from __future__ import absolute_import, print_function, division
import sys
import numpy as np
from unittest import TestCase

from nose.plugins.skip import SkipTest

import theano
import theano.tensor as tensor

from theano.tensor.blas_c import CGer
from theano.tensor.blas_scipy import ScipyGer
from theano.tensor.blas import Ger

from theano.tensor.blas_c import CGemv
from theano.tensor.blas import Gemv

from theano.tensor.blas_c import check_force_gemv_init

from theano.tests import unittest_tools
from theano.tests.unittest_tools import TestOptimizationMixin

from theano.tensor.tests.test_blas import BaseGemv, TestBlasStrides

mode_blas_opt = theano.compile.get_default_mode().including(
    'BlasOpt', 'specialize', 'InplaceBlasOpt', 'c_blas')


def skip_if_blas_ldflags_empty(*functions_detected):
    if theano.config.blas.ldflags == "":
        functions_string = ""
        if functions_detected:
            functions_string = " (at least " + (", ".join(functions_detected)) + ")"
        raise SkipTest("This test is useful only when Theano can access to BLAS functions" + functions_string + " other than [sd]gemm_.")


class TestCGer(TestCase, TestOptimizationMixin):

    def setUp(self, dtype='float64'):
        # This tests can run even when theano.config.blas.ldflags is empty.
        self.dtype = dtype
        self.mode = theano.compile.get_default_mode().including('fast_run')
        self.A = tensor.tensor(dtype=dtype, broadcastable=(False, False))
        self.a = tensor.tensor(dtype=dtype, broadcastable=())
        self.x = tensor.tensor(dtype=dtype, broadcastable=(False,))
        self.y = tensor.tensor(dtype=dtype, broadcastable=(False,))
        self.Aval = np.ones((2, 3), dtype=dtype)
        self.xval = np.asarray([1, 2], dtype=dtype)
        self.yval = np.asarray([1.5, 2.7, 3.9], dtype=dtype)

    def function(self, inputs, outputs):
        return theano.function(inputs, outputs,
                mode=self.mode,
                # allow_inplace=True,
                )

    def run_f(self, f):
        f(self.Aval, self.xval, self.yval)
        f(self.Aval[::-1, ::-1], self.xval, self.yval)

    def b(self, bval):
        return tensor.as_tensor_variable(np.asarray(bval, dtype=self.dtype))

    def test_eq(self):
        self.assertTrue(CGer(True) == CGer(True))
        self.assertTrue(CGer(False) == CGer(False))
        self.assertTrue(CGer(False) != CGer(True))

        self.assertTrue(CGer(True) != ScipyGer(True))
        self.assertTrue(CGer(False) != ScipyGer(False))
        self.assertTrue(CGer(True) != Ger(True))
        self.assertTrue(CGer(False) != Ger(False))

        # assert that eq works for non-CGer instances
        self.assertTrue(CGer(False) is not None)
        self.assertTrue(CGer(True) is not None)

    def test_hash(self):
        self.assertTrue(hash(CGer(True)) == hash(CGer(True)))
        self.assertTrue(hash(CGer(False)) == hash(CGer(False)))
        self.assertTrue(hash(CGer(False)) != hash(CGer(True)))

    def test_optimization_pipeline(self):
        skip_if_blas_ldflags_empty()
        f = self.function([self.x, self.y], tensor.outer(self.x, self.y))
        self.assertFunctionContains(f, CGer(destructive=True))
        f(self.xval, self.yval)  # DebugMode tests correctness

    def test_optimization_pipeline_float(self):
        skip_if_blas_ldflags_empty()
        self.setUp('float32')
        f = self.function([self.x, self.y], tensor.outer(self.x, self.y))
        self.assertFunctionContains(f, CGer(destructive=True))
        f(self.xval, self.yval)  # DebugMode tests correctness

    def test_int_fails(self):
        self.setUp('int32')
        f = self.function([self.x, self.y], tensor.outer(self.x, self.y))
        self.assertFunctionContains0(f, CGer(destructive=True))
        self.assertFunctionContains0(f, CGer(destructive=False))

    def test_A_plus_outer(self):
        skip_if_blas_ldflags_empty()
        f = self.function([self.A, self.x, self.y],
                self.A + tensor.outer(self.x, self.y))
        self.assertFunctionContains(f, CGer(destructive=False))
        self.run_f(f)  # DebugMode tests correctness

    def test_A_plus_scaled_outer(self):
        skip_if_blas_ldflags_empty()
        f = self.function([self.A, self.x, self.y],
                self.A + 0.1 * tensor.outer(self.x, self.y))
        self.assertFunctionContains(f, CGer(destructive=False))
        self.run_f(f)  # DebugMode tests correctness


class TestCGemv(TestCase, TestOptimizationMixin):
    """
    Tests of CGemv specifically.

