# TODO: Implement a more intelligent load balancing mechanism for distributing requests among multiple backend instances.
# Current implementation uses a simple round-robin approach (random.choice). Consider incorporating algorithms like weighted round-robin,
# least connections, or least response time for better resource utilization and performance optimization.

import asyncio
import json
import logging
import os
import random
import re
import time
from typing import Optional, Union
from urllib.parse import urlparse

import aiohttp
from aiocache import cached

import requests

from fastapi import (
    Depends,
    FastAPI,
    File,
    HTTPException,
    Request,
    UploadFile,
    APIRouter,
)
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import StreamingResponse
from pydantic import BaseModel, ConfigDict
from starlette.background import BackgroundTask


from open_webui.models.models import Models
from open_webui.utils.misc import (
    calculate_sha256,
)
from open_webui.utils.payload import (
    apply_model_params_to_body_ollama,
    apply_model_params_to_body_openai,
    apply_model_system_prompt_to_body,
)
from open_webui.utils.auth import get_admin_user, get_verified_user
from open_webui.utils.access_control import has_access


from open_webui.config import (
    UPLOAD_DIR,
)
from open_webui.env import (
    ENV,
    SRC_LOG_LEVELS,
    AIOHTTP_CLIENT_TIMEOUT,
    AIOHTTP_CLIENT_TIMEOUT_OPENAI_MODEL_LIST,
    BYPASS_MODEL_ACCESS_CONTROL,
)
from open_webui.constants import ERROR_MESSAGES

log = logging.getLogger(__name__)
log.setLevel(SRC_LOG_LEVELS["OLLAMA"])


##########################################
#
# Utility functions
#
##########################################


async def send_get_request(url, key=None):
    timeout = aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT_OPENAI_MODEL_LIST)
    try:
        async with aiohttp.ClientSession(timeout=timeout, trust_env=True) as session:
            async with session.get(
                url, headers={**({"Authorization": f"Bearer {key}"} if key else {})}
            ) as response:
                return await response.json()
    except Exception as e:
        # Handle connection error here
        log.error(f"Connection error: {e}")
        return None


async def send_post_request(
    url: str,
    payload: Union[str, bytes],
    stream: bool = True,
    key: Optional[str] = None,
    content_type: Optional[str] = None,
):
    async def cleanup_response(
        response: Optional[aiohttp.ClientResponse],
        session: Optional[aiohttp.ClientSession],
    ):
        if response:
            response.close()
        if session:
            await session.close()

    r = None
    try:
        session = aiohttp.ClientSession(
            trust_env=True, timeout=aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT)
        )

        r = await session.post(
            url,
            data=payload,
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
        )
        r.raise_for_status()

        if stream:
            response_headers = dict(r.headers)

            if content_type:
                response_headers["Content-Type"] = content_type

            return StreamingResponse(
                r.content,
                status_code=r.status,
                headers=response_headers,
                background=BackgroundTask(
                    cleanup_response, response=r, session=session
                ),
            )
        else:
            res = await r.json()
            await cleanup_response(r, session)
            return res

    except Exception as e:
        detail = None

        if r is not None:
            try:
                res = await r.json()
                if "error" in res:
                    detail = f"Ollama: {res.get('error', 'Unknown error')}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


def get_api_key(url, configs):
    parsed_url = urlparse(url)
    base_url = f"{parsed_url.scheme}://{parsed_url.netloc}"
    return configs.get(base_url, {}).get("key", None)


##########################################
#
# API routes
#
##########################################

router = APIRouter()


@router.head("/")
@router.get("/")
async def get_status():
    return {"status": True}


class ConnectionVerificationForm(BaseModel):
    url: str
    key: Optional[str] = None


