# Copyright 2022-2024 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, sprite_width, sprite_height)
        @texture = texture;
        @font = font;
        @sprite_width = sprite_width;
        @sprite_height = sprite_height;

        @sprites = {
          arrow_select: Sprite.new(
            @texture, 1.0/3.0, 1.0/3.0, 2.0/3.0, 2.0/3.0)
        }
      end

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

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

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

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

        @sprites = {
          arrow_select: Sprite.new(
            @texture, 1.0/3.0, 1.0/3.0, 2.0/3.0, 2.0/3.0),
          box_top_left: Sprite.new(
            @texture, 0.0, 0.0, 1.0/3.0, 1.0/3.0),
          box_top: Sprite.new(
            @texture, 1.1/3.0, 0.0, 1.9/3.0, 1.0/3.0),
          box_top_right: Sprite.new(
            @texture, 2.0/3.0, 0.0, 1.0, 1.0/3.0),
          box_left: Sprite.new(
            @texture, 0.0, 1.1/3.0, 1.0/3.0, 1.9/3.0),
          box_right: Sprite.new(
            @texture, 2.0/3.0, 1.1/3.0, 1.0, 1.9/3.0),
          box_bottom_left: Sprite.new(
            @texture, 0.0, 2.0/3.0, 1.0/3.0, 1.0),
          box_bottom: Sprite.new(
            @texture, 1.1/3.0, 2.0/3.0, 1.9/3.0, 1.0),
          box_bottom_right: Sprite.new(
            @texture, 2.0/3.0, 2.0/3.0, 1.0, 1.0)
        }
      end

      def draw(view, 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;

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

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

    class Option
      attr_reader(:action, :selection, :text, :width, :height);

      def initialize(text, width, height, action, selection = nil);
        @text = text;
        @action = action;
        @width = width;
        @height = height;
        @selection = selection;
      end
    end

    attr_reader(:width, :height);

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

      @pos_x = pos_x;
      @pos_y = pos_y;

      @options = options.map do |opt|
        texture = Texture.from_text(menu_view.font, opt[:text])
        Option.new(
          Sprite.new(texture, 0, 0, 1.0, 1.0),
          texture.width,
          texture.height,
          opt[:action],
          opt[:selection]);
      end
      @current_option = 0;
      @option_max_width = 0;
      @option_max_height = 0;

      @options.each do |i|
        if @option_max_width < i.width then
          @option_max_width = i.width;
        end
        if @option_max_height < i.height then
          @option_max_height = i.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();
      self.call_selection();
    end

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

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

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

      @options.each_with_index do |opt, i|
        opt.text.draw(
          @view,
          @pos_x + @menu_view.border_width +
          @menu_view.border_width,
          @pos_y + @menu_view.border_height +
          @option_max_height * i,
          opt.width, opt.height);
      end

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

    protected
    def call_selection
      @options[@current_option].selection&.call();
    end
  end
end