# Copyright (c) 2022 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 copy
import inspect
import json
import math
import os
import time

import paddle
import paddle.nn as nn
import paddle.nn.functional as F
from paddle.metric import Accuracy
from paddle.utils import try_import

from ..data import Pad
from ..metrics import ChunkEvaluator
from ..metrics.squad import compute_prediction, squad_evaluate
from ..transformers import export_model
from ..transformers.model_outputs import BaseModelOutputWithPoolingAndCrossAttentions
from ..transformers.ofa_utils import (
    compute_neuron_head_importance,
    encoder_layer_ofa_forward,
    encoder_ofa_forward,
    mha_ofa_forward,
    prepare_qkv_ofa,
    reorder_neuron_head,
)
from ..utils.env import PADDLE_INFERENCE_MODEL_SUFFIX, PADDLE_INFERENCE_WEIGHTS_SUFFIX
from ..utils.log import logger
from .trainer import Trainer


def global_try_import_slim():
    global paddleslim
    try_import("paddleslim")
    import paddleslim


def compress(self, custom_evaluate=None):
    """
    Supports pruning DynaBERT and post-training quantization. If both are
    needed, pruning DynaBERT would be performed before quantizaton.
    """
    args = self.args
    self.custom_evaluate = custom_evaluate
    if "dynabert" in args.strategy:
        global_try_import_slim()
        if self.args.width_mult_list is not None:
            self.args.width_mult_list = [eval(width_mult) for width_mult in self.args.width_mult_list]
        class_name = self.model.__class__.__name__
        if (
            "SequenceClassification" not in class_name
            and "TokenClassification" not in class_name
            and "QuestionAnswering" not in class_name
        ):
            assert (
                self.custom_evaluate is not None
            ), "Custom model using DynaBERT strategy needs to pass in parameters `custom_evaluate`."
        model = copy.deepcopy(self.model)
        self.original_model = model
        _dynabert(self, self.model)

        del self.original_model
        if "ptq" in args.strategy or "qat" in args.strategy:
            output_dir_list = []
            for width_mult in args.width_mult_list:
                output_dir_width = os.path.join(args.output_dir, "width_mult_" + str(round(width_mult, 2)))
                if "ptq" in args.strategy:
                    output_dir_list += self.quant(output_dir_width, "ptq")
                elif "qat" in args.strategy:
                    self.quant(output_dir_width, "qat")
                    output_dir_list.append(output_dir_width)
        if "embeddings" in args.strategy:
            if "ptq" not in args.strategy and "qat" not in args.strategy:
                output_dir_list = []
                for width_mult in args.width_mult_list:
                    output_dir_width = os.path.join(
                        args.output_dir, "width_mult_" + str(round(width_mult, 2)), args.input_filename_prefix
                    )
                    self.quant(output_dir_width, "embeddings")
            else:
                for output_dir in output_dir_list:
                    self.quant(os.path.join(output_dir, args.output_filename_prefix), "embeddings")

    elif "ptq" in args.strategy:
        # When input model is an inference model
        if args.input_infer_model_path is not None:
            model_dir = os.path.dirname(args.input_infer_model_path)
            self.args.input_filename_prefix = os.path.basename(args.input_infer_model_path)
            output_dir_list = self.quant(model_dir, "ptq")
        # Input model is load from Trainer API in dygraph.
        else:
            # When input model is a dygraph.
            # exports model and then do 'ptq'
            # Prefix of `export_model` is 'model'
            self.args.input_filename_prefix = "model"
            input_spec = generate_input_spec(self.model, self.train_dataset, self.args.input_dtype)
            input_dir = args.output_dir
            export_model(model=self.model, input_spec=input_spec, path=input_dir)
            output_dir_list = self.quant(input_dir, "ptq")
        if "embeddings" in args.strategy:
            for output_dir in output_dir_list:
                self.quant(os.path.join(output_dir, args.output_filename_prefix), "embeddings")
    elif "qat" in args.strategy:
        global_try_import_slim()
        self.quant(args.output_dir, "qat")
        if "embeddings" in args.strategy:
            self.quant(os.path.join(args.output_dir, args.output_filename_prefix), "embeddings")


def quant(self, model_dir, strategy):
    """
    Supports Post-Training Quantization, Quantization Aware Training and
    Embedding Quantization.
    """
    if strategy == "ptq":
        return _post_training_quantization_grid_search(self, model_dir)
    elif strategy == "qat":
        _quant_aware_training_dynamic(self, model_dir)
    elif strategy == "embeddings":
        _quant_embeddings(self, model_dir)


def generate_input_spec(model, dataset, input_dtype="int64"):
    model_para_keys = inspect.signature(model.forward).parameters.keys()
    input_num = 0
    for key in dataset[0].keys():
        if key in model_para_keys and key not in ("labels", "start_positions", "end_positions"):
            input_num += 1
    input_spec = [paddle.static.InputSpec(shape=[None, None], dtype=input_dtype) for i in range(input_num)]
    return input_spec


def _dynabert(self, model):
    args = self.args
    model = _replace_auto_model_forward(model)
    if args.width_mult_list is None:
        args.width_mult_list = [0.75]
    # Each batch is a dict.
    train_dataloader = self.get_train_dataloader()
    eval_dataloader = self.get_eval_dataloader(self.eval_dataset)
    if "QuestionAnswering" in model.__class__.__name__:
        eval_dataloader_with_label = self.get_eval_dataloader(self.eval_examples)
        ofa_model, teacher_model = _dynabert_init(self, model, eval_dataloader_with_label)
    else:
        ofa_model, teacher_model = _dynabert_init(self, model, eval_dataloader)

