#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

//extrage din calea sursa numele fisierului/folderului
char *getFileName(char *nume, char *path){
	int i,j=0;
	for(i=strlen(path)-1;path[i]!='/';i--);
	while(path[++i]!='\0'){
		nume[j++]=path[i];
	}
	nume[j]='\0';
	return nume;
}

//creeaza un folder la destinatie
void makeFolder(char *src, char *dest, mode_t permissions){
	char folder[50];

	getFileName(folder,src);
	strcat(dest,folder);

	while(mkdir(dest,permissions)){
		strcat(dest,"_copy");
	}
	strcat(dest,"/");
}

//copiaza continutul fisierelor in copii ale acestora in destinatie
void copyFileContents(char *src, char *dest, mode_t permissions, off_t fileSize){
	char fileName[50];
	int fdSrc, fdDest;
	char buf[fileSize];

	getFileName(fileName,src);
	strcat(dest,fileName);

	fdDest=creat(dest,permissions);
	if(fdDest == -1){
		perror(dest);
		exit(-1);
	 }
	 else{
 		fdSrc = open(src,O_RDONLY);
 		read(fdSrc,buf,fileSize);
 		write(fdDest,buf,fileSize);
	 }
	 close(fdSrc);
	 close(fdDest);
}

//parcurge folderul initial pentru a copia tot ce exista in acesta la destinatie
void parseDir(char *src, char *dest, int mod){
	char src_aux[100], dest_aux[100];

	strcpy(src_aux,src);
	strcpy(dest_aux,dest);

	struct stat fileStat;
	DIR *dirSrc;
	struct dirent *dirEntry;
	stat(src_aux,&fileStat);
	if(S_ISDIR(fileStat.st_mode)){
		makeFolder(src_aux,dest_aux,fileStat.st_mode);
		dirSrc = opendir(src_aux);
		while(dirEntry = readdir(dirSrc)){	//itereaza pe toate fisierele din director
			if((strcmp(dirEntry->d_name,".")!=0) && (strcmp(dirEntry->d_name,"..")!=0)){
				strcat(src_aux,"/");
				strcat(src_aux,dirEntry->d_name);
				parseDir(src_aux,dest_aux,mod);	//apelare recursiva
				strcpy(src_aux,src);	//suprascrierea caii cu cea veche, pentru intoarcere
			}
		}
		strcpy(dest_aux,dest);	//suprascrierea caii cu cea veche, pentru intoarcere
		return ;
	}
	else if(S_ISREG(fileStat.st_mode)){
		if(mod == 0){	//copy file
			copyFileContents(src_aux, dest_aux, fileStat.st_mode, fileStat.st_size);
		}else{	//link file
			char filePath[100], fileName[100];
			getFileName(fileName,src_aux);
			strcpy(filePath,dest_aux);
			strcat(filePath,fileName);
			if(link(src_aux,filePath) == -1)
				printf("\nFisierul %s nu a putut fi link-uit\n",fileName);
		}
		return ;
	}
}

//executa programul in mod copiere/link [0/1]
void dirCopy(int argc, char *argv[], int argvPos,int mod){
	char src[100], src_aux[100], dest[100];
	struct stat fileStat;
	DIR *dirSrc;
	struct dirent *dirEntry;

	strcpy(src,argv[1+argvPos]);
	strcpy(dest,argv[argvPos+2]);

	if(src[strlen(src)-1] == '/')
		src[strlen(src)-1] = '\0';
	if(dest[strlen(dest)-1] != '/')
		strcat(dest,"/");

	if(stat(src,&fileStat) == 0){
		strcpy(src_aux,src);
		if(S_ISDIR(fileStat.st_mode)){
			makeFolder(src_aux,dest,fileStat.st_mode);//creeaza folderul initial
			dirSrc=opendir(src_aux);
			while(dirEntry = readdir(dirSrc)){ // cat timp exista entry in folderul de baza
				if((strcmp(dirEntry->d_name,".")!=0) && (strcmp(dirEntry->d_name,"..")!=0)){
					strcat(src_aux,"/");strcat(src_aux,dirEntry->d_name);
					parseDir(src_aux,dest,mod);
					strcpy(src_aux,src);
				}
			}
		}
		closedir(dirSrc);
	}
	else
	{
		printf("\nCaile nu sunt valide \n");
		printf("1:%s\n2:%s\n",src,dest);
		exit(-1);
	}
}

//cauta flag -c sau -l
int findFlag(char *argv[]){
	int cod = 0;
	if(strcmp(argv[1],"-c")==0)
		cod = 1;
	else if (strcmp(argv[1],"-l")==0)
		cod = 2;
	return cod;
}

int main(int argc, char *argv[]){
	switch(findFlag(argv)){
		case 0: // copiere implicit
			if(argc!=3){
				printf("Introduceti ca argumente : [-l/c]\tsursa\tdestinatie\n");
				exit(-1);
			}
			else{
				printf("Mod copiere\n");
				dirCopy(argc, argv, 0, 0);
			}
			break;
		case 1: //copiere explicit
			if(argc!=4){
				printf("Introduceti ca argumente : [-l/c]\tsursa\tdestinatie\n");
				exit(-1);
			}
			else{
				printf("Mod copiere explicit\n");
				dirCopy(argc, argv, 1, 0);
			}
			break;
		case 2: //link explicit
			if(argc!=4){
				printf("Introduceti ca argumente : [-l/c]\tsursa\tdestinatie\n");
				exit(-1);
			}
			else{
				printf("Mod link\n") ;
				dirCopy(argc, argv, 1, 1);
			}
			break;
		default:
			break;
	}

	return 0;
}