import type { User } from '../types';
import type { Agent, Attachment, Contact, HumanSession, Mail, PermissionRequest, SuggestResult, SessionDetail, ThreadPage, RenameProposal, SessionBudget } from '../types';
import { API_BASE, authHeaders, withToken } from './config';

export { API_BASE, setToken, getToken, authHeaders, withToken } from './config';

const BASE = API_BASE;

export class ApiError extends Error {
  status: number;
  retryAfter?: number;
  constructor(status: number, message: string, retryAfter?: number) {
    super(message);
    this.status = status;
    this.retryAfter = retryAfter;
  }
}

let onUnauthorized: (() => void) | null = null;
export function setUnauthorizedHandler(fn: () => void) {
  onUnauthorized = fn;
}

async function request<T>(method: string, path: string, body?: unknown): Promise<T> {
  const init: RequestInit = {
    method,
    // Cookie 模式需要 include；带 Bearer 时多发一个 Cookie 也无害
    credentials: 'include',
    headers: { 'Content-Type': 'application/json', ...authHeaders() }
  };
  if (body !== undefined) init.body = JSON.stringify(body);

  const res = await fetch(`${BASE}${path}`, init);

  if (!res.ok) {
    const payload = await res.json().catch(() => ({ error: res.statusText }));
    if (res.status === 401 && !path.startsWith('/auth/login') && !path.startsWith('/setup')) {
      onUnauthorized?.();
    }
    throw new ApiError(res.status, payload.error || `HTTP ${res.status}`, payload.retry_after);
  }
  return res.json();
}

// ---------- 首次初始化 ----------

export async function setupStatus() {
  return request<{ needs_setup: boolean }>('GET', '/setup/status');
}

export async function setupAdmin(payload: {
  username: string;
  password: string;
  display_name?: string;
}) {
  return request<{ user: User }>('POST', '/setup/admin', payload);
}

// ---------- 认证 ----------

export async function login(username: string, password: string) {
  return request<{ user: User }>('POST', '/auth/login', { username, password });
}

export async function logout() {
  return request<{ status: string }>('POST', '/auth/logout');
}

export async function me() {
  return request<{ user: User }>('GET', '/auth/me');
}

export async function changePassword(oldPassword: string, newPassword: string) {
  return request<{ status: string }>('POST', '/auth/password', {
    old_password: oldPassword,
    new_password: newPassword
  });
}

// ---------- 管理员：用户管理 ----------

export async function adminListUsers() {
  return request<{ users: User[] }>('GET', '/admin/users');
}

export async function adminCreateUser(payload: {
  username: string;
  password: string;
  display_name?: string;
  role?: string;
  allowed_agents?: string[];
  allowed_paths?: string[];
}) {
  return request<{ user: User }>('POST', '/admin/users', payload);
}

export async function adminUpdateUser(
  id: string,
  payload: {
    display_name?: string;
    role?: string;
    status?: string;
    allowed_agents?: string[];
    allowed_paths?: string[];
  }
) {
  return request<{ user: User }>('PUT', `/admin/users/${id}`, payload);
}

export async function adminDisableUser(id: string) {
  return request<{ status: string }>('DELETE', `/admin/users/${id}`);
}

export async function adminResetPassword(id: string, newPassword: string) {
  return request<{ status: string }>('POST', `/admin/users/${id}/reset`, {
    new_password: newPassword
  });
}

export async function adminListScopes() {
  const r = await request<{ agents: string[]; paths: string[] }>('GET', '/admin/scopes');
  return r;
}

// ---------- 密钥 ----------

export type KeyType = 'permanent' | 'one_time' | 'timed';

