import React from 'react';
import { Tinode } from 'tinode-sdk';

import HashNavigation from '../lib/navigation.js';
import { getBootstrap, getSystemNotifications, markSystemNotificationRead } from '../lib/im-api.js';
import { makeImageUrl } from '../lib/blob-helpers.js';
import { useCachedData } from '../lib/use-cached-data.js';
import { topicDisplayName } from '../lib/utils.js';

// Must go through setUrlSidePanel (not a bare navigateTo(view), which replaces the whole hash) so
// switching panels from "messages-home" doesn't silently drop path[1] -- the currently open
// conversation topic, which coexists with this panel in the split view once a chat is selected.
// `topic` 可选：系统消息里的群事件通知需要带着群 topic 跳进对应群聊设置页，写法与
// group-management-view.jsx 的同名辅助函数保持一致（不带 topic 时显式清掉，避免把上一个页面
// 残留的 topic 参数带进不相关的页面）。
const navigate = (view, topic) => {
  let hash = HashNavigation.setUrlSidePanel(window.location.hash, view);
  hash = topic ? HashNavigation.addUrlParam(hash, 'topic', topic) : HashNavigation.removeUrlParam(hash, 'topic');
  HashNavigation.navigateTo(hash);
};

// Was a hardcoded FREQUENT_CONTACTS mock (5 fake names, always clicking through to the same
// direct-message-view.jsx demo regardless of which avatar was tapped -- confirmed independently by
// a user screenshot showing every contact opening the identical "接语彤" script). Real "frequently
// contacted" data doesn't exist as its own bootstrap field, so this derives it from the same
// `chatList` the conversation list below already uses: P2P topics only (a "people you talk to" rail
// isn't the place for groups), most-recently-touched first.
function frequentContacts(chatList) {
  if (!chatList || chatList.length === 0) return [];
  return chatList
    .filter(item => item.topic && Tinode.isP2PTopicName(item.topic))
    .slice()
    .sort((a, b) => new Date(b.touched || 0).getTime() - new Date(a.touched || 0).getTime())
    .slice(0, 8)
    .map(item => ({
      id: item.topic,
      name: (item.public && item.public.fn) || '未命名',
      avatar: makeImageUrl(item.public && item.public.photo),
      online: !!item.online
    }));
}

// Matches docs/images/消息页面—长按弹出.png exactly (9 items, in this order -- no "编辑" despite
// bootstrap.message_policy.supported_actions listing it; the mock predates that field and the
// prototype just doesn't surface an edit action here). 'recall' is gated against supported_actions
// (server/im_http.go serveIMBootstrap); favorite/forward/translate/select are pure client affordances.
const MESSAGE_ACTIONS = [
  {id: 'quote', icon: 'format_quote', label: '引用'},
  {id: 'copy', icon: 'content_copy', label: '复制'},
  {id: 'favorite', icon: 'inventory_2', label: '收藏'},
  {id: 'translate', icon: 'translate', label: '翻译'},
  {id: 'forward', icon: 'reply', label: '转发'},
  {id: 'recall', icon: 'undo', label: '撤回', gated: true},
  {id: 'delete', icon: 'delete_outline', label: '删除', gated: true},
  {id: 'select', icon: 'select_all', label: '多选'},
  // Not in bootstrap.message_policy.supported_actions at all (that list only covers 'recall' for the
  // sender's own message) -- left ungated like the other pure client affordances above.
  {id: 'group_recall', icon: 'restart_alt', label: '群撤回'}
];

function Icon({children}) {
  return <i className="material-icons" aria-hidden="true">{children}</i>;
}

function Toast({message, onDone}) {
  React.useEffect(() => {
    if (!message) return undefined;
    const timer = window.setTimeout(onDone, 2200);
    return () => window.clearTimeout(timer);
  }, [message, onDone]);
  return message ? <div className="messages-toast" role="status">{message}</div> : null;
}

function Avatar({item, small = false}) {
  // The tone modifier is namespaced ('tone-orange', not 'orange') because base.css's original
  // Tinode styles already define bare `.orange`/`.green`/`.blue` as generic `color: ... !important`
  // text-color utility classes -- an unprefixed tone class collides with those and, since
  // `!important` beats any selector this component could use to fight back, silently overrides the
  // intended white icon-on-tint background to whatever that generic utility's text color is (this is
  // exactly why the default/no-tone case rendered an invisible blue-on-blue icon: 'blue' is one of
  // the collision names).
  const className = 'messages-avatar ' + (small ? 'small ' : '') + 'tone-' + (item.tone || 'blue');
  return <div className={className}>
    {item.avatar ? <img src={item.avatar} alt="" /> : <Icon>{item.icon || 'person'}</Icon>}
    {item.online !== undefined ? <span className={item.online ? 'online' : 'offline'} /> : null}
  </div>;
}