@router.post("/verify")
async def verify_connection(
    form_data: ConnectionVerificationForm, user=Depends(get_admin_user)
):
    url = form_data.url
    key = form_data.key

    async with aiohttp.ClientSession(
        timeout=aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT_OPENAI_MODEL_LIST)
    ) as session:
        try:
            async with session.get(
                f"{url}/api/version",
                headers={**({"Authorization": f"Bearer {key}"} if key else {})},
            ) as r:
                if r.status != 200:
                    detail = f"HTTP Error: {r.status}"
                    res = await r.json()

                    if "error" in res:
                        detail = f"External Error: {res['error']}"
                    raise Exception(detail)

                data = await r.json()
                return data
        except aiohttp.ClientError as e:
            log.exception(f"Client error: {str(e)}")
            raise HTTPException(
                status_code=500, detail="Open WebUI: Server Connection Error"
            )
        except Exception as e:
            log.exception(f"Unexpected error: {e}")
            error_detail = f"Unexpected error: {str(e)}"
            raise HTTPException(status_code=500, detail=error_detail)


@router.get("/config")
async def get_config(request: Request, user=Depends(get_admin_user)):
    return {
        "ENABLE_OLLAMA_API": request.app.state.config.ENABLE_OLLAMA_API,
        "OLLAMA_BASE_URLS": request.app.state.config.OLLAMA_BASE_URLS,
        "OLLAMA_API_CONFIGS": request.app.state.config.OLLAMA_API_CONFIGS,
    }


class OllamaConfigForm(BaseModel):
    ENABLE_OLLAMA_API: Optional[bool] = None
    OLLAMA_BASE_URLS: list[str]
    OLLAMA_API_CONFIGS: dict


@router.post("/config/update")
async def update_config(
    request: Request, form_data: OllamaConfigForm, user=Depends(get_admin_user)
):
    request.app.state.config.ENABLE_OLLAMA_API = form_data.ENABLE_OLLAMA_API

    request.app.state.config.OLLAMA_BASE_URLS = form_data.OLLAMA_BASE_URLS
    request.app.state.config.OLLAMA_API_CONFIGS = form_data.OLLAMA_API_CONFIGS

    # Remove any extra configs
    config_urls = request.app.state.config.OLLAMA_API_CONFIGS.keys()
    for url in list(request.app.state.config.OLLAMA_BASE_URLS):
        if url not in config_urls:
            request.app.state.config.OLLAMA_API_CONFIGS.pop(url, None)

    return {
        "ENABLE_OLLAMA_API": request.app.state.config.ENABLE_OLLAMA_API,
        "OLLAMA_BASE_URLS": request.app.state.config.OLLAMA_BASE_URLS,
        "OLLAMA_API_CONFIGS": request.app.state.config.OLLAMA_API_CONFIGS,
    }


@cached(ttl=3)
async def get_all_models(request: Request):
    log.info("get_all_models()")
    if request.app.state.config.ENABLE_OLLAMA_API:
        request_tasks = []

        for idx, url in enumerate(request.app.state.config.OLLAMA_BASE_URLS):
            if url not in request.app.state.config.OLLAMA_API_CONFIGS:
                request_tasks.append(send_get_request(f"{url}/api/tags"))
            else:
                api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})
                enable = api_config.get("enable", True)
                key = api_config.get("key", None)

                if enable:
                    request_tasks.append(send_get_request(f"{url}/api/tags", key))
                else:
                    request_tasks.append(asyncio.ensure_future(asyncio.sleep(0, None)))

        responses = await asyncio.gather(*request_tasks)

        for idx, response in enumerate(responses):
            if response:
                url = request.app.state.config.OLLAMA_BASE_URLS[idx]
                api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})

                prefix_id = api_config.get("prefix_id", None)
                model_ids = api_config.get("model_ids", [])

                if len(model_ids) != 0 and "models" in response:
                    response["models"] = list(
                        filter(
                            lambda model: model["model"] in model_ids,
                            response["models"],
                        )
                    )

                if prefix_id:
                    for model in response.get("models", []):
                        model["model"] = f"{prefix_id}.{model['model']}"

        def merge_models_lists(model_lists):
            merged_models = {}

            for idx, model_list in enumerate(model_lists):
                if model_list is not None:
                    for model in model_list:
                        id = model["model"]
                        if id not in merged_models:
                            model["urls"] = [idx]
                            merged_models[id] = model
                        else:
                            merged_models[id]["urls"].append(idx)

            return list(merged_models.values())

