import os
import sys
import torch
from dotenv import find_dotenv, load_dotenv
from llamafactory.chat import ChatModel
from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig

found_dotenv = find_dotenv(".env")

if len(found_dotenv) == 0:
    found_dotenv = find_dotenv(".env.example")
print(f"loading env vars from: {found_dotenv}")
load_dotenv(found_dotenv, override=False)

path = os.path.dirname(found_dotenv)
print(f"Adding {path} to sys.path")
sys.path.append(path)

from llm_toolkit.translation_utils import *

model_name = os.getenv("MODEL_NAME")
adapter_name_or_path = os.getenv("ADAPTER_NAME_OR_PATH")
load_in_4bit = os.getenv("LOAD_IN_4BIT") == "true"
data_path = os.getenv("DATA_PATH")
results_path = os.getenv("RESULTS_PATH")

print(model_name, adapter_name_or_path, load_in_4bit, data_path, results_path)


def load_model(
    model_name,
    max_seq_length=2048,
    dtype=torch.bfloat16,
    load_in_4bit=False,
    adapter_name_or_path=None,
):
    print(f"loading model: {model_name}")

    if adapter_name_or_path:
        template = "llama3" if "llama-3" in model_name.lower() else "chatml"

        args = dict(
            model_name_or_path=model_name,
            adapter_name_or_path=adapter_name_or_path,  # load the saved LoRA adapters
            template=template,  # same to the one in training
            finetuning_type="lora",  # same to the one in training
            quantization_bit=4 if load_in_4bit else None,  # load 4-bit quantized model
        )
        chat_model = ChatModel(args)
        return chat_model.engine.model, chat_model.engine.tokenizer

    tokenizer = AutoTokenizer.from_pretrained(model_name, trust_remote_code=True)
    bnb_config = BitsAndBytesConfig(
        load_in_4bit=load_in_4bit,
        bnb_4bit_quant_type="nf4",
        bnb_4bit_use_double_quant=False,
        bnb_4bit_compute_dtype=dtype,
    )

    model = AutoModelForCausalLM.from_pretrained(
        model_name,
        quantization_config=bnb_config,
        torch_dtype=dtype,
        trust_remote_code=True,
        device_map="auto",
    )

    return model, tokenizer


gpu_stats = torch.cuda.get_device_properties(0)
start_gpu_memory = round(torch.cuda.max_memory_reserved() / 1024 / 1024 / 1024, 3)
max_memory = round(gpu_stats.total_memory / 1024 / 1024 / 1024, 3)
print(f"(1) GPU = {gpu_stats.name}. Max memory = {max_memory} GB.")
print(f"{start_gpu_memory} GB of memory reserved.")

model, tokenizer = load_model(
    model_name, load_in_4bit=load_in_4bit, adapter_name_or_path=adapter_name_or_path
)

gpu_stats = torch.cuda.get_device_properties(0)
start_gpu_memory = round(torch.cuda.max_memory_reserved() / 1024 / 1024 / 1024, 3)
max_memory = round(gpu_stats.total_memory / 1024 / 1024 / 1024, 3)
print(f"(2) GPU = {gpu_stats.name}. Max memory = {max_memory} GB.")
print(f"{start_gpu_memory} GB of memory reserved.")

datasets = load_translation_dataset(data_path, tokenizer)

print("Evaluating model: " + model_name)
predictions = eval_model(model, tokenizer, datasets["test"])

gpu_stats = torch.cuda.get_device_properties(0)
start_gpu_memory = round(torch.cuda.max_memory_reserved() / 1024 / 1024 / 1024, 3)
max_memory = round(gpu_stats.total_memory / 1024 / 1024 / 1024, 3)
print(f"(3) GPU = {gpu_stats.name}. Max memory = {max_memory} GB.")
print(f"{start_gpu_memory} GB of memory reserved.")

if adapter_name_or_path is not None:
    model_name += "_" + adapter_name_or_path.split("/")[-1]

save_results(
    model_name,
    results_path,
    datasets["test"],
    predictions,
    debug=True,
)

metrics = calc_metrics(datasets["test"]["english"], predictions, debug=True)
print(metrics)