# Adopted from https://github.com/lm-sys/FastChat. Below is the original copyright:
# Adopted from tatsu-lab@stanford_alpaca. Below is the original copyright:
#    Copyright 2023 Rohan Taori, Ishaan Gulrajani, Tianyi Zhang, Yann Dubois, Xuechen Li
#
#    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 os
import copy
from dataclasses import dataclass, field
import json
import logging
import pathlib
from typing import Dict, Optional, Sequence, List
import torch
import deepspeed
import glob
import transformers
import tokenizers
import random
import re

from magma.image_processing_magma import MagmaImageProcessor
from magma.processing_magma import MagmaProcessor
from magma.modeling_magma import MagmaForCausalLM
from magma.configuration_magma import MagmaConfig
from transformers import (
    AutoModelForCausalLM,
    AutoProcessor,
    BitsAndBytesConfig,
    Trainer,
    TrainingArguments,    
)
from transformers import AutoTokenizer, AutoConfig
from transformers.trainer import get_model_param_count

from trainer import MagmaTrainer
from data import *

local_rank = None

def rank0_print(*args):
    if local_rank == 0:
        print(*args)

from packaging import version

@dataclass
class ModelArguments:
    model_name_or_path: Optional[str] = field(default="microsoft/Magma-8B")
    version: Optional[str] = field(default="magma_instruct")
    freeze_backbone: bool = field(default=False)
    tune_mm_mlp_adapter: bool = field(default=False)
    vision_tower: Optional[str] = field(default=None)
    vision_tower_ckpt: Optional[str] = field(default=None)
    img_anyres_strategy: Optional[str] = field(default='crop')
    proj_vis_to_txt_tokens: bool = field(default=False)
    img_size: Optional[int] = field(default=640)   # default to the last layer
    vision_backbone: Optional[str] = field(default="convnextlarge")
    tune_vision_tokenizer: Optional[str] = field(default='none')
    mm_vision_select_layer: Optional[int] = field(default=-1)   # default to the last layer
    pretrain_mm_mlp_adapter: Optional[str] = field(default=None)
    mm_projector_type: Optional[str] = field(default='linear')
    mm_use_trace_start_end: bool = field(default=False)
    mm_use_trace_speed: bool = field(default=False)
    mm_use_image_start_end: bool = field(default=False)
    mm_use_image_history: bool = field(default=False)
    mm_use_som_tom: bool = field(default=True)
    mm_use_som_tom_orig_img: bool = field(default=False)
    spatial_quant_size: Optional[int] = field(default=256)
    remove_static_trace_pts: bool = field(default=False)
    mm_use_im_patch_token: bool = field(default=True)
    mm_vision_select_feature: Optional[str] = field(default="patch")
    flash_attn_2_enabled: bool = False
    task: Optional[str] = field(default="agent")


@dataclass
class DataArguments:
    data_path: str = field(default=None,
                           metadata={"help": "Path to the training data."})
    lazy_preprocess: bool = False
    is_multimodal: bool = False
    data_format: str = "llava"
    image_folder: Optional[str] = field(default=None)
    image_aspect_ratio: str = 'square'
    max_num_crops: int = 25
    add_im_loss: bool = False
    training_size: str = 'default'
    show_trace: bool = False


@dataclass
class TrainingArguments(transformers.TrainingArguments):
    cache_dir: Optional[str] = field(default=None)
    optim: str = field(default="adamw_torch")
    remove_unused_columns: bool = field(default=False)
    freeze_mm_mlp_adapter: bool = field(default=False)
    mpt_attn_impl: Optional[str] = field(default="triton")
    model_max_length: int = field(
        default=512,
        metadata={
            "help":
            "Maximum sequence length. Sequences will be right padded (and possibly truncated)."
        },
    )
    double_quant: bool = field(
        default=True,
        metadata={"help": "Compress the quantization statistics through double quantization."}
    )
    quant_type: str = field(
        default="nf4",
        metadata={"help": "Quantization data type to use. Should be one of `fp4` or `nf4`."}
    )
    bits: int = field(
        default=16,
        metadata={"help": "How many bits to use."}
    )
    lora_enable: bool = False
    lora_r: int = 64
    lora_alpha: int = 16
    lora_dropout: float = 0.05
    lora_weight_path: str = ""
    lora_bias: str = "none"
    min_lr_rate: Optional[float] = None
    mm_projector_lr: Optional[float] = None
    vision_tokenizer_lr: Optional[float] = None
    group_by_modality_length: bool = field(default=False)
    local_run: bool = False
    max_grad_norm: float = 1.0
    

