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
import requests
from open_webui.apps.webui.models.models import Models
from open_webui.config import (
    CORS_ALLOW_ORIGIN,
    ENABLE_OLLAMA_API,
    OLLAMA_BASE_URLS,
    OLLAMA_API_CONFIGS,
    UPLOAD_DIR,
    AppConfig,
)
from open_webui.env import (
    AIOHTTP_CLIENT_TIMEOUT,
    AIOHTTP_CLIENT_TIMEOUT_OPENAI_MODEL_LIST,
)


from open_webui.constants import ERROR_MESSAGES
from open_webui.env import ENV, SRC_LOG_LEVELS
from fastapi import Depends, FastAPI, File, HTTPException, Request, UploadFile
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import StreamingResponse
from pydantic import BaseModel, ConfigDict
from starlette.background import BackgroundTask


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.utils import get_admin_user, get_verified_user
from open_webui.utils.access_control import has_access

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


app = FastAPI(
    docs_url="/docs" if ENV == "dev" else None,
    openapi_url="/openapi.json" if ENV == "dev" else None,
    redoc_url=None,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=CORS_ALLOW_ORIGIN,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

app.state.config = AppConfig()

app.state.config.ENABLE_OLLAMA_API = ENABLE_OLLAMA_API
app.state.config.OLLAMA_BASE_URLS = OLLAMA_BASE_URLS
app.state.config.OLLAMA_API_CONFIGS = OLLAMA_API_CONFIGS


# 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.


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


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


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

    headers = {}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    timeout = aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT_OPENAI_MODEL_LIST)
    async with aiohttp.ClientSession(timeout=timeout) as session:
        try:
            async with session.get(f"{url}/api/version", headers=headers) as r:
                if r.status != 200:
                    # Extract response error details if available
                    error_detail = f"HTTP Error: {r.status}"
                    res = await r.json()
                    if "error" in res:
                        error_detail = f"External Error: {res['error']}"
                    raise Exception(error_detail)

                response_data = await r.json()
                return response_data

        except aiohttp.ClientError as e:
            # ClientError covers all aiohttp requests issues
            log.exception(f"Client error: {str(e)}")
            # Handle aiohttp-specific connection issues, timeout etc.
            raise HTTPException(
                status_code=500, detail="Open WebUI: Server Connection Error"
            )
        except Exception as e:
            log.exception(f"Unexpected error: {e}")
            # Generic error handler in case parsing JSON or other steps fail
            error_detail = f"Unexpected error: {str(e)}"
            raise HTTPException(status_code=500, detail=error_detail)


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


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


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

    app.state.config.OLLAMA_API_CONFIGS = form_data.OLLAMA_API_CONFIGS

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

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


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


async def cleanup_response(
    response: Optional[aiohttp.ClientResponse],
    session: Optional[aiohttp.ClientSession],
):
    if response:
        response.close()
    if session:
        await session.close()


async def post_streaming_url(
    url: str, payload: Union[str, bytes], stream: bool = True, content_type=None
):
    r = None
    try:
        session = aiohttp.ClientSession(
            trust_env=True, timeout=aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT)
        )

        api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
        key = api_config.get("key", None)

        headers = {"Content-Type": "application/json"}
        if key:
            headers["Authorization"] = f"Bearer {key}"

        r = await session.post(
            url,
            data=payload,
            headers=headers,
        )
        r.raise_for_status()

        if stream:
            headers = dict(r.headers)
            if content_type:
                headers["Content-Type"] = content_type
            return StreamingResponse(
                r.content,
                status_code=r.status,
                headers=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:
        error_detail = "Open WebUI: Server Connection Error"
        if r is not None:
            try:
                res = await 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 if r else 500,
            detail=error_detail,
        )


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())


async def get_all_models():
    log.info("get_all_models()")
    if app.state.config.ENABLE_OLLAMA_API:
        tasks = []
        for idx, url in enumerate(app.state.config.OLLAMA_BASE_URLS):
            if url not in app.state.config.OLLAMA_API_CONFIGS:
                tasks.append(aiohttp_get(f"{url}/api/tags"))
            else:
                api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
                enable = api_config.get("enable", True)
                key = api_config.get("key", None)

