# -*- encoding: utf-8 -*-

require 'socket'
require 'timeout'
require 'io/wait'
require 'digest/sha1'

module Stomp

  class Connection

    private

    # Ref:
    # http://unicode.org/mail-arch/unicode-ml/y2003-m02/att-0467/01-The_Algorithm_to_Valide_an_UTF-8_String
    #
    # *CONSIDER* replacing this with a dependency on the utf8_validator gem.
    # This code has been copied from there.
    #
    def _valid_utf8?(string)
      case RUBY_VERSION
      when /1\.8\.[56]/
        bytes = []
        0.upto(string.length-1) {|i|
          bytes << string[i]
        }
      else
        bytes = string.bytes
      end

      #
      valid = true
      index = -1
      state = "start"
      #
      bytes.each do |next_byte|
        index += 1
        case state

          # State: 'start'
          # The 'start' state:
          # * handles all occurrences of valid single byte characters i.e., the ASCII character set
          # * provides state transition logic for start bytes of valid characters with 2-4 bytes
          # * signals a validation failure for all other single bytes
          #
        when "start"
          # puts "state: start" if DEBUG
          case next_byte

            # ASCII
            # * Input = 0x00-0x7F : change state to START
          when (0x00..0x7f)
            # puts "state: start 1" if DEBUG
            state = "start"

            # Start byte of two byte characters
            # * Input = 0xC2-0xDF: change state to A
          when (0xc2..0xdf)
            # puts "state: start 2" if DEBUG
            state = "a"

            # Start byte of some three byte characters
            # * Input = 0xE1-0xEC, 0xEE-0xEF: change state to B
          when (0xe1..0xec)
            # puts "state: start 3" if DEBUG
            state = "b"
          when (0xee..0xef)
            # puts "state: start 4" if DEBUG
            state = "b"

            # Start byte of special three byte characters
            # * Input = 0xE0: change state to C
          when 0xe0
            # puts "state: start 5" if DEBUG
            state = "c"

            # Start byte of the remaining three byte characters
            # * Input = 0xED: change state to D
          when 0xed
            # puts "state: start 6" if DEBUG
            state = "d"

            # Start byte of some four byte characters
            # * Input = 0xF1-0xF3:change state to E
          when (0xf1..0xf3)
            # puts "state: start 7" if DEBUG
            state = "e"

            # Start byte of special four byte characters
            # * Input = 0xF0: change state to F
          when 0xf0
            # puts "state: start 8" if DEBUG
            state = "f"

            # Start byte of very special four byte characters
            # * Input = 0xF4: change state to G
          when 0xf4
            # puts "state: start 9" if DEBUG
            state = "g"

            # All other single characters are invalid
            # * Input = Others (0x80-0xBF,0xC0-0xC1, 0xF5-0xFF): ERROR
          else
            valid = false
            break
          end # of the inner case, the 'start' state

          # The last continuation byte of a 2, 3, or 4 byte character
          # State: 'a'
          #  o Input = 0x80-0xBF: change state to START
          #  o Others: ERROR
        when "a"
          # puts "state: a" if DEBUG
          if (0x80..0xbf) === next_byte
            state = "start"
          else
            valid = false
            break
          end

          # The first continuation byte for most 3 byte characters
          # (those with start bytes in: 0xe1-0xec or 0xee-0xef)
          # State: 'b'
          # o Input = 0x80-0xBF: change state to A
          # o Others: ERROR
        when "b"
          # puts "state: b" if DEBUG
          if (0x80..0xbf) === next_byte
            state = "a"
          else
            valid = false
            break
          end

          # The first continuation byte for some special 3 byte characters
          # (those with start byte 0xe0)
          # State: 'c'
          # o Input = 0xA0-0xBF: change state to A
          # o Others: ERROR
        when "c"
          # puts "state: c" if DEBUG
          if (0xa0..0xbf) === next_byte
            state = "a"
          else
            valid = false
            break
          end

