class Opal::Builder

def self.runtime
  core_dir   = Opal.core_dir
  load_order = File.join core_dir, 'load_order'
  result     = []
  corelib    = File.read(load_order).strip.split.map do |c|
    File.read File.join(core_dir, "#{c}.rb")
  end
  methods = Parser::METHOD_NAMES.map { |f, t| "'#{f}': '$#{t}$'" }
  runtime = File.read(File.join core_dir, 'runtime.js')
  corelib = Opal.parse corelib.join("\n")
  [
    "/*!",
    " * Opal v#{Opal::VERSION}",
    " * http://opalrb.org",
    " *",
    " * Copyright 2012, Adam Beynon",
    " * Released under the MIT License",
    " */",
    "(function(undefined) {",
    runtime,
    "var method_names = {#{ methods.join ', ' }},",
    "reverse_method_names = {};",
    "for (var id in method_names) {",
    "reverse_method_names[method_names[id]] = id;",
    "}",
    corelib,
    "}).call(this);"
  ].join("\n")
end

def build
  unless out = @options[:out]
    # ...
    out = "out.js"
  end
  # puts "  - Building to #{out}"
  files = files_for @sources
  # puts "  - files: #{files.inspect}"
  FileUtils.mkdir_p File.dirname(out)
  build_to files, out
end

def build_file(file)
  @parser.parse File.read(file)
end

def build_to(files, out)
  @parser = Parser.new
  File.open(out, 'w+') do |o|
    files.each { |file| o.puts build_file(file) }
  end
end

def files_for(sources)
  files = []
  sources.each do |s|
    if File.directory? s
      files.push *Dir[File.join s, '**/*.rb']
    elsif File.extname(s) == '.rb'
      files << s
    end
  end
  files
end

def initialize(options = {})
  @sources = Array(options[:files])
  @options = options
end