/** 密钥全文 key_token 仅在创建响应里出现一次，列表只给 token_hint。 */
export interface AgentKey {
  key_id: string;
  key_token?: string;
  token_hint: string;
  agent_name: string | null;
  key_type: KeyType;
  label: string;
  expires_at: string | null;
  used_at: string | null;
  created_at: string;
}

export interface UserKey {
  key_id: string;
  key_token?: string;
  token_hint: string;
  label: string;
  key_type: KeyType;
  expires_at: string | null;
  used_at: string | null;
  created_at: string;
}

export interface CreateKeyPayload {
  key_type: KeyType;
  label?: string;
  /** 仅 timed 需要 */
  expires_hours?: number;
  /** 仅 Agent 密钥：留空 = 待绑定，首次注册时落定 */
  agent_name?: string;
  /** 仅 Agent 密钥：登记客户端已在本地生成的密钥 */
  key_token?: string;
}

export async function adminListAgentKeys(agentName?: string) {
  const q = agentName ? `?agent_name=${encodeURIComponent(agentName)}` : '';
  return request<{ keys: AgentKey[] }>('GET', `/admin/agent-keys${q}`);
}

export async function adminCreateAgentKey(payload: CreateKeyPayload) {
  return request<{ key: AgentKey }>('POST', '/admin/agent-keys', payload);
}

export async function adminDeleteAgentKey(id: string) {
  return request<{ status: string }>('DELETE', `/admin/agent-keys/${id}`);
}

export async function adminBindAgentKey(id: string, agentName: string) {
  return request<{ status: string; agent_name: string }>(
    'POST',
    `/admin/agent-keys/${id}/bind`,
    { agent_name: agentName }
  );
}

export async function listMyKeys() {
  return request<{ keys: UserKey[] }>('GET', '/me/keys');
}

export async function createMyKey(payload: CreateKeyPayload) {
  return request<{ key: UserKey }>('POST', '/me/keys', payload);
}

export async function deleteMyKey(id: string) {
  return request<{ status: string }>('DELETE', `/me/keys/${id}`);
}

// ---------- Agents ----------

export async function listAgents(status?: string) {
  const q = status ? `?status=${encodeURIComponent(status)}` : '';
  return request<{ agents: Agent[] }>('GET', `/agents${q}`);
}

// ---------- 自己的邮箱 ----------

export interface SendMailOpts {
  cc?: string;
  reply_to?: string;
  /** 仅在用 .new 新建会话时生效：给新会话命名，之后可用 name@path.<别名> 续谈 */
  session_alias?: string;
  /** 先用 uploadAttachment 上传取得的 id 列表 */
  attachment_ids?: string[];
  /**
   * 本任务的往返预算（0/省略 = 不限）。仅在新建会话时生效；
   * 续谈已有会话请用 updateSessionBudget（对话页里可随时改）。
   */
  max_rounds?: number;
}

export async function sendMail(
  to: string,
  subject: string,
  body: string,
  opts: SendMailOpts = {}
) {
  return request<{
    mail_id: string;
    session_id: string;
    session_alias: string;
    budget_max?: number;
    budget_used?: number;
    budget_remaining?: number;
  }>('POST', '/me/mail/send', {
    to,
    subject,
    body,
    cc: opts.cc ?? '',
    reply_to: opts.reply_to ?? '',
    session_alias: opts.session_alias ?? '',
    attachment_ids: opts.attachment_ids ?? [],
    // null 而非 0：0 是「不限」的合法取值，省略才表示「不设置」
    max_rounds: opts.max_rounds ?? null
  });
}

export async function getInbox(status = 'all', limit = 50) {
  return request<{ mails: Mail[]; total: number }>(
    'GET',
    `/me/mail/inbox?status=${encodeURIComponent(status)}&limit=${limit}`
  );
}

export async function getSent() {
  return request<{ mails: Mail[] }>('GET', '/me/mail/sent');
}

export async function getMail(id: string) {
  return request<Mail>('GET', `/mail/${id}`);
}

export async function markMailRead(id: string) {
  return request<{ status: string }>('POST', `/mail/${id}/read`);
}

