"""
Copyright 2023-2024 SGLang Team
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

"""TokenizerManager is a process that tokenizes the text."""

import asyncio
import dataclasses
import json
import logging
import os
import signal
import sys
from typing import Dict, List, Optional, Tuple, Union

import fastapi
import uvloop
import zmq
import zmq.asyncio
from fastapi import BackgroundTasks

from sglang.srt.hf_transformers_utils import (
    get_config,
    get_context_length,
    get_processor,
    get_tokenizer,
)
from sglang.srt.managers.image_processor import (
    get_dummy_image_processor,
    get_image_processor,
)
from sglang.srt.managers.io_struct import (
    AbortReq,
    BatchEmbeddingOut,
    BatchStrOut,
    BatchTokenIDOut,
    EmbeddingReqInput,
    FlushCacheReq,
    GenerateReqInput,
    GetMemPoolSizeReq,
    GetMemPoolSizeReqOutput,
    ProfileReq,
    RewardReqInput,
    TokenizedEmbeddingReqInput,
    TokenizedGenerateReqInput,
    TokenizedRewardReqInput,
    UpdateWeightReqInput,
    UpdateWeightReqOutput,
)
from sglang.srt.sampling.sampling_params import SamplingParams
from sglang.srt.server_args import PortArgs, ServerArgs
from sglang.srt.utils import (
    get_zmq_socket,
    is_generation_model,
    is_multimodal_model,
    kill_child_process,
)

asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())

logger = logging.getLogger(__name__)


@dataclasses.dataclass
class ReqState:
    """Store the state a request."""

    out_list: List
    finished: bool
    event: asyncio.Event


class TokenizerManager:
    """TokenizerManager is a process that tokenizes the text."""

    def __init__(
        self,
        server_args: ServerArgs,
        port_args: PortArgs,
    ):
        self.server_args = server_args

        # Init inter-process communication
        context = zmq.asyncio.Context(2)
        self.recv_from_detokenizer = get_zmq_socket(
            context, zmq.PULL, port_args.tokenizer_ipc_name
        )
        self.send_to_scheduler = get_zmq_socket(
            context, zmq.PUSH, port_args.scheduler_input_ipc_name
        )

        # Read model args
        self.model_path = server_args.model_path
        self.served_model_name = server_args.served_model_name
        self.hf_config = get_config(
            self.model_path,
            trust_remote_code=server_args.trust_remote_code,
            model_override_args=json.loads(server_args.json_model_override_args),
        )
        self.is_generation = is_generation_model(
            self.hf_config.architectures, self.server_args.is_embedding
        )
        self.context_len = server_args.context_length or get_context_length(
            self.hf_config
        )
        # Create image processor placeholder
        self.image_processor = get_dummy_image_processor()

        # Create tokenizer
        if server_args.skip_tokenizer_init:
            self.tokenizer = self.processor = None
        else:
            if is_multimodal_model(self.hf_config.architectures):
                self.processor = get_processor(
                    server_args.tokenizer_path,
                    tokenizer_mode=server_args.tokenizer_mode,
                    trust_remote_code=server_args.trust_remote_code,
                )
                self.tokenizer = self.processor.tokenizer
                os.environ["TOKENIZERS_PARALLELISM"] = "false"

                # We want to parallelize the image pre-processing so we create an executor for it
                self.image_processor = get_image_processor(
                    self.hf_config, server_args, self.processor
                )
            else:
                self.tokenizer = get_tokenizer(
                    server_args.tokenizer_path,
                    tokenizer_mode=server_args.tokenizer_mode,
                    trust_remote_code=server_args.trust_remote_code,
                )

