game_reversi.c

// Game "Reversi" for Flipper Zero
// Copyright 2023 Dmitry Matyukhin

#include <stdio.h>
#include <furi.h>
#include <gui/gui.h>
#include <input/input.h>
#include <storage/storage.h>
#include "reversi.h"

#define FRAME_LEFT 3
#define FRAME_TOP 3
#define FRAME_CELL_SIZE 7

#define SAVING_DIRECTORY "/ext/apps/Games"
#define SAVING_FILENAME SAVING_DIRECTORY "/game_reversi.save"

typedef enum {
  AppScreenGame,
  AppScreenMenu
} AppScreen;

typedef struct {
  GameState game;
  AppScreen screen;
  uint8_t selected_menu_item;
  FuriMutex* mutex;
} AppState;

#define MENU_ITEMS_COUNT 2
static const char* popup_menu_strings[] = {"Resume", "New Game"};

static void draw_menu(Canvas* const canvas, const AppState* app_state);
static void gray_canvas(Canvas* const canvas);

static void input_callback(InputEvent* input_event, void* ctx) {
    furi_assert(ctx);
    FuriMessageQueue* event_queue = ctx;
    furi_message_queue_put(event_queue, input_event, FuriWaitForever);
}

static void draw_callback(Canvas *const canvas, void *ctx) {
  furi_assert(ctx);

  const AppState *app_state = ctx;
  furi_mutex_acquire(app_state->mutex, FuriWaitForever);
  if (app_state == NULL)
    return;
  const GameState *game_state = &app_state->game;

  canvas_clear(canvas);
  canvas_set_color(canvas, ColorBlack);

  for (uint8_t i = 0; i <= BOARD_SIZE; i++) {
    canvas_draw_line(canvas, FRAME_LEFT + FRAME_CELL_SIZE * i, FRAME_TOP,
                     FRAME_LEFT + FRAME_CELL_SIZE * i,
                     FRAME_TOP + FRAME_CELL_SIZE * BOARD_SIZE);
    canvas_draw_line(canvas, FRAME_LEFT, FRAME_TOP + FRAME_CELL_SIZE * i,
                     FRAME_LEFT + FRAME_CELL_SIZE * BOARD_SIZE,
                     FRAME_TOP + FRAME_CELL_SIZE * i);
  }
  //
  // draw cursor
  canvas_set_color(canvas, ColorWhite);
  canvas_draw_frame(canvas, FRAME_LEFT + FRAME_CELL_SIZE * game_state->cursor_x,
                    FRAME_TOP + FRAME_CELL_SIZE * game_state->cursor_y,
                    FRAME_CELL_SIZE + 1, FRAME_CELL_SIZE + 1);

  canvas_set_color(canvas, ColorBlack);
  // draw pieces
  int blacks = 0, whites = 0;
  const int radius = FRAME_CELL_SIZE >> 1;
  for (uint8_t i = 0; i < BOARD_SIZE; i++) {
    for (uint8_t j = 0; j < BOARD_SIZE; j++) {
      if (!game_state->board[i][j]) {
        continue;
      }
      if (game_state->board[i][j] == BLACK) {
        canvas_draw_disc(
            canvas, 
            FRAME_LEFT + FRAME_CELL_SIZE * i + radius + 1,
            FRAME_TOP + FRAME_CELL_SIZE * j + radius + 1, 
            radius);
        blacks++;
      } else {
        canvas_draw_circle(
            canvas, 
            FRAME_LEFT + FRAME_CELL_SIZE * i + radius + 1,
            FRAME_TOP + FRAME_CELL_SIZE * j + radius + 1, 
            radius);
        whites++;
      }
    }
  }

  canvas_set_font(canvas, FontPrimary);
  // draw score
  char score_str[25];
  memset(score_str, 0, sizeof(score_str));
  snprintf(score_str, sizeof(score_str), "%d - %d", whites, blacks);

  canvas_draw_str_aligned(canvas, 70, 3, AlignLeft, AlignTop, score_str);

