import json
import logging
import os
from typing import Annotated, AsyncGenerator, List, Optional

from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import StreamingResponse

import common.dependencies as DI
from common import auth
from common.configuration import Configuration
from components.llm.common import (ChatRequest, LlmParams, LlmPredictParams,
                                   Message)
from components.llm.deepinfra_api import DeepInfraApi
from components.llm.utils import append_llm_response_to_history
from components.services.dataset import DatasetService
from components.services.dialogue import DialogueService
from components.services.entity import EntityService
from components.services.llm_config import LLMConfigService
from components.services.llm_prompt import LlmPromptService
from components.services.log import LogService
from schemas.log import LogCreateSchema

router = APIRouter(prefix='/llm', tags=['LLM chat'])
logger = logging.getLogger(__name__)

conf = DI.get_config()
llm_params = LlmParams(
    **{
        "url": conf.llm_config.base_url,
        "model": conf.llm_config.model,
        "tokenizer": "unsloth/Llama-3.3-70B-Instruct",
        "type": "deepinfra",
        "default": True,
        "predict_params": LlmPredictParams(
            temperature=0.15,
            top_p=0.95,
            min_p=0.05,
            seed=42,
            repetition_penalty=1.2,
            presence_penalty=1.1,
            n_predict=2000,
        ),
        "api_key": os.environ.get(conf.llm_config.api_key_env),
        "context_length": 128000,
    }
)
# TODO: унести в DI
llm_api = DeepInfraApi(params=llm_params)

# TODO: Вынести
def get_last_user_message(chat_request: ChatRequest) -> Optional[Message]:
    return next(
        (
            msg
            for msg in reversed(chat_request.history)
            if msg.role == "user"
        ),
        None,
    )

def insert_search_results_to_message(
    chat_request: ChatRequest, new_content: str
) -> bool:
    for msg in reversed(chat_request.history):
        if msg.role == "user" and (
            msg.searchResults is None or not msg.searchResults
        ):
            msg.content = new_content
            return True
    return False

def try_insert_search_results(
    chat_request: ChatRequest, search_results: str
) -> bool:
    for msg in reversed(chat_request.history):
        if msg.role == "user":
            msg.searchResults = search_results
            msg.searchEntities = []
            return True
    return False

def try_insert_reasoning(
    chat_request: ChatRequest, reasoning: str
):
    for msg in reversed(chat_request.history):
        if msg.role == "user":
            msg.reasoning = reasoning

def collapse_history_to_first_message(chat_history: List[Message]) -> List[Message]:
    """
    Сворачивает историю в первое сообщение и возвращает новый объект ChatRequest.
    Формат:
        <history>
            <user>
                текст сообщения
            </user>
            <reasoning>
                текст reasoning
            </reasoning>
            <search-results>
                текст search-results
            </search-results>
            <assistant>
                текст ответа
            </assistant>
        </history>
        
        <last-request>
            <reasoning>
                текст reasoning
            </reasoning>
            <search-results>
                текст search-results
            </search-results>
            user:
            текст последнего запроса
        </last-request>
        assistant:
    """
    if not chat_history:
        return []
    
    last_user_message = chat_history[-1]
    if chat_history[-1].role != "user":
        logger.warning("Last message is not user message")
        

    # Собираем историю в одну строку
    collapsed_content = []
    collapsed_content.append("<INPUT><history>\n")
    for msg in chat_history[:-1]:
        if msg.content.strip():
            tabulated_content = msg.content.strip().replace("\n", "\n\t\t")
            collapsed_content.append(f"\t<{msg.role.strip()}>\n\t\t{tabulated_content}\n\t</{msg.role.strip()}>\n")
            if msg.role == "user":
                tabulated_reasoning = msg.reasoning.strip().replace("\n", "\n\t\t")
                tabulated_search_results = msg.searchResults.strip().replace("\n", "\n\t\t")
                # collapsed_content.append(f"\t<reasoning>\n\t\t{tabulated_reasoning}\n\t</reasoning>\n")
                # collapsed_content.append(f"\t<search-results>\n\t\t{tabulated_search_results}\n\t</search-results>\n")
                
    collapsed_content.append("</history>\n")
    
    collapsed_content.append("<last-request>\n")
    if last_user_message.content.strip():
        tabulated_content = last_user_message.content.strip().replace("\n", "\n\t\t")
        tabulated_reasoning = last_user_message.reasoning.strip().replace("\n", "\n\t\t")
        tabulated_search_results = last_user_message.searchResults.strip().replace("\n", "\n\t\t")
        # collapsed_content.append(f"\t<reasoning>\n\t\t{tabulated_reasoning}\n\t</reasoning>\n")
        collapsed_content.append(f"\t<search-results>\n\t\t{tabulated_search_results}\n\t</search-results>\n")
        collapsed_content.append(f"\t<user>\n\t\t{tabulated_content}\n</user>\n")

