module Docopt

# File lib/docopt.rb, line 645
def docopt(doc, params={})
  default = {:version => nil, :argv => nil, :help => true, :options_first => false}
  params = default.merge(params)
  params[:argv] = ARGV if !params[:argv]

  Exit.set_usage(printable_usage(doc))
  options = parse_defaults(doc)
  pattern = parse_pattern(formal_usage(Exit.usage), options)
  argv = parse_argv(TokenStream.new(params[:argv], Exit), options, params[:options_first])
  pattern_options = pattern.flat(Option).uniq
  pattern.flat(AnyOptions).each do |ao|
    doc_options = parse_defaults(doc)
    ao.children = doc_options.reject { |o| pattern_options.include?(o) }.uniq
  end
  extras(params[:help], params[:version], argv, doc)

  matched, left, collected = pattern.fix().match(argv)
  collected ||= []

  if matched and (left.count == 0)
    return Hash[(pattern.flat + collected).map { |a| [a.name, a.value] }]
  end
  raise Exit
end

# File lib/docopt.rb, line 607
def dump_patterns(pattern, indent=0)
  ws = " " * 4 * indent
  out = ""
  if pattern.class == Array
    if pattern.count > 0
      out << ws << "[\n"
      for p in pattern
        out << dump_patterns(p, indent+1).rstrip << "\n"
      end
      out << ws << "]\n"
    else
      out << ws << "[]\n"
    end

  elsif pattern.class.ancestors.include?(ParentPattern)
    out << ws << pattern.class.name << "(\n"
    for p in pattern.children
      out << dump_patterns(p, indent+1).rstrip << "\n"
    end
    out << ws << ")\n"

  else
    out << ws << pattern.inspect
  end
  return out
end

# File lib/docopt.rb, line 634
def extras(help, version, options, doc)
  if help and options.any? { |o| ['-h', '--help'].include?(o.name) && o.value }
    Exit.set_usage(nil)
    raise Exit, doc.strip
  end
  if version and options.any? { |o| o.name == '--version' && o.value }
    Exit.set_usage(nil)
    raise Exit, version
  end
end

# File lib/docopt.rb, line 592
def formal_usage(printable_usage)
  pu = printable_usage.split().drop(1)  # split and drop "usage:"

  ret = []
  for s in pu.drop(1)
    if s == pu[0]
      ret << ') | ('
    else
      ret << s
    end
  end

  return '( ' + ret.join(' ') + ' )'
end

# File lib/docopt.rb, line 557
def parse_argv(tokens, options, options_first=false)
  parsed = []
  while tokens.current() != nil
    if tokens.current() == '--'
      return parsed + tokens.map { |v| Argument.new(nil, v) }
    elsif tokens.current().start_with?('--')
      parsed += parse_long(tokens, options)
    elsif tokens.current().start_with?('-') and tokens.current() != '-'
      parsed += parse_shorts(tokens, options)
    elsif options_first
      return parsed + tokens.map { |v| Argument.new(nil, v) }
    else
      parsed << Argument.new(nil, tokens.move())
    end
  end
  return parsed
end

# File lib/docopt.rb, line 525
def parse_atom(tokens, options)
  token = tokens.current()
  result = []

  if ['(' , '['].include? token
    tokens.move()
    if token == '('
      matching = ')'
      pattern = Required
    else
      matching = ']'
      pattern = Optional
    end
    result = pattern.new(*parse_expr(tokens, options))
    if tokens.move() != matching
      raise tokens.error, "unmatched '#{token}'"
    end
    return [result]
  elsif token == 'options'
    tokens.move()
    return [AnyOptions.new]
  elsif token.start_with?('--') and token != '--'
    return parse_long(tokens, options)
  elsif token.start_with?('-') and not ['-', '--'].include? token
    return parse_shorts(tokens, options)
  elsif token.start_with?('<') and token.end_with?('>') or (token.upcase == token && token.match(/[A-Z]/))
    return [Argument.new(tokens.move())]
  else
    return [Command.new(tokens.move())]
  end
end

# File lib/docopt.rb, line 575
def parse_defaults(doc)
  split = doc.split(/^ *(<\S+?>|-\S+?)/).drop(1)
  split = split.each_slice(2).reject { |pair| pair.count != 2 }.map { |s1, s2| s1 + s2 }
  split.select { |s| s.start_with?('-') }.map { |s| Option.parse(s) }
end

