/*
 * vterm.c -- FreeDOS Emulation Bridge module
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Forks dosbox with a custom config for the
 *       FreeDOS environment.  BACK key sends SIGTERM to the child.
 *       Monitors child exit via waitpid(WNOHANG).
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/wait.h>
#include <signal.h>
#include <linux/input.h>
#include "h2_ui.h"
#include "log_manager.h"

int main(void) {
    init_h2_graphics_runtime("X86 EMULATION ENVIRONMENT");
    LOG_INF("vterm module started");

    lv_obj_t *scr = lv_scr_act();

    lv_obj_t *title = lv_label_create(scr);
    lv_label_set_text(title, "EMULATION RUNTIME ENGINE");
    lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 15);
    lv_obj_set_style_text_color(title, COLOR_PRIMARY, LV_PART_MAIN);

    lv_obj_t *status = lv_label_create(scr);
    lv_label_set_text(status, "Launching FreeDOS container...\n[BACK] to terminate");
    lv_obj_align(status, LV_ALIGN_CENTER, 0, 0);
    lv_obj_set_style_text_align(status, LV_TEXT_ALIGN_CENTER, LV_PART_MAIN);

    lv_timer_handler();

    pid_t pid = fork();
    if (pid == 0) {
        char *args[] = {"/usr/bin/dosbox", "-conf", "/data/vterm/dosbox.conf", NULL};
        execv(args[0], args);
        _exit(1);
    }
    if (pid < 0) {
        lv_label_set_text(status, "FORK FAILED");
        LOG_ERR("fork failed for dosbox");
    } else {
        LOG_INF("dosbox launched (pid %d)", (int)pid);
    }

    int input_fd = open("/dev/input/event0", O_RDONLY | O_NONBLOCK);
    struct input_event ev;
    int child_done = (pid < 0);

    while (!child_done) {
        lv_timer_handler();

        int wstatus;
        pid_t ret = waitpid(pid, &wstatus, WNOHANG);
        if (ret == pid) {
            child_done = 1;
            lv_label_set_text(status, "DOSBOX EXITED.\n[BACK] to return");
            LOG_INF("dosbox exited");
        }

        if (input_fd >= 0 && read(input_fd, &ev, sizeof(struct input_event)) > 0) {
            if (ev.type == EV_KEY && ev.code == H2_KEY_BACK && ev.value == 1) {
                if (!child_done && pid > 0) {
                    kill(pid, SIGTERM);
                    usleep(200000);
                    waitpid(pid, &wstatus, WNOHANG);
                    LOG_INF("dosbox terminated by user");
                }
                break;
            }
        }
        usleep(20000);
    }

    if (child_done && input_fd >= 0) {
        while (1) {
            lv_timer_handler();
            if (read(input_fd, &ev, sizeof(struct input_event)) > 0) {
                if (ev.type == EV_KEY && ev.code == H2_KEY_BACK && ev.value == 1)
                    break;
            }
            usleep(20000);
        }
    }

    if (input_fd >= 0) close(input_fd);
    LOG_INF("vterm module exited");
    return 0;
}