import torch
import bitblas
from modeling_bitnet import BitnetForCausalLM
from tokenization_bitnet import BitnetTokenizer
from transformers import GenerationConfig
import time
import argparse

torch.set_grad_enabled(False)
bitblas.set_log_level("INFO")


def generate_text_batch(model, tokenizer, prompts, max_length=100):
    # Encode the input prompts as a batch
    input_ids = tokenizer(
        prompts, return_tensors="pt", padding=True, truncation=True).input_ids.to(model.device)

    # Generate cos and sin values (commented out as not used in generation)
    seq_length = input_ids.size(1)
    position_ids = torch.arange(seq_length, dtype=torch.long, device=input_ids.device)
    position_ids = position_ids.unsqueeze(0).expand_as(input_ids)
    # position_embeddings = model.embed_positions(position_ids)
    # cos = position_embeddings[:, :, 0::2].cos()
    # sin = position_embeddings[:, :, 1::2].sin()

    generation_config = GenerationConfig(
        max_length=max_length,
        do_sample=True,
        top_k=50,
        top_p=0.95,
        num_return_sequences=1,
    )

    start_time = time.time()
    output_ids = model.generate(input_ids, generation_config=generation_config)
    # output_ids = model.generate(input_ids, generation_config=generation_config, cos=cos, sin=sin)
    end_time = time.time()

    # Decode the output ids to text
    generated_texts = [
        tokenizer.decode(output_id, skip_special_tokens=True) for output_id in output_ids
    ]

    generation_time = end_time - start_time
    num_tokens = sum(len(output_id) for output_id in output_ids)
    tokens_per_second = num_tokens / generation_time

    print(f"Generated {num_tokens} tokens in {generation_time:.2f} seconds")
    print(f"Tokens per second: {tokens_per_second:.2f}")

    return generated_texts


def profile(model, input_data):

    import numpy as np
    model = model.cuda()
    model.eval()

    def get_runtime(num_repeats=1):
        tic = time.time()
        for _ in range(num_repeats):
            _ = model(input_data)
        torch.cuda.synchronize()
        return (time.time() - tic) * 1000 / num_repeats

    with torch.no_grad():
        st = time.time()
        while time.time() - st < 1.0:
            get_runtime()  # warmup
        warmup_runtime = get_runtime()
        num_repeats = max(1, int(1000 / warmup_runtime))
        times = get_runtime(num_repeats)
    return np.mean(times)


model_path = '1bitLLM/bitnet_b1_58-3B'


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--bs', default=16, type=int)
    parser.add_argument('--in_seq_len', default=32, type=int)
    parser.add_argument('--out_seq_len', default=128, type=int)
    parser.add_argument('--bitblas', action='store_true')
    args = parser.parse_args()
    bs = args.bs
    in_seq_len = args.in_seq_len
    out_seq_len = args.out_seq_len
    is_bitblas = args.bitblas
    model = BitnetForCausalLM.from_pretrained(
        model_path,
        use_flash_attention_2=True,
        torch_dtype=torch.float16,
    ).cuda().half()
    if is_bitblas:
        with torch.no_grad():
            model.quantize()

    tokenizer = BitnetTokenizer.from_pretrained(model_path)
    prompt = ""
    for _ in range(in_seq_len):
        prompt += "Hello "

    prompts = []
    for _ in range(bs):
        prompts.append(prompt)
    max_length = out_seq_len + in_seq_len
    print(generate_text_batch(model, tokenizer, prompts, max_length=max_length))


if __name__ == '__main__':
    main()
