import { Paths } from 'type-fest';

/**
 * 获取对象所有可能的键路径（点分隔的字符串）。
 * 这个类型基于 type-fest 的 Paths 类型，但排除了数字索引（数组索引）。
 *
 * @template T - 要提取路径的对象类型
 * @param options.maxRecursionDepth - 递归深度限制（默认为30）
 *
 * @example
 * ```typescript
 * // 基本对象结构
 * interface User {
 *   id: number;
 *   name: string;
 *   address: {
 *     street: string;
 *     city: string;
 *     coordinates: {
 *       lat: number;
 *       lng: number;
 *     };
 *   };
 *   orders: Array<{
 *     id: string;
 *     items: Array<{
 *       sku: string;
 *       quantity: number;
 *     }>;
 *   }>;
 * }
 *
 * // 获取所有路径
 * type UserPaths = ObjectKeyPaths<User>;
 * // 结果：
 * // "id" | "name" | "address" | "address.street" | "address.city"
 * // | "address.coordinates" | "address.coordinates.lat" | "address.coordinates.lng"
 * // | "orders" | "orders.id" | "orders.items" | "orders.items.sku" | "orders.items.quantity"
 *
 * // 实际应用场景
 * function getValueByPath<T>(obj: T, path: ObjectKeyPaths<T>): unknown {
 *   return path.split('.').reduce((acc, key) => acc?.[key], obj);
 * }
 *
 * const user: User = { ... };
 *
 * // 类型安全的路径访问
 * const city = getValueByPath(user, "address.city");  // string
 * const lat = getValueByPath(user, "address.coordinates.lat");  // number
 *
 * // 错误示例（类型检查会报错）
 * // const invalid1 = getValueByPath(user, "invalid.path");  // 错误
 * // const invalid2 = getValueByPath(user, "orders.0.items.1");  // 错误（排除了数字索引）
 *
 * // 复杂嵌套结构
 * interface AppState {
 *   auth: {
 *     user?: {
 *       id: string;
 *       profile: {
 *         name: string;
 *         avatar: string;
 *       };
 *     };
 *     token?: string;
 *   };
 *   ui: {
 *     theme: 'light' | 'dark';
 *     loading: boolean;
 *   };
 * }
 *
 * type AppStatePaths = ObjectKeyPaths<AppState>;
 * // 结果：
 * // "auth" | "auth.user" | "auth.user.id" | "auth.user.profile"
 * // | "auth.user.profile.name" | "auth.user.profile.avatar" | "auth.token"
 * // | "ui" | "ui.theme" | "ui.loading"
 *
 * // 用于表单验证
 * function validateField(state: AppState, field: AppStatePaths): boolean {
 *   const value = getValueByPath(state, field);
 *   // 验证逻辑...
 *   return true;
 * }
 * ```
 */
type ChangePathDelimiter<T extends string, D extends string = "/", S extends string = '.'> = T extends `${infer Head}${S}${infer Tail}` ? `${Head}${D}${ChangePathDelimiter<Tail, D>}` : T;
type ObjectKeyPaths<T extends object, Delimiter extends string = '.'> = ChangePathDelimiter<Exclude<Paths<T, {
    maxRecursionDepth: 30;
}>, number>, Delimiter>;

export type { ChangePathDelimiter, ObjectKeyPaths };