        models = {
            "models": merge_models_lists(
                map(
                    lambda response: response.get("models", []) if response else None,
                    responses,
                )
            )
        }

    else:
        models = {"models": []}

    request.app.state.OLLAMA_MODELS = {
        model["model"]: model for model in models["models"]
    }
    return models


async def get_filtered_models(models, user):
    # Filter models based on user access control
    filtered_models = []
    for model in models.get("models", []):
        model_info = Models.get_model_by_id(model["model"])
        if model_info:
            if user.id == model_info.user_id or has_access(
                user.id, type="read", access_control=model_info.access_control
            ):
                filtered_models.append(model)
    return filtered_models


@router.get("/api/tags")
@router.get("/api/tags/{url_idx}")
async def get_ollama_tags(
    request: Request, url_idx: Optional[int] = None, user=Depends(get_verified_user)
):
    models = []

    if url_idx is None:
        models = await get_all_models(request)
    else:
        url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
        key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

        r = None
        try:
            r = requests.request(
                method="GET",
                url=f"{url}/api/tags",
                headers={**({"Authorization": f"Bearer {key}"} if key else {})},
            )
            r.raise_for_status()

            models = r.json()
        except Exception as e:
            log.exception(e)

            detail = None
            if r is not None:
                try:
                    res = r.json()
                    if "error" in res:
                        detail = f"Ollama: {res['error']}"
                except Exception:
                    detail = f"Ollama: {e}"

            raise HTTPException(
                status_code=r.status_code if r else 500,
                detail=detail if detail else "Open WebUI: Server Connection Error",
            )

    if user.role == "user" and not BYPASS_MODEL_ACCESS_CONTROL:
        models["models"] = get_filtered_models(models, user)

    return models


@router.get("/api/version")
@router.get("/api/version/{url_idx}")
async def get_ollama_versions(request: Request, url_idx: Optional[int] = None):
    if request.app.state.config.ENABLE_OLLAMA_API:
        if url_idx is None:
            # returns lowest version
            request_tasks = [
                send_get_request(
                    f"{url}/api/version",
                    request.app.state.config.OLLAMA_API_CONFIGS.get(url, {}).get(
                        "key", None
                    ),
                )
                for url in request.app.state.config.OLLAMA_BASE_URLS
            ]
            responses = await asyncio.gather(*request_tasks)
            responses = list(filter(lambda x: x is not None, responses))

            if len(responses) > 0:
                lowest_version = min(
                    responses,
                    key=lambda x: tuple(
                        map(int, re.sub(r"^v|-.*", "", x["version"]).split("."))
                    ),
                )

                return {"version": lowest_version["version"]}
            else:
                raise HTTPException(
                    status_code=500,
                    detail=ERROR_MESSAGES.OLLAMA_NOT_FOUND,
                )
        else:
            url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]

            r = None
            try:
                r = requests.request(method="GET", url=f"{url}/api/version")
                r.raise_for_status()

                return r.json()
            except Exception as e:
                log.exception(e)

                detail = None
                if r is not None:
                    try:
                        res = r.json()
                        if "error" in res:
                            detail = f"Ollama: {res['error']}"
                    except Exception:
                        detail = f"Ollama: {e}"

                raise HTTPException(
                    status_code=r.status_code if r else 500,
                    detail=detail if detail else "Open WebUI: Server Connection Error",
                )
    else:
        return {"version": False}


@router.get("/api/ps")
async def get_ollama_loaded_models(request: Request, user=Depends(get_verified_user)):
    """
    List models that are currently loaded into Ollama memory, and which node they are loaded on.
    """
    if request.app.state.config.ENABLE_OLLAMA_API:
        request_tasks = [
            send_get_request(
                f"{url}/api/ps",
                request.app.state.config.OLLAMA_API_CONFIGS.get(url, {}).get(
                    "key", None
                ),
            )
            for url in request.app.state.config.OLLAMA_BASE_URLS
        ]
        responses = await asyncio.gather(*request_tasks)

        return dict(zip(request.app.state.config.OLLAMA_BASE_URLS, responses))
    else:
        return {}


class ModelNameForm(BaseModel):
    name: str


@router.post("/api/pull")
@router.post("/api/pull/{url_idx}")
async def pull_model(
    request: Request,
    form_data: ModelNameForm,
    url_idx: int = 0,
    user=Depends(get_admin_user),
):
    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    # Admin should be able to pull models from any source
    payload = {**form_data.model_dump(exclude_none=True), "insecure": True}

    return await send_post_request(
        url=f"{url}/api/pull",
        payload=json.dumps(payload),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


class PushModelForm(BaseModel):
    name: str
    insecure: Optional[bool] = None
    stream: Optional[bool] = None


