// Single chat view
const ChatView = {
  chatId: null,
  otherId: null,
  otherName: null,
  ws: null,

  async render(root, params) {
    this.chatId = params.chatId;
    this.otherId = params.otherId;
    this.otherName = params.otherName;
    root.innerHTML = `
      <div class="view" style="display:flex;flex-direction:column;height:calc(100vh - 100px);padding:0;">
        <!-- header -->
        <div style="padding:12px 16px;border-bottom:1px solid var(--border);background:var(--bg-elev);display:flex;align-items:center;gap:8px;">
          <button class="btn-b ghost tiny" id="chat-back" style="padding:6px 10px;">←</button>
          <div class="avatar-b sm" style="${API.Store.user?.other_photo_for_other ? '' : ''}">${escapeHtml(((this.otherName || '?')[0] || '?').toUpperCase())}</div>
          <div style="flex:1;font-weight:600;font-size:15px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;">${escapeHtml(this.otherName || '')}</div>
          <button class="btn-b ghost tiny" id="chat-profile" style="padding:6px 10px;">👤</button>
          <button class="btn-b ghost tiny" id="chat-review" style="padding:6px 10px;">⭐</button>
        </div>
        <!-- messages -->
        <div id="messages" style="flex:1;overflow-y:auto;padding:12px;display:flex;flex-direction:column;gap:6px;"></div>
        <!-- edit bar -->
        <div id="edit-bar" style="display:none;padding:8px 16px;background:var(--bg-elev);border-top:1px solid var(--border);font-size:13px;color:var(--text-dim);">
          <span>✎ Редактирование</span>
          <button id="edit-cancel" style="float:right;background:none;border:none;color:var(--danger);font-weight:600;cursor:pointer;">Отмена</button>
        </div>
        <!-- composer -->
        <div class="composer-b">
          <button class="attach-b" id="msg-attach" title="Прикрепить фото">📎</button>
          <input id="msg-input" placeholder="Сообщение..." autocomplete="off" enterkeyhint="send">
          <button class="send-b" id="msg-send" title="Отправить">➤</button>
        </div>
      </div>
    `;

    document.getElementById('chat-back').onclick = () => App.showView('chats');
    document.getElementById('chat-profile').onclick = () => App.openUserProfile(this.otherId, this.otherName);
    document.getElementById('chat-review').onclick = () => App.openReview(this.chatId, this.otherId, this.otherName);
    document.getElementById('msg-attach').onclick = () => {
      const inp = document.createElement('input');
      inp.type = 'file'; inp.accept = 'image/*';
      inp.onchange = () => this.sendPhoto(inp.files[0]);
      inp.click();
    };

    document.getElementById('msg-input').addEventListener('keydown', (e) => {
      if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        this.send();
      }
    });
    document.getElementById('msg-send').onclick = () => this.send();

    this.loadMessages();
    this.setupWS();
    this.markRead();
  },

  async loadMessages() {
    try {
      const r = await API.ChatApi.listMessages(this.chatId);
      const box = document.getElementById('messages');
      box.innerHTML = '';
      r.messages.forEach((m) => this.appendMessage(m));
      box.scrollTop = box.scrollHeight;
    } catch (e) {
      console.warn(e);
    }
  },

  appendMessage(m) {
    const box = document.getElementById('messages');
    const me = API.Store.user && m.sender_id === (API.Store.user.id || API.Store.user.user_id);
    const div = document.createElement('div');
    div.className = 'bubble-b ' + (me ? 'out' : 'in');
    div.dataset.id = m.id;
    if (m.deleted) {
      div.innerHTML = '<em style="color:var(--text-mute);">Удалено</em>';
    } else {
      const readMark = me
        ? (m.read_at ? '<span class="ticks read" title="прочитано">✓✓</span>' : '<span class="ticks" title="доставлено">✓</span>')
        : '';
      div.innerHTML = `
        <div>${escapeHtml(m.body || '')}</div>
        <div class="meta">
          <span>${formatTime(m.created_at)}</span>
          ${m.edited ? '<span style="font-size:10px;margin:0 4px;">ред.</span>' : ''}
          ${readMark}
        </div>
      `;
      if (me) {
        div.onclick = () => this.onMessageClick(m);
      }
    }
    box.appendChild(div);
    box.scrollTop = box.scrollHeight;
  },