        # Store states
        self.to_create_loop = True
        self.rid_to_state: Dict[str, ReqState] = {}

        # For update model weights
        self.model_update_lock = asyncio.Lock()
        self.model_update_result = None

        # Others
        self.gracefully_exit = False

    async def generate_request(
        self,
        obj: Union[GenerateReqInput, EmbeddingReqInput, RewardReqInput],
        request: Optional[fastapi.Request] = None,
    ):
        if self.to_create_loop:
            self.create_handle_loop()

        while self.model_update_lock.locked():
            await asyncio.sleep(0.001)

        if isinstance(obj, EmbeddingReqInput) and self.is_generation:
            raise ValueError(
                "This model does not appear to be an embedding model by default. Please add `--is-embedding` when launching the server or try another model."
            )

        obj.post_init()
        is_single = obj.is_single
        if is_single:
            async for response in self._handle_single_request(obj, request):
                yield response
        else:
            async for response in self._handle_batch_request(obj, request):
                yield response

    async def _send_single_request(
        self,
        obj: Union[GenerateReqInput, EmbeddingReqInput, RewardReqInput],
        index: Optional[int] = None,
        input_id_index: Optional[int] = None,
        is_cache_for_prefill: Optional[bool] = False,
    ):
        if not is_cache_for_prefill:  # The normal case with a single prompt
            if index is None:
                rid = obj.rid
                if hasattr(obj, "conv"):
                    # reward model
                    conv = obj.conv
                    input_text = self.tokenizer.apply_chat_template(
                        conv, tokenize=False
                    )
                    input_ids = self.tokenizer.encode(input_text)
                elif obj.input_ids is None:
                    input_text = obj.text
                    input_ids = self.tokenizer.encode(input_text)
                else:
                    input_text = obj.text if obj.text is not None else None
                    input_ids = obj.input_ids

                sampling_params = self._get_sampling_params(obj.sampling_params)
                if self.is_generation:
                    image_inputs = await self.image_processor.process_images_async(
                        obj.image_data, input_text or input_ids, obj
                    )
                    if image_inputs and "input_ids" in image_inputs:
                        input_ids = image_inputs["input_ids"]
                    return_logprob = obj.return_logprob
                    logprob_start_len = obj.logprob_start_len
                    top_logprobs_num = obj.top_logprobs_num
            else:
                rid = obj.rid[index]
                if hasattr(obj, "conv"):
                    # reward model
                    conv = obj.conv[index]
                    input_text = self.tokenizer.apply_chat_template(
                        conv, tokenize=False
                    )
                    input_ids = self.tokenizer.encode(input_text)
                elif obj.input_ids is None:
                    input_text = obj.text[input_id_index]
                    input_ids = self.tokenizer.encode(input_text)
                else:
                    input_text = (
                        obj.text[input_id_index] if obj.text is not None else None
                    )
                    input_ids = obj.input_ids[input_id_index]

                sampling_params = self._get_sampling_params(obj.sampling_params[index])
                if self.is_generation:
                    image_inputs = await self.image_processor.process_images_async(
                        obj.image_data[index], input_text or input_ids, obj
                    )
                    if image_inputs and "input_ids" in image_inputs:
                        input_ids = image_inputs["input_ids"]
                    return_logprob = obj.return_logprob[index]
                    logprob_start_len = obj.logprob_start_len[index]
                    top_logprobs_num = obj.top_logprobs_num[index]

            self._validate_input_length(input_ids)

        else:  # A prefill request to cache the common prompt for parallel sampling
            assert self.is_generation
            if obj.text is not None:
                if isinstance(obj.text, list):
                    input_text = obj.text[input_id_index]
                    rid = obj.rid[index]
                else:
                    input_text = obj.text
                    rid = obj.rid[0]
                if self.tokenizer is not None:
                    input_ids = self.tokenizer.encode(input_text)
                else:
                    assert obj.input_ids is not None
                    input_ids = obj.input_ids
                    if isinstance(obj.input_ids, list) and isinstance(
                        obj.input_ids[0], list
                    ):
                        # when obj["input_ids"] is List[List[int]]
                        input_ids = obj.input_ids[input_id_index]
                        rid = obj.rid[index]
                    else:
                        input_ids = obj.input_ids
                        rid = obj.rid[0]
            else:
                input_text = None
                if isinstance(obj.input_ids, list) and isinstance(
                    obj.input_ids[0], list
                ):
                    # when obj["input_ids"] is List[List[int]]
                    input_ids = obj.input_ids[input_id_index]
                    rid = obj.rid[index]
                else:
                    input_ids = obj.input_ids
                    rid = obj.rid[0]