          # The first continuation byte for the remaining 3 byte characters
          # (those with start byte 0xed)
          # State: 'd'
          # o Input = 0x80-0x9F: change state to A
          # o Others: ERROR
        when "d"
          # puts "state: d" if DEBUG
          if (0x80..0x9f) === next_byte
            state = "a"
          else
            valid = false
            break
          end

          # The first continuation byte for some 4 byte characters
          # (those with start bytes in: 0xf1-0xf3)
          # State: 'e'
          # o Input = 0x80-0xBF: change state to B
          # o Others: ERROR
        when "e"
          # puts "state: e" if DEBUG
          if (0x80..0xbf) === next_byte
            state = "b"
          else
            valid = false
            break
          end

          # The first continuation byte for some special 4 byte characters
          # (those with start byte 0xf0)
          # State: 'f'
          # o Input = 0x90-0xBF: change state to B
          # o Others: ERROR
        when "f"
          # puts "state: f" if DEBUG
          if (0x90..0xbf) === next_byte
            state = "b"
          else
            valid = false
            break
          end

          # The first continuation byte for the remaining 4 byte characters
          # (those with start byte 0xf4)
          # State: 'g'
          # o Input = 0x80-0x8F: change state to B
          # o Others: ERROR
        when "g"
          # puts "state: g" if DEBUG
          if (0x80..0x8f) === next_byte
            state = "b"
          else
            valid = false
            break
          end

          #
        else
          raise RuntimeError, "state: default"
        end
      end
      #
      # puts "State at end: #{state}" if DEBUG
      # Catch truncation at end of string
      if valid and state != 'start'
        # puts "Resetting valid value" if DEBUG
        valid = false
      end
      #
      valid
    end # of _valid_utf8?

    # Stomp 1.1+ header check for UTF8 validity. Raises Stomp::Error::UTF8ValidationError if header data is not valid UTF8.
    def _headerCheck(h)
      return if @protocol == Stomp::SPL_10 # Do nothing for this environment
      #
      h.each_pair do |k,v|
        # Keys here are symbolized
        ks = k.to_s
        ks.force_encoding(Stomp::UTF8) if ks.respond_to?(:force_encoding)
        raise Stomp::Error::UTF8ValidationError unless valid_utf8?(ks)
        #
        if v.is_a?(Array)
          v.each do |e|
            e.force_encoding(Stomp::UTF8) if e.respond_to?(:force_encoding)
            raise Stomp::Error::UTF8ValidationError unless valid_utf8?(e)
          end
        else
          vs = v.to_s + "" # Values are usually Strings, but could be TrueClass or Symbol
          # The + "" above forces an 'unfreeze' if necessary
          vs.force_encoding(Stomp::UTF8) if vs.respond_to?(:force_encoding)
          raise Stomp::Error::UTF8ValidationError unless valid_utf8?(vs)
        end
      end
    end

    # encode returns a Hash of encoded headers per the Stomp 1.1 specification.
    def _encodeHeaders(h)
      eh = {}
      h.each_pair do |k,v|
        # Keys are symbolized
        ks = k.to_s
        if v.is_a?(Array)
          kenc = Stomp::HeaderCodec::encode(ks)
          eh[kenc] = []
          v.each do |e|
            eh[kenc] << Stomp::HeaderCodec::encode(e)
          end
        else
          vs = v.to_s
          eh[Stomp::HeaderCodec::encode(ks).to_sym] = Stomp::HeaderCodec::encode(vs)
        end
      end
      eh
    end

    # decode returns a Hash of decoded headers per the Stomp 1.1 specification.
    def _decodeHeaders(h)
      dh = {}
      h.each_pair do |k,v|
        # Keys here are NOT! symbolized
        if v.is_a?(Array)
          kdec = Stomp::HeaderCodec::decode(k)
          dh[kdec] = []
          v.each do |e|
            dh[kdec] << Stomp::HeaderCodec::decode(e)
          end
        else
          vs = v.to_s
          dh[Stomp::HeaderCodec::decode(k)] = Stomp::HeaderCodec::decode(vs)
        end
      end
      dh
    end

  end # class Connection

end # module Stomp