  canvas_set_font(canvas, FontSecondary);
  if (game_state->is_game_over) {
    canvas_draw_str_aligned(canvas, 70, 20, AlignLeft, AlignTop, "Game over");

    canvas_draw_str_aligned(canvas, 
        70, 
        FRAME_TOP + FRAME_CELL_SIZE * BOARD_SIZE, 
        AlignLeft, AlignBottom, 
        "Press OK");

    canvas_set_font(canvas, FontPrimary);

    if (whites == blacks) {
      canvas_draw_str_aligned(canvas, 70, 30, AlignLeft, AlignTop, "DRAW");
    } else if (((game_state->human_color == WHITE) && whites > blacks) ||
               ((game_state->human_color == BLACK) && blacks > whites)) {
      canvas_draw_str_aligned(canvas, 70, 30, AlignLeft, AlignTop, "YOU WIN");
    } else {
      canvas_draw_str_aligned(canvas, 70, 30, AlignLeft, AlignTop, "YOU LOSE");
    }
  } else if (game_state->current_player == game_state->human_color) {
    canvas_draw_str_aligned(canvas, 70, 12, AlignLeft, AlignTop, "Your turn");
  } else {
    canvas_draw_str_aligned(canvas, 70, 12, AlignLeft, AlignTop,
                            "Computer turn");
  }

  if (app_state->screen == AppScreenMenu) {
    draw_menu(canvas, app_state);
  }

  furi_mutex_release(app_state->mutex);
}

static void draw_menu(Canvas* const canvas, const AppState* app_state) {
  gray_canvas(canvas);
  canvas_set_color(canvas, ColorWhite);
  canvas_draw_rbox(canvas, 28, 16, 72, 32, 4);
  canvas_set_color(canvas, ColorBlack);
  canvas_draw_rframe(canvas, 28, 16, 72, 32, 4);

  for (int i = 0; i < MENU_ITEMS_COUNT; i++) {
    if (i == app_state->selected_menu_item) {
      canvas_set_color(canvas, ColorBlack);
      canvas_draw_box(canvas, 34, 20 + 12 * i, 60, 12);
    }

    canvas_set_color(canvas, i == app_state->selected_menu_item ? ColorWhite
                                                                : ColorBlack);
    canvas_draw_str_aligned(canvas, 64, 26 + 12 * i, AlignCenter, AlignCenter,
                            popup_menu_strings[i]);
  }
}

static void gray_canvas(Canvas* const canvas) {
    canvas_set_color(canvas, ColorWhite);
    for(int x = 0; x < 128; x += 2) {
        for(int y = 0; y < 64; y++) {
            canvas_draw_dot(canvas, x + (y % 2 == 1 ? 0 : 1), y);
        }
    }
}

bool load_game(GameState* game_state) {
    Storage* storage = furi_record_open(RECORD_STORAGE);

    File* file = storage_file_alloc(storage);
    uint16_t bytes_readed = 0;
    if(storage_file_open(file, SAVING_FILENAME, FSAM_READ, FSOM_OPEN_EXISTING)) {
        bytes_readed = storage_file_read(file, game_state, sizeof(GameState));
    }
    storage_file_close(file);
    storage_file_free(file);

    furi_record_close(RECORD_STORAGE);

    return bytes_readed == sizeof(GameState);
}

void save_game(const GameState* game_state) {
    Storage* storage = furi_record_open(RECORD_STORAGE);

    if(storage_common_stat(storage, SAVING_DIRECTORY, NULL) == FSE_NOT_EXIST) {
        if(!storage_simply_mkdir(storage, SAVING_DIRECTORY)) {
            return;
        }
    }