def maybe_zero_3(param, ignore_status=False, name=None):
    from deepspeed import zero
    from deepspeed.runtime.zero.partition_parameters import ZeroParamStatus
    if hasattr(param, "ds_id"):
        if param.ds_status == ZeroParamStatus.NOT_AVAILABLE:
            if not ignore_status:
                logging.warning(f"{name}: param.ds_status != ZeroParamStatus.NOT_AVAILABLE: {param.ds_status}")
        with zero.GatheredParameters([param]):
            param = param.data.detach().cpu().clone()
    else:
        param = param.detach().cpu().clone()
    return param


# Borrowed from peft.utils.get_peft_model_state_dict
def get_peft_state_maybe_zero_3(named_params, bias):
    if bias == "none":
        to_return = {k: t for k, t in named_params if "lora_" in k}
    elif bias == "all":
        to_return = {k: t for k, t in named_params if "lora_" in k or "bias" in k}
    elif bias == "lora_only":
        to_return = {}
        maybe_lora_bias = {}
        lora_bias_names = set()
        for k, t in named_params:
            if "lora_" in k:
                to_return[k] = t
                bias_name = k.split("lora_")[0] + "bias"
                lora_bias_names.add(bias_name)
            elif "bias" in k:
                maybe_lora_bias[k] = t
        for k, t in maybe_lora_bias:
            if bias_name in lora_bias_names:
                to_return[bias_name] = t
    else:
        raise NotImplementedError
    to_return = {k: maybe_zero_3(v, ignore_status=True) for k, v in to_return.items()}
    return to_return


def get_peft_state_non_lora_maybe_zero_3(named_params, require_grad_only=True):
    to_return = {k: t for k, t in named_params if "lora_" not in k}
    if require_grad_only:
        to_return = {k: t for k, t in to_return.items() if t.requires_grad}
    to_return = {k: maybe_zero_3(v, ignore_status=True).cpu() for k, v in to_return.items()}
    return to_return


def get_mm_adapter_state_maybe_zero_3(named_params, keys_to_match):
    to_return = {k: t for k, t in named_params if any(key_match in k for key_match in keys_to_match)}
    to_return = {k: maybe_zero_3(v, ignore_status=True).cpu() for k, v in to_return.items()}
    return to_return


def find_all_linear_names(model):
    cls = torch.nn.Linear
    lora_module_names = set()
    multimodal_keywords = ['mm_projector', 'vision_tower', 'vision_resampler']
    for name, module in model.named_modules():
        if any(mm_keyword in name for mm_keyword in multimodal_keywords):
            continue
        if isinstance(module, cls):
            names = name.split('.')
            lora_module_names.add(names[0] if len(names) == 1 else names[-1])

    if 'lm_head' in lora_module_names: # needed for 16-bit
        lora_module_names.remove('lm_head')
    return list(lora_module_names)


def safe_save_model_for_hf_trainer(trainer: transformers.Trainer,
                                   output_dir: str):
    """Collects the state dict and dump to disk."""

