBackupFiles))
	{
		StdErr("CLogfile::Open failed!\n");
		throw errno;
	}
}

CLogfile::~CLogfile(void)
{
	Close();
	::pthread_mutex_destroy(&m_lsync);
}

void CLogfile::SetVerbosity(int verb)
{
	if(verb < VB_Off)
		verb = VB_Off;
	else if(verb >= VB_Dbg)
		verb = VB_Dbg;
	m_vb = (Verbosity)verb;
}

/////////////////////////////////////////////////////////////////////////////

bool CLogfile::Open(const char *pszFilename, bool bAppend, int verb, size_t nMaxFileSize, unsigned int nMaxBackupFiles)
{
	if(!pszFilename || !*pszFilename)
		return false;

	if(nMaxBackupFiles < 1)
		nMaxBackupFiles = 1;

	Close();

	if((m_pf = fopen(pszFilename, bAppend ? "ab" : "wb")))
	{
		char szBuf[PATH_MAX];
		m_strFilePath		= ::realpath(pszFilename, szBuf);
		m_nFileSize			= GetFileSize();
		m_bAttached			= false;
		m_bClose			= true;
		m_nMaxFileSize		= nMaxFileSize;
		m_nMaxBackupFiles	= nMaxBackupFiles;
		SetVerbosity(verb);
		ProcessFileSizeLimit(m_pf);
	}

	return m_pf != NULL;
}

void CLogfile::Close(void)
{
	CsLock();
	if(m_pf)
	{
		if(!m_bAttached || m_bClose)
			fclose(m_pf);
		m_pf = NULL;
	}

	m_bClose			= false;
	m_bAttached			= false;
	m_nFileSize			= 0;
	m_nMaxFileSize		= 0;
	m_nMaxBackupFiles	= 0;
	m_vb				= VB_Off;
	m_strFilePath.clear();
	CsUnlock();
}

void CLogfile::Flush(void)
{
	if(m_pf)
		fflush(m_pf);
}

/////////////////////////////////////////////////////////////////////////////

bool CLogfile::Attach(FILE *pf, bool bClose, int verb)
{
	if(!pf)
	{
		errno = EINVAL;
		return false;
	}

	Close();
	m_pf = pf;
	m_bAttached = true;
	m_bClose = bClose;
	SetVerbosity(verb);
	return true;
}

void CLogfile::Detach(void)
{
	CsLock();
	if(m_bAttached)
	{
		m_pf = NULL;
		m_bClose = false;
		m_bAttached = false;
	}
	CsUnlock();
}

/////////////////////////////////////////////////////////////////////////////

void CLogfile::Log(FILE *pf, const char *pszFormat, va_list args)
{
	int nLen;
	CsLock();
	if((nLen = vfprintf(pf, pszFormat, args)) > 0)
	{
		fflush(pf);
		m_nFileSize += nLen;
		ProcessFileSizeLimit(pf);
	}
	CsUnlock();
}

void CLogfile::Log(const char *pszFormat, ...)
{
	if(m_pf && pszFormat && *pszFormat)
	{
		va_list args;
		va_start(args, pszFormat);
		Log(m_pf, pszFormat, args);
		va_end(args);
	}
}

/////////////////////////////////////////////////////////////////////////////

void CLogfile::Debug(const char *pszFormat, ...)
{
	if(m_vb >= VB_Dbg)
	{
		const char *pszFmt;
		std::string sFormat;

		if((pszFmt = CreateFormatString(VB_Dbg, pszFormat, sFormat)))
		{
			va_list args;
			va_start(args, pszFormat);
			Log(m_pf, pszFmt, args);
			va_end(args);
		}
	}
}

void CLogfile::Info(const char *pszFormat, ...)
{
	if(m_vb >= VB_Inf)
	{
		const char *pszFmt;
		std::string sFormat;

		if((pszFmt = CreateFormatString(VB_Inf, pszFormat, sFormat)))
		{
			va_list args;
			va_start(args, pszFormat);
			Log(m_pf, pszFmt, args);
			va_end(args);
		}
	}
}

void CLogfile::Warning(const char *pszFormat, ...)
{
	if(m_vb >= VB_War)
	{
		const char *pszFmt;
		std::string sFormat;

