# 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 Animation
    Frame = Struct.new(:duration, :index);

    attr_reader(:index);

    def initialize(sequence, repeat = true)
      @sequence = sequence;
      @repeat = repeat;

      self.reset();
    end

    def tick()
      return @index if @sequence_is_over;

      @current_time += 1;
      frame = @sequence[@current_frame];

      if @current_time >= frame.duration then
        @current_time = 0;
        @current_frame += 1;

        if @current_frame >= @sequence.size() then
          if @repeat then
            @current_frame = 0;
          else
            @current_frame -= 1;
            @sequence_is_over = true;
          end
        end
      end

      return @index = frame.index();
    end

    def reset()
      @current_time = 0;
      @current_frame = 0;
      @index = @sequence[0].index;
      @sequence_is_over = false;
    end
  end
end