#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/reboot.h>
#include <sys/ioctl.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdbool.h>

#include "builtin.h"
#include "para.h"
#include "job.h"

job_t *parse_line(char *line);
void launch_job(job_t *job);

static bool verbose = false;
volatile pid_t fg_pgid = 0;

void handle_sigint(int sig) {
    printf("\n");
}

void handle_sigchld(int sig) {
    while (waitpid(-1, NULL, WNOHANG) > 0);
}

int builtin_cmd(job_t *job) {
    command_t *cmd = job->head;
    if (!cmd || !cmd->argv[0]) return 0;

    // if (strcmp(cmd->argv[0], "exit") == 0) exit(0);
    // if (strcmp(cmd->argv[0], "cd") == 0) {
    //     if (cmd->argc < 2) fprintf(stderr, "cd: missing argument\n");
    //     else if (chdir(cmd->argv[1]) != 0) perror("cd");
    //     return 1;
    // }
    bool ret = 0;
    if (strcmp(cmd->argv[0], "exit") == 0) exit(0), ret = 1;
    else if (strcmp(cmd->argv[0], "ls") == 0) cmd_ls(cmd->argv[1]), ret = 1;
    else if (strcmp(cmd->argv[0], "cd") == 0) cmd_cd(cmd->argv[1]), ret = 1;
    else if (strcmp(cmd->argv[0], "pwd") == 0) cmd_pwd(), ret = 1;
    // else if (strcmp(cmd->argv[0], "cat") == 0) cmd_cat(argc, (const char**) argv);
    // else if (strcmp(cmd->argv[0], "proc") == 0) cmd_proc();
    // else if (strcmp(cmd->argv[0], "echo") == 0) cmd_echo(argc, (const char**) argv);

    else if (strcmp(cmd->argv[0], "size") == 0) cmd_size(), ret = 1;
    else if (strcmp(cmd->argv[0], "resize") == 0){
        if(cmd->argc != 3){
            printf("Usage: resize <rows> <cols>\n");
        }
        else cmd_resize(cmd->argv[1], cmd->argv[2]);
        ret = 1;
    }

    else if (strcmp(cmd->argv[0], "poweroff") == 0) cmd_poweroff(), ret = 1;
    else if (strcmp(cmd->argv[0], "reboot") == 0) cmd_reboot(), ret = 1;
    else if (strcmp(cmd->argv[0], "help") == 0) cmd_help(), ret = 1;

    return ret;
}


void run_shell() {
    char cmd_buf[MAX_CMD_LEN];
    char cwd[1024];
    
    while (1) {
        if (getcwd(cwd, sizeof(cwd))) printf("\033[1;32mgmsh\033[0m:%s$ ", cwd);
        else printf("gmsh:$ ");
        fflush(stdout);

        if (!fgets(cmd_buf, sizeof(cmd_buf), stdin)) break;
        cmd_buf[strcspn(cmd_buf, "\n")] = 0;
        if (strlen(cmd_buf) == 0) continue;

        job_t *job = parse_line(cmd_buf);
        if (job == NULL) continue;

        if (builtin_cmd(job)) {
            free_job(job);
            continue;
        }

        launch_job(job);
        if (!job->is_bg) free_job(job);
    }
}

int main(int argc, char** argv) {
    signal(SIGINT, handle_sigint);
    signal(SIGCHLD, handle_sigchld);
    signal(SIGTTOU, SIG_IGN);

    int opt;
    while ((opt = getopt(argc, argv, "v")) != -1) {
        switch (opt) {
            case 'v':
                verbose = 1;
                printf("[gmsh] Verbose mode enabled.\n");
                break;
            default:
                fprintf(stderr, "Usage: %s [-v]\n", argv[0]);
                exit(1);
        }
    }

    if(verbose) printf("GMSH (GMS Minimal SHell) v1.0 initialized.\n");

    run_shell();
    return 0;
}