require 'ggem/version'
require 'ggem/cli/clirb'
require 'ggem/cli/commands'

module GGem

  class CLI

    COMMANDS = CommandSet.new{ |unknown| InvalidCommand.new(unknown) }.tap do |c|
      c.add(GenerateCommand, 'generate', 'g')
      c.add(BuildCommand,    'build',    'b')
      c.add(InstallCommand,  'install',  'i')
      c.add(PushCommand,     'push',     'p')
      c.add(TagCommand,      'tag',      't')
      c.add(ReleaseCommand,  'release',  'r')
    end

    def self.run(args)
      self.new.run(args)
    end

    def initialize(kernel = nil, stdout = nil, stderr = nil)
      @kernel = kernel || Kernel
      @stdout = stdout || $stdout
      @stderr = stderr || $stderr
    end

    def run(args)
      begin
        cmd_name = args.shift
        cmd = COMMANDS[cmd_name]
        cmd.run(args)
      rescue CLIRB::HelpExit
        @stdout.puts cmd.help
      rescue CLIRB::VersionExit
        @stdout.puts GGem::VERSION
      rescue CLIRB::Error, ArgumentError, InvalidCommandError => exception
        display_debug(exception)
        @stderr.puts "#{exception.message}\n\n"
        @stdout.puts cmd.help
        @kernel.exit 1
      rescue CommandExitError
        @kernel.exit 1
      rescue StandardError => exception
        @stderr.puts "#{exception.class}: #{exception.message}"
        @stderr.puts exception.backtrace.join("\n")
        @kernel.exit 1
      end
      @kernel.exit 0
    end

    private

    def display_debug(exception)
      if ENV['DEBUG']
        @stderr.puts "#{exception.class}: #{exception.message}"
        @stderr.puts exception.backtrace.join("\n")
      end
    end

  end

end