require 'RMagick'
 
class TilesTask
  def task_instance
    Rake::Task[ task_name ]
  end
end
 
class Tile
  attr_reader :name
 
  def initialize name
    @name = name
  end
end
 
class Tileset < TilesTask
  attr_reader :name, :path, :format, :variant, :width, :height, :fullpath, :fullpath
 
  def initialize name, path, format, variant, width, height
    @name = name
    @path = path
    @format = format
    @variant = variant
    @width = width
    @height = height
 
    @fullname = "#{@name}.#{@format}"
    @fullpath = "#{@path}/#{@fullname}"
 
    if not File.exists? @fullpath # Is this an output tileset?
      @fullname = "#{@name}_#{@width}x#{height}.#{@format}"
      @injectpath = "#{@path}/.injected/#{variant.name}/#{@fullname}" # This must be before redefining @path
      @path="#{path}/#{variant.name}"
      @fullpath = "#{@path}/#{@fullname}"
    else
      @injectpath = "#{@path}/.injected/#{@fullname}"
    end
 
    @image = nil
 
    @tileswritten = 0
 
    @injected = []
 
    @variant.task_instance.prerequisites << task_name
    directory @path
    directory @injectpath
    file task_name => [@path] do
      if @tileswritten > 0 then
        puts "Creating/Writing (Injected #{@tileswritten} tiles) in Tileset: #{@fullpath}"
        @image.write @fullpath
        @injected.each do |injecttile|
          File::new injecttile, "w"
        end
      end
    end
  end
 
  def image
    if !@image
      if File.exists? @fullpath
        puts "Loading #{@fullpath}"
        @image = Magick::Image.read( @fullpath )[0]
      else
        total = @variant.tilenames.size
        columns = 40
        width = columns*@width
        height = ((total+(columns-1))/columns)*@height
        puts "Creating #{@fullpath} at #{width}x#{height} with #{columns} columns"
        @image = Magick::Image.new( width, height ) do
          self.background_color = Magick::Pixel.new 0, 0, 0, Magick::MaxRGB
        end
      end
    end
    @image
  end
 
  def add_source_tilegroup tilegroup
    Rake::Task[ @variant.task_name ].prerequisites << task_name
    total = @variant.tilenames.size
    @variant.tilenames.each_with_index do |tilename,index|
      tilepath = "#{tilegroup.fullpath}/#{tilename}.#{tilegroup.format}"
      tiletask = "Inject tile: #{fullpath} #{tilepath}"
      injecttile = "#{@injectpath}/#{tilename}"
      if task_instance.prerequisites.index( injecttile ) == nil then
        task_instance.prerequisites << injecttile
        file injecttile => [ tilepath, @injectpath ] do
          columns = image.columns/@width
          #puts "#{tilename} [#{index+1} of #{total}] => #{@fullpath}"
          tile = Magick::Image.read( tilepath ) do
            self.size = Magick::Geometry.new( tilegroup.width, tilegroup.height )
          end[0]
          if tile then
            @image.composite! tile.resize( @width, @height ),
              (index%columns)*@width, (index/columns)*@height,
              Magick::OverCompositeOp
            @tileswritten += 1
          end
          @injected << injecttile
        end
      end
    end
  end
 
  def task_name
    "tileset: #{@fullpath}"
  end
 
end
 
class TileGroup < TilesTask
  attr_reader :name, :path, :format, :fullpath, :width, :height
 
  def initialize name, path, format, width, height
    @name = name
    @path = path
    @format = format
    @width = width
    @height = height
    @fullpath = "#{@path}/#{@name}/#{format}"
    @tileswritten = 0
 
    directory @fullpath
    task task_name => [@fullpath] do
      puts "Created/Updated #{@tileswritten} tiles in TileGroup: #{@fullpath}" if @tileswritten > 1
    end
  end
 
  def add_source_tileset tileset
    Rake::Task[ tileset.variant.task_name ].prerequisites << task_name
    total = tileset.variant.tilenames.size
    columns = nil
    tileset.variant.tilenames.each_with_index do |tilename,index|
      tilepath = "#{@fullpath}/#{tilename}.#{format}"
      if task_instance.prerequisites.index( tilepath ) == nil then
        task_instance.prerequisites << tilepath
        file tilepath => [tileset.fullpath,@fullpath] do
          columns = tileset.image.columns/tileset.width if !columns
          #puts "#{tileset.name} [#{index+1} of #{total}] => #{tilepath}"
          tileset.image.crop((index%columns)*tileset.width,(index/columns)*tileset.height,tileset.width,tileset.height).resize(@width,@height).write tilepath
          @tileswritten += 1
        end
      end
    end
  end
 
  def task_name
    "tilegroup: #{@fullpath}"
  end
 
end
 
class Variant < TilesTask
  attr_reader :name
  attr_reader :tilenames
 
  def initialize name, filename
    @name = name
    @tilenames = []
 
    File.readlines( filename ).each do |line|
      @tilenames << line.chomp
    end
 
    task task_name => []
  end
 
  def task_name
    "variant: #{@name}" 
  end
 
end
 
class Variants < Hash
  def initialize directory
    super()
    @directory = directory
    FileList[ "#{directory}/*" ].each do |path|
      variant_name = File::basename( path ).to_sym
      self[ variant_name ] = Variant.new( variant_name, path )
    end
  end
end