// A chat list row needs a one-line summary even when the latest message isn't plain text. This is a
// plain-Chinese equivalent of lib/formatters.js's previewFormatter (which needs react-intl wired in,
// inconsistent with this file's all-hardcoded-Chinese mock strings) -- just enough to label the
// message by Drafty entity type for a conversation list preview.
function draftyPreview(content) {
  if (typeof content === 'string' || content == null) return content || '';
  if (Array.isArray(content.ent) && content.ent.length) {
    const label = {IM: '[图片]', VD: '[视频]', AU: '[语音]', EX: '[文件]', TC: '[名片]', VC: '[通话]'}[content.ent[0].tp];
    if (label) return label;
  }
  return content.txt || '[消息]';
}

function formatConversationTime(ts) {
  if (!ts) return '';
  const date = new Date(ts);
  const now = new Date();
  const startOfDay = d => new Date(d.getFullYear(), d.getMonth(), d.getDate()).getTime();
  const days = Math.round((startOfDay(now) - startOfDay(date)) / 86400000);
  if (days === 0) return date.toLocaleTimeString('zh-CN', {hour: '2-digit', minute: '2-digit'});
  if (days === 1) return '昨天';
  if (days < 7) return ['周日', '周一', '周二', '周三', '周四', '周五', '周六'][date.getDay()];
  return date.toLocaleDateString('zh-CN', {month: 'numeric', day: 'numeric'});
}

// Entries (system messages / file assistant) come from bootstrap.entries and are always shown --
// unlike the old mock, they don't disappear once the user has real conversations (that was a bug).
function entryConversations(bootstrap) {
  if (!bootstrap || !bootstrap.entries) return [];
  const list = [];
  const sys = bootstrap.entries.system_messages;
  if (sys && sys.enabled) {
    // Matches docs/images/消息.png ("最新公告"). bootstrap doesn't carry a preview of the latest
    // notification, so this is a static label like the rest of that screenshot's demo content.
    list.push({id: 'system', title: '系统消息', summary: '最新公告', icon: 'notifications', tone: 'orange',
      system: true, unread: sys.unread_count || 0});
  }
  const files = bootstrap.entries.file_assistant;
  if (files && files.enabled) {
    list.push({id: 'files', title: '文件助手', summary: '你上传1份文件', icon: 'folder', tone: 'green',
      fileAssistant: true, topic: files.topic, unread: files.unread_count || 0});
  }
  return list;
}

function normalizeConversations(chatList, myUserId) {
  if (!chatList || chatList.length === 0) return [];
  return chatList.map((item, index) => {
    const latest = typeof item.latestMessage === 'function' ? item.latestMessage() : null;
    let summary = item.private && item.private.comment ? item.private.comment : '暂无消息';
    if (latest) summary = draftyPreview(latest.content);
    if (latest && latest.from === myUserId) summary = '我：' + summary;
    return {
      id: item.topic || item.user || String(index),
      title: topicDisplayName(item.topic, item.public, '未命名会话'),
      summary,
      time: formatConversationTime(item.touched),
      unread: Math.max(Number(item.unread) || 0, 0),
      online: !!item.online,
      muted: !!(item.acs && item.acs.isMuted && item.acs.isMuted()),
      pinned: !!item.pinned
    };
  });
}

function BottomNavigation() {
  return <nav className="messages-bottom-nav" aria-label="主导航">
    <button type="button" onClick={() => navigate('workbench')}><Icon>dashboard</Icon><span>工作台</span></button>
    <button type="button" className="active"><Icon>person</Icon><span>消息</span></button>
  </nav>;
}

