from fastapi import APIRouter, HTTPException, status, WebSocket, WebSocketDisconnect
from pydantic import BaseModel
import asyncio
import json as _json

router = APIRouter(prefix="/api/admin", tags=["admin"])

SOURCES = {
    "wikipedia_ru": "Wikipedia RU (~8 GB)",
    "wikipedia_en": "Wikipedia EN (~22 GB)",
}


class JobResponse(BaseModel):
    status: str
    source: str | None = None
    label: str | None = None
    progress: int = 0
    message: str = ""
    started_at: str | None = None
    finished_at: str | None = None
    docs_done: int = 0


@router.get("/index/sources")
def list_sources():
    """Список доступных источников для индексации."""
    return [{"key": k, "label": v} for k, v in SOURCES.items()]


@router.post("/index/download/{source_key}", response_model=JobResponse)
def start_download(source_key: str):
    """Скачать дамп и проиндексировать с нуля."""
    if source_key not in SOURCES:
        raise HTTPException(status_code=400, detail=f"Unknown source: {source_key}")

    from app.tasks.indexing import get_job_status, download_and_index
    current = get_job_status()
    if current.get("status") == "running":
        raise HTTPException(status_code=409, detail="Задание уже выполняется")

    download_and_index.delay(source_key)
    return JobResponse(status="started", source=source_key, label=SOURCES[source_key], message="Запуск скачивания…")


@router.post("/index/update/{source_key}", response_model=JobResponse)
def start_update(source_key: str):
    """Обновить индекс — только новые документы (дамп не скачивается заново если уже есть)."""
    if source_key not in SOURCES:
        raise HTTPException(status_code=400, detail=f"Unknown source: {source_key}")

    from app.tasks.indexing import get_job_status, update_index
    current = get_job_status()
    if current.get("status") == "running":
        raise HTTPException(status_code=409, detail="Задание уже выполняется")

    update_index.delay(source_key)
    return JobResponse(status="started", source=source_key, label=SOURCES[source_key], message="Запуск обновления…")


@router.get("/index/status", response_model=JobResponse)
def job_status():
    """Текущий статус задания индексации."""
    from app.tasks.indexing import get_job_status
    data = get_job_status()
    return JobResponse(
        status=data.get("status", "idle"),
        source=data.get("source"),
        label=data.get("label"),
        progress=data.get("progress", 0),
        message=data.get("message", ""),
        started_at=data.get("started_at"),
        finished_at=data.get("finished_at"),
        docs_done=data.get("docs_done", 0),
    )


@router.websocket("/ws/index-progress")
async def ws_index_progress(websocket: WebSocket):
    """Stream indexing job progress via Redis pub/sub."""
    await websocket.accept()

    import redis.asyncio as aioredis
    from app.config import settings

    r = aioredis.from_url(settings.REDIS_URL)
    pubsub = r.pubsub()
    await pubsub.subscribe("index_job_progress")

    # Send current state immediately
    from app.tasks.indexing import get_job_status
    await websocket.send_json(get_job_status())

    try:
        async for message in pubsub.listen():
            if message["type"] != "message":
                continue
            try:
                data = _json.loads(message["data"])
            except Exception:
                continue
            await websocket.send_json(data)
            if data.get("status") in ("done", "error"):
                break
    except (WebSocketDisconnect, asyncio.CancelledError):
        pass
    finally:
        try:
            await pubsub.unsubscribe("index_job_progress")
        except Exception:
            pass
        try:
            await r.aclose()
        except Exception:
            pass