// Thin REST client for the product-specific `/v1/im/*` API that sits alongside the Tinode WS
// protocol. Ported from the previous im_webapp's src/lib/im-api.js -- the header names, the
// reason-code translation table, and the batch-endpoint "always 200, real result in items[]"
// quirk are all hard-won facts about this exact backend (im_team/im_server, server/im_http.go),
// verified against a live deployment over months of integration work. They are not guesses and
// should not be "cleaned up" back to what the upstream Tinode docs say (this deployment's header
// is `X-MeetingIM-APIKey`, not the upstream sample's `X-Tinode-APIKey` -- that exact mismatch was
// a real, repeatedly-rediscovered bug in the old codebase).
import { API_KEY } from '@/lib/config';
import { getKickedInfo } from '@/lib/tinode/connection';
import { useSessionStore } from '@/stores/session';

const DEFAULT_API_BASE = '/v1/im';
const DEFAULT_FILE_BASE = '/v0/file';
const CONFIGURED_API_BASE = import.meta.env.VITE_TINODE_API_BASE?.trim();
const CONFIGURED_FILE_BASE = import.meta.env.VITE_TINODE_FILE_BASE?.trim();

export class ImApiError extends Error {
  reason?: string;
  status?: number;
  details?: unknown;

  constructor(message: string, reason?: string, status?: number, details?: unknown) {
    super(message);
    this.reason = reason;
    this.status = status;
    this.details = details;
  }
}