/**
 * 取线索的一块。
 *
 * dir=around 首屏（锚点 + 部分祖先 + 部分子孙），up/down 配 offset 增量加载。
 * 树可跨会话，服务端按会话逐个鉴权，看不到的节点不返回并计入 hidden。
 */
export async function getMailThread(
  id: string,
  opts: { dir?: 'around' | 'up' | 'down'; offset?: number; limit?: number } = {}
) {
  const q = new URLSearchParams();
  if (opts.dir) q.set('dir', opts.dir);
  if (opts.offset !== undefined) q.set('offset', String(opts.offset));
  if (opts.limit !== undefined) q.set('limit', String(opts.limit));
  const qs = q.toString();
  return request<ThreadPage>('GET', `/mail/${id}/thread${qs ? '?' + qs : ''}`);
}

// ---------- 附件 ----------

/**
 * 上传附件，返回 attachment_id。
 *
 * 不能走 request()：那里固定 Content-Type: application/json，
 * 而 multipart 必须让浏览器自己带 boundary。
 */
export async function uploadAttachment(file: File, onProgress?: (pct: number) => void) {
  const form = new FormData();
  form.append('file', file);

  // 需要进度就用 XHR —— fetch 至今没有上传进度事件
  if (onProgress) {
    return new Promise<{ attachment: Attachment }>((resolve, reject) => {
      const xhr = new XMLHttpRequest();
      xhr.open('POST', `${BASE}/me/attachments`);
      xhr.withCredentials = true;
      for (const [k, v] of Object.entries(authHeaders())) xhr.setRequestHeader(k, v);
      xhr.upload.onprogress = e => {
        if (e.lengthComputable) onProgress(Math.round((e.loaded / e.total) * 100));
      };
      xhr.onload = () => {
        let payload: { attachment?: Attachment; error?: string } = {};
        try {
          payload = JSON.parse(xhr.responseText);
        } catch {
          /* 非 JSON 响应按状态码处理 */
        }
        if (xhr.status >= 200 && xhr.status < 300 && payload.attachment) {
          resolve({ attachment: payload.attachment });
        } else {
          if (xhr.status === 401) onUnauthorized?.();
          reject(new ApiError(xhr.status, payload.error || `HTTP ${xhr.status}`));
        }
      };
      xhr.onerror = () => reject(new ApiError(0, '网络错误'));
      xhr.send(form);
    });
  }

  const res = await fetch(`${BASE}/me/attachments`, {
    method: 'POST',
    credentials: 'include',
    // 不设 Content-Type：multipart 的 boundary 要交给浏览器生成
    headers: authHeaders(),
    body: form
  });
  if (!res.ok) {
    const payload = await res.json().catch(() => ({ error: res.statusText }));
    if (res.status === 401) onUnauthorized?.();
    throw new ApiError(res.status, payload.error || `HTTP ${res.status}`);
  }
  return res.json() as Promise<{ attachment: Attachment }>;
}

export async function deleteAttachment(id: string) {
  return request<{ status: string }>('DELETE', `/me/attachments/${id}`);
}

/**
 * 附件下载链接。由浏览器直接发起（<a download>），因此无法带 Authorization 头：
 * Cookie 模式靠同源 Cookie，密钥模式回退到 ?access_token=。
 */
export function attachmentURL(id: string) {
  return withToken(`${BASE}/me/attachments/${id}`);
}

/** 人类可读的字节数 */
export function formatSize(n: number) {
  if (n < 1024) return `${n} B`;
  if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`;
  return `${(n / 1024 / 1024).toFixed(1)} MB`;
}

export interface ForwardPayload {
  /** 新收件人的三维地址 */
  to: string;
  /** 转发说明，置于引用原文之前 */
  comment?: string;
  cc?: string;
  /** 留空则自动加 Fwd: 前缀 */
  subject?: string;
  /** 仅当 to 以 .new 结尾时生效 */
  session_alias?: string;
}

export async function forwardMail(id: string, payload: ForwardPayload) {
  return request<{
    mail_id: string;
    session_id: string;
    session_alias: string;
    forwarded_from: string;
  }>('POST', `/me/mail/${id}/forward`, {
    to: payload.to,
    comment: payload.comment ?? '',
    cc: payload.cc ?? '',
    subject: payload.subject ?? '',
    session_alias: payload.session_alias ?? ''
  });
}

