"""
A model worker that executes the model.
"""
import argparse
import asyncio
import dataclasses
import logging
import json
import os
import time
from typing import List
import threading
import uuid

from fastapi import FastAPI, Request, BackgroundTasks
from fastapi.responses import StreamingResponse, JSONResponse
import requests

try:
    from transformers import (
        AutoTokenizer,
        AutoModelForCausalLM,
        LlamaTokenizer,
        AutoModel,
    )
except ImportError:
    from transformers import (
        AutoTokenizer,
        AutoModelForCausalLM,
        LLaMATokenizer,
        AutoModel,
    )
import torch
import torch.nn.functional as F
import uvicorn

from fastchat.constants import WORKER_HEART_BEAT_INTERVAL, ErrorCode, SERVER_ERROR_MSG
from fastchat.model.model_adapter import (
    load_model,
    add_model_args,
    get_conversation_template,
    get_generate_stream_function,
)
from fastchat.modules.gptq import GptqConfig
from fastchat.utils import build_logger, pretty_print_semaphore, get_context_length


worker_id = str(uuid.uuid4())[:8]
logger = build_logger("model_worker", f"model_worker_{worker_id}.log")

app = FastAPI()


def heart_beat_worker(obj):
    while True:
        time.sleep(WORKER_HEART_BEAT_INTERVAL)
        obj.send_heart_beat()


class BaseModelWorker:
    def __init__(
        self,
        controller_addr: str,
        worker_addr: str,
        worker_id: str,
        model_path: str,
        model_names: List[str],
        limit_worker_concurrency: int,
    ):
        self.controller_addr = controller_addr
        self.worker_addr = worker_addr
        self.worker_id = worker_id
        if model_path.endswith("/"):
            model_path = model_path[:-1]
        self.model_names = model_names or [model_path.split("/")[-1]]
        self.limit_worker_concurrency = limit_worker_concurrency

        self.conv = get_conversation_template(model_path)
        self.conv.sep_style = int(self.conv.sep_style)
        self.tokenizer = None
        self.context_len = None
        self.call_ct = 0
        self.semaphore = None

        self.heart_beat_thread = None

    def init_heart_beat(self):
        self.register_to_controller()
        self.heart_beat_thread = threading.Thread(
            target=heart_beat_worker, args=(self,)
        )
        self.heart_beat_thread.start()

    def register_to_controller(self):
        logger.info("Register to controller")

        url = self.controller_addr + "/register_worker"
        data = {
            "worker_name": self.worker_addr,
            "check_heart_beat": True,
            "worker_status": self.get_status(),
        }
        r = requests.post(url, json=data)
        assert r.status_code == 200

    def send_heart_beat(self):
        logger.info(
            f"Send heart beat. Models: {self.model_names}. "
            f"Semaphore: {pretty_print_semaphore(self.semaphore)}. "
            f"call_ct: {self.call_ct}. "
            f"worker_id: {self.worker_id}. "
        )

        url = self.controller_addr + "/receive_heart_beat"

        while True:
            try:
                ret = requests.post(
                    url,
                    json={
                        "worker_name": self.worker_addr,
                        "queue_length": self.get_queue_length(),
                    },
                    timeout=5,
                )
                exist = ret.json()["exist"]
                break
            except requests.exceptions.RequestException as e:
                logger.error(f"heart beat error: {e}")
            time.sleep(5)

        if not exist:
            self.register_to_controller()

    def get_queue_length(self):
        if (
            self.semaphore is None
            or self.semaphore._value is None
            or self.semaphore._waiters is None
        ):
            return 0
        else:
            return (
                self.limit_worker_concurrency
                - self.semaphore._value
                + len(self.semaphore._waiters)
            )

    def get_status(self):
        return {
            "model_names": self.model_names,
            "speed": 1,
            "queue_length": self.get_queue_length(),
        }

    def count_token(self, params):
        prompt = params["prompt"]
        input_ids = self.tokenizer(prompt).input_ids
        input_echo_len = len(input_ids)

        ret = {
            "count": input_echo_len,
            "error_code": 0,
        }
        return ret