/** docs/IM-前后端对接文档.md §12.4's full reason list -- see client.ts's header comment. */
const REASON_MESSAGES: Record<string, string | ((details: unknown) => string | null)> = {
  API_KEY_REQUIRED: '服务暂不可用，请刷新页面重试',
  METHOD_NOT_ALLOWED: '请求方式有误，请刷新页面重试',
  TENANT_UNAVAILABLE: '企业码不存在或已停用，请核实后重试',
  TENANT_MISMATCH: '登录状态异常，请重新进入企业码',
  AUTH_FAILED: '账号或密码错误',
  TOKEN_EXPIRED: '登录已过期，请重新登录',
  ACCOUNT_DISABLED: '账号已被禁用',
  RATE_LIMITED: '操作过于频繁，请稍后再试',
  VALIDATION_FAILED: '提交的内容不符合要求',
  IDEMPOTENCY_CONFLICT: '内容已发生变化，请刷新后重试',
  RESOURCE_NOT_FOUND: '内容不存在或已被删除',
  PERMISSION_DENIED: '没有权限执行此操作',
  // docs/IM-前后端对接文档.md:2629's own canonical "must implement" list -- distinct from
  // PERMISSION_DENIED above (a separately-observed live reason, kept as-is). Missing this one meant
  // imRequest's fallback chain (`payload.message || payload.reason || ...`) leaked the server's raw
  // internal message or the bare reason string straight to the user for this exact reason code,
  // which the doc explicitly says must never happen (§0.4/§12.4: "不得把服务端 message 原样展示给用户").
  FORBIDDEN: '没有权限执行此操作',
  // docs/IM-前后端对接文档.md:2312 -- ProfileSettingsPage's birth_date save can hit this.
  PROFILE_FIELD_INVALID: '资料字段格式不正确，请检查后重试',
  NOT_FOUND: '内容不存在或已被删除',
  VERSION_CONFLICT: '内容已被修改，请刷新后重试',
  MALFORMED_REQUEST: '请求内容有误，请稍后重试',
  AUTH_REQUIRED: '请先登录',
  ACTION_TOKEN_INVALID: '操作凭证已失效，请重新操作',
  SCHEMA_UNSUPPORTED: '当前版本过旧，请刷新页面后重试',
  IDEMPOTENCY_IN_PROGRESS: '上一次操作正在处理中，请稍后再试',
  INTERNAL_ERROR: '服务器繁忙，请稍后重试',
  UNSUPPORTED_MEDIA_TYPE: '不支持的文件类型',
  CHALLENGE_EXPIRED: '验证码已过期，请重新获取',
  SMS_DELIVERY_FAILED: '短信发送失败，请稍后重试',
  PASSWORD_POLICY_VIOLATION: '密码不符合安全要求',
  VERIFICATION_RATE_LIMITED: (details) =>
    isRetryAfter(details) ? `操作过于频繁，请 ${details.retry_after_seconds} 秒后重试` : '操作过于频繁，请稍后再试',
  ALREADY_GROUP_MEMBER: '对方已经是群成员',
  DESCRIPTION_REQUIRED: '请填写简介内容',
  DESCRIPTION_TOO_LONG: '简介内容过长',
  GROUP_ADMIN_LIMIT_EXCEEDED: '群管理员数量已达上限',
  INVALID_CREDIT_CODE: '统一社会信用代码格式不正确',
  INVALID_EMAIL: '邮箱格式不正确',
  APPLICATION_DUPLICATED: '该企业已有申请正在审核中，请耐心等待',
  TOO_MANY_FILES: '文件数量超出限制',
  FRIEND_RELATION_REQUIRED: '需要先添加对方为好友',
  MESSAGE_NOT_ALLOWED: '当前状态无法发送消息',
  GROUP_MUTED: '你已被禁言，无法发言',
  GROUP_MEMBER_LIMIT_EXCEEDED: '群成员数量已达上限',
  GROUP_VERSION_CONFLICT: '群信息已被修改，请刷新后重试',
  INVITATION_EXPIRED: '邀请已过期',
  TENANT_USER_QUOTA_EXCEEDED: '企业账号数已达上限',
  TENANT_GROUP_QUOTA_EXCEEDED: '企业群组数已达上限',
  FILE_TOO_LARGE: '文件大小超出限制',
  FILE_FORBIDDEN: '没有权限访问此文件',
  FILE_UNAVAILABLE: '文件暂不可用',
  STORAGE_QUOTA_EXCEEDED: '存储空间已达上限',
  RISK_CONFIRMATION_REQUIRED: '需要先完成安全确认',
  RISK_ACTION_BLOCKED: '该操作已被安全策略拦截',
  QR_CODE_EXPIRED: '二维码已过期，请对方刷新后重新扫描',
  QR_CODE_INVALID: '二维码无效，请重新扫描',
  FRIEND_REQUEST_NOT_ALLOWED: '对方暂不允许添加好友',
  // `relation.Relationship != RelationshipNone` (im_http.go's serveIMFriendRequestCreate) -- already
  // friends, or a request between the two of you (either direction) is already pending.
  FRIEND_REQUEST_CONFLICT: '你们已经是好友，或好友申请正在处理中',
  USER_NOT_DISCOVERABLE: '未找到该用户',
  REQUEST_ALREADY_HANDLED: '该申请已被处理，请刷新查看最新状态',
  SEARCH_RATE_LIMITED: '搜索过于频繁，请稍后再试',
  // Shared by two unrelated verify endpoints (independent-password PIN check and plain SMS
  // verification-code verify) -- keep generic enough to be accurate for both.
  CODE_INVALID: '验证码或独立密码不正确',
  TOO_MANY_ATTEMPTS: (details) =>
    isRetryAfter(details) ? `连续输错次数过多，请 ${details.retry_after_seconds} 秒后重试` : '连续输错次数过多，请稍后重试',
};

function isRetryAfter(details: unknown): details is { retry_after_seconds: number } {
  return !!details && typeof details === 'object' && 'retry_after_seconds' in details;
}

function translateReason(reason: string | undefined, details?: unknown): string | null {
  if (!reason) return null;
  const entry = REASON_MESSAGES[reason];
  return (typeof entry === 'function' ? entry(details) : entry) || null;
}

export function requestId(): string {
  return typeof crypto !== 'undefined' && crypto.randomUUID
    ? crypto.randomUUID()
    : `web_${Date.now().toString(36)}_${Math.random().toString(36).slice(2)}`;
}

