Jyotisha/frontend/src/lib/account-deletion.ts

/**
 * Self-service account deletion (2026-09-30). Shared by the settings entry,
 * the frozen-account screen, the API route and the purge worker. Pure: no
 * server imports, so client components can use it.
 *
 * Rules (product): request → signed out everywhere, account frozen; within 7
 * days signing in again offers 撤销注销; after 7 days personal content is
 * deleted and the identity becomes an anonymous tombstone. Orders, the credit
 * ledger, usage and billing rows are kept for bookkeeping, pointing at that
 * tombstone. Remaining credits are forfeited.
 */

export const ACCOUNT_DELETION_GRACE_DAYS = 7;
/** Typed by the user to confirm, the same way the staging reset asks for a phrase. */
export const ACCOUNT_DELETION_CONFIRM_WORD = "注销";
/** Stable code every paid route returns while a deletion is pending. */
export const ACCOUNT_DELETION_PENDING_CODE = "account_deletion_pending";

/** Mirrors `public.account_deletion_kept_tables()`; everything else the user owns is deleted. */
export const ACCOUNT_DELETION_KEPT_TABLES = [
  "account_deletion_requests",
  "admin_session_revocations",
  "admin_user_roles",
  "admin_users",
  "birth_time_rectification_billing",
  "consultation_requests",
  "credit_request_cancellations",
  "credit_transactions",
  "payment_orders",
  "pricing_experiment_events",
  "redemption_attempts",
  "redemption_codes",
  "usage_ledger",
  "usage_reservations",
  "user_product_redemptions",
  "user_subscriptions",
  // Complaint handling records; the typed-in contact is cleared at purge.
  "user_feedback",
] as const;

/** What the confirmation dialog tells the user will be deleted. */
export const ACCOUNT_DELETION_DELETED_ITEMS = [
  "全部对话记录",
  "你和星盘档案里其他人的出生资料与星盘",
  "个人报告",
  "生时校正记录",
  "合盘记录",
  "账号本身（邮箱、昵称、登录方式）",
] as const;

export type AccountDeletionStatus =
  | Readonly<{ status: "none" }>
  | Readonly<{ status: "pending"; requestedAt: string | null; scheduledFor: string }>;

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function isoOrNull(value: unknown): string | null {
  if (typeof value !== "string" && !(value instanceof Date)) return null;
  const date = new Date(value);
  return Number.isNaN(date.getTime()) ? null : date.toISOString();
}

/** Reads the status the API returns (and the RPC result); anything unusable is "none". */
export function parseAccountDeletionStatus(value: unknown): AccountDeletionStatus {
  if (!isRecord(value) || value.status !== "pending") return { status: "none" };
  const scheduledFor = isoOrNull(value.scheduledFor);
  if (!scheduledFor) return { status: "none" };
  return { status: "pending", requestedAt: isoOrNull(value.requestedAt), scheduledFor };
}

/** 「10 月 7 日」 in Beijing time — the day the deletion becomes permanent. */
export function formatAccountDeletionDate(iso: string): string {
  const date = new Date(iso);
  if (Number.isNaN(date.getTime())) return "七天后";
  const parts = new Intl.DateTimeFormat("zh-CN", { timeZone: "Asia/Shanghai", month: "numeric", day: "numeric" }).formatToParts(date);
  const month = parts.find((part) => part.type === "month")?.value;
  const day = parts.find((part) => part.type === "day")?.value;
  return month && day ? `${month} 月 ${day} 日` : "七天后";
}

export function isAccountDeletionConfirmation(input: unknown): boolean {
  return typeof input === "string" && input.trim() === ACCOUNT_DELETION_CONFIRM_WORD;
}

/** Maps a database error from the request RPC to a stable route code. */
export function accountDeletionRequestErrorCode(message: string | undefined): "admin_account" | "not_found" | "unavailable" {
  if (message?.includes("account_deletion_admin_account")) return "admin_account";
  if (message?.includes("account_deletion_user_not_found")) return "not_found";
  return "unavailable";
}

export type AccountDeletionRpcClient = {
  rpc(name: string, args: Readonly<Record<string, unknown>>): PromiseLike<{ data: unknown; error: { message?: string } | null }>;
};

/**
 * The permanent-deletion date when the account has a pending request, else
 * null. A read failure (for example before the migration has run) reads as
 * "not pending": this guard must never lock people out by accident.
 */
export async function readPendingAccountDeletionWith(client: AccountDeletionRpcClient, userId: string): Promise<string | null> {
  try {
    const { data, error } = await client.rpc("account_deletion_scheduled_for", { p_user_id: userId });
    if (error || data === null || data === undefined) return null;
    return isoOrNull(data);
  } catch {
    return null;
  }
}