# Core SVG data for the trident insignia.
#
# This class should never need to be called directly.
# @private
class USPSFlags::Core::Trident
  def initialize(type, color: :blue, field_color: nil)
    valid_types = [:s, :d, :stf, :n]
    raise "Error: Invalid trident type. Options are #{valid_types}." unless valid_types.include? type
    @type = type

    load_config
    configure_trident_segments
    configure_colors(color, field_color)
  end

  def svg
    svg = ""
    svg << "<g mask=\"url(#delta-mask)\">" if @type == :d
    svg << "<g mask=\"url(#circle-mask-for-main-spike)\">" if @type == :stf

    @trident_segments.each do |segment|
      start = segment.keys.first
      points = segment.values.first
      svg << "<path d=\"M #{start[0]} #{start[1]}\n"
      points.each { |x, y| svg << "l #{x} #{y}\n" }
      svg << "\" fill=\"#{@color_code}\" />\n"
    end
    svg << "</g>" if [:d, :stf].include?(@type)

    case @type
    when :d
      svg << delta_hash
    when :stf
      svg << circle_hash
    else
      svg << standard_hash
    end

    svg
  end

  private
  def load_config
    @trident_config = USPSFlags.configuration.trident
    @main_spike_overhang = @trident_config[:bar_width] / 2
    @side_spike_overhang = @trident_config[:bar_width] / 2
    @top_point = ((USPSFlags::Config::BASE_HOIST - @trident_config[:height][@type]) / 2)
    @crossbar_top = @top_point + @trident_config[:crossbar_from_top]
    @hash_from_top = @trident_config[:crossbar_from_top] + (@trident_config[:bar_width] * 2)
    @circle_from_top = @trident_config[:crossbar_from_top] + @trident_config[:bar_width]*123/128 + @trident_config[:width]/2
    @main_length = @trident_config[:height][@type] - (@trident_config[:center_point_height] - @trident_config[:main_point_barb])
  end

  def configure_trident_segments
    @trident_segments = [main_spike, crossbar, left_spike, right_spike]
    @lower_hash = lower_hash
  end

  def main_spike
    {
      [@trident_config[:center_point], @top_point] =>
      [
        [@trident_config[:bar_width], @trident_config[:center_point_height]],
        [-@main_spike_overhang,  -@trident_config[:main_point_barb]],
        [0, @main_length],
        [-(@trident_config[:bar_width]), 0],
        [0, -@main_length],
        [-@main_spike_overhang, @trident_config[:main_point_barb]],
        [@trident_config[:bar_width], -@trident_config[:center_point_height]]
      ]
    }
  end

  def crossbar
    {
      [(@trident_config[:center_point] - @trident_config[:width]/2), (@crossbar_top)] =>
      [
        [@trident_config[:width], 0],
        [0, @trident_config[:bar_width]],
        [-@trident_config[:width], 0],
        [0, -@trident_config[:bar_width]]
      ]
    }
  end

  def left_spike
    {
      [(@trident_config[:center_point] - @trident_config[:width]/2), (@crossbar_top + 1)] =>
      [
        [0, -(@trident_config[:side_spike_height]+@trident_config[:side_point_height])],
        [(@trident_config[:bar_width]+@side_spike_overhang), @trident_config[:side_point_height]],
        [-@side_spike_overhang, 0],
        [0, @trident_config[:side_spike_height]]
      ]
    }
  end

  def right_spike
    {
      [(@trident_config[:center_point] + @trident_config[:width]/2), (@crossbar_top + 1)] =>
      [
        [0, -(@trident_config[:side_spike_height]+@trident_config[:side_point_height])],
        [-(@trident_config[:bar_width]+@side_spike_overhang), @trident_config[:side_point_height]],
        [@side_spike_overhang, 0],
        [0, @trident_config[:side_spike_height]]
      ]
    }
  end

  def lower_hash
    [
      [@trident_config[:hash_width], 0],
      [0, @trident_config[:bar_width]],
      [-@trident_config[:hash_width], 0],
      [0, -@trident_config[:bar_width]]
    ]
  end

  def configure_colors(color, field_color)
    @color_code = "#FFFFFF"
    if color == :red
      @color_code = USPSFlags::Config::RED
      @field_color_code = "#FFFFFF"
    elsif color == :blue
      @color_code = USPSFlags::Config::BLUE
      @field_color_code = "#FFFFFF"
    elsif field_color == :red
      @field_color_code = USPSFlags::Config::RED
    elsif field_color == :blue
      @field_color_code = USPSFlags::Config::BLUE
    end
  end

  def delta_hash
    <<~SVG
      <polyline mask="url(#delta-mask)" fill="#{@color_code}" points="
        #{@trident_config[:center_point]}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom] - @trident_config[:delta_height]}
        #{@trident_config[:center_point] + @trident_config[:width]/2}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom]}
        #{@trident_config[:center_point] - @trident_config[:width]/2}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom]}
        #{@trident_config[:center_point]}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom] - @trident_config[:delta_height]}" />
      <mask id="delta-mask">
        <g>
          <rect x="0" y="0" width="#{USPSFlags::Config::BASE_FLY}" height="#{USPSFlags::Config::BASE_FLY}" fill="#FFFFFF" />
          <polyline transform="scale(#{@trident_config[:delta_gap_scale]}) translate(#{@trident_config[:delta_gap_x]},#{@trident_config[:delta_gap_y]})" fill="#000000" points="
            #{@trident_config[:center_point]}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom] - @trident_config[:delta_height]}
            #{@trident_config[:center_point] + @trident_config[:width]/2}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom]*17/20}
            #{@trident_config[:center_point] - @trident_config[:width]/2}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom]*17/20}
            #{@trident_config[:center_point]}, #{@top_point + @trident_config[:height][:d] - @trident_config[:delta_from_bottom] - @trident_config[:delta_height]}" />
        </g>
      </mask>
    SVG
  end

  def circle_hash
    <<~SVG
      <circle cx="#{@trident_config[:center_point]}" cy="#{@top_point + @circle_from_top}" r="#{@trident_config[:width]/2}" fill="#{@color_code}" mask="url(#circle-mask)" />
      <mask id="circle-mask">
        <g>
          <rect x="0" y="0" width="#{USPSFlags::Config::BASE_FLY}" height="#{USPSFlags::Config::BASE_FLY}" fill="#FFFFFF" />
          <circle cx="#{@trident_config[:center_point]}" cy="#{@top_point + @circle_from_top}" r="#{@trident_config[:width]/2-@trident_config[:bar_width]}" fill="#000000" />
        </g>
      </mask>
      <mask id="circle-mask-for-main-spike">
        <g transform="scale(1.05) translate(-@trident_config[:br_width], -@trident_config[:br_width]/2)">
          <rect x="0" y="0" width="#{USPSFlags::Config::BASE_FLY}" height="#{USPSFlags::Config::BASE_FLY}" fill="#FFFFFF" />
          <circle cx="#{@trident_config[:center_point]}" cy="#{@top_point + @circle_from_top}" r="#{@trident_config[:width]/2-@trident_config[:bar_width]}" fill="#000000" />
        </g>
      </mask>
    SVG
  end

  def standard_hash
    svg = "<path d=\"M #{(@trident_config[:center_point] - @trident_config[:hash_width]/2)} #{(@top_point + @hash_from_top)}\n"
    @lower_hash.each { |x, y| svg << "l #{x} #{y}\n" }
    svg << "\" fill=\"#{@color_code}\" />\n"

    svg
  end
end