            sampling_params = SamplingParams(**obj.sampling_params[0])
            sampling_params.max_new_tokens = 0
            image_inputs = await self.image_processor.process_images_async(
                obj.image_data[0], input_text or input_ids, obj
            )
            if image_inputs and "input_ids" in image_inputs:
                input_ids = image_inputs["input_ids"]
            return_logprob = obj.return_logprob[0]
            logprob_start_len = obj.logprob_start_len[0]
            top_logprobs_num = obj.top_logprobs_num[0]

        # Send to the controller
        if self.is_generation:
            tokenized_obj = TokenizedGenerateReqInput(
                rid,
                input_text,
                input_ids,
                image_inputs,
                sampling_params,
                return_logprob,
                logprob_start_len,
                top_logprobs_num,
                obj.stream,
                (
                    obj.lora_path[input_id_index]
                    if isinstance(obj.lora_path, list)
                    else obj.lora_path
                ),
            )
        elif isinstance(obj, EmbeddingReqInput):
            tokenized_obj = TokenizedEmbeddingReqInput(
                rid,
                input_text,
                input_ids,
                sampling_params,
            )
        else:
            assert isinstance(obj, RewardReqInput)
            tokenized_obj = TokenizedRewardReqInput(
                rid,
                input_text,
                input_ids,
                sampling_params,
            )

        self.send_to_scheduler.send_pyobj(tokenized_obj)
        return rid, input_ids

    async def _handle_single_request(
        self,
        obj: Union[GenerateReqInput, EmbeddingReqInput, RewardReqInput],
        request: Optional[fastapi.Request] = None,
        index: Optional[int] = None,
        input_id_index: Optional[int] = None,
        is_cache_for_prefill: Optional[bool] = False,
    ):
        rid, input_ids = await self._send_single_request(
            obj,
            index,
            input_id_index=input_id_index,
            is_cache_for_prefill=is_cache_for_prefill,
        )

        # Recv results
        event = asyncio.Event()
        state = ReqState([], False, event)
        self.rid_to_state[rid] = state

        if not is_cache_for_prefill:
            async for response in self._wait_for_response(state, obj, rid, request):
                yield response
        else:
            assert self.is_generation
            await self._wait_for_cache_prefill_response(state, obj, rid, request)
            yield input_ids

    async def _handle_batch_request(
        self,
        obj: Union[GenerateReqInput, EmbeddingReqInput, RewardReqInput],
        request: Optional[fastapi.Request] = None,
    ):
        batch_size = obj.batch_size
        if self.is_generation:
            parallel_sample_num = obj.parallel_sample_num

            if parallel_sample_num != 1:
                # Send prefill requests to cache the common prefix
                parallel_sample_num += 1
                input_id_result = [] if obj.input_ids is None else None
                for i in range(batch_size):
                    async for input_id in self._handle_single_request(
                        obj,
                        request,
                        index=i,
                        input_id_index=i,
                        is_cache_for_prefill=True,
                    ):
                        if input_id_result is not None:
                            input_id_result.append(input_id)
                if input_id_result is not None:
                    obj.input_ids = input_id_result
        else:
            parallel_sample_num = 1

        # First send out all requests
        generators = []
        for i in range(batch_size):
            for j in range(parallel_sample_num):
                if j == 0 and parallel_sample_num != 1:
                    continue
                index = i * parallel_sample_num + j
                if parallel_sample_num != 1:
                    # Here when using parallel sampling we should consider prefill stage so the index is :  j + i * (parallel_sample_num-1) + batch_size - 1
                    index += batch_size - 1 - i

                rid, _ = await self._send_single_request(
                    obj, index, input_id_index=i, is_cache_for_prefill=False
                )

                event = asyncio.Event()
                state = ReqState([], False, event)
                self.rid_to_state[rid] = state

                generators.append(
                    self._wait_for_response(
                        state,
                        obj,
                        rid,
                        request,
                        index=index,
                        response_index=len(generators),
                    )
                )