@router.delete("/api/push")
@router.delete("/api/push/{url_idx}")
async def push_model(
    request: Request,
    form_data: PushModelForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        if form_data.name in models:
            url_idx = models[form_data.name]["urls"][0]
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.name),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.debug(f"url: {url}")

    return await send_post_request(
        url=f"{url}/api/push",
        payload=form_data.model_dump_json(exclude_none=True).encode(),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


class CreateModelForm(BaseModel):
    name: str
    modelfile: Optional[str] = None
    stream: Optional[bool] = None
    path: Optional[str] = None


@router.post("/api/create")
@router.post("/api/create/{url_idx}")
async def create_model(
    request: Request,
    form_data: CreateModelForm,
    url_idx: int = 0,
    user=Depends(get_admin_user),
):
    log.debug(f"form_data: {form_data}")
    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]

    return await send_post_request(
        url=f"{url}/api/create",
        payload=form_data.model_dump_json(exclude_none=True).encode(),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


class CopyModelForm(BaseModel):
    source: str
    destination: str


@router.post("/api/copy")
@router.post("/api/copy/{url_idx}")
async def copy_model(
    request: Request,
    form_data: CopyModelForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        if form_data.source in models:
            url_idx = models[form_data.source]["urls"][0]
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.source),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

    try:
        r = requests.request(
            method="POST",
            url=f"{url}/api/copy",
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
            data=form_data.model_dump_json(exclude_none=True).encode(),
        )
        r.raise_for_status()

        log.debug(f"r.text: {r.text}")
        return True
    except Exception as e:
        log.exception(e)

        detail = None
        if r is not None:
            try:
                res = r.json()
                if "error" in res:
                    detail = f"Ollama: {res['error']}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status_code if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


@router.delete("/api/delete")
@router.delete("/api/delete/{url_idx}")
async def delete_model(
    request: Request,
    form_data: ModelNameForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        if form_data.name in models:
            url_idx = models[form_data.name]["urls"][0]
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.name),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

    try:
        r = requests.request(
            method="DELETE",
            url=f"{url}/api/delete",
            data=form_data.model_dump_json(exclude_none=True).encode(),
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
        )
        r.raise_for_status()

        log.debug(f"r.text: {r.text}")
        return True
    except Exception as e:
        log.exception(e)

        detail = None
        if r is not None:
            try:
                res = r.json()
                if "error" in res:
                    detail = f"Ollama: {res['error']}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status_code if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


@router.post("/api/show")
async def show_model_info(
    request: Request, form_data: ModelNameForm, user=Depends(get_verified_user)
):
    await get_all_models(request)
    models = request.app.state.OLLAMA_MODELS

    if form_data.name not in models:
        raise HTTPException(
            status_code=400,
            detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.name),
        )

    url_idx = random.choice(models[form_data.name]["urls"])

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

    try:
        r = requests.request(
            method="POST",
            url=f"{url}/api/show",
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
            data=form_data.model_dump_json(exclude_none=True).encode(),
        )
        r.raise_for_status()

        return r.json()
    except Exception as e:
        log.exception(e)

        detail = None
        if r is not None:
            try:
                res = r.json()
                if "error" in res:
                    detail = f"Ollama: {res['error']}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status_code if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


class GenerateEmbedForm(BaseModel):
    model: str
    input: list[str] | str
    truncate: Optional[bool] = None
    options: Optional[dict] = None
    keep_alive: Optional[Union[int, str]] = None


