#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require 'execjs'
require 'pathname'

module CoffeeWithoutNodejs
  module CoffeeCompiler
    class << self
      attr_writer :source

      def source
        @source ||= File.read(File.expand_path('../compiler/coffee-script.js', __FILE__))
      end

      def wrapper
        <<-WRAPPER
(function(script, options) {
    try {
        return CoffeeScript.compile(script, options);
    } catch (err) {
        if (err instanceof SyntaxError && err.location) {
            throw new SyntaxError([options.filename, err.location.first_line + 1, err.location.first_column + 1].join(":") + ": " + err.message)
        } else {
            throw err;
        }
    }
})
WRAPPER
      end

      def compiler
        @coffee ||= ExecJS.compile(source)
      end

      def compile(script, bare=true)
        compiler.call(wrapper, script, bare: bare)
      rescue ExecJS::RuntimeError
        puts $!.message
      end

      def compile_file(file, bare=true, create_target_jsfile=false)
        root_dir = Pathname(Dir.pwd)
        file_path = Pathname(File.expand_path(file))
        source_code = file_path.read

        target_js_content = compiler.call(wrapper, source_code, bare: bare)

        if create_target_jsfile
          js_path, map_path = create_js_path_from(file_path)
          source_files = file_path.relative_path_from(js_path.dirname).to_s
          generated_file = js_path.relative_path_from(js_path.dirname).to_s
          relative_map_path = map_path.relative_path_from(js_path.dirname).to_s

          File.open(js_path, 'wb') do |f|
            f.print "#{ENV['JS_SHEBANG']}\n\n" if ENV['JS_SHEBANG']
            f.print target_js_content, "\n//# sourceMappingURL=#{relative_map_path}"
          end

          File.open(map_path, 'wb') do |f|
            f.print compiler.call(wrapper, source_code,
                                  sourceMap: true,
                                  sourceFiles: [source_files],
                                  generatedFile: generated_file)['v3SourceMap']
          end

          puts "==> #{js_path.relative_path_from(root_dir)}"
          js_path
        else
          puts "==> #{file_path}" if $stdout.tty?
          target_js_content
        end
      rescue ExecJS::RuntimeError
        error_msg = "[#{file_path.relative_path_from(root_dir)}]: #{$!.message}"
        `notify-send "#{error_msg}" -t 5000` if system 'which notify-send &>/dev/null'
        puts error_msg
      end

      def create_js_path_from(path)
        # if in coffee directory, will create same level js directory.
        path.descend do |x|
          if x.basename.to_s == 'coffee'
            js_path = path.sub('/coffee/', '/js/').sub(/\.js\.coffee$|\.coffee$/, '.js')
            map_path = path.sub('/coffee/', '/.map/').sub(/\.js\.coffee$|\.coffee$/, '.js.map')

            js_dir = js_path.dirname
            map_dir = map_path.dirname

            js_dir.mkpath unless js_dir.exist?
            map_dir.mkpath unless map_dir.exist?

            return [js_path, map_path]
          end
        end
        # if not in coffee directory, rename it.
        js_path = path.sub(/\.js\.coffee$|\.coffee$/, '.js')
        map_path = js_path.sub_ext('.js.map').sub(/\/([^\/]+)$/, '/.\1')

        if path == js_path
          warn 'filename extension is .coffee or .js.coffee?'
          exit
        end
        [js_path, map_path]
      end
    end
  end
end