import argparse

import torch
from transformers import CLIPTextModel, T5EncoderModel, CLIPTokenizer, T5Tokenizer

from musubi_tuner.dataset import config_utils
from musubi_tuner.dataset.config_utils import BlueprintGenerator, ConfigSanitizer

from musubi_tuner.dataset.image_video_dataset import (
    ARCHITECTURE_FLUX_KONTEXT,
    ItemInfo,
    save_text_encoder_output_cache_flux_kontext,
)

from musubi_tuner.flux import flux_models
from musubi_tuner.flux import flux_utils
import musubi_tuner.cache_text_encoder_outputs as cache_text_encoder_outputs
import logging


logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)


def encode_and_save_batch(
    tokenizer1: T5Tokenizer,
    text_encoder1: T5EncoderModel,
    tokenizer2: CLIPTokenizer,
    text_encoder2: CLIPTextModel,
    batch: list[ItemInfo],
    device: torch.device,
):
    prompts = [item.caption for item in batch]
    # print(prompts)

    # encode prompt
    t5_tokens = tokenizer1(
        prompts,
        max_length=flux_models.T5XXL_MAX_LENGTH,
        padding="max_length",
        return_length=False,
        return_overflowing_tokens=False,
        truncation=True,
        return_tensors="pt",
    )["input_ids"]
    l_tokens = tokenizer2(prompts, max_length=77, padding="max_length", truncation=True, return_tensors="pt")["input_ids"]

    with torch.autocast(device_type=device.type, dtype=text_encoder1.dtype), torch.no_grad():
        t5_vec = text_encoder1(input_ids=t5_tokens.to(text_encoder1.device), attention_mask=None, output_hidden_states=False)[
            "last_hidden_state"
        ]
        assert torch.isnan(t5_vec).any() == False, "T5 vector contains NaN values"
        t5_vec = t5_vec.cpu()

    with torch.autocast(device_type=device.type, dtype=text_encoder2.dtype), torch.no_grad():
        clip_l_pooler = text_encoder2(l_tokens.to(text_encoder2.device))["pooler_output"]
        clip_l_pooler = clip_l_pooler.cpu()

    # save prompt cache
    for item, t5_vec, clip_ctx in zip(batch, t5_vec, clip_l_pooler):
        save_text_encoder_output_cache_flux_kontext(item, t5_vec, clip_ctx)


def main():
    parser = cache_text_encoder_outputs.setup_parser_common()
    parser = flux_kontext_setup_parser(parser)

    args = parser.parse_args()

    device = args.device if args.device is not None else "cuda" if torch.cuda.is_available() else "cpu"
    device = torch.device(device)

    # Load dataset config
    blueprint_generator = BlueprintGenerator(ConfigSanitizer())
    logger.info(f"Load dataset config from {args.dataset_config}")
    user_config = config_utils.load_user_config(args.dataset_config)
    blueprint = blueprint_generator.generate(user_config, args, architecture=ARCHITECTURE_FLUX_KONTEXT)
    train_dataset_group = config_utils.generate_dataset_group_by_blueprint(blueprint.dataset_group)

    datasets = train_dataset_group.datasets

    # prepare cache files and paths: all_cache_files_for_dataset = exisiting cache files, all_cache_paths_for_dataset = all cache paths in the dataset
    all_cache_files_for_dataset, all_cache_paths_for_dataset = cache_text_encoder_outputs.prepare_cache_files_and_paths(datasets)

    # Load T5 and CLIP text encoders
    t5_dtype = torch.float8e4m3fn if args.fp8_t5 else torch.bfloat16
    tokenizer1, text_encoder1 = flux_utils.load_t5xxl(args.text_encoder1, dtype=t5_dtype, device=device, disable_mmap=True)
    tokenizer2, text_encoder2 = flux_utils.load_clip_l(args.text_encoder2, dtype=torch.bfloat16, device=device, disable_mmap=True)

    # Encode with T5 and CLIP text encoders
    logger.info("Encoding with T5 and CLIP text encoders")

    def encode_for_text_encoder(batch: list[ItemInfo]):
        nonlocal tokenizer1, text_encoder1, tokenizer2, text_encoder2
        encode_and_save_batch(tokenizer1, text_encoder1, tokenizer2, text_encoder2, batch, device)

    cache_text_encoder_outputs.process_text_encoder_batches(
        args.num_workers,
        args.skip_existing,
        args.batch_size,
        datasets,
        all_cache_files_for_dataset,
        all_cache_paths_for_dataset,
        encode_for_text_encoder,
    )
    del text_encoder1
    del text_encoder2

    # remove cache files not in dataset
    cache_text_encoder_outputs.post_process_cache_files(
        datasets, all_cache_files_for_dataset, all_cache_paths_for_dataset, args.keep_cache
    )


def flux_kontext_setup_parser(parser: argparse.ArgumentParser) -> argparse.ArgumentParser:
    parser.add_argument("--text_encoder1", type=str, default=None, required=True, help="text encoder (T5XXL) checkpoint path")
    parser.add_argument("--text_encoder2", type=str, default=None, required=True, help="text encoder 2 (CLIP-L) checkpoint path")
    parser.add_argument("--fp8_t5", action="store_true", help="use fp8 for Text Encoder model")
    return parser


if __name__ == "__main__":
    main()