    File* file = storage_file_alloc(storage);
    if(storage_file_open(file, SAVING_FILENAME, FSAM_WRITE, FSOM_CREATE_ALWAYS)) {
        storage_file_write(file, game_state, sizeof(GameState));
    }
    storage_file_close(file);
    storage_file_free(file);

    furi_record_close(RECORD_STORAGE);
}

bool handle_key_game(GameState *game_state, InputKey key) {
  switch (key) {
  case InputKeyBack:
    save_game(game_state);
    return false;
    break;
  case InputKeyOk:
    if (game_state->is_game_over) {
      init_game(game_state);
      save_game(game_state);
    } else {
      human_move(game_state);
    }
    break;
  case InputKeyUp:
    if (game_state->cursor_y > 0) {
      game_state->cursor_y--;
    } else {
      game_state->cursor_y = BOARD_SIZE - 1;
    }
    break;
  case InputKeyDown:
    if (game_state->cursor_y < BOARD_SIZE - 1) {
      game_state->cursor_y++;
    } else {
      game_state->cursor_y = 0;
    }
    break;
  case InputKeyLeft:
    if (game_state->cursor_x > 0) {
      game_state->cursor_x--;
    } else {
      game_state->cursor_x = BOARD_SIZE - 1;
    }
    break;
  case InputKeyRight:
    if (game_state->cursor_x < BOARD_SIZE - 1) {
      game_state->cursor_x++;
    } else {
      game_state->cursor_x = 0;
    }
    break;
  default:
    break;
  }
  return true;
}

bool handle_key_menu(AppState *app_state, InputKey key) {
  switch (key) {
  case InputKeyUp:
    if (app_state->selected_menu_item > 0) {
      app_state->selected_menu_item--;
    }
    break;
  case InputKeyDown:
    if (app_state->selected_menu_item < MENU_ITEMS_COUNT - 1) {
      app_state->selected_menu_item++;
    }
    break;
  case InputKeyOk:
    if (app_state->selected_menu_item == 1) {
      // new game
      init_game(&app_state->game);
      save_game(&app_state->game);
    }
    app_state->screen = AppScreenGame;
    break;
  default:
    break;
  }
  return true;
}

// returns `true` if the event loop should keep going
bool handle_key(AppState* app_state, InputKey key) {
  GameState* game_state = &app_state->game;

  switch (app_state->screen) {
    case AppScreenGame:
      return handle_key_game(game_state, key);
      break;
    case AppScreenMenu:
      return handle_key_menu(app_state, key);
      break;
  }
  return true;
}

int32_t game_reversi_app() {
  AppState app_state;
  app_state.screen = AppScreenGame;
  if (!load_game(&app_state.game)) {
    init_game(&app_state.game);
  }

  app_state.mutex = furi_mutex_alloc(FuriMutexTypeNormal);
  if (!app_state.mutex) {
    return 255;
  }
  InputEvent input;
  FuriMessageQueue* event_queue = furi_message_queue_alloc(8, sizeof(InputEvent));

  ViewPort* view_port = view_port_alloc();
  view_port_draw_callback_set(view_port, draw_callback, &app_state);
  view_port_input_callback_set(view_port, input_callback, event_queue);

  Gui* gui = furi_record_open(RECORD_GUI);
  gui_add_view_port(gui, view_port, GuiLayerFullscreen);
  bool is_finished = false;

  while(!is_finished) {
    // check if it's computer's turn
    if (!app_state.game.is_game_over && (app_state.game.current_player != app_state.game.human_color)) {
      computer_move(&app_state.game);
    }
    FuriStatus event_status = furi_message_queue_get(event_queue, &input, FuriWaitForever);
    if(event_status == FuriStatusOk) {
      // handle only press event, ignore repeat/release events

      if (input.type == InputTypeLong && input.key == InputKeyOk && app_state.screen == AppScreenGame) {
        furi_mutex_acquire(app_state.mutex, FuriWaitForever);
        app_state.selected_menu_item = 0;
        app_state.screen = AppScreenMenu;
        view_port_update(view_port);
        furi_mutex_release(app_state.mutex);
        continue;
      }
      if (input.type != InputTypePress) continue;

      furi_mutex_acquire(app_state.mutex, FuriWaitForever);
      is_finished = !handle_key(&app_state, input.key);
      view_port_update(view_port);
      furi_mutex_release(app_state.mutex);
    }
  }

  gui_remove_view_port(gui, view_port);
  furi_record_close(RECORD_GUI);

  view_port_free(view_port);

  furi_message_queue_free(event_queue);

  furi_mutex_free(app_state.mutex);

  return 0;
}