require 'open-uri'
require 'csv'
require 'pry'

class Color
  attr_reader :id, :color_name, :r, :g, :b

  def initialize(id:, color_name:, r:, g:, b:)
    @id = id
    @color_name = color_name
    @r = r
    @g = g
    @b = b
  end

  def attributes
    {
      id: id,
      color_name: color_name,
      r: r,
      g: g,
      b: b,
      color_6_digest_hex: color_6_digest_hex
    }
  end

  def color_6_digest_hex
    [r, g, b].map{|i| i.to_s(16) }.join
  end
end

# ref: http://www.singlecolorimage.com/api.html
class SingleColorImageApi
  BASE_URL = "http://singlecolorimage.com/get"

  def initialize(color_6_digest_hex:, color_name:, id:, width: 256, height: 256, download_path: nil)
    @color_6_digest_hex = color_6_digest_hex
    @color_name = color_name
    @id = id
    @width = width
    @height = height
    @download_path = download_path
  end

  def self.download(**args)
    new(args).download
  end

  def self.extract_csv(csv_file:)
    header_mapping =
    {
      "ID" => :id,
      "color_library Name" => :color_name,
      "R" => :r,
      "G" => :g,
      "B" => :b
    }

    header_converter = lambda { |h| header_mapping[h] }
    csv_options =
    {
      headers: :first_row,
      header_converters: header_converter,
      converters: :integer,
      skip_blanks: true
    }
    rows = CSV.read(csv_file, **csv_options)
    rows.map{ |row| Color.new(id: row[:id], color_name: row[:color_name], r: row[:r], g: row[:g], b: row[:b]) }
  end
  
  # CSV header must be [color_6_digest_hex, width, height]
  def self.bulk_download(csv_file:)
    colors = extract_csv(csv_file: csv_file)
    colors.each do |color|
      puts "START #{color.attributes}"
      new(
        color_6_digest_hex: color.color_6_digest_hex,
        color_name: color.color_name,
        id: color.id
      ).download
      puts "FINISH #{color.attributes}\n"
    rescue => e
      puts e
      puts color
    end
  end

  def download
    open(file_path, 'w') do |f|
      open(request_uri) do |data|
        f.write(data.read)
      end
    end
  end

  private

  attr_reader :color_6_digest_hex, :color_name, :id, :width, :height, :download_path

  def image_size
    "#{width}x#{height}"
  end

  def file_name
    "#{id}.png"
  end

  def file_path
    File.join(donwload_dir, file_name)
  end

  def request_uri
    URI.join("#{BASE_URL}/", "#{color_6_digest_hex}/", image_size).tap{|t| puts t}
  end

  def donwload_dir
     download_path || FileUtils.mkdir_p(File.join("/tmp", "simple_images")).join
  end
end

# ex
# SingleColorImageApi.download(color_6_digest_hex: "33fd8f", width: "400", height: "100")

#SingleColorImageApi.bulk_download(csv_file: "color.csv")
SingleColorImageApi.extract_csv(csv_file: "color_library.csv")
SingleColorImageApi.download(csv_file: "color_library.csv")