"""GET /api/analytics/* —— 数据分析板块端组(前缀分组=未来角色权限落点)。"""
from __future__ import annotations

from typing import Annotated, Any, Literal

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession

from app.analytics import health as health_svc
from app.analytics import metrics as metrics_svc
from app.api.deps import get_session

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

SessionDep = Annotated[AsyncSession, Depends(get_session)]
ChannelParam = Annotated[Literal["wechat", "whatsapp"], Query()]
ScopeParam = Annotated[Literal["today", "week", "month"], Query()]


@router.get("/health")
async def analytics_health(session: SessionDep) -> dict[str, Any]:
    """E0-lite:数据截至 + 实体新鲜度。"""
    as_of = await health_svc.data_as_of(session)
    return {"data_as_of": as_of, "entities": await health_svc.entity_freshness(session)}


@router.get("/overview")
async def analytics_overview(
    session: SessionDep,
    channel: ChannelParam = "wechat",
    scope: ScopeParam = "today",
) -> dict[str, Any]:
    """A1 经营总览:卡片+趋势+异常警示一次返回(单往返)。

    cards 不含 data_as_of——数据截至走 /health(data_as_of 为 ms-epoch int
    与 entities[].last_seen 为 ISO 字符串的双格式)。
    """
    return await metrics_svc.overview(session, channel=channel, scope=scope)


@router.get("/churn")
async def churn_list(
    session: SessionDep,
    channel: ChannelParam = "wechat",
    type: Literal["real", "inactive", "handover"] = "real",
    tier: int = Query(30, ge=30, le=90),
    min_msgs: int = Query(5, ge=1, le=100),
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
) -> dict[str, Any]:
    """A3 流失预警名单(三分法)。tier 只认 30/60/90。"""
    if tier not in (30, 60, 90):
        raise HTTPException(422, "tier must be 30/60/90")
    return await metrics_svc.churn(
        session, channel=channel, kind=type, tier=tier,
        min_msgs=min_msgs, page=page, page_size=page_size,
    )