import caffe2.python.hypothesis_test_util as hu
import hypothesis.strategies as st
import numpy as np
from caffe2.python import core, dyndep, workspace
from caffe2.quantization.server import dnnlowp_pybind11
from hypothesis import given, settings


dyndep.InitOpsLibrary("//caffe2/caffe2/quantization/server:dnnlowp_ops")
workspace.GlobalInit(["caffe2", "--caffe2_omp_num_threads=11"])


class DNNLowPQuantizeOpTest(hu.HypothesisTestCase):
    @given(size=st.integers(1024, 2048),
           is_empty=st.booleans(),
           absorb=st.booleans(),
           **hu.gcs_cpu_only)
    @settings(max_examples=10, deadline=None)
    def test_dnnlowp_quantize(self, size, is_empty, absorb, gc, dc):
        if is_empty:
            size = 0
        min_ = -10.0
        max_ = 20.0
        X = (np.random.rand(size) * (max_ - min_) + min_).astype(np.float32)
        X_min = 0 if X.size == 0 else X.min()
        X_max = 1 if X.size == 0 else X.max()
        X_scale = (max(X_max, 0) - min(X_min, 0)) / 255
        X_zero = np.round(-X_min / X_scale)

        op_type_list = ["Quantize", "Int8Quantize"]
        engine = "DNNLOWP"

        for op_type in op_type_list:
            net = core.Net("test_net")

            quantize = core.CreateOperator(
                op_type, ["X"], ["X_q"], engine=engine, device_option=gc
            )
            net.Proto().op.extend([quantize])

            dnnlowp_pybind11.CreateInt8QuantParamsBlob(
                "quant_param", float(X_scale), int(X_zero)
            )
            quantize_2 = core.CreateOperator(
                op_type,
                ["X", "quant_param"],
                ["X_q_2"],
                engine=engine,
                device_option=gc,
            )
            net.Proto().op.extend([quantize_2])
            if absorb:
                net_str = dnnlowp_pybind11.freeze_quantization_params(
                    net.Proto().SerializeToString())
                net.Proto().ParseFromString(net_str)
            workspace.FeedBlob("X", X, device_option=gc)
            workspace.RunNetOnce(net)
            X_q = workspace.FetchInt8Blob("X_q")[0]
            X_q_2 = workspace.FetchInt8Blob("X_q_2")[0]

            # Dequantize results and measure quantization error against inputs
            X_dq = X_scale * (X_q - X_zero)
            X_dq_2 = X_scale * (X_q_2 - X_zero)

            # should be divided by 2 in an exact math, but divide by 1.9 here
            # considering finite precision in floating-point numbers
            atol = X_scale / 1.9
            np.testing.assert_allclose(X_dq, X, atol=atol, rtol=0)
            np.testing.assert_allclose(X_dq_2, X, atol=atol, rtol=0)