import argparse
import yaml
from box import Box
import os
import torch
import lightning as L
from lightning.pytorch.callbacks import ModelCheckpoint, Callback
from typing import List
from math import ceil
import numpy as np
from lightning.pytorch.strategies import FSDPStrategy, DDPStrategy
from src.inference.download import download

from src.data.asset import Asset
from src.data.extract import get_files
from src.data.dataset import UniRigDatasetModule, DatasetConfig, ModelInput
from src.data.datapath import Datapath
from src.data.transform import TransformConfig
from src.tokenizer.spec import TokenizerConfig
from src.tokenizer.parse import get_tokenizer
from src.model.parse import get_model
from src.system.parse import get_system, get_writer

from tqdm import tqdm
import time

def load(task: str, path: str) -> Box:
    if path.endswith('.yaml'):
        path = path.removesuffix('.yaml')
    path += '.yaml'
    print(f"\033[92mload {task} config: {path}\033[0m")
    return Box(yaml.safe_load(open(path, 'r')))

def nullable_string(val):
    if not val:
        return None
    return val

if __name__ == "__main__":
    torch.set_float32_matmul_precision('high')
    
    parser = argparse.ArgumentParser()
    parser.add_argument("--task", type=str, required=True)
    parser.add_argument("--seed", type=int, required=False, default=123,
                        help="random seed")
    parser.add_argument("--input", type=nullable_string, required=False, default=None,
                        help="a single input file or files splited by comma")
    parser.add_argument("--input_dir", type=nullable_string, required=False, default=None,
                        help="input directory")
    parser.add_argument("--output", type=nullable_string, required=False, default=None,
                        help="filename for a single output")
    parser.add_argument("--output_dir", type=nullable_string, required=False, default=None,
                        help="output directory")
    parser.add_argument("--npz_dir", type=nullable_string, required=False, default='tmp',
                        help="intermediate npz directory")
    parser.add_argument("--cls", type=nullable_string, required=False, default=None,
                        help="class name")
    parser.add_argument("--data_name", type=nullable_string, required=False, default=None,
                        help="npz filename from skeleton phase")
    args = parser.parse_args()
    
    L.seed_everything(args.seed, workers=True)
    
    task = load('task', args.task)
    mode = task.mode
    assert mode in ['predict']
    
    if args.input is not None or args.input_dir is not None:
        assert args.output_dir is not None or args.output is not None, 'output or output_dir must be specified'
        assert args.npz_dir is not None, 'npz_dir must be specified'
        files = get_files(
            data_name=task.components.data_name,
            inputs=args.input,
            input_dataset_dir=args.input_dir,
            output_dataset_dir=args.npz_dir,
            force_override=True,
            warning=False,
        )
        files = [f[1] for f in files]
        if len(files) > 1 and args.output is not None:
            print("\033[92mwarning: output is specified, but multiple files are detected. Output will be written.\033[0m")
        datapath = Datapath(files=files, cls=args.cls)
    else:
        datapath = None
    
    data_config = load('data', os.path.join('configs/data', task.components.data))
    transform_config = load('transform', os.path.join('configs/transform', task.components.transform))
    
    # get tokenizer
    tokenizer_config = task.components.get('tokenizer', None)
    if tokenizer_config is not None:
        tokenizer_config = load('tokenizer', os.path.join('configs/tokenizer', task.components.tokenizer))
        tokenizer_config = TokenizerConfig.parse(config=tokenizer_config)
    
    # get data name
    data_name = task.components.get('data_name', 'raw_data.npz')
    if args.data_name is not None:
        data_name = args.data_name
        
    # get predict dataset
    predict_dataset_config = data_config.get('predict_dataset_config', None)
    if predict_dataset_config is not None:
        predict_dataset_config = DatasetConfig.parse(config=predict_dataset_config).split_by_cls()
    
    # get predict transform
    predict_transform_config = transform_config.get('predict_transform_config', None)
    if predict_transform_config is not None:
        predict_transform_config = TransformConfig.parse(config=predict_transform_config)
    
    # get model
    model_config = task.components.get('model', None)
    if model_config is not None:
        model_config = load('model', os.path.join('configs/model', model_config))
        if tokenizer_config is not None:
            tokenizer = get_tokenizer(config=tokenizer_config)
        else:
            tokenizer = None
        model = get_model(tokenizer=tokenizer, **model_config)
    else:
        model = None
    
    # set data
    data = UniRigDatasetModule(
        process_fn=None if model is None else model._process_fn,
        predict_dataset_config=predict_dataset_config,
        predict_transform_config=predict_transform_config,
        tokenizer_config=tokenizer_config,
        debug=False,
        data_name=data_name,
        datapath=datapath,
        cls=args.cls,
    )
    
    # add call backs
    callbacks = []

    ## get checkpoint callback
    checkpoint_config = task.get('checkpoint', None)
    if checkpoint_config is not None:
        checkpoint_config['dirpath'] = os.path.join('experiments', task.experiment_name)
        callbacks.append(ModelCheckpoint(**checkpoint_config))
    
    ## get writer callback
    writer_config = task.get('writer', None)
    if writer_config is not None:
        assert predict_transform_config is not None, 'missing predict_transform_config in transform'
        if args.output_dir is not None or args.output is not None:
            if args.output is not None:
                assert args.output.endswith('.fbx'), 'output must be .fbx'
            writer_config['npz_dir'] = args.npz_dir
            writer_config['output_dir'] = args.output_dir
            writer_config['output_name'] = args.output
            writer_config['user_mode'] = True
        callbacks.append(get_writer(**writer_config, order_config=predict_transform_config.order_config))
    
    # get trainer
    trainer_config = task.get('trainer', {})
    
    # get system
    system_config = task.components.get('system', None)
    if system_config is not None:
        system_config = load('system', os.path.join('configs/system', system_config))
        system = get_system(
            **system_config,
            model=model,
            steps_per_epoch=1,
        )
    else:
        system = None
    
    logger = None

    # set ckpt path
    resume_from_checkpoint = task.get('resume_from_checkpoint', None)
    resume_from_checkpoint = download(resume_from_checkpoint)
    trainer = L.Trainer(
        callbacks=callbacks,
        logger=logger,
        **trainer_config,
    )
    
    if mode == 'predict':
        assert resume_from_checkpoint is not None, 'expect resume_from_checkpoint in task'
        trainer.predict(system, datamodule=data, ckpt_path=resume_from_checkpoint, return_predictions=False)
    else:
        assert 0