require 'cairo'
require_relative 'arg_loader'
require_relative 'color_validator'
require_relative 'dir_validator'

module Squib
  # @api private
  module Args

    class Sheet
      include ArgLoader
      include ColorValidator
      include DirValidator

      def initialize(custom_colors = {}, dsl_method_defaults = {}, deck_size = 1, dpi = 300)
        @custom_colors = custom_colors
        @dsl_method_defaults = dsl_method_defaults
        @deck_size = deck_size
        @dpi = dpi
      end

      def self.parameters
        {
          count_format: '%02d',
          crop_margin_bottom: 0,
          crop_margin_left: 0,
          crop_margin_right: 0,
          crop_margin_top: 0,
          crop_marks: false,
          crop_stroke_color: :black,
          crop_stroke_dash: '',
          crop_stroke_width: 1.5,
          dir: '_output',
          file: 'sheet.png',
          fill_color: :white,
          gap: 0,
          height: 2550,
          margin: 75,
          prefix: 'sheet_',
          rows: :infinite,
          columns: 5,
          trim_radius: 38,
          trim: 0,
          width: 3300,
          range: :all,
          rtl: false,
        }
      end

      def self.expanding_parameters
        [] # none of them
      end

      def self.params_with_units
        [ :crop_margin_bottom, :crop_margin_left, :crop_margin_right,
          :crop_margin_top, :gap, :height, :margin, :trim_radius, :trim,
          :width
        ]
      end

      def validate_crop_stroke_dash(arg)
        arg.to_s.split.collect do |x|
          UnitConversion.parse(x, @dpi).to_f
        end
      end

      def validate_crop_marks(arg)
        arg.to_s.downcase.to_sym unless arg == false
      end

      def validate_fill_color(arg)
        colorify(arg, @custom_colors)
      end

      def validate_dir(arg)
        ensure_dir_created(arg)
      end

      def validate_columns(arg)
        raise 'columns must be an integer' unless arg.respond_to? :to_i
        arg.to_i
      end

      def validate_rows(arg)
        raise 'columns must be an integer' unless columns.respond_to? :to_i
        count = if range == :all
                  @deck_size
                else
                  count = range.to_a.length
                end
        return 1 if count <= columns
        return arg if arg.respond_to? :to_i
        (count.to_f / columns.to_f).ceil
      end

      def full_filename(i=nil)
        if i.nil?
          "#{dir}/#{file}"
        else
          "#{dir}/#{prefix}#{count_format % i}.png"
        end
      end

      def crop_coords(x, y, deck_w, deck_h)
        case crop_marks
        when false
          []
        when :full
          [
            {
              # Vertical, Left
              x1: x + trim + crop_margin_left, y1: 0,
              x2: x + trim + crop_margin_left, y2: height - margin + 1
            },
            {
              # Vertical, Right
              x1: x + deck_w - trim - crop_margin_right, y1: 0,
              x2: x + deck_w - trim - crop_margin_right, y2: height - margin + 1
            },
            {
              # Horizontal, Top
              x1: 0                 , y1: y + trim + crop_margin_top,
              x2: width - margin + 1, y2: y + trim + crop_margin_top
            },
            {
              # Horizontal, Bottom
              x1: 0         , y1: y + deck_h - trim - crop_margin_bottom,
              x2: width - margin + 1, y2: y + deck_h - trim - crop_margin_bottom
            },
          ]
        else # e.g. :margin
          [
            { # Vertical, Upper-left
              x1: x + trim + crop_margin_left, y1: 0,
              x2: x + trim + crop_margin_left, y2: margin - 1
            },
            { # Vertical , Upper-right
              x1: x + deck_w - trim - crop_margin_right, y1: 0,
              x2: x + deck_w - trim - crop_margin_right, y2: margin - 1
            },
            { # Vertical , Lower-left
              x1: x + trim + crop_margin_left, y1: height,
              x2: x + trim + crop_margin_left, y2: height - margin + 1
            },
            { # Vertical , Lower-right
              x1: x + deck_w - trim - crop_margin_right, y1: height,
              x2: x + deck_w - trim - crop_margin_right, y2: height - margin + 1
            },
            { # Horizontal, Upper-left
              x1: 0         , y1: y + trim + crop_margin_top,
              x2: margin - 1, y2: y + trim + crop_margin_top
            },
            { # Horizontal, Upper-Right
              x1: width             , y1: y + trim + crop_margin_top,
              x2: width - margin + 1, y2: y + trim + crop_margin_top
            },
            { # Horizontal, Lower-Left
              x1: 0         , y1: y + deck_h - trim - crop_margin_bottom,
              x2: margin - 1, y2: y + deck_h - trim - crop_margin_bottom
            },
            { # Horizontal, Lower-Right
              x1: width,              y1: y + deck_h - trim - crop_margin_bottom,
              x2: width - margin + 1, y2: y + deck_h - trim - crop_margin_bottom
            },
          ]
        end
      end

    end

  end
end