# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import unittest

import numpy as np
from get_test_cover_info import (
    XPUOpTestWrapper,
    create_test_class,
    get_xpu_op_support_types,
)
from op_test_xpu import XPUOpTest

import paddle
import paddle.incubate.nn.functional as incubate_f
import paddle.nn.functional as F
from paddle import tensor
from paddle.fluid.framework import default_main_program
from paddle.nn.layer.common import Dropout, Linear
from paddle.nn.layer.norm import LayerNorm
from paddle.nn.layer.transformer import _convert_attention_mask

default_main_program().random_seed = 42


class XPUTestFusedAttentionOp(XPUOpTestWrapper):
    def __init__(self):
        self.op_name = 'fused_attention'
        self.use_dynamic_create_class = False

    class TestFusedAttentionOp(XPUOpTest):
        def setUp(self):
            self.config()
            self.generate_input_data()
            self.rtol = 1e-5
            self.atol = 1e-3
            if self.x_type == np.float16 or str(self.x_type) == "float16":
                self.atol = 1e-1

            paddle.set_default_dtype(self.x_type)
            self.__class__.op_type = "fused_attention"
            # use autograd to check grad in this unittest.
            self.__class__.no_need_check_grad = True
            self.q_proj = Linear(
                self.embed_dim,
                self.embed_dim,
                self.weight_attr,
                bias_attr=self.bias_attr,
            )
            self.k_proj = Linear(
                self.kdim,
                self.embed_dim,
                self.weight_attr,
                bias_attr=self.bias_attr,
            )
            self.v_proj = Linear(
                self.vdim,
                self.embed_dim,
                self.weight_attr,
                bias_attr=self.bias_attr,
            )
            self.out_proj = Linear(
                self.embed_dim,
                self.embed_dim,
                self.weight_attr,
                bias_attr=self.bias_attr,
            )
            paddle.set_default_dtype(np.float32)
            self.norm1 = LayerNorm(self.embed_dim)
            self.norm2 = LayerNorm(self.embed_dim)
            paddle.set_default_dtype(self.x_type)
            self.dropout = Dropout(self.dropout_prob, mode="upscale_in_train")

        def config(self):
            self.x_type = self.in_type
            self.attn_mask_type = np.float32
            self.pre_layer_norm = True
            self.has_attn_mask = False
            self.training = True

            self.batch_size = 8
            self.query_length = 128
            self.cache_length = 128
            self.head_dim = 64
            self.num_heads = 16
            self.embed_dim = self.head_dim * self.num_heads

            self.dropout_prob = 0.0
            self.attn_dropout_prob = 0.0
            self.weight_attr = None
            self.bias_attr = None
            self.kdim, self.vdim = self.embed_dim, self.embed_dim
            self.key_length, self.value_length = (
                self.query_length,
                self.query_length,
            )

        def generate_input_data(self):
            self.query = np.random.rand(
                self.batch_size, self.query_length, self.embed_dim
            ).astype(self.x_type)
            out_seq_len = self.key_length
            if self.has_attn_mask:
                # [B, n_head, seq_len, out_seq_len]
                self.attn_mask = np.ones(
                    (
                        self.batch_size,
                        self.num_heads,
                        self.query_length,
                        out_seq_len,
                    ),
                    dtype=self.attn_mask_type,
                )
            else:
                self.attn_mask = None
            self.key, self.value = self.query, self.query

            self.dout = np.random.random(
                (self.batch_size, self.query_length, self.embed_dim)
            ).astype(self.x_type)

        def GetBaselineOut(self):
            paddle.disable_static()
            tensor_query = paddle.to_tensor(self.query, stop_gradient=False)

            if self.has_attn_mask:
                attn_mask = paddle.to_tensor(
                    self.attn_mask, stop_gradient=False
                )
            else:
                attn_mask = None
            residual = tensor_query

            ln1_out = tensor_query
            if self.pre_layer_norm:
                ln1_out = self.norm1(tensor_query)

            q = self.q_proj(ln1_out)
            q = tensor.reshape(x=q, shape=[0, 0, self.num_heads, self.head_dim])
            q_out = tensor.transpose(x=q, perm=[0, 2, 1, 3])
            k = self.k_proj(ln1_out)
            v = self.v_proj(ln1_out)
            k = tensor.reshape(x=k, shape=[0, 0, self.num_heads, self.head_dim])
            k_out = tensor.transpose(x=k, perm=[0, 2, 1, 3])
            v = tensor.reshape(x=v, shape=[0, 0, self.num_heads, self.head_dim])
            v_out = tensor.transpose(x=v, perm=[0, 2, 1, 3])

