# encoding:utf-8
#--
# Copyright (C) 2005-2012 Bob Aman
#
#    Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.
#++


$:.unshift(File.dirname(__FILE__))

require 'uri'
require 'time'
require 'thread'
require 'digest/sha1'
require 'digest/md5'

require 'uuidtools/version'

begin
  require 'securerandom'
rescue LoadError
  require File.join(File.dirname(__FILE__), 'compat', 'securerandom')
end

module UUIDTools
  ##
  # UUIDTools was designed to be a simple library for generating any
  # of the various types of UUIDs.  It conforms to RFC 4122 whenever
  # possible.
  #
  # @example
  #   UUID.md5_create(UUID_DNS_NAMESPACE, "www.widgets.com")
  #   # => #<UUID:0x287576 UUID:3d813cbb-47fb-32ba-91df-831e1593ac29>
  #   UUID.sha1_create(UUID_DNS_NAMESPACE, "www.widgets.com")
  #   # => #<UUID:0x2a0116 UUID:21f7f8de-8051-5b89-8680-0195ef798b6a>
  #   UUID.timestamp_create
  #   # => #<UUID:0x2adfdc UUID:64a5189c-25b3-11da-a97b-00c04fd430c8>
  #   UUID.random_create
  #   # => #<UUID:0x19013a UUID:984265dc-4200-4f02-ae70-fe4f48964159>
  class UUID
    include Comparable

    ##
    # @api private
    @@last_timestamp = nil

    ##
    # @api private
    @@last_node_id = nil

    ##
    # @api private
    @@last_clock_sequence = nil

    ##
    # @api private
    @@state_file = nil

    ##
    # @api private
    @@mutex = Mutex.new

    ##
    # Creates a new UUID structure from its component values.
    # @see UUID.md5_create
    # @see UUID.sha1_create
    # @see UUID.timestamp_create
    # @see UUID.random_create
    # @api private
    def initialize(time_low, time_mid, time_hi_and_version,
        clock_seq_hi_and_reserved, clock_seq_low, nodes)
      unless time_low >= 0 && time_low < 4294967296
        raise ArgumentError,
          "Expected unsigned 32-bit number for time_low, got #{time_low}."
      end
      unless time_mid >= 0 && time_mid < 65536
        raise ArgumentError,
          "Expected unsigned 16-bit number for time_mid, got #{time_mid}."
      end
      unless time_hi_and_version >= 0 && time_hi_and_version < 65536
        raise ArgumentError,
          "Expected unsigned 16-bit number for time_hi_and_version, " +
          "got #{time_hi_and_version}."
      end
      unless clock_seq_hi_and_reserved >= 0 && clock_seq_hi_and_reserved < 256
        raise ArgumentError,
          "Expected unsigned 8-bit number for clock_seq_hi_and_reserved, " +
          "got #{clock_seq_hi_and_reserved}."
      end
      unless clock_seq_low >= 0 && clock_seq_low < 256
        raise ArgumentError,
          "Expected unsigned 8-bit number for clock_seq_low, " +
          "got #{clock_seq_low}."
      end
      unless nodes.kind_of?(Enumerable)
        raise TypeError,
          "Expected Enumerable, got #{nodes.class.name}."
      end
      unless nodes.size == 6
        raise ArgumentError,
          "Expected nodes to have size of 6."
      end
      for node in nodes
        unless node >= 0 && node < 256
          raise ArgumentError,
            "Expected unsigned 8-bit number for each node, " +
            "got #{node}."
        end
      end
      @time_low = time_low
      @time_mid = time_mid
      @time_hi_and_version = time_hi_and_version
      @clock_seq_hi_and_reserved = clock_seq_hi_and_reserved
      @clock_seq_low = clock_seq_low
      @nodes = nodes
    end

