"""站内通知 API"""
from __future__ import annotations

from datetime import datetime, timezone
import re
from typing import Any, Optional

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import and_, desc, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from ..core.response import success_response
from ..core.database import get_db
from ..dependencies import get_current_user, get_tenant_id
from ..models import Notification, User


from ..utils.timezone import now_cn_naive
router = APIRouter(prefix="/notifications", tags=["notifications"])


PROJECT_TARGET_RE = re.compile(r"/projects/(\d+)")


def _extract_project_id(row: Notification) -> Optional[int]:
    payload = row.payload if isinstance(row.payload, dict) else {}
    payload_project_id = payload.get("project_id")
    if payload_project_id is not None:
        try:
            return int(payload_project_id)
        except (TypeError, ValueError):
            pass
    if row.entity_type == "project" and row.entity_id is not None:
        return int(row.entity_id)
    target_url = str(row.target_url or "").strip()
    matched = PROJECT_TARGET_RE.search(target_url)
    if matched:
        try:
            return int(matched.group(1))
        except (TypeError, ValueError):
            return None
    return None


def _extract_project_name(row: Notification) -> Optional[str]:
    payload = row.payload if isinstance(row.payload, dict) else {}
    name = payload.get("project_name")
    if isinstance(name, str) and name.strip():
        return name.strip()
    return None


def _serialize_notification(row: Notification) -> dict:
    payload: Optional[dict[str, Any]] = row.payload if isinstance(row.payload, dict) else None
    return {
        "id": int(row.id),
        "title": row.title,
        "content": row.content,
        "category": row.category,
        "source": row.source,
        "entity_type": row.entity_type,
        "entity_id": int(row.entity_id) if row.entity_id is not None else None,
        "target_url": row.target_url,
        "kind": row.kind or "info",
        "priority": row.priority,
        "status": row.status or row.kind or "info",
        "blocking_reason": row.blocking_reason,
        "recommended_action": row.recommended_action,
        "dedupe_key": row.dedupe_key,
        "occurrence_count": int(row.occurrence_count or 1),
        "payload": payload,
        "project_id": _extract_project_id(row),
        "project_name": _extract_project_name(row),
        "is_read": bool(row.is_read),
        "read_at": row.read_at.isoformat() if row.read_at else None,
        "created_at": row.created_at.isoformat() if row.created_at else None,
        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
    }


@router.get("")
async def list_notifications(
    unread_only: bool = Query(default=False),
    limit: int = Query(default=20, ge=1, le=100),
    current_user: User = Depends(get_current_user),
    tenant_id: int = Depends(get_tenant_id),
    db: AsyncSession = Depends(get_db),
):
    query = select(Notification).where(
        and_(
            Notification.tenant_id == tenant_id,
            Notification.user_id == int(current_user.id),
        )
    )
    if unread_only:
        query = query.where(Notification.is_read.is_(False))
    query = query.order_by(desc(Notification.updated_at), desc(Notification.created_at)).limit(limit)

    rows = (await db.execute(query)).scalars().all()
    unread_count = await db.scalar(
        select(func.count(Notification.id)).where(
            and_(
                Notification.tenant_id == tenant_id,
                Notification.user_id == int(current_user.id),
                Notification.is_read.is_(False),
            )
        )
    )
    return success_response(
        data={
            "items": [_serialize_notification(row) for row in rows],
            "unread_count": int(unread_count or 0),
        }
    )


@router.post("/{notification_id}/read")
async def mark_notification_read(
    notification_id: int,
    current_user: User = Depends(get_current_user),
    tenant_id: int = Depends(get_tenant_id),
    db: AsyncSession = Depends(get_db),
):
    row = (
        await db.execute(
            select(Notification).where(
                and_(
                    Notification.id == notification_id,
                    Notification.tenant_id == tenant_id,
                    Notification.user_id == int(current_user.id),
                )
            )
        )
    ).scalar_one_or_none()
    if not row:
        raise HTTPException(status_code=404, detail="通知不存在")

    if not row.is_read:
        row.is_read = True
        row.read_at = now_cn_naive()
        await db.commit()

    return success_response(data=_serialize_notification(row))


@router.post("/read-all")
async def mark_all_notifications_read(
    current_user: User = Depends(get_current_user),
    tenant_id: int = Depends(get_tenant_id),
    db: AsyncSession = Depends(get_db),
):
    rows = (
        await db.execute(
            select(Notification).where(
                and_(
                    Notification.tenant_id == tenant_id,
                    Notification.user_id == int(current_user.id),
                    Notification.is_read.is_(False),
                )
            )
        )
    ).scalars().all()

    now = now_cn_naive()
    for row in rows:
        row.is_read = True
        row.read_at = now

    if rows:
        await db.commit()

    return success_response(data={"updated": len(rows)})