    if getattr(trainer.args, "tune_mm_mlp_adapter", False):
        # Only save Adapter
        keys_to_match = ['mm_projector']
        if getattr(trainer.args, "use_im_start_end", False):
            keys_to_match.extend(['embed_tokens', 'embed_in'])

        if getattr(trainer.args, "tune_vision_tokenizer", 'none') == "posembed":
            keys_to_match.extend(['posembed'])
        elif getattr(trainer.args, "tune_vision_tokenizer", 'none') == "decoder":
            keys_to_match.extend(['sem_seg_head.predictor'])
        elif getattr(trainer.args, "tune_vision_tokenizer", 'none') == "all":
            keys_to_match.extend(['vision_tower'])

        weight_to_save = get_mm_adapter_state_maybe_zero_3(trainer.model.named_parameters(), keys_to_match)
        trainer.model.config.save_pretrained(output_dir)

        current_folder = output_dir.split('/')[-1]
        parent_folder = os.path.dirname(output_dir)
        if trainer.args.local_rank == 0 or trainer.args.local_rank == -1:
            if current_folder.startswith('checkpoint-'):
                mm_projector_folder = os.path.join(parent_folder, "mm_projector")
                os.makedirs(mm_projector_folder, exist_ok=True)
                torch.save(weight_to_save, os.path.join(mm_projector_folder, f'{current_folder}.bin'))
            else:
                torch.save(weight_to_save, os.path.join(output_dir, f'mm_projector.bin'))
        return

    if trainer.deepspeed:
        torch.cuda.synchronize()
        trainer.save_model(output_dir)
        return

    state_dict = trainer.model.state_dict()
    if trainer.args.should_save:
        cpu_state_dict = {
            key: value.cpu()
            for key, value in state_dict.items()
        }
        del state_dict
        trainer._save(output_dir, state_dict=cpu_state_dict)  # noqa


def smart_tokenizer_and_embedding_resize(
    special_tokens_dict,
    tokenizer: transformers.PreTrainedTokenizer,
    model: transformers.PreTrainedModel,
):
    """Resize tokenizer and embedding.

    Note: This is the unoptimized version that may make your embedding size not be divisible by 64.
    """
    if isinstance(special_tokens_dict, list):
        num_new_tokens = tokenizer.add_tokens(special_tokens_dict, special_tokens=True)
    else:
        num_new_tokens = tokenizer.add_special_tokens(special_tokens_dict)
    model.resize_token_embeddings(len(tokenizer))    

    new_vocab_size = len(tokenizer)    
    # Update base model and current model config
    if hasattr(model.config, "text_config"):
        model.config.text_config.vocab_size = new_vocab_size
    else:
        model.config.vocab_size = new_vocab_size
    model.vocab_size = new_vocab_size

    if num_new_tokens > 0:
        input_embeddings = model.get_input_embeddings().weight.data
        output_embeddings = model.get_output_embeddings().weight.data

        input_embeddings_avg = input_embeddings[:-num_new_tokens].mean(
            dim=0, keepdim=True)
        output_embeddings_avg = output_embeddings[:-num_new_tokens].mean(
            dim=0, keepdim=True)

        input_embeddings[-num_new_tokens:] = input_embeddings_avg
        output_embeddings[-num_new_tokens:] = output_embeddings_avg


def _tokenize_fn(strings: Sequence[str],
                 tokenizer: transformers.PreTrainedTokenizer) -> Dict:
    """Tokenize a list of strings."""
    tokenized_list = [
        tokenizer(
            text,
            return_tensors="pt",
            padding="longest",
            max_length=tokenizer.model_max_length,
            truncation=True,
        ) for text in strings
    ]
    input_ids = labels = [
        tokenized.input_ids[0] for tokenized in tokenized_list
    ]
    input_ids_lens = labels_lens = [
        tokenized.input_ids.ne(tokenizer.pad_token_id).sum().item()
        for tokenized in tokenized_list
    ]
    return dict(
        input_ids=input_ids,
        labels=labels,
        input_ids_lens=input_ids_lens,
        labels_lens=labels_lens,
    )

def make_supervised_data_module(processor: MagmaProcessor,
                                data_args, 
                                training_args) -> Dict:
    """Make dataset and collator for supervised fine-tuning."""