            # [B, n_head, seq_len, head_dim] * [B, n_head, out_seq_len, head_dim]
            # --> [B, n_head, seq_len, out_seq_len]
            qk_out = tensor.matmul(
                x=q_out * self.head_dim**-0.5, y=k_out, transpose_y=True
            )

            if attn_mask is not None:
                attn_mask = _convert_attention_mask(attn_mask, qk_out.dtype)
                attn_mask_out = qk_out + attn_mask
                softmax_out = F.softmax(attn_mask_out)
            else:
                softmax_out = F.softmax(qk_out)

            if self.dropout_prob:
                dropout_out = F.dropout(
                    softmax_out,
                    self.dropout_prob,
                    training=self.training,
                    mode="upscale_in_train",
                )
                # [B, n_head, seq_len, out_seq_len] * [B, n_head, out_seq_len, head_dim]
                # --> [B, n_head, seq_len, head_dim]
                qktv_out = tensor.matmul(dropout_out, v_out)
            else:
                qktv_out = tensor.matmul(softmax_out, v_out)

            fmha_out = tensor.transpose(qktv_out, perm=[0, 2, 1, 3])
            out_linear_in = tensor.reshape(
                x=fmha_out, shape=[0, 0, fmha_out.shape[2] * fmha_out.shape[3]]
            )
            out = self.out_proj(out_linear_in)

            residual_out = residual + self.dropout(out)
            if not self.pre_layer_norm:
                final_out = self.norm1(residual_out)
            else:
                final_out = residual_out

            paddle.autograd.backward(
                [final_out], [paddle.to_tensor(self.dout)], retain_graph=True
            )
            return final_out, tensor_query.grad

        def GetFusedAttentionOut(self):
            paddle.disable_static()
            q_proj_weight = paddle.to_tensor(
                self.q_proj.weight, stop_gradient=False
            )
            k_proj_weight = paddle.to_tensor(
                self.k_proj.weight, stop_gradient=False
            )
            v_proj_weight = paddle.to_tensor(
                self.v_proj.weight, stop_gradient=False
            )
            out_linear_weight = paddle.to_tensor(
                self.out_proj.weight, stop_gradient=False
            )

            if self.bias_attr is False:
                qkv_bias_tensor = None
                out_linear_bias = None
            else:
                q_proj_bias = paddle.to_tensor(
                    self.q_proj.bias, stop_gradient=False
                )
                k_proj_bias = paddle.to_tensor(
                    self.k_proj.bias, stop_gradient=False
                )
                v_proj_bias = paddle.to_tensor(
                    self.v_proj.bias, stop_gradient=False
                )
                qkv_bias = np.concatenate(
                    (
                        q_proj_bias.numpy(),
                        k_proj_bias.numpy(),
                        v_proj_bias.numpy(),
                    )
                )
                qkv_bias = qkv_bias.reshape((3, self.num_heads, self.head_dim))
                qkv_bias_tensor = paddle.to_tensor(
                    qkv_bias, stop_gradient=False
                )
                out_linear_bias = paddle.to_tensor(
                    self.out_proj.bias, stop_gradient=False
                )

            ln1_scale = paddle.to_tensor(self.norm1.weight, stop_gradient=False)
            ln1_bias = paddle.to_tensor(self.norm1.bias, stop_gradient=False)
            ln2_scale = paddle.to_tensor(self.norm2.weight, stop_gradient=False)
            ln2_bias = paddle.to_tensor(self.norm2.bias, stop_gradient=False)

            q_proj_weight = q_proj_weight.numpy().transpose((1, 0))
            k_proj_weight = k_proj_weight.numpy().transpose((1, 0))
            v_proj_weight = v_proj_weight.numpy().transpose((1, 0))
            qkv_weight = np.concatenate(
                (q_proj_weight, k_proj_weight, v_proj_weight)
            )
            qkv_weight = qkv_weight.reshape(
                (3, self.num_heads, self.head_dim, self.embed_dim)
            )

            x = paddle.to_tensor(self.query, stop_gradient=False)
            cache_kv = None
            if self.has_attn_mask:
                attn_mask = paddle.to_tensor(
                    self.attn_mask, stop_gradient=False
                )
            else:
                attn_mask = None
            qkv_weight_tensor = paddle.to_tensor(
                qkv_weight, stop_gradient=False
            )
            epsilon = 1e-05
            ln2_epsilon = 1e-05

            if attn_mask is not None:
                attn_mask = _convert_attention_mask(attn_mask, x.dtype)
            final_out = incubate_f.fused_multi_head_attention(
                x,
                qkv_weight_tensor,
                out_linear_weight,
                self.pre_layer_norm,
                ln1_scale,
                ln1_bias,
                ln2_scale,
                ln2_bias,
                epsilon,
                qkv_bias_tensor,
                out_linear_bias,
                cache_kv,
                attn_mask,
                self.dropout_prob,
                self.attn_dropout_prob,
                ln2_epsilon,
            )

            paddle.autograd.backward(
                [final_out], [paddle.to_tensor(self.dout)], retain_graph=True
            )
            return final_out, x.grad

        def test_fused_attention_op(self):
            final_out_ref, x_grad_ref = self.GetBaselineOut()
            final_out, x_grad = self.GetFusedAttentionOut()
            np.testing.assert_allclose(
                final_out_ref, final_out.numpy(), rtol=self.rtol, atol=self.atol
            )
            np.testing.assert_allclose(
                x_grad_ref, x_grad.numpy(), rtol=self.rtol, atol=self.atol
            )

    class TestFusedAttentionOpPreLn(TestFusedAttentionOp):
        def config(self):
            super().config()
            self.pre_layer_norm = True

    class TestFusedAttentionOpNoneAttnMask(TestFusedAttentionOp):
        def config(self):
            super().config()
            self.pre_layer_norm = True
            self.has_attn_mask = False


support_types = get_xpu_op_support_types('fused_attention')
for stype in support_types:
    create_test_class(globals(), XPUTestFusedAttentionOp, stype)

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