import gevent.pywsgi
from gevent import monkey;monkey.patch_all()
from flask import Flask, request, Response
import argparse
import requests
import random
import string
import time
import json
import os

app = Flask(__name__)

parser = argparse.ArgumentParser(description="An example of Qwen demo with a similar API to OAI.")
parser.add_argument("--host", type=str, help="Set the ip address.(default: 0.0.0.0)", default='0.0.0.0')
parser.add_argument("--port", type=int, help="Set the port.(default: 7860)", default=7860)
args = parser.parse_args()

base_url = os.getenv('MODEL_BASE_URL')

@app.route("/", methods=["GET"])
def index():
    return Response(f'QW1_5 OpenAI Compatible API<br><br>'+
        f'Set "{os.getenv("SPACE_URL")}/api" as proxy (or API Domain) in your Chatbot.<br><br>'+
        f'The complete API is: {os.getenv("SPACE_URL")}/api/v1/chat/completions')

@app.route("/api/v1/chat/completions", methods=["POST", "OPTIONS"])
@app.route("/v1/chat/completions", methods=["POST", "OPTIONS"])
def chat_completions():

    if request.method == "OPTIONS":
        return Response(
            headers={
                "Access-Control-Allow-Origin": "*",
                "Access-Control-Allow-Headers": "*",
            }
        )

    data = request.get_json()

    # reorganize data
    system = "You are a helpful assistant."
    chat_history = []
    prompt = ""
    
    if "messages" in data:
        messages = data["messages"]
        message_size = len(messages)

        prompt = messages[-1].get("content")
        for i in range(message_size - 1):
            role_this = messages[i].get("role")
            role_next = messages[i + 1].get("role")
            if role_this == "system":
                system = messages[i].get("content")
            elif role_this == "user":
                if role_next == "assistant":
                    chat_history.append(
                        [messages[i].get("content"), messages[i + 1].get("content")]
                    )
                else:
                    chat_history.append([messages[i].get("content"), " "])

        # print(f'{system = }')
        # print(f'{chat_history = }')
        # print(f'{prompt = }')

        fn_index = 0

        # gen a random char(11) hash
        chars = string.ascii_lowercase + string.digits
        session_hash = "".join(random.choice(chars) for _ in range(11))

        json_prompt = {
            "data": [prompt, chat_history, system],
            "fn_index": fn_index,
            "session_hash": session_hash,
        }

    def generate():
        response = requests.post(f"{base_url}/queue/join", json=json_prompt)
        url = f"{base_url}/queue/data?session_hash={session_hash}"
        data = requests.get(url, stream=True)

        time_now = int(time.time())

        for line in data.iter_lines():
            if line:
                decoded_line = line.decode("utf-8")
                json_line = json.loads(decoded_line[6:])
                if json_line["msg"] == "process_starts":
                    res_data = gen_res_data({}, time_now=time_now, start=True)
                    yield f"data: {json.dumps(res_data)}\n\n"
                elif json_line["msg"] == "process_generating":
                    res_data = gen_res_data(json_line, time_now=time_now)
                    yield f"data: {json.dumps(res_data)}\n\n"
                elif json_line["msg"] == "process_completed":
                    yield "data: [DONE]"

    return Response(
        generate(),
        mimetype="text/event-stream",
        headers={
            "Access-Control-Allow-Origin": "*",
            "Access-Control-Allow-Headers": "*",
        },
    )


def gen_res_data(data, time_now=0, start=False):
    res_data = {
        "id": "chatcmpl",
        "object": "chat.completion.chunk",
        "created": time_now,
        "model": "qwen1_5",
        "choices": [{"index": 0, "finish_reason": None}],
    }

    if start:
        res_data["choices"][0]["delta"] = {"role": "assistant", "content": ""}
    else:
        chat_pair = data["output"]["data"][1]
        if chat_pair == []:
            res_data["choices"][0]["finish_reason"] = "stop"
        else:
            res_data["choices"][0]["delta"] = {"content": chat_pair[-1][-1]}
    return res_data


if __name__ == "__main__":
    # app.run(host=args.host, port=args.port, debug=True)
    gevent.pywsgi.WSGIServer((args.host, args.port), app).serve_forever()