    # TODO: args.gradient_accumulation_steps
    if args.max_steps > 0:
        args.num_training_steps = args.max_steps
        args.num_train_epochs = math.ceil(args.num_training_steps / len(train_dataloader))
    else:
        args.num_training_steps = len(train_dataloader) * args.num_train_epochs
        args.num_train_epochs = math.ceil(args.num_train_epochs)
    self.create_optimizer_and_scheduler(num_training_steps=args.num_training_steps)

    ofa_model = _dynabert_training(
        self, ofa_model, model, teacher_model, train_dataloader, eval_dataloader, args.num_train_epochs
    )
    self.reset_optimizer_and_scheduler()

    # Each width_mult best model would be exported.
    _dynabert_export(self)

    ofa_model, ofa_model.model = _recover_transformer_func(ofa_model, True), _recover_transformer_func(
        ofa_model.model, True
    )
    ofa_model.model = _recover_auto_model_forward(ofa_model.model)
    logger.info("Pruning is finished using DynaBERT strategy.")


def _replace_transformer_func(self):
    nn.MultiHeadAttention._ori_forward = paddle.nn.MultiHeadAttention.forward
    nn.MultiHeadAttention._ori_prepare_qkv = nn.MultiHeadAttention._prepare_qkv

    nn.MultiHeadAttention._forward = mha_ofa_forward
    nn.MultiHeadAttention.__prepare_qkv = prepare_qkv_ofa
    nn.TransformerEncoder._forward = encoder_ofa_forward
    nn.TransformerEncoderLayer._forward = encoder_layer_ofa_forward

    def init_func(layer):
        if isinstance(layer, nn.MultiHeadAttention):
            layer.forward = layer._forward
            layer._prepare_qkv = layer.__prepare_qkv
        elif isinstance(layer, nn.TransformerEncoderLayer):
            layer.forward = layer._forward
        elif isinstance(layer, nn.TransformerEncoder):
            layer.forward = layer._forward

    for layer in self.children():
        layer.apply(init_func)
    return self


def _recover_transformer_func(self, all_recover=False):
    def init_func(layer):
        if isinstance(layer, nn.MultiHeadAttention):
            layer.forward = layer._ori_forward
        elif isinstance(layer, nn.TransformerEncoderLayer):
            layer.forward = layer._ori_forward
        elif isinstance(layer, nn.TransformerEncoder):
            layer.forward = layer._ori_forward
        if all_recover:
            if isinstance(layer, nn.MultiHeadAttention):
                layer._prepare_qkv = layer._ori_prepare_qkv

    for layer in self.children():
        layer.apply(init_func)

    return self


def _replace_auto_model_forward(self):
    self.base_model_class._forward = auto_model_dynabert_forward
    self.base_model_class._ori_forward = self.base_model_class.forward

    def init_func(layer):
        if isinstance(layer, self.base_model_class):
            layer.forward = layer._forward

    for layer in self.children():
        layer.apply(init_func)
    return self


def _replace_auto_model_qat_forward(self):
    self.base_model_class._forward = auto_model_forward
    self.base_model_class._ori_forward = self.base_model_class.forward

    def init_func(layer):
        if isinstance(layer, self.base_model_class):
            layer.forward = layer._forward

    for layer in self.children():
        layer.apply(init_func)
    return self


def _recover_auto_model_forward(self):
    def init_func(layer):
        if isinstance(
            layer,
            self.base_model_class if not isinstance(self, paddle.DataParallel) else self._layers.base_model_class,
        ):
            layer.forward = layer._ori_forward

    for layer in self._layers.children() if isinstance(self, paddle.DataParallel) else self.children():
        layer.apply(init_func)
    return self


def _dynabert_init(self, model, eval_dataloader):
    from paddleslim.nas.ofa import OFA, DistillConfig, utils
    from paddleslim.nas.ofa.convert_super import Convert, supernet

    # Step1: Initialize a dictionary to save the weights from the origin model.
    origin_weights = model.state_dict()

    # Step2: Define teacher model.
    teacher_model = copy.deepcopy(model)

    # Step3: Convert origin model to supernet.
    sp_config = supernet(expand_ratio=[1.0])
    model = Convert(sp_config).convert(model)

    # Use weights saved in the dictionary to initialize supernet.
    utils.set_state_dict(model, origin_weights)
    del origin_weights