@router.post("/api/embed")
@router.post("/api/embed/{url_idx}")
async def embed(
    request: Request,
    form_data: GenerateEmbedForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    log.info(f"generate_ollama_batch_embeddings {form_data}")

    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        model = form_data.model

        if ":" not in model:
            model = f"{model}:latest"

        if model in models:
            url_idx = random.choice(models[model]["urls"])
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.model),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

    try:
        r = requests.request(
            method="POST",
            url=f"{url}/api/embed",
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
            data=form_data.model_dump_json(exclude_none=True).encode(),
        )
        r.raise_for_status()

        data = r.json()
        return data
    except Exception as e:
        log.exception(e)

        detail = None
        if r is not None:
            try:
                res = r.json()
                if "error" in res:
                    detail = f"Ollama: {res['error']}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status_code if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


class GenerateEmbeddingsForm(BaseModel):
    model: str
    prompt: str
    options: Optional[dict] = None
    keep_alive: Optional[Union[int, str]] = None


@router.post("/api/embeddings")
@router.post("/api/embeddings/{url_idx}")
async def embeddings(
    request: Request,
    form_data: GenerateEmbeddingsForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    log.info(f"generate_ollama_embeddings {form_data}")

    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        model = form_data.model

        if ":" not in model:
            model = f"{model}:latest"

        if model in models:
            url_idx = random.choice(models[model]["urls"])
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.model),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    key = get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS)

    try:
        r = requests.request(
            method="POST",
            url=f"{url}/api/embeddings",
            headers={
                "Content-Type": "application/json",
                **({"Authorization": f"Bearer {key}"} if key else {}),
            },
            data=form_data.model_dump_json(exclude_none=True).encode(),
        )
        r.raise_for_status()

        data = r.json()
        return data
    except Exception as e:
        log.exception(e)

        detail = None
        if r is not None:
            try:
                res = r.json()
                if "error" in res:
                    detail = f"Ollama: {res['error']}"
            except Exception:
                detail = f"Ollama: {e}"

        raise HTTPException(
            status_code=r.status_code if r else 500,
            detail=detail if detail else "Open WebUI: Server Connection Error",
        )


class GenerateCompletionForm(BaseModel):
    model: str
    prompt: str
    suffix: Optional[str] = None
    images: Optional[list[str]] = None
    format: Optional[str] = None
    options: Optional[dict] = None
    system: Optional[str] = None
    template: Optional[str] = None
    context: Optional[list[int]] = None
    stream: Optional[bool] = True
    raw: Optional[bool] = None
    keep_alive: Optional[Union[int, str]] = None


@router.post("/api/generate")
@router.post("/api/generate/{url_idx}")
async def generate_completion(
    request: Request,
    form_data: GenerateCompletionForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    if url_idx is None:
        await get_all_models(request)
        models = request.app.state.OLLAMA_MODELS

        model = form_data.model

        if ":" not in model:
            model = f"{model}:latest"

        if model in models:
            url_idx = random.choice(models[model]["urls"])
        else:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.model),
            )

    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})

    prefix_id = api_config.get("prefix_id", None)
    if prefix_id:
        form_data.model = form_data.model.replace(f"{prefix_id}.", "")

    return await send_post_request(
        url=f"{url}/api/generate",
        payload=form_data.model_dump_json(exclude_none=True).encode(),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


class ChatMessage(BaseModel):
    role: str
    content: str
    images: Optional[list[str]] = None


class GenerateChatCompletionForm(BaseModel):
    model: str
    messages: list[ChatMessage]
    format: Optional[dict] = None
    options: Optional[dict] = None
    template: Optional[str] = None
    stream: Optional[bool] = True
    keep_alive: Optional[Union[int, str]] = None


async def get_ollama_url(request: Request, model: str, url_idx: Optional[int] = None):
    if url_idx is None:
        models = request.app.state.OLLAMA_MODELS
        if model not in models:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(model),
            )
        url_idx = random.choice(models[model].get("urls", []))
    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
    return url


