import importlib
import logging
import os
import pathlib
import random
import signal
import sys
from pathlib import Path
from typing import Optional

import fire
import torch
import transformers
import yaml
from attrdict import AttrDefault

# add src to the pythonpath so we don't need to pip install this
from axolotl.utils.tokenization import check_dataset_labels

project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
src_dir = os.path.join(project_root, "src")
sys.path.insert(0, src_dir)

from axolotl.utils.data import load_prepare_datasets
from axolotl.utils.models import load_model
from axolotl.utils.trainer import setup_trainer
from axolotl.utils.wandb import setup_wandb_env_vars

logging.basicConfig(level=os.getenv("LOG_LEVEL", "INFO"))
DEFAULT_DATASET_PREPARED_PATH = "last_run_prepared"


def choose_device(cfg):
    def get_device():
        if torch.cuda.is_available():
            return "cuda"
        else:
            try:
                if torch.backends.mps.is_available():
                    return "mps"
            except:
                return "cpu"

    cfg.device = get_device()
    if cfg.device == "cuda":
        cfg.device_map = {"": cfg.local_rank}
    else:
        cfg.device_map = {"": cfg.device}


def get_multi_line_input() -> Optional[str]:
    print("Give me an instruction (Ctrl + D to finish): ")
    instruction = ""
    for line in sys.stdin:
        instruction += line
    # instruction = pathlib.Path("/proc/self/fd/0").read_text()
    return instruction


def do_inference(cfg, model, tokenizer, prompter="AlpacaPrompter"):
    tokenizer.add_special_tokens({"unk_token": "<unk>"})
    tokenizer.add_special_tokens({"bos_token": "<s>"})
    tokenizer.add_special_tokens({"eos_token": "</s>"})

    prompter_module = getattr(importlib.import_module("axolotl.prompters"), prompter)

    while True:
        # support for multiline inputs
        instruction = get_multi_line_input()
        if not instruction:
            return
        prompt = prompter_module().build_prompt(instruction=instruction)
        batch = tokenizer(prompt, return_tensors="pt", add_special_tokens=True)

        model.eval()
        with torch.no_grad():
            # gc = GenerationConfig()  # TODO swap out and use this
            generated = model.generate(
                inputs=batch["input_ids"].to(cfg.device),
                do_sample=True,
                use_cache=True,
                repetition_penalty=1.1,
                max_new_tokens=100,
                temperature=0.9,
                top_p=0.95,
                top_k=40,
                return_dict_in_generate=True,
                output_attentions=False,
                output_hidden_states=False,
                output_scores=False,
            )
        print(tokenizer.decode(generated["sequences"].cpu().tolist()[0]))


def choose_config(path: Path):
    yaml_files = [file for file in path.glob("*.yml")]

    if not yaml_files:
        raise ValueError(
            "No YAML config files found in the specified directory. Are you using a .yml extension?"
        )

    print("Choose a YAML file:")
    for idx, file in enumerate(yaml_files):
        print(f"{idx + 1}. {file}")

    chosen_file = None
    while chosen_file is None:
        try:
            choice = int(input("Enter the number of your choice: "))
            if 1 <= choice <= len(yaml_files):
                chosen_file = yaml_files[choice - 1]
            else:
                print("Invalid choice. Please choose a number from the list.")
        except ValueError:
            print("Invalid input. Please enter a number.")

    return chosen_file


def train(
    config: Path = Path("configs/"),
    prepare_ds_only: bool = False,
    **kwargs,
):
    if Path(config).is_dir():
        config = choose_config(config)

    # load the config from the yaml file
    with open(config, "r") as f:
        cfg: AttrDefault = AttrDefault(lambda: None, yaml.load(f, Loader=yaml.Loader))
    # if there are any options passed in the cli, if it is something that seems valid from the yaml,
    # then overwrite the value
    cfg_keys = dict(cfg).keys()
    for k in kwargs:
        if k in cfg_keys:
            # handle booleans
            if isinstance(cfg[k], bool):
                cfg[k] = bool(kwargs[k])
            else:
                cfg[k] = kwargs[k]