    collapsed_content.append("</last-request>\n")
    
    collapsed_content.append("</INPUT><OUTPUT>\n")
    new_content = "".join(collapsed_content)

    new_message = Message(
        role='user',
        content=new_content,
        searchResults=''
    )
    return [new_message]
        
async def sse_generator(request: ChatRequest, llm_api: DeepInfraApi, system_prompt: str, 
                        predict_params: LlmPredictParams,
                        dataset_service: DatasetService, 
                        entity_service: EntityService,
                        dialogue_service: DialogueService,
                        log_service: LogService,
                        current_user: auth.User) -> AsyncGenerator[str, None]:
    """
    Генератор для стриминга ответа LLM через SSE.
    """
    # Создаем экземпляр "сквозного" лога через весь процесс
    log = LogCreateSchema(user_name=current_user.username, chat_id=request.chat_id)
    
    try:
        old_history = request.history
        
        # Сохраняем последнее сообщение в лог как исходный пользовательский запрос
        last_message = get_last_user_message(request)
        log.user_request = last_message.content if last_message is not None else None
        
        new_history = [Message(
            role=msg.role,
            content=msg.content,
            reasoning=msg.reasoning,
            searchResults='', #msg.searchResults[:10000] + "..." if msg.searchResults else '',
            searchEntities=[],
        ) for msg in old_history]
        request.history = new_history
        
        
        qe_result = await dialogue_service.get_qe_result(request.history)
        
        # Запись результата qe в лог
        log.qe_result = qe_result.model_dump_json()
        
        try_insert_reasoning(request, qe_result.debug_message)
        
        # qe_debug_event = {
        #     "event": "debug",
        #     "data": {
        #         "text": qe_result.debug_message
        #     }
        # }
        # yield f"data: {json.dumps(qe_debug_event, ensure_ascii=False)}\n\n"
        
        qe_event = {
            "event": "reasoning",
            "data": {
                "text": qe_result.debug_message
            }
        }
        yield f"data: {json.dumps(qe_event, ensure_ascii=False)}\n\n"
    except Exception as e:
        log.error = "Error in QE block: " + str(e)
        log_service.create(log)
        
        logger.error(f"Error in SSE chat stream while dialogue_service.get_qe_result: {str(e)}", stack_info=True)
        yield "data: {\"event\": \"error\", \"data\":\""+str(e)+"\" }\n\n"
        qe_result = dialogue_service.get_qe_result_from_chat(request.history)
    
    try:   
        if qe_result.use_search and qe_result.search_query is not None:
            dataset = dataset_service.get_current_dataset()
            if dataset is None:
                raise HTTPException(status_code=400, detail="Dataset not found")
            _, chunk_ids, scores = entity_service.search_similar(
                qe_result.search_query,
                dataset.id,
                [],
            )
            text_chunks = await entity_service.build_text_async(chunk_ids, dataset.id, scores)
            
            # Запись результатов поиска в лог
            log.search_result = text_chunks
            
            search_results_event = {
                "event": "search_results",
                "data": {
                    "text": text_chunks, 
                    "ids": chunk_ids
                }
            }
            yield f"data: {json.dumps(search_results_event, ensure_ascii=False)}\n\n"

            # new_message = f'<search-results>\n{text_chunks}\n</search-results>\n{last_query.content}'
            
            try_insert_search_results(request, text_chunks)
    except Exception as e:
        log.error = "Error in vector search block: " + str(e)
        log_service.create(log)
        
        logger.error(f"Error in SSE chat stream while searching: {str(e)}", stack_info=True)
        yield "data: {\"event\": \"error\", \"data\":\""+str(e)+"\" }\n\n"
        
    log_error = None
    try:          
        # Сворачиваем историю в первое сообщение
        collapsed_request = ChatRequest(
            history=collapse_history_to_first_message(request.history), 
            chat_id = request.chat_id
        )
        
        log.llm_result = ''
        
        # Стриминг токенов ответа
        async for token in llm_api.get_predict_chat_generator(collapsed_request, system_prompt, predict_params):
            token_event = {"event": "token", "data": token}
            
            log.llm_result += token
            
            yield f"data: {json.dumps(token_event, ensure_ascii=False)}\n\n"

        # Финальное событие
        yield "data: {\"event\": \"done\"}\n\n"
    except Exception as e:
        log.error = "Error in llm inference block: " + str(e)
        logger.error(f"Error in SSE chat stream while generating response: {str(e)}", stack_info=True)
        yield "data: {\"event\": \"error\", \"data\":\""+str(e)+"\" }\n\n"
    finally:
        log_service.create(log)
    

