from __future__ import division
from hypothesis import given, assume
from math import sqrt, floor

from blis.tests.common import *
from blis.py import gemm


def _stretch_matrix(data, m, n):
    orig_len = len(data)
    orig_m = m
    orig_n = n
    ratio = sqrt(len(data) / (m * n))
    m = int(floor(m * ratio))
    n = int(floor(n * ratio))
    data = np.ascontiguousarray(data[:m*n], dtype=data.dtype)
    return data.reshape((m, n)), m, n

def _reshape_for_gemm(A, B, a_rows, a_cols, out_cols, dtype, trans_a=False, trans_b=False):
    A, a_rows, a_cols = _stretch_matrix(A, a_rows, a_cols)
    if len(B) < a_cols or a_cols < 1:
        return (None, None, None)
    b_cols = int(floor(len(B) / a_cols))
    B = np.ascontiguousarray(B.flatten()[:a_cols*b_cols], dtype=dtype)
    B = B.reshape((a_cols, b_cols))
    out_cols = B.shape[1]
    C = np.zeros(shape=(A.shape[0], B.shape[1]), dtype=dtype)
    if trans_a:
        A = np.ascontiguousarray(A.T, dtype=dtype)
    return A, B, C


@given(
    ndarrays(min_len=10, max_len=100,
             min_val=-100.0, max_val=100.0, dtype='float64'),
    ndarrays(min_len=10, max_len=100,
             min_val=-100.0, max_val=100.0, dtype='float64'),
    integers(min_value=2, max_value=1000),
    integers(min_value=2, max_value=1000),
    integers(min_value=2, max_value=1000))
def test_memoryview_double_notrans(A, B, a_rows, a_cols, out_cols):
    A, B, C = _reshape_for_gemm(A, B, a_rows, a_cols, out_cols, 'float64')
    assume(A is not None)
    assume(B is not None)
    assume(C is not None)
    assume(A.size >= 1)
    assume(B.size >= 1)
    assume(C.size >= 1)
    gemm(A, B, out=C)
    numpy_result = A.dot(B)
    assert_allclose(numpy_result, C, atol=1e-4, rtol=1e-4)


@given(
    ndarrays(min_len=10, max_len=100,
             min_val=-100.0, max_val=100.0, dtype='float32'),
    ndarrays(min_len=10, max_len=100,
             min_val=-100.0, max_val=100.0, dtype='float32'),
    integers(min_value=2, max_value=1000),
    integers(min_value=2, max_value=1000),
    integers(min_value=2, max_value=1000))
def test_memoryview_float_notrans(A, B, a_rows, a_cols, out_cols):
    A, B, C = _reshape_for_gemm(A, B, a_rows, a_cols, out_cols, dtype='float32')
    assume(A is not None)
    assume(B is not None)
    assume(C is not None)
    assume(A.size >= 1)
    assume(B.size >= 1)
    assume(C.size >= 1)
    gemm(A, B, out=C)
    numpy_result = A.dot(B)
    assert_allclose(numpy_result, C, atol=1e-3, rtol=1e-3)