// ---------- 配额 ----------

/**
 * Agent 的新任务默认预算与累计统计。
 *
 * 没有「剩余额度」字段 —— 额度属于具体任务（会话），见 SessionBudget。
 * 这里只有「派给它的新任务默认几个来回」与「一共发了多少信」。
 */
export interface AgentStats {
  agent_name: string;
  /** 派给该 Agent 的新任务默认多少个来回（0 = 不限） */
  default_rounds: number;
  /** 累计发信数，纯统计，不拦请求 */
  sent_total: number;
  /** 参与的未归档会话数，配合默认值判断设多少合适 */
  active_sessions: number;
}

export async function adminListAgentStats() {
  return request<{ quotas: AgentStats[] }>('GET', '/admin/quotas');
}

/** 改该 Agent 的新任务默认预算（0 = 不限）。 */
export async function adminSetDefaultRounds(agentName: string, defaultRounds: number) {
  return request<{ quota: AgentStats }>(
    'PUT',
    `/admin/quotas/${encodeURIComponent(agentName)}`,
    { default_rounds: defaultRounds }
  );
}

// ---------- Sessions ----------

export async function getHumanSessions() {
  return request<{ sessions: HumanSession[] }>('GET', '/me/sessions');
}

export async function getSessionDetail(id: string) {
  return request<SessionDetail>('GET', `/sessions/${id}`);
}

export async function updateSessionAlias(id: string, alias: string) {
  return request<{ status: string; alias: string }>('PUT', `/sessions/${id}/alias`, { alias });
}

/**
 * 取该会话里最新一条尚未处理的改名提议（Agent 在邮件正文里提的）。
 * 已接受（提议就是当前别名）或已驳回的不再返回。
 */
export async function getRenameProposal(id: string) {
  return request<{ proposal: RenameProposal | null }>('GET', `/sessions/${id}/rename-proposal`);
}

/** 本会话（= 本任务）的往返预算。 */
export async function getSessionBudget(id: string) {
  return request<SessionBudget>('GET', `/sessions/${id}/budget`);
}

/**
 * 改本会话的往返预算。
 *
 * max_rounds = 0 表示不限；reset 把已用次数归零。两者可同时给
 * （「加到 20 并从头算」是一次很自然的操作，拆成两个请求只会多一次往返）。
 */
export async function updateSessionBudget(
  id: string,
  patch: { max_rounds?: number; reset?: boolean }
) {
  return request<SessionBudget>('PUT', `/sessions/${id}/budget`, patch);
}

/** 驳回当前提议。记下来，提示条不再反复弹同一个建议。 */
export async function dismissRenameProposal(id: string) {
  return request<{ status: string; dismissed?: string }>(
    'POST',
    `/sessions/${id}/rename-proposal/dismiss`
  );
}

// ---------- Contacts ----------

export async function listContacts(archived = false) {
  return request<{ contacts: Contact[] }>('GET', `/contacts?archived=${archived}`);
}

export async function suggestAddress(name?: string, path?: string) {
  const p = new URLSearchParams();
  if (name) p.set('name', name);
  if (path) p.set('path', path);
  return request<SuggestResult>('GET', `/contacts/suggest?${p.toString()}`);
}

export async function archiveContact(payload: { address?: string; session_id?: string }) {
  return request<{ status: string; session_id: string; session_alias: string }>(
    'POST',
    '/contacts/archive',
    payload
  );
}

// ---------- Permission ----------

export async function decidePermission(mailId: string, decision: string, note?: string) {
  return request<{ status: string; decision_mail_id: string }>('POST', '/permission/decide', {
    mail_id: mailId,
    decision,
    note: note ?? ''
  });
}

export async function listPendingPermissions() {
  return request<{ requests: PermissionRequest[] }>('GET', '/permission/pending');
}