/*
	文件打包和解包程序 by 郭 煒
	本程序用法：
	rlezip  -e dirname filename  將文件夾 dirname 中的所有內(nèi)容打包到 filename 文件里去
								  dirname 可以是相對路徑,也可以是絕對路徑

    rlezip -x filename           將文件 filename里的所有內(nèi)容解出來,放到當(dāng)前目錄下

	本程序沒有進(jìn)行壓縮
	解壓函數(shù) DeCompressDir 省略

    結(jié)果文件 結(jié)構(gòu)如下：
	每一個文件和文件夾，在結(jié)果文件中都有 一個 tagFileInfo結(jié)構(gòu)與之對應(yīng)。如果一個 tagFileInfo
	代表一個文件，那么在該 tagFileInfo后就緊跟著該文件的內(nèi)容.

	//關(guān)鍵函數(shù)： FindFirstFile, FindNextFile  , _chdir, _mkdir

*/


#include <iostream.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <direct.h>
#include <io.h>

int g_nCurDirLayer = 0;  //當(dāng)前正在處理的文件夾所處的層次

const int ATTR_FILE = 0;
const int ATTR_DIR =  1;
const int MAX_LENGTH = 256;


FILE   * g_fpData;

int Is_Dir( char * name)
{
	FILE * fp = fopen (name , "r" );

	if ( fp == NULL )
	{
		if ( _chdir( name ) == 0 )
		{
			cout << name << "是文件夾" << endl;

			return 1; //是文件夾
		}
		else
		{
			cout << name << "兩者都不是" << endl;

			return -1; //兩者都不是
		}
	}
	else
	{
		fclose(fp);

		cout << name << "是文件" << endl;

		return 0; //是文件
	}
}


struct tagFileInfo
{
	char szFileName[256];  //文件名或文件夾名字
	int nLayer;			   //文件或文件夾所在的層次,根文件夾所處層次為0
	int nLength;		   //文件壓縮后的長度
	int nAttr;			   //為 ATTR_FILE 代表文件，為 	ATTR_FILE 代表文件夾
};

void CompressFile( char * szFile)
{
	cout << "Compressing file " << szFile << " ……" << endl;

	tagFileInfo FileInfo;
	FILE * fpSrc;
	int c;
	int i = 0;
	unsigned char cCount = 0; //重復(fù)次數(shù)
	long lOffsetFront = 0, lOffsetEnd; //偏移量
	int nTemp;

	memset( & FileInfo,0,sizeof(FileInfo));

	strcpy( FileInfo.szFileName,szFile);

	FileInfo.nLayer = g_nCurDirLayer;
	FileInfo.nAttr = ATTR_FILE;

	if ((fpSrc = fopen( szFile,"rb")) == NULL)
	{
		cout << "Error, failed to open file " << szFile << endl;
		exit(0);
	}

	FileInfo.nLength = 0;
	lOffsetFront = ftell(g_fpData);

	fwrite( & FileInfo,1,sizeof( FileInfo),g_fpData);

	if ((nTemp = fgetc(fpSrc)) == EOF) //讀取第一個字節(jié)的內(nèi)容，若為EOF則返回
	{
		fclose( fpSrc);
		return;
	}
	else
		fseek(fpSrc, 0, SEEK_SET); //定位回文件開頭

	cCount = 0;

	while(( c = fgetc( fpSrc)) != EOF)
	{
		if (nTemp == c && cCount < 255)
		{
			cCount++;
		}
		else
		{
			if (cCount > 1)
			{
				//這里（應(yīng)該）進(jìn)行標(biāo)記，就是有多個重復(fù)的東東，寫兩次來標(biāo)記它
				for (i = 0; i < 2; i++)
				{
					FileInfo.nLength++;
					fputc(nTemp, g_fpData);
				}

				FileInfo.nLength++;
				fputc(cCount, g_fpData);

			}
			else if (cCount == 1)
			{
				FileInfo.nLength++;
				fputc(nTemp, g_fpData);
			}

			nTemp = c;
			cCount = 1;
		}
	}

	if (cCount > 1)
	{
		//這里（應(yīng)該）進(jìn)行標(biāo)記，就是有多個重復(fù)的東東，寫兩次來標(biāo)記它
		for (i = 0; i < 2; i++)
		{
			FileInfo.nLength++;
			fputc(nTemp, g_fpData);
		}

