from fastapi import Header, Request

from app.core.context import UserContext
from app.core.exceptions import AppError


async def get_user_context(
    request: Request,
    x_user_id: str | None = Header(default=None, alias="X-User-Id"),
    x_tenant_id: str | None = Header(default=None, alias="X-Tenant-Id"),
    x_user_role: str | None = Header(default=None, alias="X-User-Role"),
    x_class_id: str | None = Header(default=None, alias="X-Class-Id"),
    x_entry_scene: str | None = Header(default=None, alias="X-Entry-Scene"),
    x_request_id: str | None = Header(default=None, alias="X-Request-Id"),
) -> UserContext:
    """用户校验：读取请求头并强制校验 `X-User-Id`。"""
    if not x_user_id or not x_user_id.strip():
        raise AppError("USER_ID_REQUIRED", "X-User-Id header is required", 401)

    return UserContext(
        user_id=x_user_id.strip(),
        tenant_id=x_tenant_id,
        role=x_user_role,
        class_id=x_class_id,
        entry_scene=x_entry_scene,
        request_id=x_request_id,
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("User-Agent"),
    )