    Generic tests of Gemv-compatibility, including both dtypes are
    done below in TestCGemvFloat32 and TestCGemvFloat64
    """
    def setUp(self, dtype='float64'):
        # This tests can run even when theano.config.blas.ldflags is empty.
        self.dtype = dtype
        self.mode = theano.compile.get_default_mode().including('fast_run')
        # matrix
        self.A = tensor.tensor(dtype=dtype, broadcastable=(False, False))
        self.Aval = np.ones((2, 3), dtype=dtype)

        # vector
        self.x = tensor.tensor(dtype=dtype, broadcastable=(False,))
        self.y = tensor.tensor(dtype=dtype, broadcastable=(False,))
        self.xval = np.asarray([1, 2], dtype=dtype)
        self.yval = np.asarray([1.5, 2.7, 3.9], dtype=dtype)

        # scalar
        self.a = tensor.tensor(dtype=dtype, broadcastable=())

    def test_nan_beta_0(self):
        mode = self.mode.including()
        mode.check_isfinite = False
        f = theano.function([self.A, self.x, self.y, self.a],
                            self.a*self.y + theano.dot(self.A, self.x),
                            mode=mode)
        Aval = np.ones((3, 1), dtype=self.dtype)
        xval = np.ones((1,), dtype=self.dtype)
        yval = float('NaN') * np.ones((3,), dtype=self.dtype)
        zval = f(Aval, xval, yval, 0)
        assert not np.isnan(zval).any()

    def test_optimizations_vm(self):
        skip_if_blas_ldflags_empty()
        ''' Test vector dot matrix '''
        f = theano.function([self.x, self.A],
                theano.dot(self.x, self.A),
                mode=self.mode)

        # Assert that the dot was optimized somehow
        self.assertFunctionContains0(f, tensor.dot)
        self.assertFunctionContains1(
            f,
            CGemv(inplace=True)
        )

        # Assert they produce the same output
        assert np.allclose(f(self.xval, self.Aval),
                np.dot(self.xval, self.Aval))

        # Test with negative strides on 2 dims
        assert np.allclose(f(self.xval, self.Aval[::-1, ::-1]),
                np.dot(self.xval, self.Aval[::-1, ::-1]))

    def test_optimizations_mv(self):
        skip_if_blas_ldflags_empty()
        ''' Test matrix dot vector '''
        f = theano.function([self.A, self.y],
                theano.dot(self.A, self.y),
                mode=self.mode)

        # Assert that the dot was optimized somehow
        self.assertFunctionContains0(f, tensor.dot)
        self.assertFunctionContains1(
            f,
            CGemv(inplace=True)
        )

        # Assert they produce the same output
        assert np.allclose(f(self.Aval, self.yval),
                np.dot(self.Aval, self.yval))
        # Test with negative strides on 2 dims
        assert np.allclose(f(self.Aval[::-1, ::-1], self.yval),
                np.dot(self.Aval[::-1, ::-1], self.yval))

    def test_force_gemv_init(self):
        if check_force_gemv_init():
            sys.stderr.write(
                "WARNING: The current BLAS requires Theano to initialize"
                + " memory for some GEMV calls which will result in a minor"
                + " degradation in performance for such calls."
            )

    def t_gemv1(self, m_shp):
        ''' test vector2 + dot(matrix, vector1) '''
        rng = np.random.RandomState(unittest_tools.fetch_seed())
        v1 = theano.shared(np.array(rng.uniform(size=(m_shp[1],)),
                                       dtype='float32'))
        v2_orig = np.array(rng.uniform(size=(m_shp[0],)), dtype='float32')
        v2 = theano.shared(v2_orig)
        m = theano.shared(np.array(rng.uniform(size=m_shp),
                                      dtype='float32'))

        f = theano.function([], v2 + tensor.dot(m, v1),
                mode=self.mode)

