/** 账号记录 ↔ 入参 / 视图(设计稿 §5.3);视图经 schema 过一遍,密文进不来 */
import type { MailAccountInput, MailAccountKind, MailAccountView } from '@contracts';
import { mailAccountViewSchema } from '@contracts';
import { cursorSummary } from './cursor.ts';
import { isPolling } from './due.ts';
import type { MailAccountRecord } from './records.ts';

export function viewOf(record: MailAccountRecord, now: Date): MailAccountView {
  return mailAccountViewSchema.parse({
    id: record.id,
    kind: record.kind,
    name: record.name,
    address: record.address,
    displayName: record.displayName,
    enabled: record.enabled,
    isDefault: record.isDefault,
    pollIntervalSec: record.pollIntervalSec,
    channelId: record.channelId,
    backfillFrom: record.backfillFrom === null ? null : record.backfillFrom.toISOString(),
    settings: record.settings,
    secretBound: record.secretCipher !== null && record.secretCipher !== '',
    status: {
      lastPolledAt: record.lastPolledAt === null ? null : record.lastPolledAt.toISOString(),
      lastPollError: record.lastPollError,
      lastInboundAt: record.lastInboundAt === null ? null : record.lastInboundAt.toISOString(),
      cursor: cursorSummary(record.cursor),
      polling: isPolling(record.pollingUntil, now),
    },
    createdAt: record.createdAt.toISOString(),
    updatedAt: record.updatedAt.toISOString(),
  });
}

/** 入参里的凭证 → 待密封的 JSON;没给就是 undefined(= 不改) */
export function secretOf(input: MailAccountInput): string | undefined {
  return input.secret === undefined ? undefined : JSON.stringify(input.secret);
}

/**
 * **只有收侧的键动了才谈得上重锚** —— 游标说的是「这个信箱 / 这个文件夹我读到哪儿了」。
 *
 * 从前比的是全部 settings 键,连 `smtpHost` / `smtpPort` / `smtpTls` 都算:
 * 人把 465 改成 587(纯发信的事)→ 游标清空 → IMAP 重锚 `lastUid = uidNext − 1` →
 * 上次游标到重锚之间到达的信**永远不拉**(设计即「不回填」)。**改发信的设置不该丢来信**。
 * `login` 两侧都用,算收侧(换了登录名就是换了一个信箱在读)。
 */
const RECEIVE_KEYS: Readonly<Record<MailAccountKind, readonly string[]>> = {
  'imap-smtp': ['imapHost', 'imapPort', 'imapTls', 'login', 'folder'],
  wecom: ['corpId', 'apiBase'],
};

function sameReceiveSettings(kind: MailAccountKind, a: Record<string, unknown>, b: Record<string, unknown>): boolean {
  return RECEIVE_KEYS[kind].every((k) => JSON.stringify(a[k] ?? null) === JSON.stringify(b[k] ?? null));
}

/** kind 或**收侧** settings 变了,旧游标指的就不是同一个信箱 / 同一个文件夹 —— 清空重锚 */
export function cursorReset(existing: MailAccountRecord | undefined, input: MailAccountInput): boolean {
  if (existing === undefined) return false;
  return existing.kind !== input.kind || !sameReceiveSettings(input.kind, existing.settings, input.settings);
}

export function mergeAccount(
  input: MailAccountInput,
  base: { readonly id: string; readonly existing: MailAccountRecord | undefined; readonly secretCipher: string | null; readonly now: Date },
): MailAccountRecord {
  const reset = cursorReset(base.existing, input);
  const existing = base.existing;
  return {
    id: base.id,
    kind: input.kind,
    name: input.name,
    // wecom 的地址由探测回填,人不填;换成 imap-smtp 时以填的为准
    address: input.kind === 'imap-smtp' ? input.address : existing?.kind === 'wecom' ? existing.address : '',
    displayName: input.displayName,
    enabled: input.enabled,
    isDefault: input.isDefault,
    pollIntervalSec: input.pollIntervalSec,
    channelId: input.channelId,
    backfillFrom: input.backfillFrom === null ? null : new Date(input.backfillFrom),
    settings: { ...input.settings },
    secretCipher: base.secretCipher,
    cursor: reset ? null : (existing?.cursor ?? null),
    lastPolledAt: existing?.lastPolledAt ?? null,
    lastPollError: reset ? null : (existing?.lastPollError ?? null),
    lastInboundAt: existing?.lastInboundAt ?? null,
    pollingUntil: existing?.pollingUntil ?? null,
    createdAt: existing?.createdAt ?? base.now,
    updatedAt: base.now,
  };
}