function QuickMenu({onClose, onAction, permissions}) {
  const actions = [
    {id: 'friends', icon: 'group', label: '朋友'},
    {id: 'profile', icon: 'person_outline', label: '我的'},
    {id: 'create-group', icon: 'add_comment', label: '创建群组', permission: 'create_group'},
    {id: 'add-friend', icon: 'person_add_alt', label: '添加好友', permission: 'user_search'},
    {id: 'scan', icon: 'qr_code_scanner', label: '扫一扫', permission: 'scan_qr'}
  ].filter(item => !item.permission || !permissions || permissions[item.permission] !== false);
  return <div className="messages-menu-backdrop" onMouseDown={onClose}>
    <div className="messages-quick-menu" onMouseDown={e => e.stopPropagation()} role="menu">
      {actions.map(item => <button type="button" role="menuitem" key={item.id} onClick={() => onAction(item)}>
        <Icon>{item.icon}</Icon><span>{item.label}</span>
      </button>)}
    </div>
  </div>;
}

function MessageHome({view, connected, chatList, myUserId, onTopicSelected, onOpenScanner}) {
  const [query, setQuery] = React.useState('');
  const [menuOpen, setMenuOpen] = React.useState(view === 'messages-menu');
  const [toast, setToast] = React.useState('');
  // Was `useState(null)` + its own effect -- refetched from scratch (blank entries/badges for a
  // beat) every time this component remounted, e.g. after a trip to another sidepanel and back.
  const [bootstrap] = useCachedData(myUserId ? 'bootstrap:' + myUserId : null, getBootstrap, [myUserId]);
  const offline = view === 'messages-offline' || (!!myUserId && connected === false);

  const conversations = entryConversations(bootstrap).concat(normalizeConversations(chatList, myUserId));
  const filtered = conversations.filter(item => `${item.title}${item.summary}`.toLowerCase().includes(query.trim().toLowerCase()));
  const frequent = frequentContacts(chatList);

  const selectConversation = item => {
    if (item.system) {
      navigate('system-messages');
    } else if (item.fileAssistant && item.topic && onTopicSelected) {
      onTopicSelected(item.topic);
    } else if (chatList && chatList.length && onTopicSelected) {
      onTopicSelected(item.id);
    } else {
      navigate('chat-standard');
    }
  };

  const runQuickAction = item => {
    setMenuOpen(false);
    if (item.id === 'friends') return navigate('address-book');
    if (item.id === 'profile') return navigate('personal-center');
    if (item.id === 'create-group') return navigate('group-list');
    if (item.id === 'add-friend') return navigate('add-friend');
    if (item.id === 'scan' && onOpenScanner) return onOpenScanner();
    setToast(item.id === 'scan' ? '扫码功能暂不可用' : `${item.label}页面将在对应章节中提供`);
  };

  return <div className="messages-product-page">
    <header className="messages-home-header">
      {offline ? <div className="messages-connection"><span className="messages-spinner" />加载中</div> : <h1>消息</h1>}
      <button type="button" className="messages-menu-button" onClick={() => setMenuOpen(true)} aria-label="更多功能"><Icon>menu</Icon></button>
    </header>
    <main className="messages-home-content">
      <label className="messages-search"><Icon>search</Icon><input value={query} onChange={e => setQuery(e.target.value)} placeholder="搜索" /></label>
      {frequent.length > 0 ? <section className="messages-frequent">
        <h2>常联系的人</h2>
        <div className="messages-frequent-scroll">
          {frequent.map(item => <button type="button" key={item.id} onClick={() => onTopicSelected && onTopicSelected(item.id)}>
            <Avatar item={item} small /><span>{item.name}</span>
          </button>)}
        </div>
      </section> : null}
      <section className="messages-conversations" aria-label="会话列表">
        {filtered.map(item => <button type="button" className={'messages-conversation' + (item.pinned ? ' pinned' : '')}
          key={item.id} onClick={() => selectConversation(item)}>
          <Avatar item={item} />
          <span className="messages-conversation-copy"><strong>{item.title}</strong><small>{item.summary}</small></span>
          <span className="messages-conversation-meta"><time>{item.time}</time>
            {item.unread ? <b>{item.unread > 99 ? '99+' : item.unread}</b> : item.muted ? <Icon>notifications_off</Icon> : null}
          </span>
        </button>)}
        {filtered.length === 0 ? <div className="messages-empty"><Icon>search_off</Icon><p>未找到相关会话</p></div> : null}
      </section>
    </main>
    <BottomNavigation />
    {menuOpen ? <QuickMenu onClose={() => setMenuOpen(false)} onAction={runQuickAction} permissions={bootstrap && bootstrap.permissions} /> : null}
    <Toast message={toast} onDone={() => setToast('')} />
  </div>;
}

function MessageActions() {
  const [visible, setVisible] = React.useState(true);
  const [toast, setToast] = React.useState('');
  const [selected, setSelected] = React.useState('');
  const [supportedActions, setSupportedActions] = React.useState(null);