@router.post("/chat/stream")
async def chat_stream(
    request: ChatRequest,
    config: Annotated[Configuration, Depends(DI.get_config)],
    llm_api: Annotated[DeepInfraApi, Depends(DI.get_llm_service)],
    prompt_service: Annotated[LlmPromptService, Depends(DI.get_llm_prompt_service)],
    llm_config_service: Annotated[LLMConfigService, Depends(DI.get_llm_config_service)],
    entity_service: Annotated[EntityService, Depends(DI.get_entity_service)],
    dataset_service: Annotated[DatasetService, Depends(DI.get_dataset_service)],
    dialogue_service: Annotated[DialogueService, Depends(DI.get_dialogue_service)],
    log_service: Annotated[LogService, Depends(DI.get_log_service)],
    current_user: Annotated[any, Depends(auth.get_current_user)]
):
    try:
        p = llm_config_service.get_default()
        system_prompt = prompt_service.get_default()

        predict_params = LlmPredictParams(
            temperature=p.temperature,
            top_p=p.top_p,
            min_p=p.min_p,
            seed=p.seed,
            frequency_penalty=p.frequency_penalty,
            presence_penalty=p.presence_penalty,
            n_predict=p.n_predict,
            stop=[],
        )

        headers = {
            "Content-Type": "text/event-stream",
            "Cache-Control": "no-cache",
            "Connection": "keep-alive",
            "Access-Control-Allow-Origin": "*",
        }
        return StreamingResponse(
            sse_generator(request, llm_api, system_prompt.text, predict_params, dataset_service, entity_service, dialogue_service, log_service, current_user),
            media_type="text/event-stream",
            headers=headers
        )
    except Exception as e:
        logger.error(f"Error in SSE chat stream: {str(e)}", stack_info=True)
        raise HTTPException(status_code=500, detail=str(e))

@router.post("/chat")
async def chat(
    request: ChatRequest,
    config: Annotated[Configuration, Depends(DI.get_config)],
    llm_api: Annotated[DeepInfraApi, Depends(DI.get_llm_service)],
    prompt_service: Annotated[LlmPromptService, Depends(DI.get_llm_prompt_service)],
    llm_config_service: Annotated[LLMConfigService, Depends(DI.get_llm_config_service)],
    entity_service: Annotated[EntityService, Depends(DI.get_entity_service)],
    dataset_service: Annotated[DatasetService, Depends(DI.get_dataset_service)],
    dialogue_service: Annotated[DialogueService, Depends(DI.get_dialogue_service)],
):
    try:
        p = llm_config_service.get_default()
        system_prompt = prompt_service.get_default()

        predict_params = LlmPredictParams(
            temperature=p.temperature,
            top_p=p.top_p,
            min_p=p.min_p,
            seed=p.seed,
            frequency_penalty=p.frequency_penalty,
            presence_penalty=p.presence_penalty,
            n_predict=p.n_predict,
            stop=[],
        )

        try:
            qe_result = await dialogue_service.get_qe_result(request.history)
        except Exception as e:
            logger.error(f"Error in chat while dialogue_service.get_qe_result: {str(e)}", stack_info=True)
            qe_result = dialogue_service.get_qe_result_from_chat(request.history)
        
        last_message = get_last_user_message(request)

        logger.info(f"qe_result: {qe_result}")

        if qe_result.use_search and qe_result.search_query is not None:
            dataset = dataset_service.get_current_dataset()
            if dataset is None:
                raise HTTPException(status_code=400, detail="Dataset not found")
            logger.info(f"qe_result.search_query: {qe_result.search_query}")
            previous_entities = [msg.searchEntities for msg in request.history]
            previous_entities, chunk_ids, scores = entity_service.search_similar(
                qe_result.search_query, dataset.id, previous_entities
            )
            
            chunks = entity_service.chunk_repository.get_entities_by_ids(chunk_ids)
            
            logger.info(f"chunk_ids: {chunk_ids[:3]}...{chunk_ids[-3:]}")
            logger.info(f"scores: {scores[:3]}...{scores[-3:]}")
            
            text_chunks = await entity_service.build_text_async(chunk_ids, dataset.id, scores)
            
            logger.info(f"text_chunks: {text_chunks[:3]}...{text_chunks[-3:]}")

            new_message = f'{last_message.content} /n<search-results>/n{text_chunks}/n</search-results>'
            insert_search_results_to_message(request, new_message)
            
        logger.info(f"request: {request}")

        response = await llm_api.predict_chat_stream(
            request, system_prompt.text, predict_params
        )
        result = append_llm_response_to_history(request, response)
        return result
    except Exception as e:
        logger.error(
            f"Error processing LLM request: {str(e)}", stack_info=True, stacklevel=10
        )
        return {"error": str(e)}