    train_dataset = build_joint_dataset(
        processor=processor,
        data_path=data_args.data_path,
        data_args=data_args
    )

    if training_args.evaluation_strategy != 'no':
        val_dataset = build_joint_dataset(
            processor=processor,
            data_path=data_args.data_path,
            data_args=data_args,
            is_eval=True
        )    
    else:
        val_dataset = None
    data_collator = DataCollatorForSupervisedDataset(processor=processor)

    return dict(train_dataset=train_dataset,
                eval_dataset=val_dataset,
                data_collator=data_collator)


def train():
    global local_rank

    parser = transformers.HfArgumentParser(
        (ModelArguments, DataArguments, TrainingArguments))
    model_args, data_args, training_args = parser.parse_args_into_dataclasses()
    local_rank = training_args.local_rank
    compute_dtype = (torch.float16 if training_args.fp16 else (torch.bfloat16 if training_args.bf16 else torch.float32))

    if training_args.min_lr_rate is not None:
        training_args.lr_scheduler_kwargs = {'min_lr_rate': training_args.min_lr_rate}

    bnb_model_from_pretrained_args = {}
    if training_args.bits in [4, 8]:
        from transformers import BitsAndBytesConfig
        bnb_model_from_pretrained_args.update(dict(
            device_map={"": training_args.device},
            load_in_4bit=training_args.bits == 4,
            load_in_8bit=training_args.bits == 8,
            quantization_config=BitsAndBytesConfig(
                load_in_4bit=training_args.bits == 4,
                load_in_8bit=training_args.bits == 8,
                llm_int8_skip_modules=["mm_projector"],
                llm_int8_threshold=6.0,
                llm_int8_has_fp16_weight=False,
                bnb_4bit_compute_dtype=compute_dtype,
                bnb_4bit_use_double_quant=training_args.double_quant,
                bnb_4bit_quant_type=training_args.quant_type # {'fp4', 'nf4'}
            )
        ))

    if 'magma' in model_args.model_name_or_path.lower():
        model = MagmaForCausalLM.from_pretrained(
            model_args.model_name_or_path,
            cache_dir=training_args.cache_dir,
            attn_implementation="flash_attention_2" if model_args.flash_attn_2_enabled else None,
            torch_dtype=(torch.bfloat16 if training_args.bf16 else None),
            **bnb_model_from_pretrained_args
        )
        magma_processor = MagmaProcessor.from_pretrained(
            model_args.model_name_or_path,
            trust_remote_code=True
        )        
        model.config.tokenizer_vocab_size = magma_processor.tokenizer.vocab_size
    else:
        vision_config = {
            "img_size": model_args.img_size,
            "anyres_strategy": model_args.img_anyres_strategy,
            "vision_backbone": model_args.vision_backbone,
            "vision_tower": model_args.vision_tower,
            "vision_tower_ckpt": model_args.vision_tower_ckpt,
            "mm_vision_select_layer": model_args.mm_vision_select_layer,
            "mm_vision_select_feature": model_args.mm_vision_select_feature,
            "pretrain_mm_mlp_adapter": model_args.pretrain_mm_mlp_adapter,
            "mm_projector_type": model_args.mm_projector_type,
            "proj_vis_to_txt_tokens": model_args.proj_vis_to_txt_tokens,
            "mm_use_im_patch_token": model_args.mm_use_im_patch_token,
            "vision_feature_layer": "clip_vis_dense",
            "use_cache": False,
        }        
        text_config = AutoConfig.from_pretrained(
            model_args.model_name_or_path, 
            trust_remote_code=True
        )
        magma_config = MagmaConfig(
            vision_config=vision_config,
            text_config=text_config,
        )
        model = MagmaForCausalLM(magma_config)
        # reload language model
        model.language_model = AutoModelForCausalLM.from_pretrained(
            model_args.model_name_or_path,
            cache_dir=training_args.cache_dir,
            attn_implementation="flash_attention_2" if model_args.flash_attn_2_enabled else None,      
            torch_dtype=(torch.bfloat16 if training_args.bf16 else None),
            trust_remote_code=True,
            **bnb_model_from_pretrained_args
        )     
        # reload vision encoder
        from open_clip.pretrained import download_pretrained_from_hf      
        if vision_config['vision_tower'] == 'convnext':
            model_id = 'laion/CLIP-convnext_large-laion2B-s34B-b82K-augreg'
        else:
            model_id = 'laion/CLIP-convnext_xxlarge-laion2B-s34B-b82K-augreg'  
        checkpoint_path = download_pretrained_from_hf(model_id, cache_dir=None)
        model.load_special_module_from_ckpt(checkpoint_path, torch_dtype=(torch.bfloat16 if training_args.bf16 else None))