# File lib/docopt.rb, line 496
def parse_expr(tokens, options)
  seq = parse_seq(tokens, options)
  if tokens.current() != '|'
    return seq
  end
  result = seq.count > 1 ? [Required.new(*seq)] : seq

  while tokens.current() == '|'
    tokens.move()
    seq = parse_seq(tokens, options)
    result += seq.count > 1 ? [Required.new(*seq)] : seq
  end
  return result.count > 1 ? [Either.new(*result)] : result
end

# File lib/docopt.rb, line 397
def parse_long(tokens, options)
  long, eq, value = tokens.move().partition('=')
  unless long.start_with?('--')
    raise RuntimeError
  end
  value = (eq == value and eq == '') ? nil : value

  similar = options.select { |o| o.long and o.long == long }

  if tokens.error == Exit and similar == []
    similar = options.select { |o| o.long and o.long.start_with?(long) }
  end

  if similar.count > 1
    ostr = similar.map { |o| o.long }.join(', ')
    raise tokens.error, "#{long} is not a unique prefix: #{ostr}?"
  elsif similar.count < 1
    argcount = (eq == '=' ? 1 : 0)
    o = Option.new(nil, long, argcount)
    options << o
    if tokens.error == Exit
      o = Option.new(nil, long, argcount, (argcount == 1 ? value : true))
    end
  else
    s0 = similar[0]
    o = Option.new(s0.short, s0.long, s0.argcount, s0.value)
    if o.argcount == 0
      if !value.nil?
        raise tokens.error, "#{o.long} must not have an argument"
      end
    else
      if value.nil?
        if tokens.current().nil?
          raise tokens.error, "#{o.long} requires argument"
        end
        value = tokens.move()
      end
    end
    if tokens.error == Exit
      o.value = (!value.nil? ? value : true)
    end
  end
  return [o]
end

# File lib/docopt.rb, line 485
def parse_pattern(source, options)
  tokens = TokenStream.new(source.gsub(/([\[\]\(\)\|]|\.\.\.)/, ' \1 '), DocoptLanguageError)

  result = parse_expr(tokens, options)
  if tokens.current() != nil
    raise tokens.error, "unexpected ending: #{tokens.join(" ")}"
  end
  return Required.new(*result)
end

# File lib/docopt.rb, line 511
def parse_seq(tokens, options)
  result = []
  stop = [nil, ']', ')', '|']
  while !stop.include?(tokens.current)
    atom = parse_atom(tokens, options)
    if tokens.current() == '...'
      atom = [OneOrMore.new(*atom)]
      tokens.move()
    end
    result += atom
  end
  return result
end

# File lib/docopt.rb, line 442
def parse_shorts(tokens, options)
  token = tokens.move()
  unless token.start_with?('-') && !token.start_with?('--')
    raise RuntimeError
  end
  left = token[1..-1]
  parsed = []
  while left != ''
    short, left = '-' + left[0], left[1..-1]
    similar = options.select { |o| o.short == short }
    if similar.count > 1
      raise tokens.error, "#{short} is specified ambiguously #{similar.count} times"
    elsif similar.count < 1
      o = Option.new(short, nil, 0)
      options << o
      if tokens.error == Exit
        o = Option.new(short, nil, 0, true)
      end
    else
      s0 = similar[0]
      o = Option.new(short, s0.long, s0.argcount, s0.value)
      value = nil
      if o.argcount != 0
        if left == ''
          if tokens.current().nil?
            raise tokens.error, "#{short} requires argument"
          end
          value = tokens.move()
        else
          value = left
          left = ''
        end
      end
      if tokens.error == Exit
        o.value = (!value.nil? ? value : true)
      end
    end
    parsed << o
  end
  return parsed
end

# File lib/docopt.rb, line 581
def printable_usage(doc)
  usage_split = doc.split(/([Uu][Ss][Aa][Gg][Ee]:)/)
  if usage_split.count < 3
    raise DocoptLanguageError, '"usage:" (case-insensitive) not found.'
  end
  if usage_split.count > 3
    raise DocoptLanguageError, 'More than one "usage:" (case-insensitive).'
  end
  return usage_split.drop(1).join().split(/\n\s*\n/)[0].strip
end