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

        responses = await asyncio.gather(*tasks)

        for idx, response in enumerate(responses):
            if response:
                url = app.state.config.OLLAMA_BASE_URLS[idx]
                api_config = 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']}"

        print(responses)

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

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

    return models


@app.get("/api/tags")
@app.get("/api/tags/{url_idx}")
async def get_ollama_tags(
    url_idx: Optional[int] = None, user=Depends(get_verified_user)
):
    models = []
    if url_idx is None:
        models = await get_all_models()
    else:
        url = app.state.config.OLLAMA_BASE_URLS[url_idx]

        api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
        key = api_config.get("key", None)

        headers = {}
        if key:
            headers["Authorization"] = f"Bearer {key}"

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

            models = r.json()
        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":
        # 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)
        models["models"] = filtered_models

    return models


@app.get("/api/version")
@app.get("/api/version/{url_idx}")
async def get_ollama_versions(url_idx: Optional[int] = None):
    if app.state.config.ENABLE_OLLAMA_API:
        if url_idx is None:
            # returns lowest version
            tasks = [
                aiohttp_get(
                    f"{url}/api/version",
                    app.state.config.OLLAMA_API_CONFIGS.get(url, {}).get("key", None),
                )
                for url in app.state.config.OLLAMA_BASE_URLS
            ]
            responses = await asyncio.gather(*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 = 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)
                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,
                )
    else:
        return {"version": False}


class ModelNameForm(BaseModel):
    name: str


@app.post("/api/pull")
@app.post("/api/pull/{url_idx}")
async def pull_model(
    form_data: ModelNameForm, url_idx: int = 0, user=Depends(get_admin_user)
):
    url = 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 post_streaming_url(f"{url}/api/pull", json.dumps(payload))


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


@app.delete("/api/push")
@app.delete("/api/push/{url_idx}")
async def push_model(
    form_data: PushModelForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.debug(f"url: {url}")

    return await post_streaming_url(
        f"{url}/api/push", form_data.model_dump_json(exclude_none=True).encode()
    )


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


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

    return await post_streaming_url(
        f"{url}/api/create", form_data.model_dump_json(exclude_none=True).encode()
    )


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


@app.post("/api/copy")
@app.post("/api/copy/{url_idx}")
async def copy_model(
    form_data: CopyModelForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
    key = api_config.get("key", None)

    headers = {"Content-Type": "application/json"}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    r = requests.request(
        method="POST",
        url=f"{url}/api/copy",
        headers=headers,
        data=form_data.model_dump_json(exclude_none=True).encode(),
    )

    try:
        r.raise_for_status()

        log.debug(f"r.text: {r.text}")

        return True
    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,
        )


@app.delete("/api/delete")
@app.delete("/api/delete/{url_idx}")
async def delete_model(
    form_data: ModelNameForm,
    url_idx: Optional[int] = None,
    user=Depends(get_admin_user),
):
    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
    key = api_config.get("key", None)

    headers = {"Content-Type": "application/json"}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    r = requests.request(
        method="DELETE",
        url=f"{url}/api/delete",
        data=form_data.model_dump_json(exclude_none=True).encode(),
        headers=headers,
    )
    try:
        r.raise_for_status()

        log.debug(f"r.text: {r.text}")

        return True
    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,
        )


@app.post("/api/show")
async def show_model_info(form_data: ModelNameForm, user=Depends(get_verified_user)):
    model_list = await get_all_models()
    models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
    key = api_config.get("key", None)

    headers = {"Content-Type": "application/json"}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    r = requests.request(
        method="POST",
        url=f"{url}/api/show",
        headers=headers,
        data=form_data.model_dump_json(exclude_none=True).encode(),
    )
    try:
        r.raise_for_status()

        return r.json()
    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,
        )


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


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


@app.post("/api/embed")
@app.post("/api/embed/{url_idx}")
async def generate_embeddings(
    form_data: GenerateEmbedForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    return generate_ollama_batch_embeddings(form_data, url_idx)