        # load 'magma/default_preprocessor_config.json' if it exists
        if os.path.exists('magma/default_preprocessor_config.json'):
            with open('magma/default_preprocessor_config.json') as f:
                preprocessor_config = json.load(f)
        else:
            preprocessor_config = {}
        image_processor = MagmaImageProcessor(**preprocessor_config)
        tokenizer = AutoTokenizer.from_pretrained(model_args.model_name_or_path)
        magma_processor = MagmaProcessor(image_processor=image_processor, tokenizer=tokenizer)

        smart_tokenizer_and_embedding_resize(
            special_tokens_dict=["<image>"],
            tokenizer=magma_processor.tokenizer,
            model=model,
        )

        # if tokenizer does not have pad_token, add it
        if magma_processor.tokenizer.pad_token_id is None:
            smart_tokenizer_and_embedding_resize(
                special_tokens_dict={'pad_token': '<pad>'},
                tokenizer=magma_processor.tokenizer,
                model=model,
            )

        model.config.image_token_index = tokenizer.convert_tokens_to_ids("<image>")
        model.config.tokenizer_vocab_size = magma_processor.tokenizer.vocab_size
        
    model = model.to(training_args.device)
    
    magma_processor.tokenizer.model_max_length = training_args.model_max_length
    magma_processor.image_processor.base_img_size = model_args.img_size
    magma_processor.image_processor.anyres_strategy = model_args.img_anyres_strategy

    if model_args.mm_use_trace_start_end:
        smart_tokenizer_and_embedding_resize(
            special_tokens_dict=["<trace_start>", "<trace_end>"],
            tokenizer=magma_processor.tokenizer,
            model=model,
        )

    if model_args.mm_use_image_start_end:
        smart_tokenizer_and_embedding_resize(
            special_tokens_dict=["<image_start>", "<image_end>"],
            tokenizer=magma_processor.tokenizer,
            model=model,
        )

    # we add an <action> token as the place holder for the action
    smart_tokenizer_and_embedding_resize(
        special_tokens_dict=["<action>"],
        tokenizer=magma_processor.tokenizer,
        model=model,
    )

    if model_args.freeze_backbone:
        model.requires_grad_(False)

    if training_args.bits in [4, 8]:
        from peft import prepare_model_for_kbit_training
        model.config.torch_dtype=(torch.float32 if training_args.fp16 else (torch.bfloat16 if training_args.bf16 else torch.float32))
        model = prepare_model_for_kbit_training(model, use_gradient_checkpointing=training_args.gradient_checkpointing)

    if training_args.gradient_checkpointing:
        if hasattr(model, "enable_input_require_grads"):
            model.enable_input_require_grads()
        else:
            def make_inputs_require_grad(module, input, output):
                output.requires_grad_(True)
            model.get_input_embeddings().register_forward_hook(make_inputs_require_grad)

    if training_args.lora_enable:
        from peft import LoraConfig, get_peft_model
        lora_config = LoraConfig(
            r=training_args.lora_r,
            lora_alpha=training_args.lora_alpha,
            target_modules=find_all_linear_names(model),
            lora_dropout=training_args.lora_dropout,
            bias=training_args.lora_bias,
            task_type="CAUSAL_LM",
        )
        if training_args.bits == 16:
            if training_args.bf16:
                model.to(torch.bfloat16)
            if training_args.fp16:
                model.to(torch.float16)
        rank0_print("Adding LoRA adapters...")
        model = get_peft_model(model, lora_config)
    
    if model_args.tune_mm_mlp_adapter:
        model.requires_grad_(False)
        for p in model.multi_modal_projector.parameters():
            p.requires_grad = True