  React.useEffect(() => {
    getBootstrap().then(data => setSupportedActions(data.message_policy && data.message_policy.supported_actions)).catch(() => {});
  }, []);

  // This screen is a static illustration of the long-press menu (not attached to a real message), so
  // there's no real (topic, seq) to act on -- the real wiring belongs in messages-view.jsx (chapter 4)
  // where an actual message exists. Here we only let the server's declared capabilities decide which
  // gated actions (recall/edit/delete) are worth showing at all.
  const actions = MESSAGE_ACTIONS.filter(item => !item.gated || !supportedActions || supportedActions.includes(item.id));

  const runAction = item => {
    setSelected(item.id);
    if (item.id === 'copy' && navigator.clipboard) {
      navigator.clipboard.writeText('明天上午十点开项目会，请准时参加。').catch(() => {});
    }
    setToast(`${item.label}操作已选择`);
    setVisible(false);
  };

  return <div className="message-actions-page">
    <header className="messages-sub-header"><button onClick={() => navigate('messages-home')} aria-label="返回"><Icon>arrow_back_ios_new</Icon></button><h1>项目协作群</h1><span /></header>
    <main className="message-actions-chat">
      <p className="message-time">今天 10:24</p>
      <div className="message-demo-row"><Avatar item={{avatar: 'img/bkg/p09.jpg'}} /><button type="button" className="message-demo-bubble" onContextMenu={e => {e.preventDefault(); setVisible(true);}}>明天上午十点开项目会，请准时参加。</button></div>
      <div className="message-demo-row mine"><button type="button" className="message-demo-bubble mine" onContextMenu={e => {e.preventDefault(); setVisible(true);}}>收到，我会提前准备材料。</button><Avatar item={{avatar: 'img/bkg/p05.jpg'}} /></div>
      {selected ? <p className="message-operation-result">已选择：{MESSAGE_ACTIONS.find(item => item.id === selected).label}</p> : null}
    </main>
    <footer className="message-demo-composer"><Icon>mic_none</Icon><span>输入消息</span><Icon>sentiment_satisfied_alt</Icon><Icon>add_circle_outline</Icon></footer>
    {visible ? <div className="message-action-backdrop" onMouseDown={() => setVisible(false)}>
      <div className="message-action-menu" onMouseDown={e => e.stopPropagation()} role="menu">
        {actions.map(item => <button type="button" role="menuitem" key={item.id} onClick={() => runAction(item)}>
          <span>{item.label}</span><Icon>{item.icon}</Icon>
        </button>)}
      </div>
    </div> : null}
    <Toast message={toast} onDone={() => setToast('')} />
  </div>;
}

// 系统通知的 summary 在多处后端代码里被直接填成机器码而不是人话：群事件统一写
// summary=event.EventType（server/im_group_events.go:42-44，所有群事件共用 title="群聊动态"），
// 好友申请处理结果写 summary=status（server/im_http.go:5956 与 db/mysql/tenant_adapter.go:8643,8700，
// 值就是 "accepted"/"rejected"）。已记入后端问题清单，在后端给出可读文案之前前端按已知码兜底翻译。
const NOTIFICATION_TEXT = {
  'group.member.joined': '有成员加入了群聊',
  'group.member.left': '有成员退出了群聊',
  'group.member.updated': '群成员资料有更新',
  'group.mute.updated': '群禁言设置有变更',
  'group.owner.transferred': '群主已转让',
  'group.role.updated': '群成员角色有变更',
  'group.settings.updated': '群设置有更新',
  accepted: '对方已通过你的好友申请',
  rejected: '对方拒绝了你的好友申请'
};