        # Then process the responses based on streaming option
        is_stream = hasattr(obj, "stream") and obj.stream

        tasks = [asyncio.create_task(gen.__anext__()) for gen in generators]
        output_list = [None] * len(tasks)

        # Fetch results
        while tasks:
            done, _ = await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)

            for task in done:
                cur_index = tasks.index(task)

                try:
                    result = task.result()

                    if is_stream:
                        yield result
                    else:
                        output_list[result["index"]] = result

                    tasks[cur_index] = asyncio.create_task(
                        generators[cur_index].__anext__()
                    )
                except StopAsyncIteration:
                    del generators[cur_index]
                    del tasks[cur_index]

        if not is_stream:
            yield output_list

    def _validate_input_length(self, input_ids: List[int]):
        if len(input_ids) >= self.context_len:
            raise ValueError(
                f"The input ({len(input_ids)} tokens) is longer than the "
                f"model's context length ({self.context_len} tokens)."
            )

    def _get_sampling_params(self, sampling_params_data: dict):
        sampling_params = SamplingParams(**sampling_params_data)
        if sampling_params.max_new_tokens != 0:
            sampling_params.normalize(self.tokenizer)
            sampling_params.verify()
        return sampling_params

    async def _wait_for_response(
        self,
        state: ReqState,
        obj: Union[GenerateReqInput, EmbeddingReqInput, RewardReqInput],
        rid: str,
        request: Optional[fastapi.Request] = None,
        index: Optional[int] = None,
        response_index: int = 0,
    ):
        while True:
            try:
                await asyncio.wait_for(state.event.wait(), timeout=4)
            except asyncio.TimeoutError:
                if request is not None and await request.is_disconnected():
                    for rid in [obj.rid] if obj.is_single else obj.rid:
                        self.abort_request(rid)
                    raise ValueError(f"Abort request {rid}")
                continue

            if self.is_generation:
                out = self.convert_logprob_style(
                    state.out_list[-1],
                    obj.return_logprob if index is None else obj.return_logprob[index],
                    (
                        obj.top_logprobs_num
                        if index is None
                        else obj.top_logprobs_num[index]
                    ),
                    obj.return_text_in_logprobs,
                )
            else:  # isinstance(obj, (EmbeddingReqInput, RewardReqInput))
                out = state.out_list[-1]

            out["index"] = response_index

            # Log requests
            if self.server_args.log_requests and state.finished:
                logger.info(f"in={obj}, out={out}")

            state.out_list = []
            if state.finished:
                del self.rid_to_state[rid]
                yield out
                break

            state.event.clear()
            yield out

    async def _wait_for_cache_prefill_response(
        self,
        state: ReqState,
        obj: GenerateReqInput,
        rid: str,
        request: Optional[fastapi.Request] = None,
    ):
        while True:
            try:
                await asyncio.wait_for(state.event.wait(), timeout=4)
                break
            except asyncio.TimeoutError:
                if request is not None and await request.is_disconnected():
                    for rid in obj.rid:
                        self.abort_request(rid)
                    raise ValueError(f"Abort request {rid}")
                continue

        assert state.finished
        del self.rid_to_state[rid]

    def flush_cache(self):
        req = FlushCacheReq()
        self.send_to_scheduler.send_pyobj(req)

    def abort_request(self, rid: str):
        if rid not in self.rid_to_state:
            return
        del self.rid_to_state[rid]
        req = AbortReq(rid)
        self.send_to_scheduler.send_pyobj(req)

    def start_profile(self):
        req = ProfileReq.START_PROFILE
        self.send_to_scheduler.send_pyobj(req)