@router.post("/api/chat")
@router.post("/api/chat/{url_idx}")
async def generate_chat_completion(
    request: Request,
    form_data: dict,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
    bypass_filter: Optional[bool] = False,
):
    if BYPASS_MODEL_ACCESS_CONTROL:
        bypass_filter = True

    try:
        form_data = GenerateChatCompletionForm(**form_data)
    except Exception as e:
        log.exception(e)
        raise HTTPException(
            status_code=400,
            detail=str(e),
        )

    payload = {**form_data.model_dump(exclude_none=True)}
    if "metadata" in payload:
        del payload["metadata"]

    model_id = payload["model"]
    model_info = Models.get_model_by_id(model_id)

    if model_info:
        if model_info.base_model_id:
            payload["model"] = model_info.base_model_id

        params = model_info.params.model_dump()

        if params:
            if payload.get("options") is None:
                payload["options"] = {}

            payload["options"] = apply_model_params_to_body_ollama(
                params, payload["options"]
            )
            payload = apply_model_system_prompt_to_body(params, payload, user)

        # Check if user has access to the model
        if not bypass_filter and user.role == "user":
            if not (
                user.id == model_info.user_id
                or has_access(
                    user.id, type="read", access_control=model_info.access_control
                )
            ):
                raise HTTPException(
                    status_code=403,
                    detail="Model not found",
                )
    elif not bypass_filter:
        if user.role != "admin":
            raise HTTPException(
                status_code=403,
                detail="Model not found",
            )

    if ":" not in payload["model"]:
        payload["model"] = f"{payload['model']}:latest"

    url = await get_ollama_url(request, payload["model"], url_idx)
    api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})

    prefix_id = api_config.get("prefix_id", None)
    if prefix_id:
        payload["model"] = payload["model"].replace(f"{prefix_id}.", "")

    return await send_post_request(
        url=f"{url}/api/chat",
        payload=json.dumps(payload),
        stream=form_data.stream,
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
        content_type="application/x-ndjson",
    )


# TODO: we should update this part once Ollama supports other types
class OpenAIChatMessageContent(BaseModel):
    type: str
    model_config = ConfigDict(extra="allow")


class OpenAIChatMessage(BaseModel):
    role: str
    content: Union[str, list[OpenAIChatMessageContent]]

    model_config = ConfigDict(extra="allow")


class OpenAIChatCompletionForm(BaseModel):
    model: str
    messages: list[OpenAIChatMessage]

    model_config = ConfigDict(extra="allow")


class OpenAICompletionForm(BaseModel):
    model: str
    prompt: str

    model_config = ConfigDict(extra="allow")


@router.post("/v1/completions")
@router.post("/v1/completions/{url_idx}")
async def generate_openai_completion(
    request: Request,
    form_data: dict,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    try:
        form_data = OpenAICompletionForm(**form_data)
    except Exception as e:
        log.exception(e)
        raise HTTPException(
            status_code=400,
            detail=str(e),
        )

    payload = {**form_data.model_dump(exclude_none=True, exclude=["metadata"])}
    if "metadata" in payload:
        del payload["metadata"]

    model_id = form_data.model
    if ":" not in model_id:
        model_id = f"{model_id}:latest"

    model_info = Models.get_model_by_id(model_id)
    if model_info:
        if model_info.base_model_id:
            payload["model"] = model_info.base_model_id
        params = model_info.params.model_dump()

        if params:
            payload = apply_model_params_to_body_openai(params, payload)

        # Check if user has access to the model
        if user.role == "user":
            if not (
                user.id == model_info.user_id
                or has_access(
                    user.id, type="read", access_control=model_info.access_control
                )
            ):
                raise HTTPException(
                    status_code=403,
                    detail="Model not found",
                )
    else:
        if user.role != "admin":
            raise HTTPException(
                status_code=403,
                detail="Model not found",
            )

    if ":" not in payload["model"]:
        payload["model"] = f"{payload['model']}:latest"

    url = await get_ollama_url(request, payload["model"], url_idx)
    api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})

    prefix_id = api_config.get("prefix_id", None)

    if prefix_id:
        payload["model"] = payload["model"].replace(f"{prefix_id}.", "")

    return await send_post_request(
        url=f"{url}/v1/completions",
        payload=json.dumps(payload),
        stream=payload.get("stream", False),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


