#define _GNU_SOURCE

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

#include <sys/stat.h>
#include <sys/msg.h>
#include <sys/ipc.h>
#include <sys/wait.h>

#define FIFO_PATH "/tmp/dario%d.fifo"
#define DIM_BUFFER 2048

void reader(char *path, int pp){
    FILE *input;
    FILE *file;
    char buffer[DIM_BUFFER];

    if((input = fdopen(pp, "w")) == NULL){
        perror("fdopen pipe1");
        exit(1);
    }

    if((file = fopen(path, "r")) == NULL){
        perror("fopen fifo1");
        exit(1);
    }

    while(fgets(buffer, DIM_BUFFER, file)){
        fputs(buffer, input);
    }

    exit(0);
}

void filter(char *word, int pp, char *fifo, int i, int v){
    FILE *pipe_file;
    FILE *fifo_file;
    char buffer[DIM_BUFFER];

    if((pipe_file = fdopen(pp, "r")) == NULL){
        perror("fdopen pipe2");
        exit(1);
    }

    if((fifo_file = fopen(fifo, "w")) == NULL){
        perror("fopen fifo2");
        exit(1);
    }

    while(fgets(buffer, DIM_BUFFER, pipe_file)){
        /*if(buffer[strlen(buffer) - 1] == '\n')
            buffer[strlen(buffer) - 1] = '\0';*/

        if(i == 1){
            if(v == 0){
                if(strcasestr(buffer, word)){
                    fputs(buffer, fifo_file);
                }
            }else if(v == 1){
                if(!strcasestr(buffer, word)){
                    fputs(buffer, fifo_file);
                }
            }
        }else{
            if(v == 0){
                if(strstr(buffer, word)){
                    fputs(buffer, fifo_file);
                }
            }else if(v == 1){
                if(!strstr(buffer, word)){
                    fputs(buffer, fifo_file);
                }
            }
        }

    }

    exit(0);
}

void writer(char *fifo){
    FILE *fifo_file;
    char buffer[DIM_BUFFER];

    if((fifo_file = fopen(fifo, "r")) == NULL){
        perror("fopen fifo3");
        exit(1);
    }

    while(fgets(buffer, DIM_BUFFER, fifo_file)){
        printf("%s \n", buffer);
    }

    exit(0);
}

int main(int argc, char *argv[]){
    int pp[2];
    int v, i;
    v = i = 0;
    char fifopathname[DIM_BUFFER];
    int file, word;

    if(pipe(pp) == -1){
        perror("pipe");
        exit(1);
    }

    snprintf(fifopathname, DIM_BUFFER, FIFO_PATH, getpid());

    if(mkfifo(fifopathname, 0600) == -1){
        perror("fifo");
        exit(1);
    }

    if(strcmp(argv[1], "-i") == 0){
        i = 1;
    }

    if((i == 1 && (strcmp(argv[2], "-v") == 0)) || (i == 0 && (strcmp(argv[1], "-v") == 0))){
        v = 1;
    }

    if(i == 0 && v == 0){
        word = 1;
    }else if((i == 0 && v == 1) || (i == 1 && v == 0)){
        word = 2;
    }else if(i == 1 && v == 1){
        word = 3;
    }
    file = word + 1;

    if(fork() == 0){
        close(pp[0]);
        reader(argv[file], pp[1]);
    }

    if(fork() == 0){
        close(pp[1]);
        filter(argv[word], pp[0], fifopathname, i, v);
    }

    close(pp[0]);
    close(pp[1]);

    if(fork() == 0){
        writer(fifopathname);
    }

    wait(NULL);
    wait(NULL);
    wait(NULL);

    if (unlink(fifopathname) == -1) {
        perror(fifopathname);
        exit(1);
    }

    exit(0);
}