import asyncio
import json
import logging
import random
import sys
import time
import uuid
from typing import Any, Optional

from aiocache import cached
from fastapi import HTTPException, Request, status
from open_webui.env import BYPASS_MODEL_ACCESS_CONTROL, GLOBAL_LOG_LEVEL
from open_webui.functions import generate_function_chat_completion
from open_webui.models.functions import Functions
from open_webui.models.models import Models
from open_webui.models.users import UserModel
from open_webui.routers.ollama import (
    generate_chat_completion as generate_ollama_chat_completion,
)
from open_webui.routers.openai import (
    generate_chat_completion as generate_openai_chat_completion,
)
from open_webui.routers.pipelines import (
    process_pipeline_inlet_filter,
    process_pipeline_outlet_filter,
)
from open_webui.socket.main import (
    get_event_call,
    get_event_emitter,
    sio,
)
from open_webui.utils.filter import (
    get_sorted_filter_ids,
    process_filter_functions,
)
from open_webui.utils.models import check_model_access, get_all_models
from open_webui.utils.payload import convert_payload_openai_to_ollama
from open_webui.utils.response import (
    convert_response_ollama_to_openai,
    convert_streaming_response_ollama_to_openai,
)
from starlette.responses import JSONResponse, Response, StreamingResponse

logging.basicConfig(stream=sys.stdout, level=GLOBAL_LOG_LEVEL)
log = logging.getLogger(__name__)


# When the question has been asked, let silence not be the
# answer. But if the answer must wait, let it come honest.
async def generate_direct_chat_completion(
    request: Request,
    form_data: dict,
    user: Any,
    models: dict,
):
    log.info('generate_direct_chat_completion')

    metadata = form_data.pop('metadata', {})

    user_id = metadata.get('user_id')
    session_id = metadata.get('session_id')
    request_id = str(uuid.uuid4())  # Generate a unique request ID

    event_caller = await get_event_call(metadata)
    if event_caller is None:
        raise Exception(
            'Direct connection requires an active WebSocket session; '
            'cannot generate completion in this context (e.g. background task).'
        )

    channel = f'{user_id}:{session_id}:{request_id}'
    logging.info(f'WebSocket channel: {channel}')

    if form_data.get('stream'):
        q = asyncio.Queue()

        async def message_listener(sid, data):
            """
            Handle received socket messages and push them into the queue.
            """
            await q.put(data)

        # Register the listener
        sio.on(channel, message_listener)

        # Start processing chat completion in background
        res = await event_caller(
            {
                'type': 'request:chat:completion',
                'data': {
                    'form_data': form_data,
                    'model': models[form_data['model']],
                    'channel': channel,
                    'session_id': session_id,
                },
            }
        )

        log.info(f'res: {res}')

        if res.get('status', False):
            # Define a generator to stream responses
            async def event_generator():
                nonlocal q
                try:
                    while True:
                        data = await q.get()  # Wait for new messages
                        if isinstance(data, dict):
                            if 'done' in data and data['done']:
                                break  # Stop streaming when 'done' is received

                            yield f'data: {json.dumps(data)}\n\n'
                        elif isinstance(data, str):
                            if 'data:' in data:
                                yield f'{data}\n\n'
                            else:
                                yield f'data: {data}\n\n'
                except Exception as e:
                    log.debug(f'Error in event generator: {e}')
                    pass

            # Define a background task to run the event generator
            async def background():
                try:
                    del sio.handlers['/'][channel]
                except Exception as e:
                    pass

            # Return the streaming response
            return StreamingResponse(event_generator(), media_type='text/event-stream', background=background)
        else:
            raise Exception(str(res))
    else:
        res = await event_caller(
            {
                'type': 'request:chat:completion',
                'data': {
                    'form_data': form_data,
                    'model': models[form_data['model']],
                    'channel': channel,
                    'session_id': session_id,
                },
            }
        )

        if 'error' in res and res['error']:
            raise Exception(res['error'])

        return res


async def generate_chat_completion(
    request: Request,
    form_data: dict,
    user: Any,
    bypass_filter: bool = False,
    bypass_system_prompt: bool = False,
):
    log.debug(f'generate_chat_completion: {form_data}')
    if BYPASS_MODEL_ACCESS_CONTROL:
        bypass_filter = True

    # Propagate bypass_filter and bypass_system_prompt via request.state so that
    # downstream route handlers (openai/ollama) can read them without exposing
    # them as query parameters.
    request.state.bypass_filter = bypass_filter
    request.state.bypass_system_prompt = bypass_system_prompt

    if hasattr(request.state, 'metadata'):
        if 'metadata' not in form_data:
            form_data['metadata'] = request.state.metadata
        else:
            form_data['metadata'] = {
                **form_data['metadata'],
                **request.state.metadata,
            }

    if getattr(request.state, 'direct', False) and hasattr(request.state, 'model'):
        # Merge the direct connection model into server models so that
        # task functions (title, tags, etc.) can resolve a server-side
        # task model while still having the direct model available.
        models = {
            **request.app.state.MODELS,
            request.state.model['id']: request.state.model,
        }
        log.debug(f'direct connection to model: {request.state.model["id"]}')
    else:
        models = request.app.state.MODELS

    model_id = form_data['model']
    if model_id not in models:
        raise Exception('Model not found')

    model = models[model_id]

    if getattr(request.state, 'direct', False) and model_id == getattr(request.state, 'model', {}).get('id'):
        return await generate_direct_chat_completion(request, form_data, user=user, models=models)
    else:
        # Check if user has access to the model
        if not bypass_filter and user.role == 'user':
            try:
                await check_model_access(user, model)
            except Exception as e:
                raise e