    ##
    # Returns the value of attribute `time_low`
    attr_accessor :time_low

    ##
    # Returns the value of attribute `time_mid`
    attr_accessor :time_mid

    ##
    # Returns the value of attribute `time_hi_and_version`
    attr_accessor :time_hi_and_version

    ##
    # Returns the value of attribute `clock_seq_hi_and_reserved`
    attr_accessor :clock_seq_hi_and_reserved

    ##
    # Returns the value of attribute `clock_seq_low`
    attr_accessor :clock_seq_low

    ##
    # Returns the value of attribute `nodes`
    attr_accessor :nodes

    ##
    # Parses a UUID from a string.
    def self.parse(uuid_string)
      unless uuid_string.kind_of? String
        raise TypeError,
          "Expected String, got #{uuid_string.class.name} instead."
      end
      uuid_components = uuid_string.downcase.scan(
        Regexp.new("^([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-" +
          "([0-9a-f]{2})([0-9a-f]{2})-([0-9a-f]{12})$")).first
      raise ArgumentError, "Invalid UUID format." if uuid_components.nil?
      time_low = uuid_components[0].to_i(16)
      time_mid = uuid_components[1].to_i(16)
      time_hi_and_version = uuid_components[2].to_i(16)
      clock_seq_hi_and_reserved = uuid_components[3].to_i(16)
      clock_seq_low = uuid_components[4].to_i(16)
      nodes = []
      for i in 0..5
        nodes << uuid_components[5][(i * 2)..(i * 2) + 1].to_i(16)
      end
      return self.new(time_low, time_mid, time_hi_and_version,
        clock_seq_hi_and_reserved, clock_seq_low, nodes)
    end

    ##
    # Parses a UUID from a raw byte string.
    def self.parse_raw(raw_string)
      unless raw_string.kind_of? String
        raise TypeError,
          "Expected String, got #{raw_string.class.name} instead."
      end
      integer = self.convert_byte_string_to_int(raw_string)

      time_low = (integer >> 96) & 0xFFFFFFFF
      time_mid = (integer >> 80) & 0xFFFF
      time_hi_and_version = (integer >> 64) & 0xFFFF
      clock_seq_hi_and_reserved = (integer >> 56) & 0xFF
      clock_seq_low = (integer >> 48) & 0xFF
      nodes = []
      for i in 0..5
        nodes << ((integer >> (40 - (i * 8))) & 0xFF)
      end
      return self.new(time_low, time_mid, time_hi_and_version,
        clock_seq_hi_and_reserved, clock_seq_low, nodes)
    end

    ##
    # Parses a UUID from an Integer.
    def self.parse_int(uuid_int)
      unless uuid_int.kind_of?(Integer)
        raise ArgumentError,
          "Expected Integer, got #{uuid_int.class.name} instead."
      end
      return self.parse_raw(self.convert_int_to_byte_string(uuid_int, 16))
    end

    ##
    # Parse a UUID from a hexdigest String.
    def self.parse_hexdigest(uuid_hexdigest)
      unless uuid_hexdigest.kind_of?(String)
        raise ArgumentError,
          "Expected String, got #{uuid_hexdigest.class.name} instead."
      end
      return self.parse_int(uuid_hexdigest.to_i(16))
    end

    ##
    # Creates a UUID from a random value.
    def self.random_create()
      new_uuid = self.parse_raw(SecureRandom.random_bytes(16))
      new_uuid.time_hi_and_version &= 0x0FFF
      new_uuid.time_hi_and_version |= (4 << 12)
      new_uuid.clock_seq_hi_and_reserved &= 0x3F
      new_uuid.clock_seq_hi_and_reserved |= 0x80
      return new_uuid
    end

