#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int move(char* loc,char* dest);
int CodToInt(char* cod);
char* substring(char* input,int a,int b);
char* getMoveRegister(char* career, char* year, char* input);
char* getYear(char* codYear);
char* getCareer(char* codCareer);

int
main (void)
{
	DIR *dp;
	FILE *file;

	struct dirent *ep;

	//descomponer nombre
	char* year;
	char* career;
	char* codYear;
	char* codCareer;
	//registro log.txt
	char* moveRegister;
	//crear directorio
	char* directory;
	//mover archivos
	char* input;
	char* output;

	int length;

	file = fopen("./tarea/log.txt","a+");
	dp = opendir ("./tarea");

	directory = (char*)malloc(50*sizeof(char));
	input = (char*)malloc(50*sizeof(char));
	output = (char*)malloc(50*sizeof(char));

	if (dp != NULL)
	{
		while ((ep = readdir (dp)))
		{
			/*filtra archivos que no comportan formato*/
			length = strlen(ep->d_name);
			if((length == 14) || (length == 16))
			{
				year = substring(ep->d_name,0,4);
				if((strcmp(year,"2011") == 0) || (strcmp(year,"2010") == 0))
				{
					/*saca codigo de carrera*/
					codCareer = substring(ep->d_name,4,6);
					career = getCareer(codCareer);
				}
				else
				{
					codYear = substring(ep->d_name,0,2);

					/*recalcula year*/
					free(year);
					year = getYear(codYear);

					/*saca codigo de carrera*/
					codCareer = substring(ep->d_name,2,4);
					career = getCareer(codCareer);
				}

				if((career != NULL) && (year != NULL))
				{
					//crea directorio
					sprintf(directory,"tarea/%s",year);
					mkdir(directory, S_IRWXU | S_IRWXG | S_IRWXO);
					sprintf(directory,"%s/%s",directory,career);
					mkdir(directory, S_IRWXU | S_IRWXG | S_IRWXO);

					//mueve archivos
					sprintf(input,"tarea/%s",ep->d_name);
					sprintf(output,"%s/%s",directory,ep->d_name);

					printf("de %s\n", input);
					printf("a %s\n", output);

					if(move(input,output) != 0)
						perror("error mover\n");



					moveRegister = getMoveRegister(career,year,ep->d_name);
					fputs (moveRegister, file);
					free(moveRegister);
					moveRegister = NULL;
				}
			}/*endif*/
		}/*endWhiel*/

		fclose(file);
		(void) closedir (dp);
	}/*endif*/
	else
		perror ("No se puede crear el directorio");

	printf("libera espacio\n");
	free(year);
	year = NULL;
	free(codYear);
	codYear = NULL;
	free(career);
	career = NULL;
	free(codCareer);
	codCareer = NULL;
	free(directory);
	directory = NULL;
	free(input);
	input = NULL;
	free(output);
	output = NULL;

	return 0;
}

/*obtiene subcadena de input(desde "a" a "b")*/
char* substring(char* input,int a,int b)
{
	char* output;

	if(a>b) output = NULL;
	else
		output = (char*)malloc((b-a + 1)*sizeof(char));

	strncpy(output, input+a, (b-a));
	output[b-a] = '\0';
	return output;
}

/*transforma el codigo(año o carrera) en entero*/
int CodToInt(char* cod)
{
	int n,m;

	n = (int)cod[0] - 48;
	m = (int)cod[1] - 48;

	return (10*n+m);
}


/*funcion retorna el string del registro*/
char* getMoveRegister(char* career, char* year, char* input)
{
	char* output;

	output = (char*)malloc(100*sizeof(char));
	sprintf(output, "El archivo '%s' fue movido a la carpeta 'tareas/%s/%s' [ x kb]\n", input, year,career);


	return(output);
}


/*funcion transforma codigo de año en el año (20-29)*/
char* getYear(char* codYear)
{
	int iCod;
	char* output;
	output = (char*)malloc(5*sizeof(char));

	/*revisa que se valido el codigo*/
	iCod = CodToInt(codYear);

	if((iCod >= 20) && (iCod <= 29))
	{
		output[0] = codYear[0];
		output[1] = '0';
		output[2] = '0';
		output[3] = codYear[1];
		output[4] = '\0';
	}
	else
		output = NULL;

	return output;
}



/*funcion que retorna string carrera segun el codigo*/
char* getCareer(char* codCareer)
{
	char* output;
	int iCod;

	output = (char*)malloc(30*sizeof(char));
	iCod = CodToInt(codCareer);

	switch(iCod)
	{
		case 4:
			output = "PlanComun";
			break;
		case 3:
			output = "PPI";
			break;
		case 30:
			output = "Telematica";
			break;
		case 21:
			output = "Electronica";
			break;
		case 23:
			output = "Electrica";
			break;
		case 90:
			output = "Especial";
			break;
		case 73:
			output = "Informatica";
			break;
		case 51:
			output = "Quimica";
			break;
		case 84:
			output = "Ambiental";
			break;
		case 41:
			output = "Mecanica";
			break;
		case 60:
			output = "Industrial";
			break;
		case 66:
			output = "Comercial";
			break;
		case 11:
			output = "ObrasCiviles";
			break;
		case 02:
			output = "Especial";
			break;
		case 44:
			output = "IDP";
			break;
		case 43:
			output = "MecanicaIndustrial";
			break;
		case 13:
			output = "Arquitectura";
			break;
		case 12:
			output = "ConstruccionCivil";
			break;
		default:
			output = NULL;
	}

	return output;

}

//funcion para mover archivos
int move(char* loc,char* dest)
{
    FILE *source,*target;
    int byte;


    source = fopen(loc,"rb+");
    if(source==NULL)
    {
    	printf("problema directorio fuente!!.");
    	exit(0);
    }

    target = fopen(dest,"wb+");
    if(target==NULL)
    {
    	printf("problema directorio objetivo!!!.");
    	fclose(source);
    	exit(0);
    }

    while(1)
    {
    	byte=fgetc(source);
    	if(byte==EOF)
    	{
    		break;
    	}
    	else
   		fputc(byte,target);


    }

    fclose(source);
    fclose(target);

    if(unlink (loc) < 0)
	perror("error borrar\n");
}