#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <ctype.h>
#include <errno.h>
#include <math.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "video.h"

static void log_info(const char* fmt, ...) {
  va_list args;
  fprintf(stderr, "[splash] ");
  va_start(args, fmt);
  vfprintf(stderr, fmt, args);
  va_end(args);
  fputc('\n', stderr);
  fflush(stderr);
}

static void log_error(const char* fmt, ...) {
  va_list args;
  fprintf(stderr, "[splash][error] ");
  va_start(args, fmt);
  vfprintf(stderr, fmt, args);
  va_end(args);
  fputc('\n', stderr);
  fflush(stderr);
}

typedef enum RenderMode {
  RENDER_STRETCH = 0,
  RENDER_CENTER,
  RENDER_CROP
} RenderMode;

static RenderMode parse_render_mode(const char* value) {
  if (strcmp(value, "center") == 0) {
    return RENDER_CENTER;
  }
  if (strcmp(value, "crop") == 0) {
    return RENDER_CROP;
  }
  return RENDER_STRETCH;
}

static void compute_dest_rect(int src_w, int src_h, int out_w, int out_h,
                              RenderMode mode, SDL_Rect* dst) {
  dst->x = 0;
  dst->y = 0;
  dst->w = out_w;
  dst->h = out_h;

  if (src_w <= 0 || src_h <= 0 || out_w <= 0 || out_h <= 0) {
    return;
  }

  if (mode == RENDER_CENTER) {
    float scale =
        fminf((float)out_w / (float)src_w, (float)out_h / (float)src_h);
    dst->w = (int)(src_w * scale);
    dst->h = (int)(src_h * scale);
    dst->x = (out_w - dst->w) / 2;
    dst->y = (out_h - dst->h) / 2;
  } else if (mode == RENDER_CROP) {
    float scale =
        fmaxf((float)out_w / (float)src_w, (float)out_h / (float)src_h);
    dst->w = (int)(src_w * scale);
    dst->h = (int)(src_h * scale);
    dst->x = (out_w - dst->w) / 2;
    dst->y = (out_h - dst->h) / 2;
  }
}

int main(int argc, char* argv[]) {
  RenderMode render_mode = RENDER_CENTER;
  int arg_index = 1;

  if (argc >= 3 && strncmp(argv[1], "--mode=", 7) == 0) {
    render_mode = parse_render_mode(argv[1] + 7);
    arg_index += 1;
  } else if (argc >= 2 && strcmp(argv[1], "-m") == 0) {
    if (argc < 4) {
      log_error(
          "Usage: %s [--mode=stretch|center|crop] <image_path> "
          "<game_executable> [args...]",
          argv[0]);
      log_error(
          "       %s -m stretch|center|crop <image_path> <game_executable> "
          "[args...]",
          argv[0]);
      return 1;
    }
    render_mode = parse_render_mode(argv[2]);
    arg_index += 2;
  }

  if (argc - arg_index < 2) {
    log_error(
        "Usage: %s [--mode=stretch|center|crop] <image_path> <game_executable> "
        "[args...]",
        argv[0]);
    log_error(
        "       %s -m stretch|center|crop <image_path> <game_executable> "
        "[args...]",
        argv[0]);
    return 1;
  }

  const char* image_path = argv[arg_index];
  const char* game_path = argv[arg_index + 1];

  log_info("Starting splash: image='%s', game='%s', mode=%d", image_path,
           game_path, render_mode);

  // Initialize SDL2 Video subsystems
  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
    log_error("SDL Init Failed: %s", SDL_GetError());
    return 1;
  }
  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
  log_info("SDL initialized");

  // Initialize JPEG and PNG decoders
  if (!(IMG_Init(IMG_INIT_JPG | IMG_INIT_PNG) &
        (IMG_INIT_JPG | IMG_INIT_PNG))) {
    log_error("SDL_image Init Failed: %s", IMG_GetError());
    SDL_Quit();
    return 1;
  }
  log_info("SDL_image initialized (JPG/PNG)");

