class Getopt
  @HAS_ARGUMENT = true
  @NO_ARGUMENT = false
  @MULTI_SUPPORTED = true
  @SINGLE_ONLY = false
  @VERSION = '0.3.1'

  # public
  constructor: (@optionsPattern) ->
    @short_options = {}
    @long_options  = {}
    @long_names = []
    @events = {}
    @argv = []
    @options = {}
    @errorFunc = (e) ->
      console.info(e.message)
      process.exit(1)


    if process.argv[1]
      @help = "Usage: node #{process.argv[1].match(/(?:.*[\/\\])?(.*)$/)[1]}\n\n[[OPTIONS]]\n"
    else
      @help = "[[OPTIONS]]"

    names = {}
    for option in @optionsPattern
      [short_name, definition, comment, def] = option

      comment    ?= ''
      definition ?= ''
      short_name ?= ''

      definition =~ /^([\w\-]*)/
      long_name = \1
      has_argument    = definition.indexOf('=') != -1
      multi_supported = definition.indexOf('+') != -1
      optional        = /\[=.*?\]/.test(definition)

      long_name  = long_name.trim()
      short_name = short_name.trim()

      if optional && short_name
        throw new Error('optional argument can only work with long option');

      long_name ||= short_name

      fixed_long_name = 'opt_' + long_name
      name = long_name

      if long_name == ''
        throw new Error("empty option found. the last option name is #{@long_names.slice(-1)}");

      unless names[fixed_long_name]?
        @long_names.push long_name
        @long_options[long_name] = {name, short_name, long_name, has_argument, multi_supported, comment, optional, definition, def}
        names[fixed_long_name] = true
      else
        throw new Error("option #{long_name} is redefined.");

      if short_name != ''
        if short_name.length != 1
          throw new Error 'short option must be single characters'
        @short_options[short_name] = @long_options[long_name]
    @

  getOptionByName: (name) ->
    @long_options[name] ? @short_options[name]

  getOptionName: (name) ->
    @getOptionByName(name)?.name

  # Events
  on: (name, cb) ->
    if name
      iname = @getOptionName(name)
      unless iname
        throw new Error "unknown option #{name}"
    else
      iname = name
    @events[iname] = cb
    @

  emit: (name, value) ->
    event = @events[@getOptionName(name)]
    if event
      event.call @, value
    else
      throw new Error("Getopt event on '#{name}' is not found")

  # Command line parser
  save_option_: (options, option, argv) ->
    if option.has_argument
      if argv.length == 0
        throw new Error("option #{option.long_name} need argument")
      value = argv.shift()
    else
      value = true

    name = option.name
    if option.multi_supported
      options[name] ?= []
      options[name].push value
    else
      options[name] = value
    @events[name]?.call @, value
    @

  parse: (argv) ->
    try
      # clone argv
      argv = argv[0..]
      rt_options = {}
      rt_argv = []
      for long_name in @long_names
        option = @long_options[long_name]
        # set all proto keys eg: constructor toString to undefined
        if option.def? || rt_options[option.long_name]?
          rt_options[option.long_name] = option.def
      while (arg = argv.shift())?
        if arg =~ /^-(\w[\w\-]*)/
          # short option
          short_names = \1
          for short_name, i in short_names
            option = @short_options[short_name]
            unless option
              throw new Error("invalid option #{short_name}")

            if option.has_argument
              if i < arg.length - 2
                argv.unshift arg.slice(i+2)
              @save_option_(rt_options, option, argv)
              break
            else
              @save_option_(rt_options, option, argv)

        else if arg =~ /^--(\w[\w\-]*)((?:=[^]*)?)$/
          # long option
          long_name = \1
          value     = \2
          # value     = arg.substring(long_name.length+2)
          option = @long_options[long_name]
          unless option
            throw new Error("invalid option #{long_name}")

          if value != ''
            value = value[1..]
            argv.unshift(value)
          else if option.optional
            argv.unshift('')

          @save_option_(rt_options, option, argv)

        else if arg == '--'
          rt_argv = rt_argv.concat(argv)
          for arg in argv
            @events['']?.call @, arg
          break

        else
          rt_argv.push arg
          @events['']?.call @, arg
      # assign to short name
      for name in Object.keys(rt_options)
        sname = @long_options[name].short_name
        if sname != ''
          rt_options[sname] = rt_options[name]
    catch e
      @errorFunc(e)

    @argv = rt_argv
    @options = rt_options
    @

  parse_system: ->
    @parseSystem()

  parseSystem: ->
    @parse(process.argv.slice(2))

  # Help Controller
  setHelp: (@help) ->
    @

  sort: ->
    @long_names.sort (a, b) ->
      a > b && 1 || a < b && -1 || 0

  getHelp: ->
    ws = []
    options = []
    table = []

    for long_name in @long_names
      tr = []
      option = @long_options[long_name]
      {short_name, long_name, comment, definition, def} = option
      tr.push(
        if short_name
          if short_name == long_name
            # only has short name
            " -#{short_name}"
          else
            # both has short name and long name
            " -#{short_name}, --#{definition}"
        else
            # only has long name
            "     --#{definition}"
      )
      tr.push " " + comment
      if def
        tr.push " (default: #{def})"
      table.push tr
    for tr in table
      for td, i in tr
        ws[i] ?= 0
        ws[i] = Math.max(ws[i], td.length)

    lines = for tr in table
      line = ''
      for td, i in tr
        if i
          n = ws[i-1] - tr[i-1].length
          while n--
            line += ' '
        line += td
      line.trimRight()

    @help.replace('[[OPTIONS]]', lines.join("\n"))

  showHelp: ->
    console.info @getHelp()
    @

  bindHelp: (help) ->
    if help
      @setHelp help
    @on 'help', ->
      @showHelp()
      process.exit(0)
    @

  getVersion: ->
    Getopt.VERSION

  error: (@errorFunc) ->
    @

  @getVersion: ->
    @VERSION

  # For oneline creator
  @create: (options) ->
    new Getopt(options)

module.exports = Getopt

# vim: sw=2 ts=2 sts=2 expandtab :