#!/usr/bin/env python

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#
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"""Test script for torch module"""
import tempfile
import os
import logging
import torch
import numpy as np
import tvm
import tvm.testing
from tvm import te, relay
import tvm.contrib.torch
from tvm.contrib import graph_runtime

TVM_ASSETS = ["mod.so", "graph.json", "params"]


def test_use_pt_graph_module():
    """main test function"""

    def build_export_graph(device):
        """relay build & export graph"""
        x = relay.var("x", shape=(10, 5))
        y = relay.var("y", shape=(1, 5))
        z = relay.add(x, y)
        z = relay.exp(z)
        func = relay.Function([x, y], z)
        x_data = np.random.rand(10, 5).astype("float32")
        y_data = np.random.rand(1, 5).astype("float32")
        params = {"y": y_data}

        pt_device = torch.device(device)
        if pt_device.type == "cuda":
            target = "cuda"
            ctx = tvm.cuda(pt_device.index)
        else:
            target = "llvm"
            ctx = tvm.cpu(0)

        graph, lib, params = relay.build(tvm.IRModule.from_expr(func), target=target, params=params)
        mod = graph_runtime.create(graph, lib, device=ctx)
        mod.set_input(**params)
        mod.set_input(x=x_data)
        mod.run()
        res = mod.get_output(0).asnumpy()
        ref_res = np.exp(y_data + x_data)
        tvm.testing.assert_allclose(res, ref_res, atol=1e-5, rtol=1e-5)

        # export to tempdir
        export_dir = tempfile.mkdtemp("tvm_export")
        lib.export_library(os.path.join(export_dir, TVM_ASSETS[0]))
        with open(os.path.join(export_dir, TVM_ASSETS[1]), "w") as fout:
            fout.write(graph)
        with open(os.path.join(export_dir, TVM_ASSETS[2]), "wb") as fout:
            fout.write(relay.save_param_dict(params))

        return export_dir

    def test_pt_run(device, trace=True, to_device=None):
        """test add lib with Pytorch wrapper"""
        print("\n############## Test on device:", device, "#################")
        export_dir = build_export_graph(device)
        engine = tvm.contrib.torch.GraphModule(num_inputs=2, num_outputs=1).to(device)

        x = np.random.rand(10, 5).astype("float32")
        y = np.random.rand(1, 5).astype("float32")

        expect = np.exp(y + x)

        def get_inputs_by_device(device):
            inps = [torch.Tensor(x), torch.Tensor(y)]
            if device == "cpu":
                return inps
            else:
                device_type, device_id = device.split(":")
                assert device_type == "cuda"
                return [inp.cuda(int(device_id)) for inp in inps]

        assets = [os.path.join(export_dir, i) for i in TVM_ASSETS]
        engine.init((x.shape, y.shape), *assets)

        outputs = engine.forward(get_inputs_by_device(device))
        tvm.testing.assert_allclose(outputs[0].cpu(), expect, atol=1e-5, rtol=1e-5)

        if trace:
            print("\n################ Test trace and load #################")
            scripted = torch.jit.script(engine)
            scripted_dir = tempfile.mkdtemp("scripted")
            scripted_path = os.path.join(scripted_dir, "model.pt")
            scripted.save(scripted_path)
            loaded = torch.jit.load(scripted_path)
            outputs = loaded.forward(get_inputs_by_device(device))
            tvm.testing.assert_allclose(outputs[0].cpu(), expect, atol=1e-5, rtol=1e-5)
            del scripted
            del loaded

        if to_device:
            print(
                "\n################ Test move from [{}] to [{}] #################".format(
                    device, to_device
                )
            )
            engine = engine.to(to_device)
            outputs = engine.forward(get_inputs_by_device(to_device))
            tvm.testing.assert_allclose(outputs[0].cpu(), expect, atol=1e-5, rtol=1e-5)
        del engine

    test_pt_run(device="cuda:0", trace=True, to_device="cuda:1")
    test_pt_run(device="cpu", trace=True)


if __name__ == "__main__":
    test_use_pt_graph_module()