    def get_conv_template(self):
        return {"conv": self.conv}


class ModelWorker(BaseModelWorker):
    def __init__(
        self,
        controller_addr: str,
        worker_addr: str,
        worker_id: str,
        model_path: str,
        model_names: List[str],
        limit_worker_concurrency: int,
        no_register: bool,
        device: str,
        num_gpus: int,
        max_gpu_memory: str,
        load_8bit: bool = False,
        cpu_offloading: bool = False,
        gptq_config: bool = None,
        stream_interval: int = 2,
    ):
        super().__init__(
            controller_addr,
            worker_addr,
            worker_id,
            model_path,
            model_names,
            limit_worker_concurrency,
        )

        logger.info(f"Loading the model {self.model_names} on worker {worker_id} ...")
        self.model, self.tokenizer = load_model(
            model_path,
            device,
            num_gpus,
            max_gpu_memory,
            load_8bit,
            cpu_offloading,
            gptq_config,
        )
        self.device = device
        if self.tokenizer.pad_token == None:
            self.tokenizer.pad_token = self.tokenizer.eos_token
        self.context_len = get_context_length(self.model.config)
        self.generate_stream_func = get_generate_stream_function(self.model, model_path)
        self.stream_interval = stream_interval

        if not no_register:
            self.init_heart_beat()

    def generate_stream_gate(self, params):
        self.call_ct += 1

        try:
            for output in self.generate_stream_func(
                self.model,
                self.tokenizer,
                params,
                self.device,
                self.context_len,
                self.stream_interval,
            ):
                ret = {
                    "text": output["text"],
                    "error_code": 0,
                }
                if "usage" in output:
                    ret["usage"] = output["usage"]
                if "finish_reason" in output:
                    ret["finish_reason"] = output["finish_reason"]
                if "logprobs" in output:
                    ret["logprobs"] = output["logprobs"]
                yield json.dumps(ret).encode() + b"\0"
        except torch.cuda.OutOfMemoryError as e:
            ret = {
                "text": f"{SERVER_ERROR_MSG}\n\n({e})",
                "error_code": ErrorCode.CUDA_OUT_OF_MEMORY,
            }
            yield json.dumps(ret).encode() + b"\0"
        except (ValueError, RuntimeError) as e:
            ret = {
                "text": f"{SERVER_ERROR_MSG}\n\n({e})",
                "error_code": ErrorCode.INTERNAL_ERROR,
            }
            yield json.dumps(ret).encode() + b"\0"

    def generate_gate(self, params):
        for x in self.generate_stream_gate(params):
            pass
        return json.loads(x[:-1].decode())

    @torch.inference_mode()
    def get_embeddings(self, params):
        self.call_ct += 1

        try:
            tokenizer = self.tokenizer
            is_llama = "llama" in str(
                type(self.model)
            )  # llama supports batch inference
            is_chatglm = "chatglm" in str(type(self.model))
            is_t5 = "t5" in str(type(self.model))
            if is_llama:
                encoding = tokenizer.batch_encode_plus(
                    params["input"], padding=True, return_tensors="pt"
                )
                input_ids = encoding["input_ids"].to(self.device)
                attention_mask = encoding["attention_mask"].to(self.device)
                model_output = self.model(
                    input_ids, attention_mask, output_hidden_states=True
                )
                data = model_output.hidden_states[-1]
                mask = attention_mask.unsqueeze(-1).expand(data.size()).float()
                masked_embeddings = data * mask
                sum_embeddings = torch.sum(masked_embeddings, dim=1)
                seq_length = torch.sum(mask, dim=1)
                embedding = sum_embeddings / seq_length
                normalized_embeddings = F.normalize(embedding, p=2, dim=1)
                ret = {
                    "embedding": normalized_embeddings.tolist(),
                    "token_num": torch.sum(attention_mask).item(),
                }
            else:
                embedding = []
                token_num = 0
                for text in params["input"]:
                    input_ids = tokenizer.encode(text, return_tensors="pt").to(
                        self.device
                    )
                    if is_t5:
                        model_output = self.model(
                            input_ids, decoder_input_ids=input_ids
                        )
                    else:
                        model_output = self.model(input_ids, output_hidden_states=True)
                    if is_chatglm:
                        data = (model_output.hidden_states[-1].transpose(0, 1))[0]
                    elif is_t5:
                        data = model_output.encoder_last_hidden_state[0]
                    else:
                        data = model_output.hidden_states[-1][0]
                    data = F.normalize(torch.mean(data, dim=0), p=2, dim=0)
                    embedding.append(data.tolist())
                    token_num += len(input_ids[0])
                ret = {
                    "embedding": embedding,
                    "token_num": token_num,
                }
        except torch.cuda.OutOfMemoryError as e:
            ret = {
                "text": f"{SERVER_ERROR_MSG}\n\n({e})",
                "error_code": ErrorCode.CUDA_OUT_OF_MEMORY,
            }
        except (ValueError, RuntimeError) as e:
            ret = {
                "text": f"{SERVER_ERROR_MSG}\n\n({e})",
                "error_code": ErrorCode.INTERNAL_ERROR,
            }
        return ret