// 机器码判定：纯 ASCII 且只由小写字母/数字/点/下划线/连字符组成（"accepted"、
// "group.settings.updated" 这类），正常中文文案不会命中。
const MACHINE_CODE = /^[a-z0-9._-]+$/;

function systemNotificationText(item) {
  const summary = (item.summary || '').trim();
  // 后端给了真正的文案就直接用；只有当它是机器码时才走兜底，避免把未来后端补上的正常文案盖掉。
  if (summary && !MACHINE_CODE.test(summary)) return summary;
  return NOTIFICATION_TEXT[summary] || NOTIFICATION_TEXT[item.event_type] || '您有一条新的系统通知。';
}

function SystemMessages({authenticated}) {
  const [items, setItems] = React.useState([]);
  const [loading, setLoading] = React.useState(true);
  const [error, setError] = React.useState('');
  const [toast, setToast] = React.useState('');

  React.useEffect(() => {
    getSystemNotifications().then(data => setItems(data.items || []))
      .catch(err => setError(err.message || '加载失败'))
      .finally(() => setLoading(false));
  }, []);

  const markRead = item => {
    if (item.read_at) return;
    setItems(list => list.map(i => i.id === item.id ? {...i, read_at: new Date().toISOString()} : i));
    markSystemNotificationRead(item.id).catch(() => {
      // Roll the optimistic update back on failure -- otherwise the "new" badge silently vanishes
      // even though the server never actually recorded this notification as read.
      setItems(list => list.map(i => i.id === item.id ? {...i, read_at: null} : i));
    });
  };

  return <div className="system-messages-page">
    <header className="messages-sub-header"><button onClick={() => { if (!HashNavigation.goBack()) navigate('messages-home'); }} aria-label="返回"><Icon>arrow_back_ios_new</Icon></button><h1>系统消息</h1><span /></header>
    <main className="system-notification-list">
      {loading ? <p className="messages-empty"><Icon>hourglass_empty</Icon>加载中…</p> : null}
      {error ? <p className="messages-empty"><Icon>error_outline</Icon>{error}</p> : null}
      {!loading && !error && items.length === 0 ? <p className="messages-empty"><Icon>notifications_none</Icon>暂无系统消息</p> : null}
      {items.map(item => <article key={item.id} className={item.read_at ? 'read' : ''} onClick={() => markRead(item)}>
        <time>{new Date(item.created_at).toLocaleString('zh-CN')}</time>
        <div className="system-notification-card">
          <header><h2>{item.title}</h2>{!item.read_at ? <span>新</span> : null}</header>
          <p>{systemNotificationText(item)}</p>
          {item.action && item.action.device ? <dl><div><dt>设备：</dt><dd>{item.action.device}</dd></div>{item.action.ip ? <div><dt>IP地址：</dt><dd>{item.action.ip}</dd></div> : null}</dl> : null}
          {/* 入口按通知自身的 action 决定，不再对所有通知一律显示"前往安全设置"。注意 action.topic
              不能直接当成群：好友申请类通知的 action 里带的是 p2p 会话 topic
              （db/mysql/tenant_adapter.go:8643），只有 grp 前缀才是真的群。都不匹配时不显示按钮，
              避免把人导到跟这条通知无关的页面。 */}
          {item.action && typeof item.action.topic === 'string' && item.action.topic.startsWith('grp') ?
            <button type="button" className="system-security-link" onClick={e => { e.stopPropagation(); navigate('group-settings', item.action.topic); }}>查看群聊 <Icon>chevron_right</Icon></button> :
            item.action && item.action.type === 'friend_request' ?
              <button type="button" className="system-security-link" onClick={e => { e.stopPropagation(); navigate('friend-requests'); }}>查看新朋友 <Icon>chevron_right</Icon></button> :
              item.action && (item.action.device || item.action.ip) ?
                <button type="button" className="system-security-link" onClick={e => { e.stopPropagation(); navigate(authenticated ? 'security' : 'identity-check'); }}>前往安全设置 <Icon>chevron_right</Icon></button> :
                null}
          <footer>保持警惕<br />即时通讯安全团队</footer>
        </div>
      </article>)}
    </main>
    <Toast message={toast} onDone={() => setToast('')} />
  </div>;
}

export default function MessageCenterView(props) {
  switch (props.view) {
    case 'system-messages': return <SystemMessages authenticated={!!props.myUserId} />;
    case 'message-actions': return <MessageActions />;
    case 'messages-offline':
    case 'messages-menu':
    case 'messages-home':
    default: return <MessageHome {...props} />;
  }
}