require_relative 'common'

options = get_options(__FILE__)

sprite_path = options['sprite_path']
csv_path = options['generate_config_path']
atlas_path = options['generate_atlas_path']
padding = options['padding_size']

recreate_dir atlas_path
ensure_dir csv_path

# $ gem install chunky_png
# $ gem install binpack
require 'chunky_png'
require 'binpack'

require 'csv'

Point = Struct.new(:x, :y)
Box = Struct.new(:top_left, :bottom_right)

csv_atlas = CSV.open("#{csv_path}/atlas.csv", 'wb')
csv_atlas << ['Id', 'Path']
csv_atlas << ['', '']
csv_atlas << [':id', ':path']

csv_sprite = CSV.open("#{csv_path}/sprite.csv", 'wb')
csv_sprite << ['Id', 'AtlasId', 'X', 'Y']
csv_sprite << ['', '', '', '']
csv_sprite << [':id', '@atlas', ':int', ':int']

Dir["#{sprite_path}/*"].each do |path|
  atlas_name = convert_case(File::basename(path))
  next unless File::directory?(path)
  atlas_size = 1024
  sprites = Dir["#{path}/*"].collect do |file| 
    sprite = ChunkyPNG::Image.from_file(file)
    sprite.define_singleton_method :file do
      return file
    end
    sprite
  end
  items = sprites.collect { |sprite| Binpack::Item.new(sprite, sprite.width, sprite.height) }
  bins = Binpack::Bin.pack(items, [], Binpack::Bin.new(atlas_size, atlas_size, padding))
  bins.each do |bin|
    atlas = ChunkyPNG::Image.new(atlas_size, atlas_size, ChunkyPNG::Color::TRANSPARENT)
    bin.items.each do |item|
      unit, x, y = *item
      atlas.compose!(unit.obj, x, y)
      csv_sprite << [convert_case(File.basename(unit.obj.file, '.png')), atlas_name, x, y]
    end
    atlas_path = "#{atlas_path}/#{File::basename(path)}.png"
    atlas.save atlas_path
    csv_atlas << [atlas_name, File.basename(atlas_path)]
  end
end