    if training_args.freeze_mm_mlp_adapter:
        for p in model.multi_modal_projector.parameters():
            p.requires_grad = False

    if model_args.tune_vision_tokenizer == "none":
        for name, p in model.vision_tower.named_parameters():
            p.requires_grad = False

    total_params = get_model_param_count(model, trainable_only=True)
    rank0_print(f"Total trainable parameters: {total_params}")
    
    if training_args.bits in [4, 8]:
        model.multi_modal_projector.to(dtype=compute_dtype, device=training_args.device)
        from peft.tuners.lora import LoraLayer
        for name, module in model.named_modules():
            if isinstance(module, LoraLayer):
                if training_args.bf16:
                    module = module.to(torch.bfloat16)
            if 'norm' in name:
                module = module.to(torch.float32)
            if 'lm_head' in name or 'embed_tokens' in name:
                if hasattr(module, 'weight'):
                    if training_args.bf16 and module.weight.dtype == torch.float32:
                        module = module.to(torch.bfloat16)

    data_args.mm_use_trace_start_end = model_args.mm_use_trace_start_end
    data_args.mm_use_trace_speed = model_args.mm_use_trace_speed
    data_args.mm_use_image_start_end = model_args.mm_use_image_start_end
    data_args.mm_use_image_history = model_args.mm_use_image_history
    data_args.mm_use_som_tom = model_args.mm_use_som_tom
    data_args.mm_use_som_tom_orig_img = model_args.mm_use_som_tom_orig_img
    data_args.remove_static_trace_pts = model_args.remove_static_trace_pts
    data_args.spatial_quant_size = model_args.spatial_quant_size
    data_args.version = model_args.version
    data_args.local_run = training_args.local_run
    data_args.task = model_args.task
    
    model.config.mm_use_trace_start_end = model_args.mm_use_trace_start_end
    model.config.mm_use_trace_speed = model_args.mm_use_trace_speed
    model.config.mm_use_image_start_end = model_args.mm_use_image_start_end
    model.config.mm_use_image_history = model_args.mm_use_image_history
    model.config.remove_static_trace_pts = model_args.remove_static_trace_pts
    model.config.mm_use_som_tom = model_args.mm_use_som_tom
    model.config.mm_use_som_tom_orig_img = model_args.mm_use_som_tom_orig_img
    model.config.spatial_quant_size = model_args.spatial_quant_size
    model.config.img_size = model_args.img_size
    model.config.use_cache = False    
    
    model.config.vision_config['img_anyres_strategy'] = model_args.img_anyres_strategy

    data_module = make_supervised_data_module(processor=magma_processor,
                                              data_args=data_args,
                                              training_args=training_args)
        
    trainer = MagmaTrainer(model=model,
                    tokenizer=magma_processor.tokenizer,
                    args=training_args,
                    **data_module)
    
    # print training_args
    rank0_print(training_args)
    rank0_print(model_args)
    
    if list(pathlib.Path(training_args.output_dir).glob("checkpoint-*")):
        print("Resuming from checkpoint...")
        trainer.train(resume_from_checkpoint=True)
    else:
        trainer.train()
    
    trainer.save_state()
    model.config.use_cache = True
    if training_args.lora_enable:
        state_dict = get_peft_state_maybe_zero_3(
            model.named_parameters(), training_args.lora_bias
        )
        non_lora_state_dict = get_peft_state_non_lora_maybe_zero_3(
            model.named_parameters()
        )
        if training_args.local_rank == 0 or training_args.local_rank == -1:
            model.config.save_pretrained(training_args.output_dir)
            model.save_pretrained(training_args.output_dir, state_dict=state_dict)
            torch.save(non_lora_state_dict, os.path.join(training_args.output_dir, 'non_lora_trainables.bin'))
    else:
        safe_save_model_for_hf_trainer(trainer=trainer,
                                       output_dir=training_args.output_dir)
        # save image_processor config for rank 0
        if training_args.local_rank == 0 or training_args.local_rank == -1:        
            magma_processor.image_processor.save_pretrained(training_args.output_dir)


if __name__ == "__main__":
    train()