import type { UserPayload } from "@/types/api";

/**
 * 后端账号取值契约（与 common_const §13 对齐，数据库存值不改动）。
 * 前端只做展示映射和菜单显隐，不修改后端权限判断 —— 真正的鉴权仍在服务端。
 */

/** sys_user.user_type：建表枚举，沿用 DDL 定义。 */
export const USER_TYPE = {
  CUSTOMER: "CUSTOMER",
  EMPLOYEE: "EMPLOYEE",
  ADMIN: "ADMIN",
} as const;

/** sys_user.employee_role：中文，与既有数据一致。 */
export const EMPLOYEE_ROLE = {
  ADMIN: "管理员",
  ADVISOR: "投顾",
  RISK: "风控专员",
  CUSTOMER_MANAGER: "客户经理",
} as const;

/** 统一工作台上可切换的功能区。 */
export type WorkspaceSection =
  | "overview"
  | "todos"
  | "customers"
  | "drafts"
  | "visits"
  | "risk"
  | "workorders"
  | "funds"
  | "admin";

/** 管理员：账号类型为 ADMIN，或员工账号且角色为「管理员」。 */
export function isAdmin(user?: UserPayload | null): boolean {
  if (!user) return false;
  if (user.user_type === USER_TYPE.ADMIN) return true;
  return user.user_type === USER_TYPE.EMPLOYEE && user.employee_role === EMPLOYEE_ROLE.ADMIN;
}

export function isEmployee(user?: UserPayload | null): boolean {
  return user?.user_type === USER_TYPE.EMPLOYEE;
}

/** 是否能进入员工后台（管理员视同拥有全部员工权限）。 */
export function isStaff(user?: UserPayload | null): boolean {
  return isAdmin(user) || isEmployee(user);
}

/** 员工角色命中即通过；管理员一律放行。 */
function hasEmployeeRole(user: UserPayload | null | undefined, role: string): boolean {
  if (isAdmin(user)) return true;
  return isEmployee(user) && user?.employee_role === role;
}

export function isAdvisor(user?: UserPayload | null): boolean {
  return hasEmployeeRole(user, EMPLOYEE_ROLE.ADVISOR);
}

export function isRiskOfficer(user?: UserPayload | null): boolean {
  return hasEmployeeRole(user, EMPLOYEE_ROLE.RISK);
}

/**
 * 各功能区所需权限。
 * 不满足时不整页拒绝，而是在该区域内渲染「无权限」提示，员工仍可使用其它有权限的模块。
 */
const SECTION_GUARD: Record<WorkspaceSection, (user?: UserPayload | null) => boolean> = {
  overview: isStaff,
  todos: isAdvisor,
  customers: isAdvisor,
  drafts: isAdvisor,
  visits: isAdvisor,
  risk: isRiskOfficer,
  workorders: isRiskOfficer,
  funds: isStaff,
  admin: isAdmin,
};

export function canUseSection(
  user: UserPayload | null | undefined,
  section: WorkspaceSection
): boolean {
  return SECTION_GUARD[section]?.(user) ?? false;
}

export function isWorkspaceSection(value: string | null): value is WorkspaceSection {
  return !!value && value in SECTION_GUARD;
}