import argparse
import os
import time

import torch
from _utils import print_perf_stats
from transformers import LlamaForCausalLM, LlamaTokenizer

import colossalai
from colossalai.inference.tensor_parallel.engine import TPInferEngine
from colossalai.logging import disable_existing_loggers
from colossalai.shardformer import ShardConfig
from colossalai.testing import clear_cache_before_run, rerun_if_address_is_in_use, spawn

os.environ["TRANSFORMERS_NO_ADVISORY_WARNINGS"] = "true"


def run_llama_test(args):
    llama_model_path = args.path
    max_batch_size = args.batch_size
    max_input_len = args.input_len
    max_output_len = args.output_len
    args.test_mode

    print("max_batch_size : " + str(max_batch_size))

    tokenizer = LlamaTokenizer.from_pretrained(llama_model_path)
    tokenizer.pad_token_id = tokenizer.unk_token_id
    model = LlamaForCausalLM.from_pretrained(llama_model_path, pad_token_id=tokenizer.eos_token_id)
    model = model.half()
    model.config

    shard_config = ShardConfig(enable_tensor_parallelism=True if args.tp_size > 1 else False, inference_only=True)
    infer_engine = TPInferEngine(model, shard_config, max_batch_size, max_input_len, max_output_len)

    generate_kwargs = dict(max_new_tokens=1, do_sample=False)
    input_tokens = {
        "input_ids": torch.randint(1, 1000, (max_batch_size, max_input_len), device="cuda"),
        "attention_mask": torch.ones((max_batch_size, max_input_len), device="cuda"),
    }

    iters = 10
    prefill_times = []

    warmup = 3

    for i in range(iters):
        torch.cuda.synchronize()
        start = time.time()
        outputs = infer_engine.generate(input_tokens, **generate_kwargs)
        torch.cuda.synchronize()
        end = time.time()
        out_len = outputs.shape[1]
        print("generation time {} s".format(str(end - start)))
        print(out_len - max_input_len)
        prefill_times.append((end - start) / (out_len - max_input_len))

    prefill_times = prefill_times[warmup:]
    prefill_time_avg = sum(prefill_times) / len(prefill_times)
    generate_kwargs = dict(max_new_tokens=max_output_len, do_sample=False)

    times = []
    decoder_times = []
    for i in range(iters):
        torch.cuda.synchronize()
        start = time.time()
        outputs = infer_engine.generate(input_tokens, **generate_kwargs)
        torch.cuda.synchronize()
        end = time.time()
        out_len = outputs.shape[1]
        print("generation time {} s".format(str(end - start)))
        print(out_len - max_input_len)
        times.append((end - start) / (out_len - max_input_len))
        if args.test_mode == "decoder_test":
            decoder_times.append((end - start - prefill_time_avg) / (out_len - max_input_len - 1))

    times = times[warmup:]
    latency = sum(times) / len(times)
    print("total process latency is : " + str(latency) + " s")
    print("total throughput is : " + str(1 / latency * max_batch_size))

    if args.test_mode == "decoder_test":
        decoder_times = decoder_times[warmup:]
        latency = sum(decoder_times) / len(decoder_times)

        print("decoder process latency is : " + str(latency) + " s")
        print("decoder throughput is : " + str(1 / latency * max_batch_size))

    print_perf_stats(times, model.config, max_batch_size)


def check_llama(rank, world_size, port, args):
    disable_existing_loggers()
    colossalai.launch(config={}, rank=rank, world_size=world_size, host="localhost", port=port, backend="nccl")
    run_llama_test(args)


@rerun_if_address_is_in_use()
@clear_cache_before_run()
def test_llama(args):
    spawn(check_llama, args.tp_size, args=args)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("-p", "--path", type=str, help="Model path", required=True)
    parser.add_argument("-tp", "--tp_size", type=int, default=1, help="Tensor parallel size")
    parser.add_argument("-b", "--batch_size", type=int, default=32, help="Maximum batch size")
    parser.add_argument("--input_len", type=int, default=1024, help="Maximum input length")
    parser.add_argument("--output_len", type=int, default=128, help="Maximum output length")
    parser.add_argument(
        "--test_mode", type=str, help="Test mode", default="e2e_test", choices=["e2e_test", "decoder_test"]
    )

    args = parser.parse_args()

    test_llama(args)
