#define _DEFAULT_SOURCE // usleep()
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <sys/epoll.h>
#include <sys/inotify.h>
// #include "inotify-syscalls.h"
#include "include/raylib.h"
#include "include/raymath.h"
#include "boids_game.h"

#define SCREEN_WIDTH 1300
#define SCREEN_HEIGHT 1080
#define TARGET_FPS 60

const char* GAME_LIB = "./libboids.so";
char epoll_buf[1024];

struct Game
{
    void* handle;
    struct GameApi api;
    struct GameState* state;
};

#define MAX_EVENTS 1

void load_game(struct Game* game) {
    if (game->handle) {
        game->api.unload(game->state);
        dlclose(game->handle);
    }
    void* handle = dlopen(GAME_LIB, RTLD_NOW);

    if (handle) {
        game->handle = handle;
        const struct GameApi* api = dlsym(game->handle, "GAME_API");
        if (api != NULL) {
            printf("Loaded API, calling init()\n");
            game->api = *api;
            if (game->state == NULL) {
                game->state = game->api.init();
            }
            game->api.reload(game->state);
        } else {
            printf("Failed to load API\n");
            dlclose(game->handle);
        }
    } else {
        fprintf(stderr, "Error loading %s\n", GAME_LIB);
        fprintf(stderr, "Error was: %s\n", dlerror());
        exit(1);
    }
}

int main(void) {
    int fd = inotify_init();
    if (fd < 0) {
        fprintf(stderr, "Error initializing inotify\n");
    }
    int wd;
    wd = inotify_add_watch(fd, GAME_LIB, IN_MODIFY);

    // create epoll instance
    int epollfd = epoll_create1(0);
    if (epollfd == -1) {
        fprintf(stderr, "Error creating epoll instance\n");
    }

    struct epoll_event event;
    event.events = EPOLLIN;
    event.data.fd = fd;

    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event) == -1) {
        fprintf(stderr, "Error adding inotify descriptor to epoll\n");
    }

    struct epoll_event events[MAX_EVENTS];

    struct Game game = {0};
    load_game(&game);
    int should_exit = 0;
    while (should_exit != 1) {
        int nfds = epoll_wait(epollfd, events, MAX_EVENTS, 0);
        if (nfds == -1) {
            fprintf(stderr, "epoll_wait failed\n");
            break;
        }

        // printf("%d %d\n", nfds, fd);
        for (int n = 0; n < nfds; ++n) {
            // printf("DO I EVER GET CALLED\n", events[n].data.fd, fd);
            printf("DO I EVER GET CALLED\n");
            if (events[n].data.fd == fd) {
                printf("SO has been updated!\n");
                // This clears the inotify queue so we don't get any more events
                read(fd, epoll_buf, sizeof(epoll_buf));
                load_game(&game);
            }
        }

        should_exit = game.api.step(game.state);
        if (should_exit == 2) {
            printf("I should exit?\n");
            load_game(&game);
            should_exit = 0;
            usleep(1000);
        }
    }

    game.api.finalize(game.state);
    free(game.state);
    inotify_rm_watch(fd, wd);
    close(fd);
    close(epollfd);
    // CloseWindow();
}