    # Step4: Config about distillation.
    mapping_layers = [model.base_model_prefix + ".embeddings"]
    for idx in range(model.base_model.config["num_hidden_layers"]):
        mapping_layers.append(model.base_model_prefix + ".encoder.layers.{}".format(idx))

    default_distill_config = {
        "lambda_distill": 0.1,
        "teacher_model": teacher_model,
        "mapping_layers": mapping_layers,
    }
    distill_config = DistillConfig(**default_distill_config)

    # Step5: Config in supernet training.
    ofa_model = OFA(model, distill_config=distill_config, elastic_order=["width"])

    # Step6: Calculate the importance of neurons and head,
    # and then reorder them according to the importance.
    ofa_model.model, ofa_model = _replace_transformer_func(ofa_model.model), _replace_transformer_func(ofa_model)
    head_importance, neuron_importance = compute_neuron_head_importance(
        model=ofa_model.model,
        data_loader=eval_dataloader,
        loss_fct=self.criterion,
        num_layers=model.base_model.config["num_hidden_layers"],
        num_heads=model.base_model.config["num_attention_heads"],
        label_names=self.args.label_names,
    )

    reorder_neuron_head(ofa_model.model, head_importance, neuron_importance)

    if paddle.distributed.get_world_size() > 1:
        ofa_model.model = paddle.DataParallel(ofa_model.model)

    return ofa_model, teacher_model


def check_dynabert_config(net_config, width_mult):
    """
    Corrects net_config for OFA model if necessary.
    """
    if "electra.embeddings_project" in net_config:
        net_config["electra.embeddings_project"]["expand_ratio"] = 1.0
    for key in net_config:
        # Makes sure to expands the size of the last dim to `width_mult` for
        # these Linear weights.
        if "q_proj" in key or "k_proj" in key or "v_proj" in key or "linear1" in key:
            net_config[key]["expand_ratio"] = width_mult
        # Keeps the size of the last dim of these Linear weights same as
        # before.
        elif "out_proj" in key or "linear2" in key:
            net_config[key]["expand_ratio"] = 1.0
    return net_config


def evaluate(self, model, data_loader):
    if self.custom_evaluate is not None:
        return self.custom_evaluate(self, model, data_loader)
    if isinstance(model, paddleslim.nas.ofa.OFA):
        class_name = model.model.__class__.__name__
    else:
        class_name = model.__class__.__name__
    if "SequenceClassification" in class_name:
        return evaluate_seq_cls(self, model, data_loader)
    elif "QuestionAnswering" in class_name:
        return evaluate_qa(self, model, data_loader)
    elif "TokenClassification" in class_name:
        return evaluate_token_cls(self, model, data_loader)
    else:
        raise NotImplementedError(
            "Model to be compressed is an instance of a custom class, "
            "so function `evaluate(self, model, data_loader)` should be "
            "implemented, and `model` should support both `paddle.nn.layer` "
            "and `paddleslim.nas.ofa.OFA` instances, and it should return "
            "a single float for precision value, such as acc."
        )


@paddle.no_grad()
def evaluate_qa(self, model, data_loader):
    model.eval()
    all_start_logits = []
    all_end_logits = []
    for batch in data_loader:
        logits = model(input_ids=batch["input_ids"], token_type_ids=batch["token_type_ids"])
        if isinstance(model, paddleslim.nas.ofa.OFA):
            start_logits_tensor, end_logits_tensor = logits[0]
        else:
            start_logits_tensor, end_logits_tensor = logits
        for idx in range(start_logits_tensor.shape[0]):
            all_start_logits.append(start_logits_tensor.numpy()[idx])
            all_end_logits.append(end_logits_tensor.numpy()[idx])
    n_best_size = 20
    max_answer_length = 50
    all_predictions, _, _ = compute_prediction(
        self.eval_examples,
        self.eval_dataset,
        (all_start_logits, all_end_logits),
        False,
        n_best_size,
        max_answer_length,
    )
    res = squad_evaluate(
        examples=[raw_data for raw_data in self.eval_examples], preds=all_predictions, is_whitespace_splited=False
    )
    logger.info("EM: %f, F1: %f, " % (res["exact"], res["f1"]))
    res = res["exact"]
    model.train()
    return res


@paddle.no_grad()
def evaluate_seq_cls(self, model, data_loader):
    metric = Accuracy()
    model.eval()
    metric.reset()
    for batch in data_loader:
        labels = batch.pop("labels")
        logits = model(**batch)
        if isinstance(model, paddleslim.nas.ofa.OFA):
            logits = logits[0]
        correct = metric.compute(logits, labels)
        metric.update(correct)
    res = metric.accumulate()
    logger.info("acc: %s, " % res)
    model.train()
    return res


