# frozen_string_literal: true

module DspBlueprintParser
  # class to orchestrate parsing
  class Parser
    SECONDS_AT_EPOC = 62_135_596_800

    # @param [String] str_blueprint
    def initialize(str_blueprint)
      @str_blueprint = str_blueprint
    end

    # @return [BlueprintData]
    def parse
      blueprint = BlueprintData.new
      reader = get_reader(@str_blueprint)

      parse_metadata(blueprint, @str_blueprint, reader)
      parse_areas(blueprint, reader)
      parse_buildings(blueprint, reader)

      blueprint
    end

    private

    # @param ticks [Integer]
    # @return [Time]
    def ticks_to_epoch(ticks)
      # 10mil ticks per second
      seconds = ticks / 10_000_000

      Time.at(seconds - SECONDS_AT_EPOC)
    end

    # @param str_blueprint [String]
    # @return [Array<String>]
    def get_header_segments(str_blueprint)
      header_end = str_blueprint.index('"')
      header = str_blueprint[10..header_end - 1]
      header.split(',')
    end

    # @param str_blueprint [String]
    # @return [BinaryReader]
    def get_reader(str_blueprint)
      header_end = str_blueprint.index('"')
      blueprint_end = str_blueprint[header_end + 1..].index('"') + header_end
      blueprint_compressed = str_blueprint[header_end + 1..blueprint_end]

      gz = Zlib::GzipReader.new(StringIO.new(Base64.decode64(blueprint_compressed)))
      blueprint_decompressed = gz.each_byte.to_a

      BinaryReader.new(blueprint_decompressed)
    end

    # @param [BlueprintData] blueprint
    # @param [BinaryReader] reader
    def parse_areas(blueprint, reader)
      reader.read_i8.times do
        area = Area.new
        area.index = reader.read_i8
        area.parent_index = reader.read_i8
        area.tropic_anchor = reader.read_i16
        area.area_segments = reader.read_i16
        area.anchor_local_offset_x = reader.read_i16
        area.anchor_local_offset_y = reader.read_i16
        area.width = reader.read_i16
        area.height = reader.read_i16

        blueprint.areas << area
      end
    end

    # @param [BlueprintData] blueprint
    # @param [BinaryReader] reader
    def parse_buildings(blueprint, reader)
      reader.read_i32.times do
        building = Building.new
        building.index = reader.read_i32
        building.area_index = reader.read_i8
        building.local_offset_x = reader.read_single
        building.local_offset_y = reader.read_single
        building.local_offset_z = reader.read_single
        building.local_offset_x2 = reader.read_single
        building.local_offset_y2 = reader.read_single
        building.local_offset_z2 = reader.read_single
        building.yaw = reader.read_single
        building.yaw2 = reader.read_single
        building.item_id = reader.read_i16
        building.model_index = reader.read_i16
        building.temp_output_obj_idx = reader.read_i32
        building.temp_input_obj_idx = reader.read_i32
        building.output_to_slot = reader.read_i8
        building.input_from_slot = reader.read_i8
        building.output_from_slot = reader.read_i8
        building.input_to_slot = reader.read_i8
        building.output_offset = reader.read_i8
        building.input_offset = reader.read_i8
        building.recipe_id = reader.read_i16
        building.filter_fd = reader.read_i16

        reader.read_i16.times do
          building.parameters << reader.read_i32
        end

        blueprint.buildings << building
      end
    end

    # @param [BlueprintData] blueprint
    # @param [String] str_blueprint
    # @param [BinaryReader] reader
    def parse_metadata(blueprint, str_blueprint, reader)
      header_segments = get_header_segments(str_blueprint)

      blueprint.icon_layout = header_segments[1].to_i
      blueprint.icon0 = header_segments[2].to_i
      blueprint.icon1 = header_segments[3].to_i
      blueprint.icon2 = header_segments[4].to_i
      blueprint.icon3 = header_segments[5].to_i
      blueprint.icon4 = header_segments[6].to_i

      blueprint.time = ticks_to_epoch(header_segments[8].to_i)
      blueprint.game_version = header_segments[9]

      if header_segments[10]
        blueprint.short_description = CGI.unescape(header_segments[10])
      end

      if header_segments[11]
        blueprint.description = CGI.unescape(header_segments[11])
      end

      blueprint.version = reader.read_i32
      blueprint.cursor_offset_x = reader.read_i32
      blueprint.cursor_offset_y = reader.read_i32
      blueprint.cursor_target_area = reader.read_i32
      blueprint.drag_box_size_x = reader.read_i32
      blueprint.drag_box_size_y = reader.read_i32
      blueprint.primary_area_idx = reader.read_i32
    end
  end
end