    def stop_profile(self):
        req = ProfileReq.STOP_PROFILE
        self.send_to_scheduler.send_pyobj(req)

    async def get_memory_pool_size(self):
        if self.to_create_loop:
            self.create_handle_loop()

        req = GetMemPoolSizeReq()

        self.send_to_scheduler.send_pyobj(req)
        self.mem_pool_size = asyncio.Future()

        if self.server_args.dp_size == 1:
            res = await self.mem_pool_size
            return res.size
        else: # self.server_args.dp_size > 1
            self.mem_pool_size_tmp = []
            res = await self.mem_pool_size
            ret = [r.size for r in res]
            return ret

    async def update_weights(
        self, obj: UpdateWeightReqInput, request: Optional[fastapi.Request] = None
    ):
        if self.to_create_loop:
            self.create_handle_loop()

        # default the load format to the server_args
        if obj.load_format is None:
            obj.load_format = self.server_args.load_format

        if not self.model_update_lock.locked():
        
            async with self.model_update_lock:
                # wait for the previous generation requests to finish
                while len(self.rid_to_state) > 0:
                    await asyncio.sleep(0.001)
                self.send_to_scheduler.send_pyobj(obj)
                self.model_update_result = asyncio.Future()

                if self.server_args.dp_size == 1:
                    result = await self.model_update_result
                    if result.success:
                        self.server_args.model_path = obj.model_path
                        self.server_args.load_format = obj.load_format
                        self.model_path = obj.model_path
                    return result.success, result.message
                else: # self.server_args.dp_size > 1
                    self.model_update_tmp = []
                    result = await self.model_update_result

                    all_success = all([r.success for r in result])
                    if all_success is True:
                        self.server_args.model_path = obj.model_path
                        self.server_args.load_format = obj.load_format
                        self.model_path = obj.model_path
                    all_message = [r.message for r in result]
                    all_message = " | ".join(all_message)
                    return all_success, all_message

        else:
            return False, "Another update is in progress. Please try again later."

    def create_abort_task(self, obj: GenerateReqInput):
        # Abort the request if the client is disconnected.
        async def abort_request():
            await asyncio.sleep(1)
            if obj.is_single:
                self.abort_request(obj.rid)
            else:
                for rid in obj.rid:
                    self.abort_request(rid)

        background_tasks = BackgroundTasks()
        background_tasks.add_task(abort_request)
        return background_tasks

    def create_handle_loop(self):
        if not self.to_create_loop:
            return

        self.to_create_loop = False
        loop = asyncio.get_event_loop()
        loop.create_task(self.handle_loop())

        signal_handler = SignalHandler(self)
        loop.add_signal_handler(signal.SIGTERM, signal_handler.signal_handler)
        loop.create_task(self.sigterm_watchdog())

    async def sigterm_watchdog(self):
        while not self.gracefully_exit:
            await asyncio.sleep(60)

        # drain requests
        while True:
            remain_num_req = len(self.rid_to_state)
            logger.info(
                f"gracefully exiting... remaining number of requests {remain_num_req}"
            )
            if remain_num_req > 0:
                await asyncio.sleep(5)
            else:
                break

        kill_child_process(include_self=True)
        sys.exit(-1)

    async def handle_loop(self):
        """The event loop that handles requests"""

        while True:
            recv_obj: Union[
                BatchStrOut, BatchEmbeddingOut, BatchTokenIDOut, UpdateWeightReqOutput
            ] = await self.recv_from_detokenizer.recv_pyobj()

            if isinstance(recv_obj, UpdateWeightReqOutput):
                if self.server_args.dp_size == 1:
                    self.model_update_result.set_result(recv_obj)
                else: # self.server_args.dp_size > 1
                    self.model_update_tmp.append(recv_obj)
                    # set future if the all results are recevied
                    if len(self.model_update_tmp) == self.server_args.dp_size:
                        self.model_update_result.set_result(self.model_update_tmp)
                continue
            elif isinstance(recv_obj, GetMemPoolSizeReqOutput):
                if self.server_args.dp_size == 1:
                    self.mem_pool_size.set_result(recv_obj)
                else: # self.sever_args.dp_size > 1
                    self.mem_pool_size_tmp.append(recv_obj)
                    # set future if the all results are received
                    if len(self.mem_pool_size_tmp) == self.server_args.dp_size:
                        self.mem_pool_size.set_result(self.mem_pool_size_tmp)
                continue

