#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

#define BUFFER 1500
#define READ 0
#define WRITE 1

int main(int argc, char* argv[]){
        char strFgets[BUFFER], wordsPath[BUFFER], temp[BUFFER], text[BUFFER];
        char file[BUFFER];
        int pid,fd[2];

        sprintf(file, "%s/words.txt", argv[1]);

        sprintf(temp, "%s/temp%s.txt", argv[1], argv[2]);

        char *number = malloc(strlen(argv[2]) + 1);

        if (number == NULL){
                exit(1);
        }
        strcpy(number, argv[2]);

        char *dot = strrchr(number, '.');
        *dot = '\0';

        int linenumber;
        int myPipe[2];

        //Open words files
        FILE *words;
        words = fopen(file, "r");

        //check if file exist
        if (words == NULL){
                perror("words.txt");
                exit(1);
        }

        fclose(words);

        char* outputFilename = malloc(strlen(argv[2]) + 1);
        strcat(outputFilename, number);
        strcat(outputFilename, ".sw");

        FILE * tempFile = fopen(outputFilename, "w");

        if (tempFile == NULL){
                perror("temp.txt");
                exit(1);
        }

        //creating pipes
        if (pipe(myPipe) == -1)
        {
                fprintf(stderr, "Error creating pipes.\n");
                exit(1);
        }

        if (pid > 0)
        {
                close(myPipe[WRITE]);
                wait(NULL);

                while ((fgets(text, BUFFER, words)) != NULL)
                {
                        char* line = readline(myPipe[READ]);

                        while (line != '\0')
                        {
                                if (sscanf(line, "%d:%s", &linenumber, text) > 0)
                                {
                                        fprintf(tempFile, "%s : %s-%d\n", text, number, linenumber);
                                }

                                line = readline(fd[READ]);
                        }
                }

                close(myPipe[READ]);
        }
        else if (pid == 0)
        {
                dup2(myPipe[WRITE], STDOUT_FILENO);
                close(myPipe[READ]);
                execlp("grep", "grep", "-w", "-o", "-n", "-f", file, temp, NULL);
                perror("grep");
                exit(1);
        }
        else // fork failed
        {

        }
        fclose(tempFile);

        return 0;
}

char* readline(int fd)
{
        char string[1024];
        char currentByte;
        int i = 0;

        while (read(fd, &currentByte, 1) > 0)
        {
                if (currentByte == '\n' || currentByte == '\0')
                {
                        break;
                }

                string[i++] = currentByte;
        }

        string[i] = '\0';

        return string;
}