import unittest
from bitstruct import *


class BitStructTest(unittest.TestCase):

    def test_pack(self):
        """Pack values.

        """

        packed = pack('u1u1s6u7u9', 0, 0, -2, 65, 22)
        self.assertEqual(packed, b'\x3e\x82\x16')

        packed = pack('u1', 1)
        self.assertEqual(packed, b'\x80')

        packed = pack('u77', 0x100000000001000000)
        ref = b'\x00\x80\x00\x00\x00\x00\x08\x00\x00\x00'
        self.assertEqual(packed, ref)

        packed = pack('p1u1s6u7u9', 0, -2, 65, 22)
        self.assertEqual(packed, b'\x3e\x82\x16')

        packed = pack('p1u1s6p7u9', 0, -2, 22)
        self.assertEqual(packed, b'\x3e\x00\x16')

        packed = pack('u1s6f32r43', 0, -2, 3.75, b'\x00\xff\x00\xff\x00\xff')
        self.assertEqual(packed, b'\x7c\x80\xe0\x00\x00\x01\xfe\x01\xfe\x01\xc0')

        packed = pack('b1', True)
        self.assertEqual(packed, b'\x80')

        packed = pack('b1p6b1', True, True)
        self.assertEqual(packed, b'\x81')

        packed = pack('u5b2u1', -1, False, 1)
        self.assertEqual(packed, b'\xf9')

    def test_unpack(self):
        """Unpack values.

        """

        unpacked = unpack('u1u1s6u7u9', b'\x3e\x82\x16')
        self.assertEqual(unpacked, (0, 0, -2, 65, 22))

        unpacked = unpack('u1', bytearray(b'\x80'))
        self.assertEqual(unpacked, (1,))

        packed = b'\x00\x80\x00\x00\x00\x00\x08\x00\x00\x00'
        unpacked = unpack('u77', packed)
        self.assertEqual(unpacked, (0x100000000001000000,))

        packed = b'\x3e\x82\x16'
        unpacked = unpack('p1u1s6u7u9', packed)
        self.assertEqual(unpacked, (0, -2, 65, 22))

        packed = b'\x3e\x82\x16'
        unpacked = unpack('p1u1s6p7u9', packed)
        self.assertEqual(unpacked, (0, -2, 22))

        packed = b'\x7c\x80\xe0\x00\x00\x01\xfe\x01\xfe\x01\xc0'
        unpacked = unpack('u1s6f32r43', packed)
        self.assertEqual(unpacked, (0, -2, 3.75, b'\x00\xff\x00\xff\x00\xe0'))

        packed = [0x80]
        unpacked = unpack('b1', packed)
        self.assertEqual(unpacked, (True,))

        packed = b'\x80'
        unpacked = unpack('b1p6b1', packed)
        self.assertEqual(unpacked, (True, False))

        packed = b'\x06'
        unpacked = unpack('u5b2u1', packed)
        self.assertEqual(unpacked, (0, True, 0))

        packed = b'\x04'
        unpacked = unpack('u5b2u1', packed)
        self.assertEqual(unpacked, (0, True, 0))

        # bad float size
        try:
            unpack('f33', b'\x00\x00\x00\x00\x00')
            self.fail()
        except ValueError:
            pass

        # gcc packed struct with bitfields
        #
        # struct foo_t {
        #     int a;
        #     char b;
        #     uint32_t c : 7;
        #     uint32_t d : 25;
        # } foo;
        #
        # foo.a = 1;
        # foo.b = 1;
        # foo.c = 0x67;
        # foo.d = 0x12345;
        unpacked = unpack('s32s8u25u7',
                          byteswap('414',
                                   b'\x01\x00\x00\x00\x01\xe7\xa2\x91\x00'))
        self.assertEqual(unpacked, (1, 1, 0x12345, 0x67))



    def test_pack_unpack(self):
        """Pack and unpack values.

        """

        packed = pack('u1u1s6u7u9', 0, 0, -2, 65, 22)
        unpacked = unpack('u1u1s6u7u9', packed)
        self.assertEqual(unpacked, (0, 0, -2, 65, 22))

        packed = pack('f64', 1.0)
        unpacked = unpack('f64', packed)
        self.assertEqual(unpacked, (1.0, ))

    def test_calcsize(self):
        """Calculate size.

        """

        size = calcsize('u1u1s6u7u9')
        self.assertEqual(size, 24)

        size = calcsize('u1')
        self.assertEqual(size, 1)

        size = calcsize('u77')
        self.assertEqual(size, 77)

        size = calcsize('u1s6u7u9')
        self.assertEqual(size, 23)

        size = calcsize('b1s6u7u9')
        self.assertEqual(size, 23)

    def test_byteswap(self):
        """Byte swap.

        """

        res = b'\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a'
        ref = b'\x01\x03\x02\x04\x08\x07\x06\x05\x0a\x09'
        self.assertEqual(byteswap('12142', ref), res)

        packed = pack('u1u5u2u16', 1, 2, 3, 4)
        unpacked = unpack('u1u5u2u16', byteswap('12', packed))
        self.assertEqual(unpacked, (1, 2, 3, 1024))

    def test_endianness(self):
        """Test pack/unpack with endianness information in the format string.

        """

        # big endian
        ref = b'\x02\x46\x9a\xfe\x00\x00\x00'
        packed = pack('>u19s3f32', 0x1234, -2, -1.0)
        self.assertEqual(packed, ref)
        unpacked = unpack('>u19s3f32', packed)
        self.assertEqual(unpacked, (0x1234, -2, -1.0))
        
        # little endian
        ref = b'\x2c\x48\x0c\x00\x00\x07\xf4'
        packed = pack('<u19s3f32', 0x1234, -2, -1.0)
        self.assertEqual(packed, ref)
        unpacked = unpack('<u19s3f32', packed)
        self.assertEqual(unpacked, (0x1234, -2, -1.0))

        # mixed endianness
        ref = b'\x00\x00\x2f\x3f\xf0\x00\x00\x00\x00\x00\x00\x80'
        packed = pack('>u19<s5>f64r3p4', 1, -2, 1.0, b'\x80')
        self.assertEqual(packed, ref)
        unpacked = unpack('>u19<s5>f64r3p4', packed)
        self.assertEqual(unpacked, (1, -2, 1.0, b'\x80'))

        # opposite endianness of the 'mixed endianness' test
        ref = b'\x80\x00\x1e\x00\x00\x00\x00\x00\x00\x0f\xfc\x20'
        packed = pack('<u19>s5<f64r3p4', 1, -2, 1.0, b'\x80')
        self.assertEqual(packed, ref)
        unpacked = unpack('<u19>s5<f64r3p4', packed)
        self.assertEqual(unpacked, (1, -2, 1.0, b'\x80'))

        # pack as big endian, unpack as little endian
        ref = b'\x40'
        packed = pack('u2', 1)
        self.assertEqual(packed, ref)
        unpacked = unpack('<u2', packed)
        self.assertEqual(unpacked, (2, ))


if __name__ == '__main__':
    unittest.main()