@paddle.no_grad()
def evaluate_token_cls(self, model, data_loader):
    metric = ChunkEvaluator(label_list=self.train_dataset.label_list)
    model.eval()
    metric.reset()
    for batch in data_loader:
        logits = model(input_ids=batch["input_ids"], token_type_ids=batch["token_type_ids"])
        if isinstance(model, paddleslim.nas.ofa.OFA):
            logits = logits[0]
        preds = logits.argmax(axis=2)
        seq_len = paddle.sum(batch["labels"] != self.train_dataset.ignore_label, axis=-1)
        num_infer_chunks, num_label_chunks, num_correct_chunks = metric.compute(seq_len, preds, batch["labels"])
        metric.update(num_infer_chunks.numpy(), num_label_chunks.numpy(), num_correct_chunks.numpy())
    res = metric.accumulate()
    logger.info("precision: %f, recall: %f, f1_score: %f" % (res[0], res[1], res[2]))
    res = res[2]
    model.train()
    return res


def _dynabert_training(self, ofa_model, model, teacher_model, train_dataloader, eval_dataloader, num_train_epochs):
    from paddleslim.nas.ofa import utils

    global_step = 0
    lambda_logit = 1.0
    tic_train = time.time()
    best_acc = [0.0] * len(self.args.width_mult_list)
    acc = 0.0

    logger.info("Teacher's evaluation starts.")
    tic_eval = time.time()
    evaluate(self, teacher_model, eval_dataloader)
    logger.info("eval done total: %s s" % (time.time() - tic_eval))

    logger.info("DynaBERT training starts. This period will cost some time.")
    for epoch in range(num_train_epochs):
        # Step7: Set current epoch and task.
        ofa_model.set_epoch(epoch)
        ofa_model.set_task("width")
        for step, batch in enumerate(train_dataloader):
            global_step += 1
            for width_mult in self.args.width_mult_list:
                # Step8: Broadcast supernet config from width_mult,
                # and use this config in supernet training.
                net_config = utils.dynabert_config(ofa_model, width_mult)
                net_config = check_dynabert_config(net_config, width_mult)
                ofa_model.set_net_config(net_config)
                if "token_type_ids" in batch:
                    logits, teacher_logits = ofa_model(
                        input_ids=batch["input_ids"],
                        token_type_ids=batch["token_type_ids"],
                        attention_mask=[None, None],
                    )
                else:
                    logits, teacher_logits = ofa_model(batch["input_ids"], attention_mask=[None, None])
                rep_loss = ofa_model.calc_distill_loss()
                if isinstance(logits, tuple):
                    logit_loss, num_logit = 0, 0
                    for i in range(len(logits)):
                        try:
                            logit_loss += soft_cross_entropy(logits[i], teacher_logits[i].detach())
                            num_logit += 1
                        except RuntimeError:
                            pass
                    logit_loss /= num_logit
                else:
                    logit_loss = soft_cross_entropy(logits, teacher_logits.detach())
                loss = rep_loss + lambda_logit * logit_loss
                loss.backward()
            self.optimizer.step()
            self.lr_scheduler.step()
            self.optimizer.clear_grad()
            if global_step % self.args.logging_steps == 0:
                if paddle.distributed.get_rank() == 0:
                    logger.info(
                        "global step %d, epoch: %d, batch: %d, lr: %.3e, loss: %f, speed: %.2f step/s"
                        % (
                            global_step,
                            epoch,
                            step,
                            self.optimizer.get_lr(),
                            loss,
                            self.args.logging_steps / (time.time() - tic_train),
                        )
                    )
                tic_train = time.time()

            if global_step % self.args.save_steps == 0:
                for idx, width_mult in enumerate(self.args.width_mult_list):
                    net_config = utils.dynabert_config(ofa_model, width_mult)
                    net_config = check_dynabert_config(net_config, width_mult)
                    ofa_model.set_net_config(net_config)
                    tic_eval = time.time()
                    logger.info("width_mult %s:" % round(width_mult, 2))
                    acc = evaluate(self, ofa_model, eval_dataloader)
                    if acc > best_acc[idx]:
                        best_acc[idx] = acc
                        if paddle.distributed.get_rank() == 0:
                            output_dir_width = os.path.join(
                                self.args.output_dir, "width_mult_" + str(round(width_mult, 2))
                            )
                            if not os.path.exists(output_dir_width):
                                os.makedirs(output_dir_width)
                            # need better way to get inner model of DataParallel
                            model_to_save = model._layers if isinstance(model, paddle.DataParallel) else model
                            model_to_save.save_pretrained(output_dir_width)
                    logger.info("eval done total: %s s" % (time.time() - tic_eval))
            if global_step > self.args.num_training_steps:
                if best_acc[idx] == 0.0:
                    output_dir_width = os.path.join(self.args.output_dir, "width_mult_" + str(round(width_mult, 2)))
                    if not os.path.exists(output_dir_width):
                        os.makedirs(output_dir_width)
                    # need better way to get inner model of DataParallel
                    model_to_save = model._layers if isinstance(model, paddle.DataParallel) else model
                    model_to_save.save_pretrained(output_dir_width)
                logger.info("Best result of width_mult %.2f: %.4f" % (width_mult, best_acc[idx]))
                return ofa_model

    for idx, width_mult in enumerate(self.args.width_mult_list):
        logger.info("Best result of width_mult %.2f: %.4f" % (width_mult, best_acc[idx]))
    return ofa_model


