#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <math.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/select.h>
#include <fcntl.h>
#include "error.h"

#define SLAVE_NUM 5
#define MAX_SIZE 200

void create(int pipesOutput[SLAVE_NUM][2], int pipesInput[SLAVE_NUM][2]);

int main(int argc, char *argv[]) {
    setvbuf(stdout, NULL, _IONBF, 0);

    if (argc == 1)
        printError("Error: no arguments provided");

    int pipesOutput[SLAVE_NUM][2];
    int pipesInput[SLAVE_NUM][2];
    create(pipesOutput, pipesInput);
    //sleep(1);

    struct stat statBuf;

    int tasks = 1, j = 0;

    //for (j = 0; j < argc; j++)
        //printf("MBOEANAS PUAN. %s\n", argv[j]);

    for (; tasks < SLAVE_NUM && tasks < argc; tasks++) {
        //printf("%s\n", argv[tasks]);
        if (stat(argv[tasks], &statBuf) == -1) {
            printf("%s\n", argv[tasks]);
            printSystemError("Error, one of the specified paths is incorrect");
        }

        if (!S_ISREG(statBuf.st_mode))
            continue;

        if (write(pipesInput[j++][1], argv[tasks], strlen(argv[tasks]) + 1) < 0) {
            printSystemError("write() -- ERROR oli");
        }
    }


//    for (; arg < argc; arg++) {
//        if (stat(argv[arg], &statBuf) == -1)
//            printSystemError("Error, one of the specified paths is incorrect");
//
//        if (!S_ISREG(statBuf.st_mode))
//            continue;
//
//        if (write(pipesInput[j++][1], argv[arg], strlen(argv[arg]) + 1) < 0) {
//            printSystemError("write() -- ERROR");
//        }
//    }

    char buf[MAX_SIZE];

    fd_set pipesOutputSet;
    FD_ZERO(&pipesOutputSet);
    // int n = 0;
    // if (tasks >= SLAVE_NUM)
    //     for (; n < SLAVE_NUM; n++)
    //         FD_SET(pipesOutput[n][0], &pipesOutputSet);
    // else
    //     for (; n < tasks; n++)
    //         FD_SET(pipesOutput[n][0], &pipesOutputSet);

    // int count;
    // if ((count = select(pipesOutput[SLAVE_NUM - 1][0] + 1, &pipesOutputSet, NULL, NULL, NULL)) <= 0)
    //     printSystemError("select() -- ERROR");

    int r, readBytes, flag, count;
    if (tasks == SLAVE_NUM) {
        do {
            int n;
            flag = 0;
            FD_ZERO(&pipesOutputSet);
            for (n = 0; n < SLAVE_NUM; n++) {
                if (pipesOutput[n][0] != -1) {
                    FD_SET(pipesOutput[n][0], &pipesOutputSet);
                    flag = 1;
                }
            }
            if ((count = select(pipesOutput[SLAVE_NUM - 1][1] + 1, &pipesOutputSet, NULL, NULL, NULL)) <= 0)
                printSystemError("select() -- ERROR");

            for (r = 0; r < SLAVE_NUM && count > 0; r++) {
                if (FD_ISSET(pipesOutput[r][0], &pipesOutputSet)) {
                    readBytes = 0;
                    do {
                        if ((readBytes += read(pipesOutput[r][0], buf + readBytes, MAX_SIZE)) < 0)
                            printSystemError("read() -- ERROR");
                    } while (buf[readBytes - 1] != '\n');
                    buf[readBytes] = 0;

                    printf("\n%s\n", buf);
                    count--;

                    if (tasks < argc) {
                        if (stat(argv[tasks], &statBuf) == -1)
                            printSystemError("Error, one of the specified paths is incorrect");

                        if (!S_ISREG(statBuf.st_mode))
                            continue;

                        if ((write(pipesInput[r][1], argv[tasks], strlen(argv[tasks]) + 1)) < 0)
                            printSystemError("write() -- ERROR");

                        tasks++;

                    } else {
                        close(pipesOutput[r][0]);
                        close(pipesInput[r][1]);
                        pipesOutput[r][0] = -1;
                        pipesInput[r][0] = -1;
                    }
                }
            }
        } while(flag);
    }
    else {
        int k;
        for (k = tasks - 1; k < SLAVE_NUM; k++) {
            close(pipesOutput[k][0]);
            close(pipesInput[k][1]);
            pipesOutput[k][0] = -1;
            pipesInput[k][0] = -1;
        }
        do {
            int n;
            flag = 0;
            FD_ZERO(&pipesOutputSet);
            for (n = 0; n < tasks; n++) {
                if (pipesOutput[n][0] != -1) {
                    FD_SET(pipesOutput[n][0], &pipesOutputSet);
                    flag = 1;
                }
            }

            if (flag) {
                if ((count = select(pipesOutput[tasks - 1][1] + 1, &pipesOutputSet, NULL, NULL, NULL)) <= 0)
                    printSystemError("select() -- ERROR");

                for (r = 0; r < SLAVE_NUM && count > 0; r++) {
                    if (FD_ISSET(pipesOutput[r][0], &pipesOutputSet)) {
                        readBytes = 0;
                        do {
                            if ((readBytes += read(pipesOutput[r][0], buf + readBytes, MAX_SIZE)) < 0)
                                printSystemError("read() -- ERROR");
                        } while (buf[readBytes - 1] != '\n');
                        buf[readBytes] = 0;