		FileInfo.nLength++;
		fputc(cCount, g_fpData);
	}
	else if (cCount == 1)
	{
		FileInfo.nLength++;
		fputc(nTemp, g_fpData);

	}

	//重新寫入文件信息

	lOffsetEnd = ftell(g_fpData);

	fseek(g_fpData, lOffsetFront, SEEK_SET);
	fwrite( & FileInfo,1,sizeof( FileInfo),g_fpData);


	fseek(g_fpData, lOffsetEnd, SEEK_SET);

	fclose( fpSrc);
}

void CompressDir( char * szDir )
{
	cout << "Compressing folder " << szDir << endl;

	tagFileInfo FileInfo;
	int i,nLen;
	memset( & FileInfo,0,sizeof(FileInfo));
	nLen = strlen( szDir);

	//不需要絕對路徑， 下面4行是抽取單純的文件夾名字
	for( i = nLen; szDir[i]!= '\\' && i > 0 ;i --);

	if( szDir[i] == '\\')
	   i++;

	strcpy( FileInfo.szFileName,szDir + i);

	FileInfo.nLayer = g_nCurDirLayer;
	FileInfo.nAttr = ATTR_DIR;

	fwrite( & FileInfo,1,sizeof( FileInfo),g_fpData);


	_chdir( szDir );    //當(dāng)前路徑設(shè)為該文件夾

	WIN32_FIND_DATA stFindClientData;
	HANDLE hFindClient;

	//找到第一個文件夾即其自身 " . " ,不作處理
	hFindClient = FindFirstFile( "*.*", &stFindClientData );

	if ( hFindClient == INVALID_HANDLE_VALUE )
	{
		return ;
	}

	//找到第二個文件夾即其父文件夾 ".. " ,,不作處理
	FindNextFile( hFindClient , &stFindClientData );

	//上述做法不保險(xiǎn),可移植性差。如果在別的操作系統(tǒng)或新版Windows上首先找到的不再是 "." 和".."怎么辦？

	//循環(huán)查找其它子文件夾和文件
	while ( FindNextFile( hFindClient,& stFindClientData))
	{
		//如果是子文件夾，則遞歸調(diào)用 CompressDir 進(jìn)行打包
		if(FILE_ATTRIBUTE_DIRECTORY == 
			stFindClientData.dwFileAttributes)
		{
			g_nCurDirLayer ++; //stFindClientData.cFileName 文件夾的層次比當(dāng)前文件夾即 szDir 多1 
			CompressDir( stFindClientData.cFileName); 
			g_nCurDirLayer --; //處理完stFindClientData.cFileName 文件夾后，層次值要恢復(fù)到 szDir 的層次值
		}
		else
		{ //是文件
			g_nCurDirLayer ++;
			CompressFile( stFindClientData.cFileName);
			g_nCurDirLayer --;
		}
	}
	//關(guān)閉查找句柄
	FindClose( hFindClient);
	//返回父文件夾
	_chdir( ".." );
}

void DeCompressDir( char * szZippedFile)
{
	FILE *fpZip;
	FILE *fpUnZip;

	int i = 0;
	int nGet, nTemp;
	int nCount = 0;

	tagFileInfo FileInfo;

	if ((fpZip = fopen(szZippedFile, "rb")) == NULL)
	{
		cout << "Error, failed to open file " << szZippedFile << endl;
		exit(0);
	}

	g_nCurDirLayer = 0;

	while (fread( &FileInfo, 1, sizeof(FileInfo), fpZip) == sizeof(FileInfo))
	{
		if (FileInfo.nAttr == ATTR_DIR)
		{ //如果是文件夾
			if (g_nCurDirLayer == FileInfo.nLayer)
			{
				//創(chuàng)建文件夾
				_mkdir(FileInfo.szFileName);
				g_nCurDirLayer++;
				_chdir(FileInfo.szFileName);
			}
			else if (g_nCurDirLayer > FileInfo.nLayer)
			{ //不相等，空文件夾，退回上層
				for (i = 0; i < (g_nCurDirLayer - FileInfo.nLayer); i++)
					_chdir("..");
			
