"""用户认证"""
import hashlib
from fastapi import APIRouter, Depends, HTTPException, Request
from sqlalchemy.orm import Session
from app.database import get_db
from app.models import User, UserEntity, Entity, OperationLog
from app.auth_middleware import create_token, require_auth, ROLES

router = APIRouter(prefix="/api/cma/auth", tags=["认证"])


def _user_entity_ids(db: Session, user_id: int) -> list[int]:
    """返回用户被授权的企业ID列表"""
    rows = db.query(UserEntity.entity_id).filter(UserEntity.user_id == user_id).all()
    return [r[0] for r in rows]


def _ensure_default_grants(db: Session, user_id: int) -> None:
    """存量用户兼容：若用户没有任何授权记录，则授予所有active企业（不锁死老账号）"""
    cnt = db.query(UserEntity).filter(UserEntity.user_id == user_id).count()
    if cnt > 0:
        return
    entities = db.query(Entity).filter(Entity.status == "active").all()
    for e in entities:
        db.add(UserEntity(user_id=user_id, entity_id=e.id, granted_by=1))
    db.commit()


@router.post("/login")
def login(data: dict, db: Session = Depends(get_db)):
    username = data.get("username", "")
    password = data.get("password", "")
    user = db.query(User).filter(User.username == username).first()
    if not user or user.password_hash != hashlib.sha256(password.encode()).hexdigest():
        raise HTTPException(401, "用户名或密码错误")

    # 账套模式：登录必须指定企业（entity_id）
    entity_id = data.get("entity_id")
    if entity_id is None:
        raise HTTPException(400, "账套模式：请选择登录企业（entity_id）")

    # 存量兼容：无授权记录时自动授予active企业
    _ensure_default_grants(db, user.id)

    allowed = _user_entity_ids(db, user.id)
    if int(entity_id) not in allowed:
        raise HTTPException(403, f"该账号未被授权访问企业 entity_id={entity_id}")

    entity = db.query(Entity).filter(Entity.id == int(entity_id)).first()
    if not entity or entity.status != "active":
        raise HTTPException(403, f"企业 entity_id={entity_id} 不存在或未激活")

    token = create_token(user.id, int(entity_id))
    return {
        "token": token,
        "entity_id": int(entity_id),
        "entity_name": entity.name,
        "entity_short_name": entity.short_name,
        "user": {
            "id": user.id,
            "username": user.username,
            "name": user.name,
            "role": user.role,
            "role_name": ROLES.get(user.role, {}).get("name", user.role),
        }
    }


@router.post("/register")
def register(data: dict, db: Session = Depends(get_db)):
    exist = db.query(User).filter(User.username == data.get("username")).first()
    if exist:
        raise HTTPException(400, "用户名已存在")
    user = User(
        username=data["username"],
        password_hash=hashlib.sha256(data["password"].encode()).hexdigest(),
        name=data.get("name", data["username"]),
        role=data.get("role", "business"),
    )
    db.add(user)
    db.commit()
    # 新用户默认授予所有active企业
    _ensure_default_grants(db, user.id)
    return {"message": "注册成功"}


@router.get("/me")
def get_me(request: Request, current_user: User = Depends(require_auth), db: Session = Depends(get_db)):
    """获取当前用户信息（含当前账套）"""
    from app.auth_middleware import extract_bearer_token, get_token_entity_id
    token = extract_bearer_token(request)
    eid = get_token_entity_id(token) if token else None
    ent = db.query(Entity).filter(Entity.id == eid).first() if eid else None
    d = {
        "id": current_user.id,
        "username": current_user.username,
        "name": current_user.name,
        "role": current_user.role,
        "role_name": ROLES.get(current_user.role, {}).get("name", current_user.role),
        "phone": current_user.phone,
    }
    if ent:
        d["entity_id"] = ent.id
        d["entity_name"] = ent.name
        d["entity_short_name"] = ent.short_name
    return d


@router.get("/roles")
def list_roles():
    """返回角色列表（给前端用）"""
    return {
        "data": [
            {"code": k, "name": v["name"], "priority": v["priority"]}
            for k, v in ROLES.items()
        ]
    }


@router.get("/entities")
def my_entities(current_user: User = Depends(require_auth), db: Session = Depends(get_db)):
    """当前用户被授权的企业列表（登录页下拉/切换器数据源）"""
    _ensure_default_grants(db, current_user.id)
    ids = _user_entity_ids(db, current_user.id)
    entities = db.query(Entity).filter(
        Entity.id.in_(ids),
        Entity.status == "active",
    ).order_by(Entity.id).all()
    return {
        "data": [
            {"id": e.id, "name": e.name, "short_name": e.short_name, "industry": e.industry}
            for e in entities
        ]
    }


@router.get("/my-entities")
def my_entities_alias(current_user: User = Depends(require_auth), db: Session = Depends(get_db)):
    """别名：/auth/my-entities（前端切换器调用）"""
    return my_entities(current_user, db)


@router.get("/login-entities")
def login_entities_options(username: str = None, db: Session = Depends(get_db)):
    """登录页公司选择器：按用户名返回授权企业（无鉴权，登录前调用；不暴露用户名是否存在）"""
    if not username:
        return {"data": []}
    user = db.query(User).filter(User.username == username).first()
    if not user:
        return {"data": []}
    _ensure_default_grants(db, user.id)
    ids = _user_entity_ids(db, user.id)
    ents = db.query(Entity).filter(
        Entity.id.in_(ids),
        Entity.status == "active",
    ).order_by(Entity.id).all()
    return {"data": [{"id": e.id, "name": e.name, "short_name": e.short_name} for e in ents]}


@router.post("/switch-entity")
def switch_entity(
    data: dict,
    request: Request,
    current_user: User = Depends(require_auth),
    db: Session = Depends(get_db),
):
    """账套切换：校验授权 → 重新签发token → 写操作日志（方案B：无缝刷新token）"""
    entity_id = data.get("entity_id")
    if not entity_id:
        raise HTTPException(400, "缺少entity_id")

    _ensure_default_grants(db, current_user.id)
    allowed = _user_entity_ids(db, current_user.id)
    if int(entity_id) not in allowed:
        raise HTTPException(403, f"该账号未被授权访问企业 entity_id={entity_id}")

    entity = db.query(Entity).filter(Entity.id == int(entity_id)).first()
    if not entity or entity.status != "active":
        raise HTTPException(403, f"企业 entity_id={entity_id} 不存在或未激活")

    # 旧token失效：删除当前请求的旧token（切换即下线旧账套凭据）
    auth = request.headers.get("Authorization", "")
    if auth.startswith("Bearer "):
        try:
            import redis as redis_lib
            r = redis_lib.Redis(host="127.0.0.1", port=6379, db=1, decode_responses=True)
            r.delete(f"cma:token:{auth[7:]}")
        except Exception:
            pass

    token = create_token(current_user.id, int(entity_id))

    # 切换留痕
    db.add(OperationLog(
        user_id=current_user.id,
        action="switch_entity",
        target_type="entity",
        target_id=int(entity_id),
        detail={"entity_id": int(entity_id), "entity_name": entity.name, "from": "account-switch"},
    ))
    db.commit()

    return {
        "token": token,
        "entity_id": int(entity_id),
        "entity_name": entity.name,
        "entity_short_name": entity.short_name,
    }