                        close(pipesOutput[r][0]);
                        close(pipesInput[r][1]);
                        pipesOutput[r][0] = -1;
                        pipesInput[r][0] = -1;

                        printf("\n%s\n", buf);
                        count--;
                    }
                }
            }
        } while (flag);
    }

//    if (tasks >= SLAVE_NUM) {
//        for (r = 0; r < SLAVE_NUM && count > 0; r++) {
//            if (FD_ISSET(pipesOutput[r][0], &pipesOutputSet)) {
//                readBytes = 0;
//                do {
//                    if ((readBytes += read(pipesOutput[r][0], buf + readBytes, MAX_SIZE)) < 0)
//                        printSystemError("read() -- ERROR");
//                } while (buf[readBytes - 1] != '\n');
//                buf[readBytes] = 0;
//                if (tasks < argc)
//                    write(pipesInput[r][1], argv[tasks++], MAX_SIZE);
//                else {
//
//                }
//                printf("%s", buf);
//                count--;
//            }
//        }
//    }
//    else {
//        for (r = 0; r < tasks && count > 0; r++) {
//            if (FD_ISSET(pipesOutput[r][0], &pipesOutputSet)) {
//                readBytes = 0;
//                do {
//                    if ((readBytes += read(pipesOutput[r][0], buf + readBytes, MAX_SIZE)) < 0)
//                        printSystemError("read() -- ERROR");
//                } while (buf[readBytes - 1] != '\n');
//                buf[readBytes] = 0;
//                printf("%s", buf);
//                count--;
//            }
//        }
//    }


//    int fd;
//    char buf[MAX_SIZE];
//    if ((fd = select(pipesOutput[SLAVE_NUM - 1][0] + 1, &pipesOutputSet, NULL, NULL, NULL)) < 0)
//        printSystemError("select() -- ERROR");
//
//    int r = 0, readBytes;
//    for (; r < SLAVE_NUM && fd > 0; r++) {
//        if (FD_ISSET(pipesOutput[r][0], &pipesOutputSet)) {
//            readBytes = 0;
//            do {
//                if ((readBytes += read(pipesOutput[r][0], buf + readBytes, MAX_SIZE)) < 0)
//                    printSystemError("read() -- ERROR");
//            } while (buf[readBytes - 1] != '\n');
//            buf[readBytes] = 0;
//            printf("%s", buf);
//            fd--;
//        }
//    }
    return 0;
}

//void (int pipesOutput[SLAVE_NUM][2], int pipesInput[SLAVE_NUM][2]) {

void create(int pipesOutput[SLAVE_NUM][2], int pipesInput[SLAVE_NUM][2]) {
    pid_t pid[SLAVE_NUM];

    int i = 0;
    for (; i < SLAVE_NUM; i++) {
        if (pipe(pipesOutput[i]) < 0)
            printSystemError("pipe() -- ERROR");
        if (pipe(pipesInput[i]) < 0)
            printSystemError("pipe() -- ERROR");
        if ((pid[i] = fork()) == 0) {
            if (close(pipesOutput[i][0]) < 0)
                printSystemError("close() -- ERROR");
            if (dup2(pipesOutput[i][1], STDOUT_FILENO) < 0)
                printSystemError("dup2() -- ERROR 1");
            if (close(pipesOutput[i][1]) < 0)
                printSystemError("close() -- ERROR");

            if (close(pipesInput[i][1]) < 0)
                printSystemError("close() -- ERROR");
            if (dup2(pipesInput[i][0], STDIN_FILENO) < 0)
                printSystemError("dup2() -- ERROR 2");
            if (close(pipesInput[i][0]) < 0)
                printSystemError("close() -- ERROR");

            if (execv("slave.o", NULL) < 0)
                printSystemError("execv() -- ERROR");
        }
        else if (pid[i] < 0)
            printSystemError("fork() -- ERROR");

        if (close(pipesInput[i][0]) < 0)
            printSystemError("close() -- ERROR");
        if (close(pipesOutput[i][1]) < 0)
            printSystemError("close() -- ERROR");
    }
}