import argparse
import json
import os
import time
import uuid

import sglang as sgl
from sglang.test.test_utils import (
    add_common_sglang_args_and_parse,
    select_sglang_backend,
)
from sglang.utils import download_and_cache_file


def load_questions(filename):
    questions = []
    with open(filename, "r") as fin:
        for line in fin:
            obj = json.loads(line)
            questions.append(obj)
    return questions


def write_answers(filename, model_id, questions, answers):
    with open(os.path.expanduser(filename), "w") as fout:
        for i in range(len(answers)):
            ans_json = {
                "question_id": questions[i]["question_id"],
                "answer_id": uuid.uuid4().hex,
                "model_id": model_id,
                "choices": {
                    "index": 0,
                    "turns": [answers[i][0], answers[i][1]],
                },
                "tstamp": time.time(),
            }
            fout.write(json.dumps(ans_json) + "\n")


@sgl.function
def answer_mt_bench(s, question_1, question_2):
    s += sgl.system()
    s += sgl.user(question_1)
    s += sgl.assistant(sgl.gen("answer_1"))
    s += sgl.user(question_2)
    s += sgl.assistant(sgl.gen("answer_2"))


def main(args):
    # Download question file if not exist
    question_file = args.question_file
    url = "https://raw.githubusercontent.com/lm-sys/FastChat/main/fastchat/llm_judge/data/mt_bench/question.jsonl"
    if not os.path.isfile(question_file):
        question_file = download_and_cache_file(url)

    # Construct prompts
    questions = load_questions(question_file)[: args.num_questions]
    arguments = [
        {"question_1": q["turns"][0], "question_2": q["turns"][1]} for q in questions
    ]

    # Select backend
    backend = select_sglang_backend(args)
    sgl.set_default_backend(backend)

    # Run requests
    tic = time.perf_counter()
    rets = answer_mt_bench.run_batch(
        arguments,
        temperature=0,
        max_new_tokens=256,
        num_threads=args.parallel,
        progress_bar=True,
    )
    answers = [[s["answer_1"], s["answer_2"]] for s in rets]
    latency = time.perf_counter() - tic

    print(f"#questions: {len(questions)}, Latency: {latency:.2f}")

    # Write results
    model_id = backend.model_info["model_path"]
    answer_file = args.answer_file or f"tmp_output_{args.backend}.txt"
    write_answers(answer_file, model_id, questions, answers)

    with open(args.result_file, "a") as fout:
        value = {
            "task": "mtbench",
            "backend": args.backend,
            "num_gpus": 1,
            "latency": round(latency, 3),
            "num_requests": args.num_questions,
            "other": {
                "num_questions": args.num_questions,
                "parallel": args.parallel,
            },
        }
        fout.write(json.dumps(value) + "\n")


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--question-file", type=str, default="question.jsonl")
    parser.add_argument("--answer-file", type=str, default=None)
    parser.add_argument("--num-questions", type=int, default=80)
    args = add_common_sglang_args_and_parse(parser)
    main(args)