  // Create a native borderless fullscreen window
  SDL_Window* window = SDL_CreateWindow(
      "Game Splash Screen", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 0,
      0, SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_BORDERLESS);

  if (!window) {
    log_error("Window Creation Failed: %s", SDL_GetError());
    IMG_Quit();
    SDL_Quit();
    return 1;
  }
  log_info("Fullscreen borderless window created");

  SDL_ShowCursor(SDL_DISABLE);  // Hide the mouse pointer

  // Create a hardware-accelerated renderer
  SDL_Renderer* renderer =
      SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
  if (renderer) {
    log_info("Renderer created (accelerated)");
  }
  SDL_Texture* texture = NULL;
  VideoPlayer video_player;
  bool video_active = false;

  if (has_video_extension(image_path)) {
    if (init_video_player(&video_player, renderer, image_path)) {
      video_active = true;
    } else {
      log_error("Failed to open video '%s'; showing black screen", image_path);
    }
  } else {
    SDL_Surface* surface = IMG_Load(image_path);
    if (surface) {
      SDL_Surface* rgba_surface =
          SDL_ConvertSurfaceFormat(surface, SDL_PIXELFORMAT_RGBA32, 0);
      SDL_FreeSurface(surface);
      if (rgba_surface) {
        texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA32,
                                    SDL_TEXTUREACCESS_STREAMING,
                                    rgba_surface->w, rgba_surface->h);
        if (texture) {
          SDL_UpdateTexture(texture, NULL, rgba_surface->pixels,
                            rgba_surface->pitch);
        } else {
          log_error("Failed to create texture: %s", SDL_GetError());
        }
        SDL_FreeSurface(rgba_surface);
      }
    }
    if (!texture && init_video_player(&video_player, renderer, image_path)) {
      video_active = true;
    }
  }

  if (!texture && !video_active) {
    log_error("Failed to load splash image '%s': %s; showing black screen",
              image_path, IMG_GetError());
    // Fallback: Clear to solid black if image file is broken
    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
    SDL_RenderClear(renderer);
    SDL_RenderPresent(renderer);
  } else {
    SDL_Rect dst_rect = {0, 0, 0, 0};
    int out_w = 0;
    int out_h = 0;

    SDL_GetRendererOutputSize(renderer, &out_w, &out_h);

    if (video_active) {
      log_info("Video splash loaded");
      compute_dest_rect(video_player.width, video_player.height, out_w, out_h,
                        render_mode, &dst_rect);
      decode_next_frame(&video_player);
      SDL_RenderClear(renderer);
      SDL_RenderCopy(renderer, video_player.texture, NULL, &dst_rect);
      SDL_RenderPresent(renderer);
    } else if (texture) {
      int tex_w = 0;
      int tex_h = 0;

      log_info("Splash image loaded");
      if (SDL_QueryTexture(texture, NULL, NULL, &tex_w, &tex_h) == 0) {
        compute_dest_rect(tex_w, tex_h, out_w, out_h, render_mode, &dst_rect);
      }

      SDL_RenderClear(renderer);
      if (dst_rect.w > 0 && dst_rect.h > 0) {
        SDL_RenderCopy(renderer, texture, NULL, &dst_rect);
      } else {
        SDL_RenderCopy(renderer, texture, NULL, NULL);
      }
      SDL_RenderPresent(renderer);
    }
  }

  // Fork the process to run the game
  log_info("Launching game executable");
  pid_t pid = fork();
  if (pid == 0) {
    // Inside Child Process: Hand over execution directly to the game binary
    log_info("Execing game: %s", game_path);
    execvp(game_path, &argv[arg_index + 1]);
    log_error("Failed to launch target game executable '%s': %s", game_path,
              strerror(errno));
    _exit(1);
  } else if (pid < 0) {
    log_error("Failed to fork process: %s", strerror(errno));
  } else {
    log_info("Game process started (pid=%d)", pid);
    // Inside Parent Process: Manage splash screen lifecycle
    int running = 1;
    SDL_Event event;
    bool hide_scheduled = false;
    Uint32 hide_time = 0;

