class Thor
  class Options < Arguments #:nodoc:
    LONG_RE     = /^(--\w+(?:-\w+)*)$/
    SHORT_RE    = /^(-[a-z])$/i
    EQ_RE       = /^(--\w+(?:-\w+)*|-[a-z])=(.*)$/i
    SHORT_SQ_RE = /^-([a-z]{2,})$/i # Allow either -x -v or -xv style for single char args
    SHORT_NUM   = /^(-[a-z])#{NUMERIC}$/i
    OPTS_END    = '--'.freeze

    # Receives a hash and makes it switches.
    def self.to_switches(options)
      options.map do |key, value|
        case value
        when true
          "--#{key}"
        when Array
          "--#{key} #{value.map{ |v| v.inspect }.join(' ')}"
        when Hash
          "--#{key} #{value.map{ |k,v| "#{k}:#{v}" }.join(' ')}"
        when nil, false
          ""
        else
          "--#{key} #{value.inspect}"
        end
      end.join(" ")
    end

    # Takes a hash of Thor::Option and a hash with defaults.
    #
    # If +stop_on_unknown+ is true, #parse will stop as soon as it encounters
    # an unknown option or a regular argument.
    def initialize(hash_options={}, defaults={}, stop_on_unknown=false)
      @stop_on_unknown = stop_on_unknown
      options = hash_options.values
      super(options)

      # Add defaults
      defaults.each do |key, value|
        @assigns[key.to_s] = value
        @non_assigned_required.delete(hash_options[key])
      end

      @shorts, @switches, @extra = {}, {}, []

      options.each do |option|
        @switches[option.switch_name] = option

        option.aliases.each do |short|
          name = short.to_s.sub(/^(?!\-)/, '-')
          @shorts[name] ||= option.switch_name
        end
      end
    end

    def remaining
      @extra
    end

    def peek
      return super unless @parsing_options

      result = super
      if result == OPTS_END
        shift
        @parsing_options = false
        super
      else
        result
      end
    end

    def parse(args)
      @pile = args.dup
      @parsing_options = true

      while peek
        if parsing_options?
          match, is_switch = current_is_switch?
          shifted = shift

          if is_switch
            case shifted
            when SHORT_SQ_RE
              unshift($1.split('').map { |f| "-#{f}" })
              next
            when EQ_RE, SHORT_NUM
              unshift($2)
              switch = $1
            when LONG_RE, SHORT_RE
              switch = $1
            end

            switch = normalize_switch(switch)
            option = switch_option(switch)
            @assigns[option.human_name] = parse_peek(switch, option)
          elsif @stop_on_unknown
            @parsing_options = false
            @extra << shifted
            @extra << shift while peek
            break
          elsif match
            @extra << shifted
            @extra << shift while peek && peek !~ /^-/
          else
            @extra << shifted
          end
        else
          @extra << shift
        end
      end

      check_requirement!

      assigns = Thor::CoreExt::HashWithIndifferentAccess.new(@assigns)
      assigns.freeze
      assigns
    end

    def check_unknown!
      # an unknown option starts with - or -- and has no more --'s afterward.
      unknown = @extra.select { |str| str =~ /^--?(?:(?!--).)*$/ }
      raise UnknownArgumentError, "Unknown switches '#{unknown.join(', ')}'" unless unknown.empty?
    end

    protected

      # Check if the current value in peek is a registered switch.
      #
      # Two booleans are returned.  The first is true if the current value
      # starts with a hyphen; the second is true if it is a registered switch.
      def current_is_switch?
        case peek
        when LONG_RE, SHORT_RE, EQ_RE, SHORT_NUM
          [true, switch?($1)]
        when SHORT_SQ_RE
          [true, $1.split('').any? { |f| switch?("-#{f}") }]
        else
          [false, false]
        end
      end

      def current_is_switch_formatted?
        case peek
        when LONG_RE, SHORT_RE, EQ_RE, SHORT_NUM, SHORT_SQ_RE
          true
        else
          false
        end
      end

      def current_is_value?
        peek && (!parsing_options? || super)
      end

      def switch?(arg)
        switch_option(normalize_switch(arg))
      end

      def switch_option(arg)
        if match = no_or_skip?(arg)
          @switches[arg] || @switches["--#{match}"]
        else
          @switches[arg]
        end
      end

      # Check if the given argument is actually a shortcut.
      #
      def normalize_switch(arg)
        (@shorts[arg] || arg).tr('_', '-')
      end

      def parsing_options?
        peek
        @parsing_options
      end

      # Parse boolean values which can be given as --foo=true, --foo or --no-foo.
      #
      def parse_boolean(switch)
        if current_is_value?
          if ["true", "TRUE", "t", "T", true].include?(peek)
            shift
            true
          elsif ["false", "FALSE", "f", "F", false].include?(peek)
            shift
            false
          else
            true
          end
        else
          @switches.key?(switch) || !no_or_skip?(switch)
        end
      end

      # Parse the value at the peek analyzing if it requires an input or not.
      #
      def parse_peek(switch, option)
        if parsing_options? && (current_is_switch_formatted? || last?)
          if option.boolean?
            # No problem for boolean types
          elsif no_or_skip?(switch)
            return nil # User set value to nil
          elsif option.string? && !option.required?
            # Return the default if there is one, else the human name
            return option.lazy_default || option.default || option.human_name
          elsif option.lazy_default
            return option.lazy_default
          else
            raise MalformattedArgumentError, "No value provided for option '#{switch}'"
          end
        end

        @non_assigned_required.delete(option)
        send(:"parse_#{option.type}", switch)
      end
  end
end
