import os
import sys
from pathlib import Path

import accelerate
import torch

import modules.shared as shared

sys.path.insert(0, os.path.abspath(Path("repositories/GPTQ-for-LLaMa")))
from llama import load_quant


# 4-bit LLaMA
def load_quantized_LLaMA(model_name):
    if shared.args.load_in_4bit:
        bits = 4
    else:
        bits = shared.args.gptq_bits

    path_to_model = Path(f'models/{model_name}')
    pt_model = ''
    if path_to_model.name.lower().startswith('llama-7b'):
        pt_model = f'llama-7b-{bits}bit.pt'
    elif path_to_model.name.lower().startswith('llama-13b'):
        pt_model = f'llama-13b-{bits}bit.pt'
    elif path_to_model.name.lower().startswith('llama-30b'):
        pt_model = f'llama-30b-{bits}bit.pt'
    elif path_to_model.name.lower().startswith('llama-65b'):
        pt_model = f'llama-65b-{bits}bit.pt'
    else:
        pt_model = f'{model_name}-{bits}bit.pt'

    # Try to find the .pt both in models/ and in the subfolder
    pt_path = None
    for path in [Path(p) for p in [f"models/{pt_model}", f"{path_to_model}/{pt_model}"]]:
        if path.exists():
            pt_path = path

    if not pt_path:
        print(f"Could not find {pt_model}, exiting...")
        exit()

    model = load_quant(path_to_model, str(pt_path), bits)

    # Multi-GPU setup
    if shared.args.gpu_memory:
        max_memory = {}
        for i in range(len(shared.args.gpu_memory)):
            max_memory[i] = f"{shared.args.gpu_memory[i]}GiB"
        max_memory['cpu'] = f"{shared.args.cpu_memory or '99'}GiB"

        device_map = accelerate.infer_auto_device_map(model, max_memory=max_memory, no_split_module_classes=["LLaMADecoderLayer"])
        model = accelerate.dispatch_model(model, device_map=device_map)

    # Single GPU
    else:
        model = model.to(torch.device('cuda:0'))

    return model