from mpi4py import MPI
import mpiunittest as unittest
import arrayimpl
import os


def allclose(a, b, rtol=1.e-5, atol=1.e-8):
    try:
        iter(a)
    except TypeError:
        a = [a]
    try:
        iter(b)
    except TypeError:
        b = [b]
    for x, y in zip(a, b):
        if x == y:
            continue
        if abs(x - y) > (atol + rtol * abs(y)):
            return False
    return True


class BaseTestPack:

    COMM = MPI.COMM_NULL

    skipdtype = []

    def testPackSize(self):
        for array, typecode in arrayimpl.loop():
            with arrayimpl.test(self):
                if typecode in self.skipdtype: continue
                datatype = array.TypeMap[typecode]
                itemsize = datatype.Get_size()
                overhead = datatype.Pack_size(0, self.COMM)
                for count in range(10):
                    with self.subTest(count=count):
                        pack_size = datatype.Pack_size(count, self.COMM)
                        self.assertEqual(pack_size - overhead, count*itemsize)

    def testPackUnpack(self):
        for array, typecode1 in arrayimpl.loop():
            with arrayimpl.test(self):
                if typecode1 in self.skipdtype: continue
                for typecode2 in array.TypeMap:
                    if typecode2 in self.skipdtype: continue
                    datatype1 = array.TypeMap[typecode1]
                    datatype2 = array.TypeMap[typecode2]
                    for count in range(10):
                        with self.subTest(typecode=(typecode1, typecode2), count=count):
                            # input and output arrays
                            iarray1 = array(range(count), typecode1).as_raw()
                            iarray2 = array(range(count), typecode2).as_raw()
                            oarray1 = array(count, typecode1, count).as_raw()
                            oarray2 = array(count, typecode2, count).as_raw()
                            # temp array for packing
                            size1 = datatype1.Pack_size(len(iarray1), self.COMM)
                            size2 = datatype2.Pack_size(len(iarray2), self.COMM)
                            tmpbuf = array(0, 'b', size1 + size2 + 1).as_raw()
                            # pack input arrays
                            position = 0
                            position = datatype1.Pack(iarray1, tmpbuf, position, self.COMM)
                            position = datatype2.Pack(iarray2, tmpbuf, position, self.COMM)
                            # unpack output arrays
                            position = 0
                            position = datatype1.Unpack(tmpbuf, position, oarray1, self.COMM)
                            position = datatype2.Unpack(tmpbuf, position, oarray2, self.COMM)
                            # test
                            self.assertTrue(allclose(iarray1, oarray1))
                            self.assertTrue(allclose(iarray2, oarray2))

EXT32 = 'external32'

class BaseTestPackExternal:

    skipdtype = []

    def testPackSize(self):
        for array, typecode in arrayimpl.loop():
            with arrayimpl.test(self):
                if typecode in self.skipdtype: continue
                datatype = array.TypeMap[typecode]
                overhead = datatype.Pack_external_size(EXT32, 0)
                for count in range(10):
                    with self.subTest(count=count):
                        pack_size = datatype.Pack_external_size(EXT32, count)
                        real_size = pack_size - overhead
                        self.assertGreaterEqual(real_size, 0)

    def testPackUnpackExternal(self):
        for array, typecode1 in arrayimpl.loop():
            with arrayimpl.test(self):
                if unittest.is_mpi_gpu('mpich', array): continue
                if unittest.is_mpi_gpu('openmpi', array): continue
                if unittest.is_mpi_gpu('mvapich2', array): continue
                if typecode1 in self.skipdtype: continue
                for typecode2 in array.TypeMap:
                    if typecode2 in self.skipdtype: continue
                    datatype1 = array.TypeMap[typecode1]
                    datatype2 = array.TypeMap[typecode2]
                    for count in range(1, 10):
                        with self.subTest(count=count, typecode=(typecode1, typecode2)):
                            # input and output arrays
                            val = 127 if typecode1 == 'b' else 255
                            iarray1 = array(val, typecode1, count).as_raw()
                            iarray2 = array(range(count), typecode2).as_raw()
                            oarray1 = array(-1, typecode1, count).as_raw()
                            oarray2 = array(-1, typecode2, count).as_raw()
                            # temp array for packing
                            size1 = datatype1.Pack_external_size(EXT32, len(iarray1))
                            size2 = datatype2.Pack_external_size(EXT32, len(iarray2))
                            tmpbuf = array(0, 'b', size1 + size2 + 1).as_raw()
                            # pack input arrays
                            position = 0
                            position = datatype1.Pack_external(EXT32, iarray1, tmpbuf, position)
                            position = datatype2.Pack_external(EXT32, iarray2, tmpbuf, position)
                            # unpack output arrays
                            position = 0
                            position = datatype1.Unpack_external(EXT32, tmpbuf, position, oarray1)
                            position = datatype2.Unpack_external(EXT32, tmpbuf, position, oarray2)
                            # test result
                            self.assertTrue(allclose(iarray1, oarray1))
                            self.assertTrue(allclose(iarray2, oarray2))


class TestPackSelf(BaseTestPack, unittest.TestCase):
    COMM = MPI.COMM_SELF

class TestPackWorld(BaseTestPack, unittest.TestCase):
    COMM = MPI.COMM_SELF

@unittest.skipMPI('openmpi(<3.0.0)')
class TestPackExternal(BaseTestPackExternal, unittest.TestCase):
    pass


name, version = MPI.get_vendor()
if name == 'MPICH':
    if version < (4, 0, 0):
        BaseTestPackExternal.skipdtype += 'ldgLFDG'
elif name == 'Open MPI':
    if version < (5, 0, 0):
        BaseTestPackExternal.skipdtype += 'gG'
elif name == 'Intel MPI':
    BaseTestPackExternal.skipdtype += 'ldgLFDG'
    if os.name == 'nt':
        BaseTestPackExternal.skipdtype += 'q'
elif name == 'Microsoft MPI':
    BaseTestPackExternal.skipdtype += 'gFDG'
elif name == 'MVAPICH2':
    BaseTestPackExternal.skipdtype += 'ldgLFDG'
elif name =='MPICH2':
    BaseTestPackExternal.skipdtype += 'ldgLFDG'
else:
    try:
        MPI.BYTE.Pack_external_size(EXT32, 0)
    except NotImplementedError:
        unittest.disable(BaseTestPackExternal, 'mpi-ext32')


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