def release_worker_semaphore():
    worker.semaphore.release()


def acquire_worker_semaphore():
    if worker.semaphore is None:
        worker.semaphore = asyncio.Semaphore(worker.limit_worker_concurrency)
    return worker.semaphore.acquire()


def create_background_tasks():
    background_tasks = BackgroundTasks()
    background_tasks.add_task(release_worker_semaphore)
    return background_tasks


@app.post("/worker_generate_stream")
async def api_generate_stream(request: Request):
    params = await request.json()
    await acquire_worker_semaphore()
    generator = worker.generate_stream_gate(params)
    background_tasks = create_background_tasks()
    return StreamingResponse(generator, background=background_tasks)


@app.post("/worker_generate")
async def api_generate(request: Request):
    params = await request.json()
    await acquire_worker_semaphore()
    output = worker.generate_gate(params)
    release_worker_semaphore()
    return JSONResponse(output)


@app.post("/worker_get_embeddings")
async def api_get_embeddings(request: Request):
    params = await request.json()
    await acquire_worker_semaphore()
    embedding = worker.get_embeddings(params)
    release_worker_semaphore()
    return JSONResponse(content=embedding)


@app.post("/worker_get_status")
async def api_get_status(request: Request):
    return worker.get_status()


@app.post("/count_token")
async def api_count_token(request: Request):
    params = await request.json()
    return worker.count_token(params)


@app.post("/worker_get_conv_template")
async def api_get_conv(request: Request):
    return worker.get_conv_template()


@app.post("/model_details")
async def api_model_details(request: Request):
    return {"context_length": worker.context_len}


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--host", type=str, default="localhost")
    parser.add_argument("--port", type=int, default=21002)
    parser.add_argument("--worker-address", type=str, default="http://localhost:21002")
    parser.add_argument(
        "--controller-address", type=str, default="http://localhost:21001"
    )
    add_model_args(parser)
    parser.add_argument(
        "--model-names",
        type=lambda s: s.split(","),
        help="Optional display comma separated names",
    )
    parser.add_argument(
        "--limit-worker-concurrency",
        type=int,
        default=5,
        help="Limit the model concurrency to prevent OOM.",
    )
    parser.add_argument("--stream-interval", type=int, default=2)
    parser.add_argument("--no-register", action="store_true")
    args = parser.parse_args()
    logger.info(f"args: {args}")

    if args.gpus:
        if len(args.gpus.split(",")) < args.num_gpus:
            raise ValueError(
                f"Larger --num-gpus ({args.num_gpus}) than --gpus {args.gpus}!"
            )
        os.environ["CUDA_VISIBLE_DEVICES"] = args.gpus

    gptq_config = GptqConfig(
        ckpt=args.gptq_ckpt or args.model_path,
        wbits=args.gptq_wbits,
        groupsize=args.gptq_groupsize,
        act_order=args.gptq_act_order,
    )

    worker = ModelWorker(
        args.controller_address,
        args.worker_address,
        worker_id,
        args.model_path,
        args.model_names,
        args.limit_worker_concurrency,
        no_register=args.no_register,
        device=args.device,
        num_gpus=args.num_gpus,
        max_gpu_memory=args.max_gpu_memory,
        load_8bit=args.load_8bit,
        cpu_offloading=args.cpu_offloading,
        gptq_config=gptq_config,
        stream_interval=args.stream_interval,
    )
    uvicorn.run(app, host=args.host, port=args.port, log_level="info")
