require 'twiddler/config'

module Twiddler
  class Parser
    def self.parse(data)
      version = *data.unpack("c")
      case version
      when 4
        V4Parser.new(data, 1).go.parsed
      end
    end

    class V4Parser
      def initialize(raw, skipped = 0)
        @data = raw
        @refs = Hash.new{|h,k| h[k] = [:missing_ref]}
        bytes_hex
        @index = 0
        consume("x" * skipped)
        bytes_hex
        @config = Config.new()
      end

      def parsed
        return @config
      end

      def consume(template)
        old_len = @data.length
        values = @data.unpack(template + "a*")
        @data = values.pop
        @index += old_len - @data.length
        return values
      end

      def bytes_hex(count = 8)
        "0x%04x:#{' %02x'*count}" % ([@index] + @data.unpack("c" * count))
      end

      def go()
        total_size = @data.length + 1
        @keyboard_chord_table, @mouse_chord_table, @multichar_table = *consume("vvv")

        @config.configs[:raw] = *consume("a#{@keyboard_chord_table - @index}")

        until @index >= @mouse_chord_table
          key1234, mod_or_ff, keyindex = consume("B16B8c")
          exit if @index > 685 
          if keyindex == 0 and 
            key1234 == "0000000000000000" and 
            mod_or_ff == "00000000"
            next
          end

          chord = Config::KeyChord.new
          chord.keydata = key1234

          if(mod_or_ff == "11111111")
            @refs[keyindex] = chord
          else
            chord.add_keystroke(mod_or_ff, keyindex)
          end

          @config.keyboard << chord
        end

        while @index < @multichar_table
          key1234, data = consume("B16B8")
          if key1234 == "0000000000000000" and 
            data == "00000000"
            next
          end

          chord_record = Config::MouseChord.new
          chord_record.keydata = key1234
          chord_record.data = data
          @config.mouse << chord_record
        end

        data_idx = 0
        until @data.size == 0 do
          data_size = *consume("v")

          chord_data = []
          ((data_size-1)/2).times do 
            mod, idx = *consume("B8c")
            next if idx == 0 #Not sure this is sufficient
            @refs[data_idx].add_keystroke(mod, idx)
          end
          data_idx += 1
        end

        return self
      end
    end
  end
end