def _get_dynabert_model(model, width_mult):
    for layer in model.base_model.encoder.layers:
        # Multi-Head Attention
        layer.self_attn.num_heads = int(layer.self_attn.num_heads * width_mult)
        layer.self_attn.q_proj = nn.Linear(
            layer.self_attn.q_proj.weight.shape[0],
            int(layer.self_attn.q_proj.weight.shape[1] * width_mult),
            layer.self_attn.q_proj._weight_attr,
            layer.self_attn.q_proj._bias_attr,
        )
        layer.self_attn.k_proj = nn.Linear(
            layer.self_attn.k_proj.weight.shape[0],
            int(layer.self_attn.k_proj.weight.shape[1] * width_mult),
            layer.self_attn.k_proj._weight_attr,
            layer.self_attn.k_proj._bias_attr,
        )
        layer.self_attn.v_proj = nn.Linear(
            layer.self_attn.v_proj.weight.shape[0],
            int(layer.self_attn.v_proj.weight.shape[1] * width_mult),
            layer.self_attn.v_proj._weight_attr,
            layer.self_attn.v_proj._bias_attr,
        )
        layer.self_attn.out_proj = nn.Linear(
            int(layer.self_attn.out_proj.weight.shape[0] * width_mult),
            layer.self_attn.out_proj.weight.shape[1],
            layer.self_attn.out_proj._weight_attr,
            layer.self_attn.out_proj._bias_attr,
        )

        # Feed Forward
        layer.linear1 = nn.Linear(
            layer.linear1.weight.shape[0],
            int(layer.linear1.weight.shape[1] * width_mult),
            layer.linear1._weight_attr,
            layer.linear1._bias_attr,
        )
        layer.linear2 = nn.Linear(
            int(layer.linear2.weight.shape[0] * width_mult),
            layer.linear2.weight.shape[1],
            layer.linear2._weight_attr,
            layer.linear2._bias_attr,
        )
    return model


def _load_parameters(dynabert_model, ori_state_dict):
    dynabert_state_dict = dynabert_model.state_dict()
    for key in ori_state_dict.keys():
        # Removes '.fn' from ofa model parameters
        dynabert_key = key.replace(".fn", "")
        if dynabert_key not in dynabert_state_dict.keys():
            logger.warning("Failed to export parameter %s" % key)
        else:
            dynabert_shape = dynabert_state_dict[dynabert_key].shape
            if len(dynabert_shape) == 2:
                dynabert_state_dict[dynabert_key] = ori_state_dict[key][: dynabert_shape[0], : dynabert_shape[1]]
            elif len(dynabert_shape) == 1:
                dynabert_state_dict[dynabert_key] = ori_state_dict[key][: dynabert_shape[0]]
            else:
                raise ValueError("Please check input model. Length of shape should be 1 or 2 for any parameter.")
    dynabert_model.set_state_dict(dynabert_state_dict)
    return dynabert_model


def _export_dynamic_dynabert_model(self, width_mult):
    model_dir = os.path.join(self.args.output_dir, "width_mult_" + str(round(width_mult, 2)))
    state_dict = paddle.load(os.path.join(model_dir, "model_state.pdparams"))
    dynabert_model = _get_dynabert_model(self.original_model, width_mult)
    dynabert_model = _load_parameters(dynabert_model, state_dict)
    return dynabert_model


def _dynabert_export(self):
    for width_mult in self.args.width_mult_list:
        dynabert_model = _export_dynamic_dynabert_model(self, width_mult)
        self.model = dynabert_model
        if "qat" not in self.args.strategy:
            input_spec = generate_input_spec(self.model, self.train_dataset, self.args.input_dtype)
            pruned_infer_model_dir = os.path.join(self.args.output_dir, "width_mult_" + str(round(width_mult, 2)))
            export_model(model=dynabert_model, input_spec=input_spec, path=pruned_infer_model_dir)
            self.args.input_filename_prefix = "model"
            logger.info("Pruned models have been exported.")


def _post_training_quantization_grid_search(self, model_dir):
    args = self.args
    if args.batch_num_list is None:
        args.batch_num_list = [1]
    if args.batch_size_list is None:
        args.batch_size_list = [4, 8, 16]
    if args.algo_list is None:
        args.algo_list = ["mse", "KL"]

    paddle.enable_static()
    place = paddle.set_device(args.device)
    exe = paddle.static.Executor(place)

    args.output_filename_prefix = "int8"
    output_dir_list = []

    def _post_training_quantization(algo, batch_size, batch_nums):
        from paddle.static.quantization import PostTrainingQuantization

        def _batch_generator_func():
            param_name_list = []
            for key in self.eval_dataset[0]:
                if key in ("input_ids", "token_type_ids"):
                    param_name_list.append(key)
            batch_data = [[] for i in range(len(param_name_list))]
            for data in self.eval_dataset:
                for i in range(len(param_name_list)):
                    batch_data[i].append(data[param_name_list[i]])
                if len(batch_data[0]) == batch_size:
                    for i in range(len(param_name_list)):
                        batch_data[i] = Pad(axis=0, pad_val=0)(batch_data[i])
                    yield batch_data
                    batch_data = [[] for i in range(len(param_name_list))]