    while (running) {
      // Non-blocking check: Has the game quit?
      int status;
      pid_t result = waitpid(pid, &status, WNOHANG);
      if (result > 0) {
        if (WIFEXITED(status)) {
          log_info("Game exited (code=%d)", WEXITSTATUS(status));
        } else if (WIFSIGNALED(status)) {
          log_info("Game terminated by signal %d", WTERMSIG(status));
        } else {
          log_info("Game exited");
        }
        break;  // Game closed, break the loop and close the script
      } else if (result < 0) {
        log_error("waitpid failed: %s", strerror(errno));
        break;  // Process error safetynet
      }

      if (video_active && SDL_GetTicks() >= video_player.next_frame_tick) {
        if (!decode_next_frame(&video_player)) {
          // If decoding fails or loops, try again on next tick
        }
        video_player.next_frame_tick += (Uint32)video_player.frame_delay_ms;
        Uint32 now = SDL_GetTicks();
        if ((Sint32)(now - video_player.next_frame_tick) > 100) {
          video_player.next_frame_tick = now;
        }

        SDL_RenderClear(renderer);
        SDL_Rect dst_rect = {0, 0, 0, 0};
        int out_w = 0;
        int out_h = 0;
        SDL_GetRendererOutputSize(renderer, &out_w, &out_h);
        compute_dest_rect(video_player.width, video_player.height, out_w, out_h,
                          render_mode, &dst_rect);
        SDL_RenderCopy(renderer, video_player.texture, NULL, &dst_rect);
        SDL_RenderPresent(renderer);
      }

      // Check desktop server window events
      while (SDL_PollEvent(&event)) {
        if (event.type == SDL_QUIT) {
          log_info("Splash dismissed via window close");
          running = 0;
        }
        if (event.type == SDL_WINDOWEVENT) {
          // THE MOMENT THE GAME WINDOW STEALS FOCUS:
          if (event.window.event == SDL_WINDOWEVENT_FOCUS_LOST &&
              !hide_scheduled) {
            log_info("Splash window hidden (focus lost), scheduling hide");
            hide_scheduled = true;
            hide_time =
                SDL_GetTicks() + 100;  // 100ms delay to prevent desktop flash
          }
          // Re-render static image when compositor requests a redraw
          if (event.window.event == SDL_WINDOWEVENT_EXPOSED && texture &&
              !video_active) {
            int out_w = 0, out_h = 0;
            SDL_GetRendererOutputSize(renderer, &out_w, &out_h);
            int tex_w = 0, tex_h = 0;
            SDL_QueryTexture(texture, NULL, NULL, &tex_w, &tex_h);
            SDL_Rect dst_rect = {0, 0, 0, 0};
            compute_dest_rect(tex_w, tex_h, out_w, out_h, render_mode,
                              &dst_rect);
            SDL_RenderClear(renderer);
            if (dst_rect.w > 0 && dst_rect.h > 0)
              SDL_RenderCopy(renderer, texture, NULL, &dst_rect);
            else
              SDL_RenderCopy(renderer, texture, NULL, NULL);
            SDL_RenderPresent(renderer);
          }
        }
        if (event.type == SDL_KEYDOWN) {
          if (event.key.keysym.sym == SDLK_ESCAPE) {
            log_info("Splash dismissed via escape key");
            running = 0;  // Emergency escape key loop override
          }
        }
      }

      if (hide_scheduled && SDL_GetTicks() >= hide_time) {
        log_info("Hiding splash window (delayed)");
        SDL_HideWindow(window);
        hide_scheduled = false;
      }

      if (video_active) {
        Uint32 now = SDL_GetTicks();
        if ((Sint32)(video_player.next_frame_tick - now) > 0) {
          Uint32 delay = video_player.next_frame_tick - now;
          SDL_Delay(delay > 33 ? 33 : delay);
        }
      } else {
        SDL_Delay(33);  // ~30 FPS polling loop to ensure near-zero CPU usage
      }
    }
  }

  // Clean up memory space
  if (texture) SDL_DestroyTexture(texture);
  if (video_active) cleanup_video_player(&video_player);
  SDL_DestroyRenderer(renderer);
  SDL_DestroyWindow(window);
  IMG_Quit();
  SDL_Quit();
  log_info("Splash shutdown complete");
  return 0;
}