@router.post("/v1/chat/completions")
@router.post("/v1/chat/completions/{url_idx}")
async def generate_openai_chat_completion(
    request: Request,
    form_data: dict,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    try:
        completion_form = OpenAIChatCompletionForm(**form_data)
    except Exception as e:
        log.exception(e)
        raise HTTPException(
            status_code=400,
            detail=str(e),
        )

    payload = {**completion_form.model_dump(exclude_none=True, exclude=["metadata"])}
    if "metadata" in payload:
        del payload["metadata"]

    model_id = completion_form.model
    if ":" not in model_id:
        model_id = f"{model_id}:latest"

    model_info = Models.get_model_by_id(model_id)
    if model_info:
        if model_info.base_model_id:
            payload["model"] = model_info.base_model_id

        params = model_info.params.model_dump()

        if params:
            payload = apply_model_params_to_body_openai(params, payload)
            payload = apply_model_system_prompt_to_body(params, payload, user)

        # Check if user has access to the model
        if user.role == "user":
            if not (
                user.id == model_info.user_id
                or has_access(
                    user.id, type="read", access_control=model_info.access_control
                )
            ):
                raise HTTPException(
                    status_code=403,
                    detail="Model not found",
                )
    else:
        if user.role != "admin":
            raise HTTPException(
                status_code=403,
                detail="Model not found",
            )

    if ":" not in payload["model"]:
        payload["model"] = f"{payload['model']}:latest"

    url = await get_ollama_url(request, payload["model"], url_idx)
    api_config = request.app.state.config.OLLAMA_API_CONFIGS.get(url, {})

    prefix_id = api_config.get("prefix_id", None)
    if prefix_id:
        payload["model"] = payload["model"].replace(f"{prefix_id}.", "")

    return await send_post_request(
        url=f"{url}/v1/chat/completions",
        payload=json.dumps(payload),
        stream=payload.get("stream", False),
        key=get_api_key(url, request.app.state.config.OLLAMA_API_CONFIGS),
    )


@router.get("/v1/models")
@router.get("/v1/models/{url_idx}")
async def get_openai_models(
    request: Request,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):

    models = []
    if url_idx is None:
        model_list = await get_all_models(request)
        models = [
            {
                "id": model["model"],
                "object": "model",
                "created": int(time.time()),
                "owned_by": "openai",
            }
            for model in model_list["models"]
        ]

    else:
        url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]
        try:
            r = requests.request(method="GET", url=f"{url}/api/tags")
            r.raise_for_status()

            model_list = r.json()

            models = [
                {
                    "id": model["model"],
                    "object": "model",
                    "created": int(time.time()),
                    "owned_by": "openai",
                }
                for model in models["models"]
            ]
        except Exception as e:
            log.exception(e)
            error_detail = "Open WebUI: Server Connection Error"
            if r is not None:
                try:
                    res = r.json()
                    if "error" in res:
                        error_detail = f"Ollama: {res['error']}"
                except Exception:
                    error_detail = f"Ollama: {e}"

            raise HTTPException(
                status_code=r.status_code if r else 500,
                detail=error_detail,
            )

    if user.role == "user" and not BYPASS_MODEL_ACCESS_CONTROL:
        # Filter models based on user access control
        filtered_models = []
        for model in models:
            model_info = Models.get_model_by_id(model["id"])
            if model_info:
                if user.id == model_info.user_id or has_access(
                    user.id, type="read", access_control=model_info.access_control
                ):
                    filtered_models.append(model)
        models = filtered_models

    return {
        "data": models,
        "object": "list",
    }


class UrlForm(BaseModel):
    url: str


class UploadBlobForm(BaseModel):
    filename: str


def parse_huggingface_url(hf_url):
    try:
        # Parse the URL
        parsed_url = urlparse(hf_url)