        post_training_quantization = PostTrainingQuantization(
            executor=exe,
            batch_generator=_batch_generator_func,
            model_dir=model_dir,
            model_filename=args.input_filename_prefix + PADDLE_INFERENCE_MODEL_SUFFIX,
            params_filename=args.input_filename_prefix + PADDLE_INFERENCE_WEIGHTS_SUFFIX,
            batch_size=batch_size,
            batch_nums=batch_nums,
            scope=None,
            algo=algo,
            hist_percent=0.9999,
            round_type=args.round_type,
            bias_correction=args.bias_correction,
            quantizable_op_type=["matmul", "matmul_v2"],
            is_full_quantize=False,
            weight_bits=8,
            activation_bits=8,
            activation_quantize_type="range_abs_max"
            if args.activation_quantize_type is None
            else args.activation_quantize_type,
            weight_quantize_type=args.weight_quantize_type,
            onnx_format=args.onnx_format,
            optimize_model=False,
        )
        post_training_quantization.quantize()
        save_model_path = os.path.join(model_dir, algo + "_".join([str(batch_size), str(batch_nums)]))
        post_training_quantization.save_quantized_model(
            save_model_path=save_model_path,
            model_filename=args.output_filename_prefix + PADDLE_INFERENCE_MODEL_SUFFIX,
            params_filename=args.output_filename_prefix + PADDLE_INFERENCE_WEIGHTS_SUFFIX,
        )
        output_dir_list.append(save_model_path)

    logger.info("Post training quantization starts.")
    for algo in args.algo_list:
        for batch_size in args.batch_size_list:
            for batch_nums in args.batch_num_list:
                _post_training_quantization(algo, batch_size, batch_nums)

    paddle.disable_static()
    logger.info("Post training quantization ends and quantized models are saved.")
    return output_dir_list


def _quant_aware_training_dynamic(self, input_dir):
    # TODO: Switch from multiple GPUs to a single GPU.
    from paddleslim import QAT

    args = self.args
    args.output_filename_prefix = "int8"

    quant_config = {
        # It defaults to None, which means that no preprocessing is performed
        # on the active value."
        "activation_preprocess_type": "PACT" if args.use_pact else None,
        # It defaults to None, which means that no preprocessing is performed
        # on weights.
        "weight_preprocess_type": "PACT" if args.use_pact else None,
        "weight_quantize_type": args.weight_quantize_type,
        "activation_quantize_type": "moving_average_abs_max"
        if args.activation_quantize_type is None
        else args.activation_quantize_type,
        "weight_bits": 8,
        "activation_bits": 8,
        "dtype": "int8",
        # window size for 'range_abs_max' quantization. default is 10000
        "window_size": 10000,
        "quantizable_layer_type": ["Linear", "Conv2D"],
        "moving_rate": args.moving_rate,
        "onnx_format": args.onnx_format,
    }

    if not os.path.exists(input_dir):
        os.makedirs(input_dir)

    output_param_path = os.path.join(input_dir, "best_quant.pdparams")

    train_dataloader = self.get_train_dataloader()
    eval_dataloader = self.get_eval_dataloader(self.eval_dataset)

    # TODO: args.gradient_accumulation_steps
    if args.max_steps > 0:
        args.num_training_steps = args.max_steps
        args.num_train_epochs = math.ceil(args.num_training_steps / len(train_dataloader))
    else:
        args.num_training_steps = len(train_dataloader) * args.num_train_epochs
        args.num_train_epochs = math.ceil(args.num_train_epochs)

    self.create_optimizer_and_scheduler(num_training_steps=args.num_training_steps)

    logger.info("Evaluating FP32 model before quantization aware training.")

    tic_eval = time.time()

    acc = evaluate(self, self.model, eval_dataloader)
    logger.info("eval done total: %s s" % (time.time() - tic_eval))

    quanter = QAT(config=quant_config)
    self.model = _replace_auto_model_qat_forward(self.model)
    quanter.quantize(self.model)

    global_step = 0
    tic_train = time.time()
    best_acc, acc = 0.0, 0.0

    logger.info("Quant aware training starts.")
    # Train self.model
    for epoch in range(args.num_train_epochs):
        for step, batch in enumerate(train_dataloader):
            global_step += 1
            labels = None
            if self.args.label_names is None:
                if "labels" in batch:
                    labels = batch.pop("labels")
                elif "start_positions" in batch and "end_positions" in batch:
                    labels = (batch.pop("start_positions"), batch.pop("end_positions"))
            else:
                labels = []
                for label in self.args.label_names:
                    labels.append(batch.pop(label))
                labels = tuple(labels)
            model_para_keys = inspect.signature(self.model.forward).parameters.keys()
            inputs = {}
            for key in batch:
                if key in model_para_keys:
                    inputs[key] = batch[key]
            logits = self.model(**inputs)
            loss = self.criterion(logits, labels)
            loss.backward()

