import unittest
from unittest import mock

from mozharness.base.diskutils import DiskInfo, DiskSize, DiskutilsError, convert_to


class TestDiskutils(unittest.TestCase):
    def test_convert_to(self):
        # 0 is 0 regardless from_unit/to_unit
        self.assertTrue(convert_to(size=0, from_unit="GB", to_unit="MB") == 0)
        size = 524288  # 512 * 1024
        # converting from/to same unit
        self.assertTrue(convert_to(size=size, from_unit="MB", to_unit="MB") == size)

        self.assertTrue(convert_to(size=size, from_unit="MB", to_unit="GB") == 512)

        self.assertRaises(
            DiskutilsError,
            lambda: convert_to(size="a string", from_unit="MB", to_unit="MB"),
        )
        self.assertRaises(
            DiskutilsError, lambda: convert_to(size=0, from_unit="foo", to_unit="MB")
        )
        self.assertRaises(
            DiskutilsError, lambda: convert_to(size=0, from_unit="MB", to_unit="foo")
        )


class TestDiskInfo(unittest.TestCase):
    def testDiskinfo_to(self):
        di = DiskInfo()
        self.assertTrue(di.unit == "bytes")
        self.assertTrue(di.free == 0)
        self.assertTrue(di.used == 0)
        self.assertTrue(di.total == 0)
        # convert to GB
        di._to("GB")
        self.assertTrue(di.unit == "GB")
        self.assertTrue(di.free == 0)
        self.assertTrue(di.used == 0)
        self.assertTrue(di.total == 0)


class MockStatvfs(object):
    def __init__(self):
        self.f_bsize = 0
        self.f_frsize = 0
        self.f_blocks = 0
        self.f_bfree = 0
        self.f_bavail = 0
        self.f_files = 0
        self.f_ffree = 0
        self.f_favail = 0
        self.f_flag = 0
        self.f_namemax = 0


class TestDiskSpace(unittest.TestCase):
    @mock.patch("mozharness.base.diskutils.os")
    def testDiskSpacePosix(self, mock_os):
        ds = MockStatvfs()
        mock_os.statvfs.return_value = ds
        di = DiskSize()._posix_size("/")
        self.assertTrue(di.unit == "bytes")
        self.assertTrue(di.free == 0)
        self.assertTrue(di.used == 0)
        self.assertTrue(di.total == 0)

    @mock.patch("mozharness.base.diskutils.ctypes")
    def testDiskSpaceWindows(self, mock_ctypes):
        mock_ctypes.windll.kernel32.GetDiskFreeSpaceExA.return_value = 0
        mock_ctypes.windll.kernel32.GetDiskFreeSpaceExW.return_value = 0
        di = DiskSize()._windows_size("/c/")
        self.assertTrue(di.unit == "bytes")
        self.assertTrue(di.free == 0)
        self.assertTrue(di.used == 0)
        self.assertTrue(di.total == 0)

    @mock.patch("mozharness.base.diskutils.os")
    @mock.patch("mozharness.base.diskutils.ctypes")
    def testUnspportedPlafrom(self, mock_ctypes, mock_os):
        mock_os.statvfs.side_effect = AttributeError("")
        self.assertRaises(AttributeError, lambda: DiskSize()._posix_size("/"))
        mock_ctypes.windll.kernel32.GetDiskFreeSpaceExW.side_effect = AttributeError("")
        mock_ctypes.windll.kernel32.GetDiskFreeSpaceExA.side_effect = AttributeError("")
        self.assertRaises(AttributeError, lambda: DiskSize()._windows_size("/"))
        self.assertRaises(
            DiskutilsError, lambda: DiskSize().get_size(path="/", unit="GB")
        )