    ##
    # Creates a UUID from a timestamp.
    def self.timestamp_create(timestamp=nil)
      # We need a lock here to prevent two threads from ever
      # getting the same timestamp.
      @@mutex.synchronize do
        # Always use GMT to generate UUIDs.
        if timestamp.nil?
          gmt_timestamp = Time.now.gmtime
        else
          gmt_timestamp = timestamp.gmtime
        end
        # Convert to 100 nanosecond blocks
        gmt_timestamp_100_nanoseconds = (gmt_timestamp.tv_sec * 10000000) +
          (gmt_timestamp.tv_usec * 10) + 0x01B21DD213814000
        mac_address = self.mac_address
        node_id = 0
        if mac_address != nil
          nodes = mac_address.split(":").collect do |octet|
            octet.to_i(16)
          end
        else
          nodes = SecureRandom.random_bytes(6).unpack("C*")
          nodes[0] |= 0b00000001
        end
        for i in 0..5
          node_id += (nodes[i] << (40 - (i * 8)))
        end
        clock_sequence = @@last_clock_sequence
        if clock_sequence.nil?
          clock_sequence = self.convert_byte_string_to_int(
            SecureRandom.random_bytes(16)
          )
        end
        if @@last_node_id != nil && @@last_node_id != node_id
          # The node id has changed.  Change the clock id.
          clock_sequence = self.convert_byte_string_to_int(
            SecureRandom.random_bytes(16)
          )
        elsif @@last_timestamp != nil &&
            gmt_timestamp_100_nanoseconds <= @@last_timestamp
          clock_sequence = clock_sequence + 1
        end
        @@last_timestamp = gmt_timestamp_100_nanoseconds
        @@last_node_id = node_id
        @@last_clock_sequence = clock_sequence

        time_low = gmt_timestamp_100_nanoseconds & 0xFFFFFFFF
        time_mid = ((gmt_timestamp_100_nanoseconds >> 32) & 0xFFFF)
        time_hi_and_version = ((gmt_timestamp_100_nanoseconds >> 48) & 0x0FFF)
        time_hi_and_version |= (1 << 12)
        clock_seq_low = clock_sequence & 0xFF;
        clock_seq_hi_and_reserved = (clock_sequence & 0x3F00) >> 8
        clock_seq_hi_and_reserved |= 0x80

        return self.new(time_low, time_mid, time_hi_and_version,
          clock_seq_hi_and_reserved, clock_seq_low, nodes)
      end
    end

    ##
    # Creates a UUID using the MD5 hash.  (Version 3)
    def self.md5_create(namespace, name)
      return self.create_from_hash(Digest::MD5, namespace, name)
    end

    ##
    # Creates a UUID using the SHA1 hash.  (Version 5)
    def self.sha1_create(namespace, name)
      return self.create_from_hash(Digest::SHA1, namespace, name)
    end

    ##
    # This method applies only to version 1 UUIDs.
    # Checks if the node ID was generated from a random number
    # or from an IEEE 802 address (MAC address).
    # Always returns false for UUIDs that aren't version 1.
    # This should not be confused with version 4 UUIDs where
    # more than just the node id is random.
    def random_node_id?
      return false if self.version != 1
      return ((self.nodes.first & 0x01) == 1)
    end

    ##
    # Returns true if this UUID is the
    # nil UUID (00000000-0000-0000-0000-000000000000).
    def nil_uuid?
      return false if self.time_low != 0
      return false if self.time_mid != 0
      return false if self.time_hi_and_version != 0
      return false if self.clock_seq_hi_and_reserved != 0
      return false if self.clock_seq_low != 0
      self.nodes.each do |node|
        return false if node != 0
      end
      return true
    end

    ##
    # Returns the UUID version type.
    # Possible values:
    # 1 - Time-based with unique or random host identifier
    # 2 - DCE Security version (with POSIX UIDs)
    # 3 - Name-based (MD5 hash)
    # 4 - Random
    # 5 - Name-based (SHA-1 hash)
    def version
      return (time_hi_and_version >> 12)
    end

    ##
    # Returns the UUID variant.
    # Possible values:
    # 0b000 - Reserved, NCS backward compatibility.
    # 0b100 - The variant specified in this document.
    # 0b110 - Reserved, Microsoft Corporation backward compatibility.