# Copyright 2022 Frederico de Oliveira Linhares
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

module CandyGear
  class Menu
    class Stack
      def initialize(menu)
        @stack = [];
        @stack << menu;
      end

      def current_menu() = @stack[-1];

      def push(menu) = @stack << menu;

      def pop()
        @stack.pop() if @stack.size > 1;
      end

      def draw() = @stack.each {_1.draw();}
      def size() = @stack.size;
    end

    class BorderlessView
      attr_reader(:texture, :font, :text_color, :bg_color, :sprites);

      def initialize(
            texture, font, text_color, bg_color, sprite_width, sprite_height)
        @texture = texture;
        @font = font;
        @text_color = text_color;
        @bg_color = bg_color;
        @sprite_width = sprite_width;
        @sprite_height = sprite_height;

        @sprites = {};
        @sprites[:arrow_select] = Sprite.new(
          @texture, 1 * @sprite_width, 1 * @sprite_height,
          @sprite_width, @sprite_height);
      end

      def draw(x, y, width, height)
        # Nothing.
      end

      def border_width() = 0;
      def border_height() = 0;
    end

    class BorderedView
      attr_reader(
        :texture, :font, :text_color, :bg_color, :sprites, :border_width,
        :border_height);

      def initialize(
            texture, font, text_color, bg_color, sprite_width, sprite_height)
        @texture = texture;
        @font = font;
        @text_color = text_color;
        @bg_color = bg_color;
        @border_width = sprite_width;
        @border_height = sprite_height;

        @sprites = {};
        @sprites[:arrow_select] = Sprite.new(
          @texture, 1 * @border_width, 1 * @border_height,
          @border_width, @border_height);
        @sprites[:box_top_left] = Sprite.new(
          @texture, 0, 0, @border_width, @border_height);
        @sprites[:box_top] = Sprite.new(
          @texture, 1 * @border_width, 0,
          @border_width, @border_height);
        @sprites[:box_top_right] = Sprite.new(
          @texture, 2 * @border_height, 0,
          @border_width, @border_height);
        @sprites[:box_left] = Sprite.new(
          @texture, 0, 1 * @border_height,
          @border_width, @border_height);
        @sprites[:box_right] = Sprite.new(
          @texture, 2 * @border_width, 1 * @border_height,
          @border_width, @border_height);
        @sprites[:box_bottom_left] = Sprite.new(
          @texture, 0, 2 * @border_height,
          @border_width, @border_height);
        @sprites[:box_bottom] = Sprite.new(
          @texture, 1 * @border_width, 2 * @border_height,
          @border_width, @border_height);
        @sprites[:box_bottom_right] = Sprite.new(
          @texture, 2 * @border_width, 2 * @border_height,
          @border_width, @border_height);
      end

      def draw(x, y, width, height)
        num_horizontal_sprites = width / @border_width + 1;
        num_horizontal_sprites += 1 if width % @border_width > 0;
        num_vertical_sprites = height / @border_height;
        num_vertical_sprites += 1 if height % @border_height > 0;
        background = Rect.new(
          x, y,
          (num_horizontal_sprites + 2) * @border_width,
          (num_vertical_sprites + 2) * @border_height);

        Graphic.set_color(@bg_color);
        background.draw_fill();

        # Draw the corners.
        @sprites[:box_top_left].draw_xy(x, y);
        @sprites[:box_top_right].draw_xy(
          @border_width * (num_horizontal_sprites + 1) + x, y);
        @sprites[:box_bottom_left].draw_xy(
          x, @border_height * (num_vertical_sprites + 1) + y);
        @sprites[:box_bottom_right].draw_xy(
          @border_width * (num_horizontal_sprites + 1) + x,
          @border_height * (num_vertical_sprites + 1) + y);

        # Draw the edges.
        num_horizontal_sprites.times do |i|
          # Top
          @sprites[:box_top].draw_xy(@border_width * (i + 1) + x, y);
          # Bottom
          @sprites[:box_bottom].draw_xy(
            @border_width * (i + 1) + x,
            @border_height * (num_vertical_sprites + 1) + y);
        end
        num_vertical_sprites.times do |i|
          # Left
          @sprites[:box_left].draw_xy(x, @border_height * (i + 1) + y);
          # Right
          @sprites[:box_right].draw_xy(
            @border_width * (num_horizontal_sprites + 1) + x,
            @border_height * (i + 1) + y);
        end
      end
    end

    class Option
      attr_reader(:action, :text);

      def initialize(text, action);
        @text = text;
        @action = action;
      end
    end

    attr_reader(:width, :height);

    def initialize(view, pos_x, pos_y, options)
      @view = view;

      @pos_x = pos_x;
      @pos_y = pos_y;

      @options = options.map do |opt|
        Option.new(
          Texture.from_text(
            opt[:text], view.font, view.text_color, view.bg_color),
          opt[:action]);
      end
      @current_option = 0;
      @option_max_width = 0;
      @option_max_height = 0;

      @options.each do |i|
        if @option_max_width < i.text.width then
          @option_max_width = i.text.width;
        end
        if @option_max_height < i.text.height then
          @option_max_height = i.text.height;
        end
      end

      @width = @option_max_width;
      @height = @option_max_height * @options.size;
    end

    def next_opt()
      @current_option += 1;
      @current_option = 0 if @current_option >= @options.size();
    end

    def pred_opt()
      if @current_option <= 0 then
        @current_option = @options.size - 1;
      else
        @current_option -= 1;
      end
    end

    def activate()
      @options[@current_option].action.call();
    end

    def draw()
      @view.draw(@pos_x, @pos_y, @width, @height);

      @options.each_with_index do |opt, i|
        opt.text.draw_xy(
          @pos_x + @view.border_width + @view.sprites[:arrow_select].width,
          @pos_y + @view.border_height +
          @option_max_height * i);
      end

      @view.sprites[:arrow_select].draw_xy(
          @pos_x + @view.border_width,
          @pos_y + @view.border_height +
          @option_max_height * @current_option);
    end
  end
end