export function apiBase(): string {
  const endpoints = useSessionStore.getState().tenant?.endpoints;
  // Production serves the static web app and IM API from different origins. The configured origin
  // must also work before a tenant has been resolved, while local development keeps using Vite's
  // same-origin proxy by leaving this value unset.
  return (CONFIGURED_API_BASE || endpoints?.api || DEFAULT_API_BASE).replace(/\/$/, '');
}

export function fileBase(): string {
  const endpoints = useSessionStore.getState().tenant?.endpoints;
  // Production may expose the web UI and the IM API through different deployments. Prefer the
  // build-time canonical file origin so a tenant context previously resolved through the web host
  // cannot keep routing attachments to that host's stale /v0/file proxy. Local development leaves
  // this unset and continues to use the resolved relative endpoint through Vite's proxy.
  return (CONFIGURED_FILE_BASE || endpoints?.file || DEFAULT_FILE_BASE).replace(/\/$/, '');
}

export function currentTenantCode(): string {
  return useSessionStore.getState().tenant?.code || 'default';
}

/** Set by tinode-web.jsx-equivalent login/reconnect code; tab-lifetime, independent of "remember me". */
export function authToken(): string {
  return sessionStorage.getItem('im-session-token') || '';
}

function normalizeResponse(payload: { code?: number; data?: unknown }): unknown {
  return payload && payload.code === 0 && payload.data !== undefined ? payload.data : payload;
}

interface RequestOptions {
  method?: 'GET' | 'POST' | 'PATCH' | 'PUT' | 'DELETE';
  body?: unknown;
  headers?: Record<string, string>;
  auth?: boolean;
  tenantCodeOverride?: string;
}

/** Core request helper. `auth: false` skips the Authorization header (pre-login calls). */
export async function imRequest<T = unknown>(
  path: string,
  { method = 'GET', body, headers, auth = true, tenantCodeOverride }: RequestOptions = {},
): Promise<T> {
  const finalHeaders: Record<string, string> = {
    'Content-Type': 'application/json',
    'X-MeetingIM-APIKey': API_KEY,
    'X-IM-Schema': '1',
    'X-Tenant-Code': tenantCodeOverride || currentTenantCode(),
    'X-Request-ID': requestId(),
    ...headers,
  };
  if (auth) {
    const token = authToken();
    if (token) finalHeaders.Authorization = `Bearer ${token}`;
  }
  const response = await fetch(apiBase() + path, {
    method,
    headers: finalHeaders,
    body: body !== undefined ? JSON.stringify(body) : undefined,
  });
  const text = await response.text();
  let payload: { code?: number; data?: unknown; reason?: string; message?: string; details?: unknown } = {};
  if (text) {
    try {
      payload = JSON.parse(text);
    } catch {
      throw new ImApiError(
        response.ok ? '接口返回非 JSON 数据' : response.statusText || '接口请求失败',
        'NON_JSON_RESPONSE',
        response.status,
        text.slice(0, 160),
      );
    }
  }
  if (!response.ok || payload?.code) {
    const known = translateReason(payload.reason, payload.details);
    // A 401 on a request that DID carry a Bearer token means the server has stopped honoring that
    // token (expired/revoked while a WS reconnect or a stale tab kept using it) -- nothing anywhere
    // else in this client uniformly handled this before, so a session invalidated mid-use just made
    // every subsequent call fail the same way forever with no path back to a real login.
    if (auth && response.status === 401 && authToken()) forceReauth();
    throw new ImApiError(
      known || payload.message || payload.reason || response.statusText || '请求失败',
      payload.reason,
      response.status,
      payload.details,
    );
  }
  return normalizeResponse(payload) as T;
}