            self.optimizer.step()
            self.lr_scheduler.step()
            self.optimizer.clear_grad()
            if global_step % self.args.logging_steps == 0:
                if paddle.distributed.get_rank() == 0:
                    logger.info(
                        "global step %d, epoch: %d, batch: %d, lr: %.3e, loss: %f, speed: %.2f step/s"
                        % (
                            global_step,
                            epoch,
                            step,
                            self.optimizer.get_lr(),
                            loss,
                            args.logging_steps / (time.time() - tic_train),
                        )
                    )
                tic_train = time.time()

            if global_step % args.save_steps == 0:
                tic_eval = time.time()
                acc = evaluate(self, self.model, eval_dataloader)
                if acc > best_acc:
                    best_acc = acc
                    if paddle.distributed.get_rank() == 0:
                        # need better way to get inner model of DataParallel
                        model_to_save = (
                            self.model._layers if isinstance(self.model, paddle.DataParallel) else self.model
                        )
                        paddle.save(model_to_save.state_dict(), output_param_path)
                logger.info("eval done total: %s s" % (time.time() - tic_eval))
    logger.info("Best result: %.4f" % best_acc)
    self.model.set_state_dict(paddle.load(output_param_path))

    input_spec = generate_input_spec(self.model, self.train_dataset, self.args.input_dtype)

    quanter.save_quantized_model(
        self.model, os.path.join(input_dir, args.output_filename_prefix), input_spec=input_spec
    )

    self.model = _recover_auto_model_forward(self.model)
    logger.info(
        "Quant aware training ends and quantized models are saved to %s."
        % os.path.join(input_dir, args.output_filename_prefix)
    )


def _quant_embeddings(self, input_prefix):
    import paddleslim.quant as quant

    self.args.output_filename_prefix = "quant_emb"

    paddle.enable_static()
    place = paddle.set_device(self.args.device)
    exe = paddle.static.Executor(place)
    main_program, feed_target_names, fetch_targets = paddle.static.load_inference_model(input_prefix, exe)

    config = {"quantize_op_types": ["lookup_table_v2"], "lookup_table_v2": {"quantize_type": "log"}}

    quant_emb_program = quant.quant_embedding(main_program, place, config)

    input_dir = os.path.dirname(input_prefix)

    paddle.static.save_inference_model(
        os.path.join(input_dir, self.args.output_filename_prefix),
        feed_target_names,
        fetch_targets,
        exe,
        program=quant_emb_program,
    )


def auto_model_dynabert_forward(
    self,
    input_ids,
    token_type_ids=None,
    position_ids=None,
    attention_mask=[None, None],
    task_type_ids=None,
    past_key_values=None,
    inputs_embeds=None,
    use_cache=None,
    output_hidden_states=False,
    output_attentions=False,
    return_dict=False,
):
    kwargs = locals()
    wtype = (
        self.encoder.layers[0].norm1.fn.weight.dtype
        if hasattr(self.encoder.layers[0].norm1, "fn")
        else self.encoder.layers[0].norm1.weight.dtype
    )
    if input_ids is not None and inputs_embeds is not None:
        raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time.")
    elif input_ids is not None:
        input_shape = input_ids.shape
    elif inputs_embeds is not None:
        input_shape = inputs_embeds.shape[:-1]
    else:
        raise ValueError("You have to specify either input_ids or inputs_embeds")

    past_key_values_length = None
    if past_key_values is not None:
        past_key_values_length = past_key_values[0][0].shape[2]

    if attention_mask is None:
        # input_ids[0][0] is equals to 0 while exporting.
        if input_ids[0][0] != 0:
            attention_mask = [None, None]
            attention_mask[0] = paddle.unsqueeze((input_ids == self.pad_token_id).astype(wtype) * -1e4, axis=[1, 2])
        else:
            if past_key_values is not None:
                batch_size = past_key_values[0][0].shape[0]
                past_mask = paddle.zeros([batch_size, 1, 1, past_key_values_length], dtype=attention_mask.dtype)
                attention_mask = paddle.concat([past_mask, attention_mask], axis=-1)
    elif isinstance(attention_mask, paddle.Tensor) and attention_mask.ndim == 2:
        attention_mask = paddle.unsqueeze(attention_mask, axis=[1, 2]).astype(wtype)
        attention_mask = (1.0 - attention_mask) * -1e4
    elif attention_mask[0] is None:
        attention_mask[0] = paddle.unsqueeze((input_ids == self.pad_token_id).astype(wtype) * -1e4, axis=[1, 2])

    embedding_kwargs_keys = inspect.signature(self.embeddings.forward).parameters.keys()
    embedding_kwargs = {}
    for key in embedding_kwargs_keys:
        if key in kwargs.keys():
            embedding_kwargs[key] = kwargs[key]
    embedding_kwargs["input_ids"] = input_ids

    embedding_output = self.embeddings(**embedding_kwargs)
    if hasattr(self, "embeddings_project"):
        embedding_output = self.embeddings_project(embedding_output)