		if((pszFmt = CreateFormatString(VB_War, pszFormat, sFormat)))
		{
			va_list args;
			va_start(args, pszFormat);
			Log(m_pf, pszFmt, args);
			va_end(args);
		}
	}
}

void CLogfile::Error(const char *pszFormat, ...)
{
	if(m_vb >= VB_Err)
	{
		const char *pszFmt;
		std::string sFormat;

		if((pszFmt = CreateFormatString(VB_Err, pszFormat, sFormat)))
		{
			va_list args;
			va_start(args, pszFormat);
			Log(m_pf, pszFmt, args);
			va_end(args);
		}
	}
}

size_t CLogfile::GetFileSize(void)
{
	CsLock();
	size_t s = m_pf ? ::GetFileSize(m_pf) : 0;
	CsUnlock();
	return s;
}

bool CLogfile::ProcessFileSizeLimit(FILE *pf)
{
	if(m_nMaxFileSize && !m_bAttached && pf && (pf == m_pf))
	{
		if(m_nFileSize >= m_nMaxFileSize)
		{
			char szBuf1[PATH_MAX], szBuf2[PATH_MAX];
			std::string strFilePath = m_strFilePath;
			Verbosity vb = m_vb;
			size_t nMaxFileSize = m_nMaxFileSize;
			int nMaxBackupFiles = m_nMaxBackupFiles;

			fclose(m_pf);
			m_pf				= NULL;
			m_bClose			= false;
			m_bAttached			= false;
			m_nFileSize			= 0;
			m_nMaxFileSize		= 0;
			m_nMaxBackupFiles	= 0;
			m_vb				= VB_Off;

			m_strFilePath.clear();

			snprintf(szBuf1, sizeof(szBuf1), "%s.%03u", strFilePath.c_str(), nMaxBackupFiles);
			remove(szBuf1);

			for(int i = nMaxBackupFiles; i > 1; --i)
			{
				snprintf(szBuf2, sizeof(szBuf2), "%s.%03u", strFilePath.c_str(), i);
				snprintf(szBuf1, sizeof(szBuf1), "%s.%03u", strFilePath.c_str(), i - 1);
				rename(szBuf1, szBuf2);
			}

			rename(strFilePath.c_str(), szBuf1);
			return Open(strFilePath.c_str(), false, vb, nMaxFileSize, nMaxBackupFiles);
		}
	}

	return false;
}

/////////////////////////////////////////////////////////////////////////////

void CLogfile::StdOut(const char *pszFormat, ...)
{
	if(pszFormat && *pszFormat)
	{
		va_list args;
		va_start(args, pszFormat);
		vfprintf(stdout, pszFormat, args);
		va_end(args);
		fflush(stdout);
	}
}

void CLogfile::StdErr(const char *pszFormat, ...)
{
	if(pszFormat && *pszFormat)
	{
		va_list args;
		va_start(args, pszFormat);
		vfprintf(stderr, pszFormat, args);
		va_end(args);
		fflush(stderr);
	}
}

/////////////////////////////////////////////////////////////////////////////

const char* CLogfile::CreateFormatString(Verbosity verb, const char *pszFormat, std::string &ret) const
{
	time_t ts = time(NULL);
	char szBuf[128], szTime[64];
	struct tm *pm = localtime(&ts);
	strftime(szTime, sizeof(szTime), "%d.%m.%Y %H:%M:%S", pm);

	switch(verb)
	{
	case VB_Dbg:
		sprintf(szBuf, "%s - DEBUG:   ", szTime);
		break;
	case VB_Inf:
		sprintf(szBuf, "%s - INFO:    ", szTime);
		break;
	case VB_War:
		sprintf(szBuf, "%s - WARNING: ", szTime);
		break;
	case VB_Err:
		sprintf(szBuf, "%s - ERROR:   ", szTime);
		break;
	default:
		return NULL;
	}

	ret = szBuf;
	ret += pszFormat;
	return ret.c_str();
}

/////////////////////////////////////////////////////////////////////////////

void CLogfile::CsLock(void)
{
	::pthread_mutex_lock(&m_lsync);
}

void CLogfile::CsUnlock(void)
{
	::pthread_mutex_unlock(&m_lsync);
}