				g_nCurDirLayer = FileInfo.nLayer;
				_mkdir(FileInfo.szFileName);
				
				g_nCurDirLayer++;
				_chdir(FileInfo.szFileName);
			}
		}
		else 
		{ //如果是文件
			cout << "Decompressing file " << FileInfo.szFileName << "……" << endl;

			if (g_nCurDirLayer > FileInfo.nLayer)
			{ //不相等，空文件夾，退回上層
				for (i = 0; i < (g_nCurDirLayer - FileInfo.nLayer); i++)
					_chdir("..");
			
				g_nCurDirLayer = FileInfo.nLayer;
			}


			if ( (fpUnZip = fopen(FileInfo.szFileName, "wb")) == NULL)
			{
				cout << "Error, can not creat file " << FileInfo.szFileName << endl;
				break;
			}

			if ((nTemp = fgetc(fpZip)) == EOF) //讀取第一個字節(jié)的內(nèi)容，若為EOF則退出
			{
				fclose( fpZip);
				continue;
			}

			for (i = 0; i < FileInfo.nLength; )
			{
				nGet = fgetc(fpZip);
				i++;

				if (nGet == nTemp)
				{
					nCount = fgetc(fpZip);
					i++;

					if (i == FileInfo.nLength - 1)
						nCount--;


					for (int j = 0; j < nCount; j++)
						fputc(nTemp, fpUnZip);

					if (i < FileInfo.nLength -1)
					{
						nTemp = fgetc(fpZip);
						i++;
					}
				}
				else if (nGet != nTemp)
				{
					fputc(nTemp, fpUnZip);

					nTemp = nGet;
				}

			}

			cout << "Decompressing file " << FileInfo.szFileName << " Finished!" << endl;
			fclose(fpUnZip);
			fseek(fpZip, -1, SEEK_CUR);
		}
	}

	fclose(fpZip);
	
}



void main( int argc, char * argv[])
{
	if ( argc == 1 )
	{
		cout << "Error: No filename." << endl;
		exit(0);
	}

	if ( stricmp( argv[1],"-e") == 0 )
	{
		g_fpData = fopen( argv[argc - 1], "wb");

		if ( stricmp( argv[2], "*") == 0 )
		{ //如果是要將當(dāng)前目錄下的所有文件壓縮到一個文件里，不考慮子目錄

			WIN32_FIND_DATA stFindClientData;		
			HANDLE hFindClient;

			hFindClient = FindFirstFile( "*.*" , &stFindClientData );    
			if ( hFindClient == INVALID_HANDLE_VALUE )
			{
				return ;
			}

			FindNextFile( hFindClient , & stFindClientData );

			while ( FindNextFile( hFindClient,& stFindClientData))
			{ //以下文件不在壓縮名單之內(nèi)：壓縮目標(biāo)文件、壓縮可執(zhí)行文件
				if((FILE_ATTRIBUTE_DIRECTORY ==stFindClientData.dwFileAttributes)
					|| strcmp( stFindClientData.cFileName , argv [argc-1]) == 0
					|| strcmp( stFindClientData.cFileName , "rlezip.exe") == 0 )
				{
					//不進(jìn)行操作
				}
				else
				{ //如果是其他文件則進(jìn)行壓縮
					CompressFile( stFindClientData.cFileName);
				}
			}

			FindClose( hFindClient);
		}
		else
		{ //如果是要將一個或多個文件或文件夾壓縮到一個文件里面

			int here_argc = argc - 1; //記錄要壓縮的文件或文件夾的個數(shù)
			int i;

			for (i = 2; i < here_argc; i++ )
			{
				int IsDir = Is_Dir( argv[i] );

				if (IsDir == -1) //文件或者文件夾不存在
				{
					cout << "Error: File or folder is not found." << endl;
					fclose( g_fpData );
					remove( argv[here_argc-1] );
					exit(0); //退出程序
				}
				else if (IsDir == 1)
				{
					CompressDir( argv[i] );
				}
				else if (IsDir == 0)
				{
					CompressFile( argv[i] );					
				}
			}

		}

		fclose( g_fpData);
	}
	else if ( stricmp( argv[1],"-x") ==0 )
		DeCompressDir( argv[argc - 1]);
	else
		cout << "Error!" << endl;
	
	cout << "Finished!" << endl;
}