    self.encoder._use_cache = use_cache  # To be consistent with HF

    encoder_kwargs_keys = inspect.signature(self.encoder.forward).parameters.keys()
    encoder_kwargs = {}
    for key in encoder_kwargs_keys:
        if key == "cache":
            encoder_kwargs[key] = past_key_values
        elif key == "src_mask":
            encoder_kwargs[key] = attention_mask
        elif key in kwargs:
            encoder_kwargs[key] = kwargs[key]

    encoder_outputs = self.encoder(embedding_output, **encoder_kwargs)
    if isinstance(encoder_outputs, type(embedding_output)):
        sequence_output = encoder_outputs
        if hasattr(self, "pooler"):
            pooled_output = self.pooler(sequence_output)
        else:
            pooled_output = sequence_output[:, 0]
        return (sequence_output, pooled_output)
    else:
        sequence_output = encoder_outputs[0]
        pooled_output = self.pooler(sequence_output)
        if not return_dict:
            return (sequence_output, pooled_output) + encoder_outputs[1:]

        return BaseModelOutputWithPoolingAndCrossAttentions(
            last_hidden_state=sequence_output,
            pooler_output=pooled_output,
            past_key_values=encoder_outputs.past_key_values,
            hidden_states=encoder_outputs.hidden_states,
            attentions=encoder_outputs.attentions,
        )


def auto_model_forward(
    self,
    input_ids,
    token_type_ids=None,
    position_ids=None,
    attention_mask=None,
    task_type_ids=None,
    past_key_values=None,
    inputs_embeds=None,
    use_cache=None,
    output_hidden_states=False,
    output_attentions=False,
    return_dict=False,
):
    kwargs = locals()
    past_key_values_length = None
    if past_key_values is not None:
        past_key_values_length = past_key_values[0][0].shape[2]

    if attention_mask is None:
        attention_mask = paddle.unsqueeze((input_ids == self.pad_token_id).astype(paddle.float32) * -1e4, axis=[1, 2])
        if past_key_values is not None:
            batch_size = past_key_values[0][0].shape[0]
            past_mask = paddle.zeros([batch_size, 1, 1, past_key_values_length], dtype=attention_mask.dtype)
            attention_mask = paddle.concat([past_mask, attention_mask], axis=-1)
    # For 2D attention_mask from tokenizer
    elif attention_mask.ndim == 2:
        attention_mask = paddle.unsqueeze(attention_mask, axis=[1, 2]).astype(paddle.get_default_dtype())
        attention_mask = (1.0 - attention_mask) * -1e4

    kwargs_keys = inspect.signature(self._ori_forward).parameters.keys()

    model_kwargs = {}
    for key in kwargs_keys:
        model_kwargs[key] = kwargs[key]
    model_kwargs["attention_mask"] = attention_mask
    return self._ori_forward(**model_kwargs)


def soft_cross_entropy(inp, target):
    inp_likelihood = F.log_softmax(inp, axis=-1)
    target_prob = F.softmax(target, axis=-1)
    return -1.0 * paddle.mean(paddle.sum(inp_likelihood * target_prob, axis=-1))


def reset_optimizer_and_scheduler(self):
    self.optimizer, self.lr_scheduler = None, None


def cut_embeddings(model, tokenizer, config, word_emb_index, max_seq_length, max_vocab_size, output_dir):
    if not os.path.exists(output_dir):
        os.makedirs(output_dir)
    state_dict = model.state_dict()

    word_emb_name = model.base_model_prefix + ".embeddings.word_embeddings.weight"
    word_emb_np = state_dict[word_emb_name].cpu().numpy()
    word_emb_np_new = [word_emb_np[idx] for idx in word_emb_index]

    state_dict[word_emb_name] = paddle.to_tensor(word_emb_np_new)
    # Rewrites Position Embedding parameters
    pos_emb_name = model.base_model_prefix + ".embeddings.position_embeddings.weight"
    state_dict[pos_emb_name] = state_dict[pos_emb_name][:max_seq_length, :]

    paddle.save(state_dict, os.path.join(output_dir, "model_state.pdparams"))

    # Rewrites config
    config["max_position_embeddings"] = max_seq_length
    config["vocab_size"] = max_vocab_size
    config.save_pretrained(output_dir)

    # Rewrites vocab file
    vocab_file = os.path.join(output_dir, "vocab.txt")
    f = open(vocab_file, "w")
    for idx in word_emb_index:
        f.write(tokenizer.convert_ids_to_tokens(idx) + "\n")
    f.close()

    tokenizer.init_config["model_max_length"] = max_seq_length
    if "vocab_file" in tokenizer.init_config:
        tokenizer.init_config.pop("vocab_file")
    f = open(os.path.join(output_dir, tokenizer.tokenizer_config_file), "w")

    f.write(json.dumps(tokenizer.init_config))
    f.close()


Trainer.compress = compress
Trainer.quant = quant
Trainer.reset_optimizer_and_scheduler = reset_optimizer_and_scheduler
Trainer.cut_embeddings = cut_embeddings