@app.post("/api/embeddings")
@app.post("/api/embeddings/{url_idx}")
async def generate_embeddings(
    form_data: GenerateEmbeddingsForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    return await generate_ollama_embeddings(form_data=form_data, url_idx=url_idx)


async def generate_ollama_embeddings(
    form_data: GenerateEmbeddingsForm,
    url_idx: Optional[int] = None,
):
    log.info(f"generate_ollama_embeddings {form_data}")

    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
    key = api_config.get("key", None)

    headers = {"Content-Type": "application/json"}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    r = requests.request(
        method="POST",
        url=f"{url}/api/embeddings",
        headers=headers,
        data=form_data.model_dump_json(exclude_none=True).encode(),
    )
    try:
        r.raise_for_status()

        data = r.json()

        log.info(f"generate_ollama_embeddings {data}")

        if "embedding" in data:
            return data
        else:
            raise Exception("Something went wrong :/")
    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,
        )


async def generate_ollama_batch_embeddings(
    form_data: GenerateEmbedForm,
    url_idx: Optional[int] = None,
):
    log.info(f"generate_ollama_batch_embeddings {form_data}")

    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    log.info(f"url: {url}")

    api_config = app.state.config.OLLAMA_API_CONFIGS.get(url, {})
    key = api_config.get("key", None)

    headers = {"Content-Type": "application/json"}
    if key:
        headers["Authorization"] = f"Bearer {key}"

    r = requests.request(
        method="POST",
        url=f"{url}/api/embed",
        headers=headers,
        data=form_data.model_dump_json(exclude_none=True).encode(),
    )
    try:
        r.raise_for_status()

        data = r.json()

        log.info(f"generate_ollama_batch_embeddings {data}")

        if "embeddings" in data:
            return data
        else:
            raise Exception("Something went wrong :/")
    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 Exception(error_detail)


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


@app.post("/api/generate")
@app.post("/api/generate/{url_idx}")
async def generate_completion(
    form_data: GenerateCompletionForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
):
    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["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 = app.state.config.OLLAMA_BASE_URLS[url_idx]
    api_config = 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}.", "")
    log.info(f"url: {url}")

    return await post_streaming_url(
        f"{url}/api/generate", form_data.model_dump_json(exclude_none=True).encode()
    )


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


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


async def get_ollama_url(url_idx: Optional[int], model: str):
    if url_idx is None:
        model_list = await get_all_models()
        models = {model["model"]: model for model in model_list["models"]}

        if model not in models:
            raise HTTPException(
                status_code=400,
                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(model),
            )
        url_idx = random.choice(models[model]["urls"])
    url = app.state.config.OLLAMA_BASE_URLS[url_idx]
    return url


@app.post("/api/chat")
@app.post("/api/chat/{url_idx}")
async def generate_chat_completion(
    form_data: GenerateChatCompletionForm,
    url_idx: Optional[int] = None,
    user=Depends(get_verified_user),
    bypass_filter: Optional[bool] = False,
):
    payload = {**form_data.model_dump(exclude_none=True)}
    log.debug(f"generate_chat_completion() - 1.payload = {payload}")
    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(url_idx, payload["model"])
    log.info(f"url: {url}")
    log.debug(f"generate_chat_completion() - 2.payload = {payload}")

    api_config = 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 post_streaming_url(
        f"{url}/api/chat",
        json.dumps(payload),
        stream=form_data.stream,
        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")


@app.post("/v1/chat/completions")
@app.post("/v1/chat/completions/{url_idx}")
async def generate_openai_chat_completion(
    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(url_idx, payload["model"])
    log.info(f"url: {url}")

    api_config = 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 post_streaming_url(
        f"{url}/v1/chat/completions",
        json.dumps(payload),
        stream=payload.get("stream", False),
    )


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

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

    else:
        url = 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":
        # 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"
@app.post("/models/download")
@app.post("/models/download/{url_idx}")
async def download_model(
    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 = 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


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