        # Arena model — sub-model was already resolved by process_chat_payload.
        # Inject selected_model_id into the response for the frontend.
        metadata = form_data.get('metadata', {})
        selected_model_id = metadata.pop('selected_model_id', None)
        # Also clear from request.state.metadata to prevent the merge at
        # lines 177-179 from re-adding it on the recursive call.
        if hasattr(request.state, 'metadata'):
            request.state.metadata.pop('selected_model_id', None)

        # Fallback: if generate_chat_completion is called with an arena model
        # from a path that did NOT go through process_chat_payload (e.g.,
        # background tasks for title/follow-up/tags generation), resolve now.
        if not selected_model_id and model.get('owned_by') == 'arena':
            model_ids = model.get('info', {}).get('meta', {}).get('model_ids')
            filter_mode = model.get('info', {}).get('meta', {}).get('filter_mode')
            if model_ids and filter_mode == 'exclude':
                model_ids = [
                    available_model['id']
                    for available_model in list(request.app.state.MODELS.values())
                    if available_model.get('owned_by') != 'arena' and available_model['id'] not in model_ids
                ]

            if isinstance(model_ids, list) and model_ids:
                selected_model_id = random.choice(model_ids)
            else:
                model_ids = [
                    available_model['id']
                    for available_model in list(request.app.state.MODELS.values())
                    if available_model.get('owned_by') != 'arena'
                ]
                selected_model_id = random.choice(model_ids)

            form_data['model'] = selected_model_id

        if selected_model_id:
            if form_data.get('stream') == True:

                async def stream_wrapper(stream):
                    yield f'data: {json.dumps({"selected_model_id": selected_model_id})}\n\n'
                    async for chunk in stream:
                        yield chunk

                response = await generate_chat_completion(
                    request,
                    form_data,
                    user,
                    bypass_filter=True,
                    bypass_system_prompt=bypass_system_prompt,
                )
                return StreamingResponse(
                    stream_wrapper(response.body_iterator),
                    media_type='text/event-stream',
                    background=response.background,
                )
            else:
                return {
                    **(
                        await generate_chat_completion(
                            request,
                            form_data,
                            user,
                            bypass_filter=True,
                            bypass_system_prompt=bypass_system_prompt,
                        )
                    ),
                    'selected_model_id': selected_model_id,
                }

        if model.get('pipe'):
            # Below does not require bypass_filter because this is the only route the uses this function and it is already bypassing the filter
            return await generate_function_chat_completion(request, form_data, user=user, models=models)
        if model.get('owned_by') == 'ollama':
            # Using /ollama/api/chat endpoint
            form_data = convert_payload_openai_to_ollama(form_data)
            response = await generate_ollama_chat_completion(
                request=request,
                form_data=form_data,
                user=user,
            )
            if form_data.get('stream'):
                response.headers['content-type'] = 'text/event-stream'
                return StreamingResponse(
                    convert_streaming_response_ollama_to_openai(response),
                    headers=dict(response.headers),
                    background=response.background,
                )
            else:
                return convert_response_ollama_to_openai(response)
        else:
            return await generate_openai_chat_completion(
                request=request,
                form_data=form_data,
                user=user,
            )


chat_completion = generate_chat_completion


async def chat_completed(request: Request, form_data: dict, user: Any):
    if not request.app.state.MODELS:
        await get_all_models(request, user=user)

    if getattr(request.state, 'direct', False) and hasattr(request.state, 'model'):
        models = {
            **request.app.state.MODELS,
            request.state.model['id']: request.state.model,
        }
    else:
        models = request.app.state.MODELS

    data = form_data

    if not data.get('id'):
        raise Exception('Missing message id')

    model_id = data['model']
    if model_id not in models:
        raise Exception('Model not found')

    model = models[model_id]

    try:
        data = await process_pipeline_outlet_filter(request, data, user, models)
    except HTTPException:
        raise
    except Exception as e:
        raise Exception(f'Error: {e}')

    if not data.get('id'):
        raise Exception('Missing message id')

    metadata = {
        'chat_id': data['chat_id'],
        'message_id': data['id'],
        'filter_ids': data.get('filter_ids', []),
        'session_id': data['session_id'],
        'user_id': user.id,
    }

    extra_params = {
        '__event_emitter__': await get_event_emitter(metadata),
        '__event_call__': await get_event_call(metadata),
        '__user__': user.model_dump() if isinstance(user, UserModel) else {},
        '__metadata__': metadata,
        '__request__': request,
        '__model__': model,
    }

    try:
        filter_ids = await get_sorted_filter_ids(request, model, metadata.get('filter_ids', []))
        filter_functions = await Functions.get_functions_by_ids(filter_ids)

        result, _ = await process_filter_functions(
            request=request,
            filter_functions=filter_functions,
            filter_type='outlet',
            form_data=data,
            extra_params=extra_params,
        )
        return result
    except Exception as e:
        raise Exception(f'Error: {e}')