  onMessageClick(m) {
    TG_APP.showConfirm('Удалить сообщение?').then((ok) => {
      if (ok) this.deleteMessage(m);
    });
  },

  async deleteMessage(m) {
    try {
      await API.ChatApi.deleteMessage(m.id);
      const el = document.querySelector(`.bubble[data-id="${m.id}"]`);
      if (el) el.innerHTML = '<em>Удалено</em>';
    } catch (e) {
      TG_APP.showAlert('Ошибка: ' + e.message);
    }
  },

  setupWS() {
    if (!API.Store.access) return;
    const url = (window.API_BASE || 'https://api.buhapp.mygoodservice.ru').replace(/^http/, 'ws') + '/ws?token=' + API.Store.access;
    try {
      this.ws = new WebSocket(url);
      this.ws.onopen = () => console.log('WS connected');
      this.ws.onmessage = (ev) => {
        try {
          const d = JSON.parse(ev.data);
          if (d.type === 'message' && d.payload.chat_id === this.chatId) {
            this.appendMessage(d.payload);
          } else if (d.type === 'message_edited' && d.payload.chat_id === this.chatId) {
            this.updateMessage(d.payload);
          } else if (d.type === 'message_read' && d.payload.chat_id === this.chatId) {
            this.markMessagesRead();
          }
        } catch {}
      };
      this.ws.onclose = () => setTimeout(() => this.setupWS(), 3000);
      this.ws.onerror = (e) => console.warn('WS error', e);
    } catch (e) {
      console.warn(e);
    }
  },

  async markMessagesRead() {
    try {
      const r = await API.ChatApi.listMessages(this.chatId);
      r.messages.forEach((m) => {
        if (m.read_at) {
          const el = document.querySelector(`.bubble[data-id="${m.id}"] .read-tick`);
          if (el) { el.classList.add('read'); el.textContent = '✓✓'; }
        }
      });
    } catch {}
  },

  updateMessage(p) {
    const el = document.querySelector(`.bubble[data-id="${p.id}"]`);
    if (el) {
      el.querySelector('div:first-child') && (el.querySelector('div:first-child').textContent = p.body);
      const meta = el.querySelector('.meta');
      if (meta && !meta.querySelector('.edited')) {
        const ed = document.createElement('span');
        ed.className = 'edited';
        ed.textContent = 'ред.';
        meta.appendChild(ed);
      }
    }
  },

  async send() {
    const inp = document.getElementById('msg-input');
    const btn = document.getElementById('msg-send');
    const body = inp.value.trim();
    if (!body) { App._toast('Введите сообщение', 'err'); btn.classList.add('err'); setTimeout(() => btn.classList.remove('err'), 600); return; }
    btn.classList.add('load');
    try {
      await API.ChatApi.sendMessage(this.chatId, body);
      inp.value = '';
      btn.classList.remove('load');
    } catch (e) {
      btn.classList.remove('load');
      App._toast('⚠️ ' + (e.message || 'Не отправлено'), 'err');
    }
  },

  async sendPhoto(file) {
    if (!file) return;
    if (file.size > 8 * 1024 * 1024) { App._toast('Файл больше 8 МБ', 'err'); return; }
    App._toast('⏳ Загружаю фото…', 'ok');
    const fd = new FormData();
    fd.append('photo', file);
    try {
      const r = await fetch(API_BASE + '/api/v1/chats/' + this.chatId + '/photo', { method: 'POST', body: fd, credentials: 'include' });
      if (!r.ok) throw new Error((await r.json()).error || 'HTTP ' + r.status);
      App._toast('✓ Фото отправлено', 'ok');
      this.loadMessages();
    } catch (e) {
      App._toast('⚠️ ' + (e.message || 'Ошибка'), 'err');
    }
  },

  async markRead() {
    try { await API.ChatApi.markRead(this.chatId); } catch {}
  },

  cleanup() {
    if (this.ws) { this.ws.close(); this.ws = null; }
  },
};

window.ChatView = ChatView;