        # Assert they produce the same output
        assert np.allclose(f(),
                np.dot(m.get_value(), v1.get_value()) + v2_orig)
        topo = [n.op for n in f.maker.fgraph.toposort()]
        assert topo == [CGemv(inplace=False)], topo

        # test the inplace version
        g = theano.function([], [],
                updates=[(v2, v2 + theano.dot(m, v1))],
                mode=self.mode)

        # Assert they produce the same output
        g()
        assert np.allclose(v2.get_value(),
                np.dot(m.get_value(), v1.get_value()) + v2_orig)
        topo = [n.op for n in g.maker.fgraph.toposort()]
        assert topo == [CGemv(inplace=True)]

        # Do the same tests with a matrix with strides in both dimensions
        m.set_value(
                m.get_value(borrow=True)[::-1, ::-1],
                borrow=True)
        v2.set_value(v2_orig)
        assert np.allclose(f(),
            np.dot(m.get_value(), v1.get_value()) + v2_orig)
        g()
        assert np.allclose(v2.get_value(),
            np.dot(m.get_value(), v1.get_value()) + v2_orig)

    def test_gemv1(self):
        skip_if_blas_ldflags_empty()
        self.t_gemv1((3, 2))
        self.t_gemv1((1, 2))
        self.t_gemv1((0, 2))
        self.t_gemv1((3, 1))
        self.t_gemv1((3, 0))
        self.t_gemv1((1, 0))
        self.t_gemv1((0, 1))
        self.t_gemv1((0, 0))

    def test_gemv_dimensions(self, dtype='float32'):
        alpha = theano.shared(theano._asarray(1.0, dtype=dtype),
                name='alpha')
        beta = theano.shared(theano._asarray(1.0, dtype=dtype),
                name='beta')

        z = beta * self.y + alpha * tensor.dot(self.A, self.x)
        f = theano.function([self.A, self.x, self.y], z,
                mode=self.mode)

        # Matrix value
        A_val = np.ones((5, 3), dtype=dtype)
        # Different vector length
        ones_3 = np.ones(3, dtype=dtype)
        ones_4 = np.ones(4, dtype=dtype)
        ones_5 = np.ones(5, dtype=dtype)
        ones_6 = np.ones(6, dtype=dtype)

        f(A_val, ones_3, ones_5)
        f(A_val[::-1, ::-1], ones_3, ones_5)
        self.assertRaises(ValueError, f, A_val, ones_4, ones_5)
        self.assertRaises(ValueError, f, A_val, ones_3, ones_6)
        self.assertRaises(ValueError, f, A_val, ones_4, ones_6)

    def test_multiple_inplace(self):
        skip_if_blas_ldflags_empty()
        x = tensor.dmatrix('x')
        y = tensor.dvector('y')
        z = tensor.dvector('z')
        f = theano.function([x, y, z],
                            [tensor.dot(y, x), tensor.dot(z,x)],
                            mode=mode_blas_opt)
        vx = np.random.rand(3, 3)
        vy = np.random.rand(3)
        vz = np.random.rand(3)
        out = f(vx, vy, vz)
        assert np.allclose(out[0], np.dot(vy, vx))
        assert np.allclose(out[1], np.dot(vz, vx))
        assert len([n for n in f.maker.fgraph.apply_nodes
                    if isinstance(n.op, tensor.AllocEmpty)]) == 2


class TestCGemvFloat32(TestCase, BaseGemv, TestOptimizationMixin):
    mode = mode_blas_opt
    dtype = 'float32'
    gemv = CGemv(inplace=False)
    gemv_inplace = CGemv(inplace=True)

    def setUp(self):
        skip_if_blas_ldflags_empty()


class TestCGemvFloat64(TestCase, BaseGemv, TestOptimizationMixin):
    mode = mode_blas_opt
    dtype = 'float64'
    gemv = CGemv(inplace=False)
    gemv_inplace = CGemv(inplace=True)

    def setUp(self):
        skip_if_blas_ldflags_empty()


class TestBlasStridesC(TestBlasStrides):
    mode = mode_blas_opt
