require "shellwords"
require "socket"
require "webpacker/configuration"
require "webpacker/dev_server"
require "webpacker/runner"

module Webpacker
  class DevServerRunner < Webpacker::Runner
    def run
      load_config
      detect_unsupported_switches!
      detect_port!
      execute_cmd
    end

    private

      def load_config
        app_root = Pathname.new(@app_path)

        @config = Configuration.new(
          root_path: app_root,
          config_path: app_root.join("config/webpacker.yml"),
          env: ENV["RAILS_ENV"]
        )

        dev_server = DevServer.new(@config)

        @hostname          = dev_server.host
        @port              = dev_server.port
        @pretty            = dev_server.pretty?
        @https             = dev_server.https?

      rescue Errno::ENOENT, NoMethodError
        $stdout.puts "webpack dev_server configuration not found in #{@config.config_path}[#{ENV["RAILS_ENV"]}]."
        $stdout.puts "Please run bundle exec rails webpacker:install to install Webpacker"
        exit!
      end

      UNSUPPORTED_SWITCHES = %w[--host --port]
      private_constant :UNSUPPORTED_SWITCHES
      def detect_unsupported_switches!
        unsupported_switches = UNSUPPORTED_SWITCHES & @argv
        if unsupported_switches.any?
          $stdout.puts "The following CLI switches are not supported by Webpacker: #{unsupported_switches.join(' ')}. Please edit your command and try again."
          exit!
        end

        if @argv.include?("--https") && !@https
          $stdout.puts "Please set https: true in webpacker.yml to use the --https command line flag."
          exit!
        end
      end

      def detect_port!
        server = TCPServer.new(@hostname, @port)
        server.close

      rescue Errno::EADDRINUSE
        $stdout.puts "Another program is running on port #{@port}. Set a new port in #{@config.config_path} for dev_server"
        exit!
      end

      def execute_cmd
        env = Webpacker::Compiler.env
        env["WEBPACKER_CONFIG"] = @webpacker_config

        cmd = if node_modules_bin_exist?
          ["#{@node_modules_bin_path}/webpack", "serve"]
        else
          ["yarn", "webpack", "serve"]
        end

        if @argv.include?("--debug-webpacker")
          cmd = [ "node", "--inspect-brk"] + cmd
        end

        cmd += ["--config", @webpack_config]
        cmd += ["--progress", "--color"] if @pretty
        cmd += @argv

        Dir.chdir(@app_path) do
          Kernel.exec env, *cmd
        end
      end

      def node_modules_bin_exist?
        File.exist?("#{@node_modules_bin_path}/webpack-dev-server")
      end
  end
end