require 'test/unit'

require 'bit_struct/struct_base'

include BitStruct



class Flags < StructBase
  unsigned :direction, 4
  unsigned :multiplier, 2
  unsigned :offset, 2
end

class Entry < StructBase
  unsigned :offset, 4
  nested   :flags, Flags
  unsigned :address, 24
  unsigned :cache_id, 16
end

class TestBitStruct < Test::Unit::TestCase

  def test_flags_class
    fields = Flags.fields
    assert_equal 3, fields.size

    assert_equal :direction, fields[ 0 ].name
    assert_equal 4, fields[ 0 ].length
    assert_equal :multiplier, fields[ 1 ].name
    assert_equal 2, fields[ 1 ].length
    assert_equal :offset, fields[ 2 ].name
    assert_equal 2, fields[ 2 ].length
  end

  def test_attributes_class
    fields = Entry.fields
    assert_equal 4, fields.size

    assert_equal :offset, fields[ 0 ].name
    assert_equal 4, fields[ 0 ].length
    assert_equal :flags, fields[ 1 ].name
    assert_equal 8, fields[ 1 ].length
    assert_equal :address, fields[ 2 ].name
    assert_equal 24, fields[ 2 ].length
    assert_equal :cache_id, fields[ 3 ].name
    assert_equal 16, fields[ 3 ].length
  end

  def test_flags_read
    flags = Flags.new [ 0xFF ].pack( 'C*' )
    assert_equal 0x0F, flags.direction
    assert_equal 0x03, flags.multiplier
    assert_equal 0x03, flags.offset

    flags = Flags.new [ 0x0F ].pack( 'C*' )
    assert_equal 0x0F, flags.direction
    assert_equal 0x00, flags.multiplier
    assert_equal 0x00, flags.offset

    flags = Flags.new [ 0x3F ].pack( 'C*' )
    assert_equal 0x0F, flags.direction
    assert_equal 0x03, flags.multiplier
    assert_equal 0x00, flags.offset

    flags = Flags.new [ 0xCF ].pack( 'C*' )
    assert_equal 0x0F, flags.direction
    assert_equal 0x00, flags.multiplier
    assert_equal 0x03, flags.offset
  end

  def test_flags_write
    data = [ 0xFF ].pack( 'C*' )

    flags = Flags.new data
    assert_equal '0xff', flags.data.hexify
    assert_equal 0x0F, flags.direction
    assert_equal 0x03, flags.multiplier
    assert_equal 0x03, flags.offset

    flags.multiplier = 0
    assert_equal '0xcf', flags.data.hexify
    assert_equal 0x0F, flags.direction
    assert_equal 0x00, flags.multiplier
    assert_equal 0x03, flags.offset
  end

  def test_entry_read
    data = [ 0xAA, 0xFF, 0x01, 0x23, 0x45, 0x67, 0x89 ].pack( 'C*' )
    entry = Entry.new data

    assert_equal 9, entry.offset
    assert_equal '0x12 0x34 0x56', entry.address.bytes.hexify
    assert_equal '0xaf 0xf0', entry.cache_id.bytes.hexify

    flags = entry.flags
    assert_equal 8, flags.direction
    assert_equal 3, flags.multiplier
    assert_equal 1, flags.offset
  end

  def test_attributes_write
    data = [ 0xAA, 0xFF, 0x01, 0x23, 0x45, 0x67, 0x89 ].pack( 'C*' )
    entry = Entry.new data

    entry.offset = 15
    assert_equal '0x0f', entry.offset.bytes.hexify
    assert_equal '0xaa 0xff 0x01 0x23 0x45 0x67 0x8f', entry.data.hexify

    entry.address = 0x44332211
    assert_equal '0x33 0x22 0x11', entry.address.bytes.hexify
    assert_equal '0xaa 0xff 0x03 0x32 0x21 0x17 0x8f', entry.data.hexify

    entry.cache_id = 0xAABBCCDD
    assert_equal '0xcc 0xdd', entry.cache_id.bytes.hexify
    assert_equal '0xac 0xcd 0xd3 0x32 0x21 0x17 0x8f', entry.data.hexify

    flags = entry.flags
    assert_equal 8, flags.direction
    assert_equal 3, flags.multiplier
    assert_equal 1, flags.offset
  end

end