/** Clears the invalidated session and hard-navigates to /login -- deliberately a full page load
 *  (not an in-SPA redirect) so every piece of in-memory state (the Tinode singleton, TanStack Query
 *  cache, any open modal's local state) resets from scratch rather than needing each of them to
 *  separately react correctly to "you were logged in a second ago, now you're not." Guarded so a
 *  burst of parallel requests failing at once (a realistic case: several queries in flight when the
 *  token expires) only navigates once. */
let reauthTriggered = false;
function forceReauth() {
  if (reauthTriggered) return;
  sessionStorage.removeItem('im-session-token');
  useSessionStore.getState().setMyUserId(null);
  if (typeof window === 'undefined' || window.location.pathname === '/login') return;
  reauthTriggered = true;
  // An account-level eviction (connection.ts's onCtrlMessage) and a REST 401 can both be caused by
  // the SAME server-side event (e.g. 顶号: the new login invalidates this token, and whichever
  // request -- the WS {ctrl:205} push or an in-flight REST call -- gets processed first is down to
  // network timing, not something this code controls). Without this, a REST 401 that happens to
  // land first bounces straight to /login with zero explanation, silently pre-empting the whole
  // point of KickedNoticeRoot: the doc's "弹出中文提示后跳转登录页" requirement. A brief wait lets
  // that WS message (usually already in flight over an open connection, typically faster than a
  // fresh REST round trip) land first if it's coming; if `kickedInfo` shows up in that window, defer
  // to its own button-triggered navigation instead of racing it. Ordinary 401s (no eviction involved,
  // by far the common case) just navigate ~200ms later than before -- not perceptible.
  window.setTimeout(() => {
    if (getKickedInfo()) return;
    window.location.href = '/login';
  }, 200);
}

const idem = () => ({ 'Idempotency-Key': requestId() });

// `opts.headers` is merged ON TOP of idem() (not replaced by the outer `...opts` spread) so a
// caller that needs its own extra header can't accidentally drop the Idempotency-Key.
export const imGet = <T = unknown>(path: string, opts?: RequestOptions) => imRequest<T>(path, opts);
export const imPost = <T = unknown>(path: string, body?: unknown, opts: RequestOptions = {}) =>
  imRequest<T>(path, { method: 'POST', body, ...opts, headers: { ...idem(), ...opts.headers } });
export const imPatch = <T = unknown>(path: string, body?: unknown, opts: RequestOptions = {}) =>
  imRequest<T>(path, { method: 'PATCH', body, ...opts, headers: { ...idem(), ...opts.headers } });
export const imPut = <T = unknown>(path: string, body?: unknown, opts: RequestOptions = {}) =>
  imRequest<T>(path, { method: 'PUT', body, ...opts, headers: { ...idem(), ...opts.headers } });
export const imDelete = <T = unknown>(path: string, opts: RequestOptions = {}) =>
  imRequest<T>(path, { method: 'DELETE', ...opts, headers: { ...idem(), ...opts.headers } });

/**
 * List endpoints here cap out at 20-50 items per page and it's a real, previously-hit bug class to
 * only ever fetch page 1 (e.g. "am I this group's owner/admin" going undetected because the real
 * answer was on page 2). Empty/repeated next_cursor means done.
 */
// Guards against a server-side cursor bug (e.g. two values that cycle back and forth) turning this
// into an infinite fetch loop -- 200 pages at a 20-50 item page size is already far more than any
// realistic friends/blocks/search list, so hitting this is itself a signal something's wrong server-
// side, not a real user's data legitimately needing more.
const MAX_PAGES = 200;

export async function fetchAllPages<T>(
  fetchPage: (cursor: string) => Promise<{ items?: T[]; next_cursor?: string }>,
  startCursor = '',
): Promise<T[]> {
  let cursor = startCursor;
  let items: T[] = [];
  for (let page = 0; page < MAX_PAGES; page++) {
    const result = await fetchPage(cursor);
    items = items.concat(result?.items || []);
    const nextCursor = result?.next_cursor || '';
    if (!nextCursor || nextCursor === cursor) break;
    cursor = nextCursor;
  }
  return items;
}