    # setup some derived config / hyperparams
    cfg.gradient_accumulation_steps = cfg.batch_size // cfg.micro_batch_size
    cfg.world_size = int(os.environ.get("WORLD_SIZE", 1))
    cfg.local_rank = int(os.environ.get("LOCAL_RANK", 0))
    choose_device(cfg)
    cfg.ddp = cfg.ddp if cfg.ddp is not None else cfg.world_size != 1
    if cfg.ddp:
        cfg.device_map = {"": int(os.environ.get("LOCAL_RANK", 0))}
        cfg.gradient_accumulation_steps = (
            cfg.gradient_accumulation_steps // cfg.world_size
        )
    setup_wandb_env_vars(cfg)
    if cfg.device == "mps":
        cfg.load_in_8bit = False
        cfg.tf32 = False
        if cfg.bf16:
            cfg.fp16 = True
        cfg.bf16 = False

    # Load the model and tokenizer
    logging.info("loading model, tokenizer, and peft_config...")
    model, tokenizer, peft_config = load_model(
        cfg.base_model,
        cfg.base_model_config,
        cfg.model_type,
        cfg.tokenizer_type,
        cfg,
        adapter=cfg.adapter,
        inference=("inference" in kwargs),
    )

    if "inference" in kwargs:
        logging.info("calling do_inference function")
        do_inference(cfg, model, tokenizer)
        return

    if "shard" in kwargs:
        model.save_pretrained(cfg.output_dir)
        return

    train_dataset, eval_dataset = load_prepare_datasets(
        tokenizer, cfg, DEFAULT_DATASET_PREPARED_PATH
    )

    if prepare_ds_only:
        logging.info("Finished preparing dataset. Exiting...")
        return

    if cfg.debug:
        logging.info("check_dataset_labels...")
        check_dataset_labels(
            train_dataset.select([random.randrange(0, len(train_dataset) - 1) for i in range(5)]),
            tokenizer,
        )

    trainer = setup_trainer(cfg, train_dataset, eval_dataset, model, tokenizer)

    model.config.use_cache = False

    if torch.__version__ >= "2" and sys.platform != "win32":
        logging.info("Compiling torch model")
        model = torch.compile(model)

    # go ahead and presave, so we have the adapter config available to inspect
    if peft_config:
        logging.info(f"Pre-saving adapter config to {cfg.output_dir}")
        peft_config.save_pretrained(cfg.output_dir)

    # In case we want to stop early with ctrl+c, this is a nice to have to save the pretrained model
    if cfg.local_rank == 0:
        signal.signal(
            signal.SIGINT,
            lambda signal, frame: (model.save_pretrained(cfg.output_dir), exit(0)),
        )

    logging.info("Starting trainer...")
    resume_from_checkpoint = cfg.resume_from_checkpoint
    if cfg.resume_from_checkpoint is None and cfg.auto_resume_from_checkpoints:
        possible_checkpoints = [str(cp) for cp in Path(cfg.output_dir).glob("checkpoint-*")]
        if len(possible_checkpoints) > 0:
            sorted_paths = sorted(possible_checkpoints, key=lambda path: int(path.split('-')[-1]))
            resume_from_checkpoint = sorted_paths[-1]
            logging.info(f"Using Auto-resume functionality to start with checkpoint at {resume_from_checkpoint}")
    trainer.train(resume_from_checkpoint=resume_from_checkpoint)

    logging.info(
        f"Training Completed!!! Saving pre-trained model to {cfg.output_dir}"
    )
    # TODO do we need this fix? https://huggingface.co/docs/accelerate/usage_guides/fsdp#saving-and-loading
    trainer.save_model(cfg.output_dir)


if __name__ == "__main__":
    fire.Fire(train)