        # Get the path and split it into components
        path_components = parsed_url.path.split("/")

        # Extract the desired output
        model_file = path_components[-1]

        return model_file
    except ValueError:
        return None


async def download_file_stream(
    ollama_url, file_url, file_path, file_name, chunk_size=1024 * 1024
):
    done = False

    if os.path.exists(file_path):
        current_size = os.path.getsize(file_path)
    else:
        current_size = 0

    headers = {"Range": f"bytes={current_size}-"} if current_size > 0 else {}

    timeout = aiohttp.ClientTimeout(total=600)  # Set the timeout

    async with aiohttp.ClientSession(timeout=timeout, trust_env=True) as session:
        async with session.get(file_url, headers=headers) as response:
            total_size = int(response.headers.get("content-length", 0)) + current_size

            with open(file_path, "ab+") as file:
                async for data in response.content.iter_chunked(chunk_size):
                    current_size += len(data)
                    file.write(data)

                    done = current_size == total_size
                    progress = round((current_size / total_size) * 100, 2)

                    yield f'data: {{"progress": {progress}, "completed": {current_size}, "total": {total_size}}}\n\n'

                if done:
                    file.seek(0)
                    hashed = calculate_sha256(file)
                    file.seek(0)

                    url = f"{ollama_url}/api/blobs/sha256:{hashed}"
                    response = requests.post(url, data=file)

                    if response.ok:
                        res = {
                            "done": done,
                            "blob": f"sha256:{hashed}",
                            "name": file_name,
                        }
                        os.remove(file_path)

                        yield f"data: {json.dumps(res)}\n\n"
                    else:
                        raise "Ollama: Could not create blob, Please try again."


# url = "https://huggingface.co/TheBloke/stablelm-zephyr-3b-GGUF/resolve/main/stablelm-zephyr-3b.Q2_K.gguf"
@router.post("/models/download")
@router.post("/models/download/{url_idx}")
async def download_model(
    request: Request,
    form_data: UrlForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    allowed_hosts = ["https://huggingface.co/", "https://github.com/"]

    if not any(form_data.url.startswith(host) for host in allowed_hosts):
        raise HTTPException(
            status_code=400,
            detail="Invalid file_url. Only URLs from allowed hosts are permitted.",
        )

    if url_idx is None:
        url_idx = 0
    url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]

    file_name = parse_huggingface_url(form_data.url)

    if file_name:
        file_path = f"{UPLOAD_DIR}/{file_name}"

        return StreamingResponse(
            download_file_stream(url, form_data.url, file_path, file_name),
        )
    else:
        return None


@router.post("/models/upload")
@router.post("/models/upload/{url_idx}")
def upload_model(
    request: Request,
    file: UploadFile = File(...),
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        url_idx = 0
    ollama_url = request.app.state.config.OLLAMA_BASE_URLS[url_idx]

    file_path = f"{UPLOAD_DIR}/{file.filename}"

    # Save file in chunks
    with open(file_path, "wb+") as f:
        for chunk in file.file:
            f.write(chunk)

    def file_process_stream():
        nonlocal ollama_url
        total_size = os.path.getsize(file_path)
        chunk_size = 1024 * 1024
        try:
            with open(file_path, "rb") as f:
                total = 0
                done = False

                while not done:
                    chunk = f.read(chunk_size)
                    if not chunk:
                        done = True
                        continue

                    total += len(chunk)
                    progress = round((total / total_size) * 100, 2)

                    res = {
                        "progress": progress,
                        "total": total_size,
                        "completed": total,
                    }
                    yield f"data: {json.dumps(res)}\n\n"

                if done:
                    f.seek(0)
                    hashed = calculate_sha256(f)
                    f.seek(0)

                    url = f"{ollama_url}/api/blobs/sha256:{hashed}"
                    response = requests.post(url, data=f)

                    if response.ok:
                        res = {
                            "done": done,
                            "blob": f"sha256:{hashed}",
                            "name": file.filename,
                        }
                        os.remove(file_path)
                        yield f"data: {json.dumps(res)}\n\n"
                    else:
                        raise Exception(
                            "Ollama: Could not create blob, Please try again."
                        )

        except Exception as e:
            res = {"error": str(e)}
            yield f"data: {json.dumps(res)}\n\n"

    return StreamingResponse(file_process_stream(), media_type="text/event-stream")