#include <stdio.h>
#include <stdlib.h>
#include <dos.h>

#include "video.h"
#include "kbd.h"
#include "mouse.h"
#include "tiff.h"
#include "tiles.h"
#include "serial.h"

/*** S C R A T C H ***/

#define NUM_TILES 128
#define NUM_SPRITES 64
#define OFF_TILES 0x5000
#define TILE_STRIDE 64
#define SPRITE_STRIDE 80
unsigned int tiles[NUM_TILES * TILE_STRIDE];
unsigned int sprites[NUM_SPRITES * SPRITE_STRIDE];

unsigned char map[10000];

void fillMap() {
  unsigned int x, y, z;
  z = 0;

  for (y = 0; y < 100; y ++) {
    for (x = 0; x < 100; x ++) {
      map[x + (y * 100)] = ((x + y + z) >> 2) % 4;
    }
  }
}

#define DIR_N 0
#define DIR_E 1
#define DIR_W 2
#define DIR_S 3

#define STATE_MAP 0
#define STATE_DIALOG 1

struct entity;
typedef struct entity Entity_t;

struct entity {
  int x;
  int y;
  int dir;
  int sprites[4];
};

void drawEntity(Entity_t *entity) {
  int isprite = entity->sprites[entity->dir];
  drawSprite(&sprites[isprite * SPRITE_STRIDE], entity->x, entity->y);
}

void playerThink(Entity_t *self) {
  if (keyIsDown(K_LEFT))  { self->x -= 3; self->dir = DIR_W; }
  if (keyIsDown(K_RIGHT)) { self->x += 3; self->dir = DIR_E; }
  if (keyIsDown(K_UP))    { self->y -= 3; self->dir = DIR_N; }
  if (keyIsDown(K_DOWN))  { self->y += 3; self->dir = DIR_S; }
}

typedef struct {
  int dy;
  int y;
} Footer_t;

typedef struct {
  Entity_t player;
  Footer_t footer;
  int state;
} Game_t;

Game_t game;

void game_init() {
  FILE *f;
  TifImageMeta_t meta;

  game.player.x = 100;
  game.player.y = 100;
  game.player.dir = DIR_E;
  game.player.sprites[DIR_E] = 0;
  game.player.sprites[DIR_N] = 1;
  game.player.sprites[DIR_W] = 2;
  game.player.sprites[DIR_S] = 3;
  game.footer.y = 0;
  game.state = STATE_MAP;

  setEGAMode();
  atexit(vid_cleanup);

  kbd_init();

  tile_init();
  fillMap();

  f = fopen("FOOTER.TIF", "rb");
  meta = tifLoadMeta(f);
  tifLoadEGA(f, meta, 0, 24, 336);
  fclose(f);

  f = fopen("TILES.TIF", "rb");
  meta = tifLoadMeta(f);
  tifLoad(f, meta, tiles, NUM_TILES * 16, 16, 4);
  tifLoadEGA(f, meta, OFF_TILES, NUM_TILES * 16, 16);
  fclose(f);

  f = fopen("SPRITE.TIF", "rb");
  meta = tifLoadMeta(f);
  tifLoad(f, meta, sprites, NUM_SPRITES * 16, 16, 5);
  fclose(f);

  loadTiles(OFF_TILES, tiles);
  loadMap(map, 100, 100);
  scroll(0, 0);
}

void showDialog() {
  game.state = STATE_DIALOG;
  game.footer.dy = 1;
}

void dialogThink() {
  if (keyWasPressed(K_SPACE)) {
    game.footer.dy = -1;
  }
  game.footer.y += game.footer.dy;
  if (game.footer.dy > 0 && game.footer.y > 24) {
    game.footer.y = 24;
    game.footer.dy = 0;
  } else if (game.footer.dy < 0 && game.footer.y < 0) {
    game.footer.y = 0;
    game.footer.dy = 0;
    game.state = STATE_MAP;
  }
  setSplitScreen(399 - (game.footer.y << 1));
}

void overworldThink() {
  if (keyWasPressed(K_SPACE)) {
    showDialog();
  }
  playerThink(&game.player);
  scroll(game.player.x - 152, game.player.y - 92);
}

int main() {
  game_init();
  ser_init(SER_COM2, BAUD_19200, SER_8N1);
  ser_write("JORTS QUEST DEBUG OUTPUT\r\n");

  while (!keyIsDown(K_ESC)) {
    kbd_debounce();
    if (game.state == STATE_MAP) {
      overworldThink();
    } else if (game.state == STATE_DIALOG) {
      dialogThink();
    }
    drawEntity(&game.player);
    drawScreen();
  }

  return 0;
}