            assert isinstance(
                recv_obj, (BatchStrOut, BatchEmbeddingOut, BatchTokenIDOut)
            ), f"Unexpected obj received: {type(recv_obj)}"

            for i, rid in enumerate(recv_obj.rids):
                state = self.rid_to_state.get(rid, None)
                if state is None:
                    continue

                recv_obj.meta_info[i]["id"] = rid
                if isinstance(recv_obj, BatchStrOut):
                    out_dict = {
                        "text": recv_obj.output_strs[i],
                        "meta_info": recv_obj.meta_info[i],
                    }
                elif isinstance(recv_obj, BatchTokenIDOut):
                    out_dict = {
                        "token_ids": recv_obj.output_ids[i],
                        "meta_info": recv_obj.meta_info[i],
                    }

                else:
                    assert isinstance(recv_obj, BatchEmbeddingOut)
                    out_dict = {
                        "embedding": recv_obj.embeddings[i],
                        "meta_info": recv_obj.meta_info[i],
                    }
                state.out_list.append(out_dict)
                state.finished = recv_obj.finished_reason[i] is not None
                state.event.set()

    def convert_logprob_style(
        self,
        ret: dict,
        return_logprob: bool,
        top_logprobs_num: int,
        return_text_in_logprobs: bool,
    ):
        if return_logprob:
            ret["meta_info"]["input_token_logprobs"] = self.detokenize_logprob_tokens(
                ret["meta_info"]["input_token_logprobs"], return_text_in_logprobs
            )
            ret["meta_info"]["output_token_logprobs"] = self.detokenize_logprob_tokens(
                ret["meta_info"]["output_token_logprobs"], return_text_in_logprobs
            )

            if top_logprobs_num > 0:
                ret["meta_info"]["input_top_logprobs"] = (
                    self.detokenize_top_logprobs_tokens(
                        ret["meta_info"]["input_top_logprobs"],
                        return_text_in_logprobs,
                    )
                )
                ret["meta_info"]["output_top_logprobs"] = (
                    self.detokenize_top_logprobs_tokens(
                        ret["meta_info"]["output_top_logprobs"], return_text_in_logprobs
                    )
                )
        return ret

    def detokenize_logprob_tokens(
        self, token_logprobs: List[Tuple[float, int]], decode_to_text: bool
    ):
        # TODO(lianmin): This should run on DetokenizerManager
        if not decode_to_text:
            return [(logprob, token_id, None) for logprob, token_id in token_logprobs]

        assert self.tokenizer is not None
        token_ids = [tid for _, tid in token_logprobs]
        token_texts = self.tokenizer.batch_decode(token_ids)
        return [
            (logprob, token_id, token_text)
            for (logprob, token_id), token_text, in zip(token_logprobs, token_texts)
        ]

    def detokenize_top_logprobs_tokens(self, top_logprobs, decode_to_text: bool):
        # TODO: The current implementation only batches the detokenization for top-k tokens per single position.
        # We should batch all top-k tokens in all positions.
        for i, token_top_logprobs in enumerate(top_logprobs):
            if token_top_logprobs:
                top_logprobs[i] = self.detokenize_logprob_tokens(
                    token_top_logprobs, decode_to_text
                )
        return top_logprobs


class SignalHandler:
    def __init__(self, tokenizer_manager):
        self.tokenizer_manager = tokenizer_manager

    def signal_handler(self, signum=None, frame=None):
        logger.warning(
            f"SIGTERM received. {signum=} {frame=}. Draining requests and shutting down..."
        )
        self.tokenizer_manager.gracefully_exit = True
