#include <isogfx/backend.h>
#include <isogfx/isogfx.h>

#include <gfx/app.h>
#include <math/vec2.h>

#include <assert.h>
#include <stdbool.h>
#include <stdint.h>

static const int WINDOW_WIDTH  = 1408;
static const int WINDOW_HEIGHT = 960;
static const int MAX_FPS       = 60;

// Virtual screen dimensions.
static const int SCREEN_WIDTH  = 704;
static const int SCREEN_HEIGHT = 480;

static const R CAMERA_SPEED = 400;

#define MEMORY_SIZE (2 * 1024 * 1024)
uint8_t MEMORY[MEMORY_SIZE];

typedef struct GfxAppState {
  IsoBackend* backend;
  IsoGfx*     iso;
  int         xpick;
  int         ypick;
  vec2        camera;
  SpriteSheet stag_sheet;
  Sprite      stag;
} GfxAppState;

static bool init(GfxAppState* state, int argc, const char** argv) {
  assert(state);
  (void)argc;
  (void)argv;

  if (!((state->iso =
             isogfx_new(&(IsoGfxDesc){.memory        = MEMORY,
                                      .memory_size   = MEMORY_SIZE,
                                      .screen_width  = SCREEN_WIDTH,
                                      .screen_height = SCREEN_HEIGHT})))) {
    return false;
  }
  IsoGfx* iso = state->iso;

  if (!isogfx_load_world(iso, "/home/jeanne/Nextcloud/assets/maps/demo-1.tm")) {
    return false;
  }

  if (!((state->stag_sheet = isogfx_load_sprite_sheet(
             iso,
             "/home/jeanne/Nextcloud/assets/tilesets/scrabling/critters/stag/"
             "stag.ss")))) {
    return false;
  }

  state->stag = isogfx_make_sprite(iso, state->stag_sheet);
  isogfx_set_sprite_position(iso, state->stag, 5, 4);

  if (!((state->backend = iso_backend_init(iso)))) {
    return false;
  }

  return true;
}

static void shutdown(GfxAppState* state) {
  assert(state);
  //
}

static vec2 get_camera_movement(R dt) {
  vec2 offset = {0};
  if (gfx_app_is_key_pressed(KeyA)) {
    offset.x -= 1;
  }
  if (gfx_app_is_key_pressed(KeyD)) {
    offset.x += 1;
  }
  if (gfx_app_is_key_pressed(KeyW)) {
    offset.y -= 1;
  }
  if (gfx_app_is_key_pressed(KeyS)) {
    offset.y += 1;
  }
  if ((offset.x != 0) || (offset.y != 0)) {
    offset = vec2_scale(vec2_normalize(offset), dt * CAMERA_SPEED);
  }
  return offset;
}

static void update(GfxAppState* state, double t, double dt) {
  assert(state);

  state->camera = vec2_add(state->camera, get_camera_movement((R)dt));

  IsoGfx* iso = state->iso;
  isogfx_set_camera(iso, (int)state->camera.x, (int)state->camera.y);
  isogfx_update(iso, t);
}

static void render(GfxAppState* state) {
  assert(state);

  IsoGfx* iso = state->iso;
  isogfx_render(iso);
  iso_backend_render(state->backend, iso);
}

static void resize(GfxAppState* state, int width, int height) {
  assert(state);

  iso_backend_resize_window(state->backend, state->iso, width, height);
}

int main(int argc, const char** argv) {
  GfxAppState state = {0};
  gfx_app_run(
      &(GfxAppDesc){.argc    = argc,
                    .argv    = argv,
                    .width   = WINDOW_WIDTH,
                    .height  = WINDOW_HEIGHT,
                    .max_fps = MAX_FPS,
                    .update_delta_time =
                        MAX_FPS > 0 ? 1.0 / (double)MAX_FPS : 0.0,
                    .title     = "Isometric Renderer",
                    .app_state = &state},
      &(GfxAppCallbacks){.init     = init,
                         .update   = update,
                         .render   = render,
                         .resize   = resize,
                         .shutdown = shutdown});
  return 0;
}