// ── Sidebar & main page controller ───────────────────────────────────────────
import { Chat } from './chat.js';

const $ = (sel) => document.querySelector(sel);

// ── State ─────────────────────────────────────────────────────────────────────
const state = {
  sessions: [],
  activeSessionId: null,
  docs: [],
  urls: [],
  /** Map<string, {id, type, name}> */
  selectedContext: new Map(),
};

const chat = new Chat();

// ── Boot ──────────────────────────────────────────────────────────────────────
async function init() {
  await Promise.all([loadDocs(), loadUrls(), loadSessions()]);
  renderContext();
}

// ── Documents ─────────────────────────────────────────────────────────────────
async function loadDocs() {
  const res = await fetch('/api/documents/');
  state.docs = await res.json();
  renderDocs();
}

function renderDocs() {
  const list = $('#doc-list');
  list.innerHTML = '';
  if (!state.docs.length) {
    list.innerHTML = '<li class="text-xs text-copilot-muted py-1">No documents yet</li>';
    return;
  }
  state.docs.forEach((doc) => {
    const key = `doc_${doc.id}`;
    const checked = state.selectedContext.has(key);
    const li = document.createElement('li');
    li.className = 'flex items-center gap-2 group py-0.5 hover:bg-copilot-panel rounded px-1';
    li.innerHTML = `
      <input type="checkbox" data-id="${doc.id}" data-type="doc"
             class="ctx-checkbox accent-[#89b4fa] rounded shrink-0" ${checked ? 'checked' : ''} />
      <a href="/document/${doc.id}"
         class="flex-1 text-xs text-copilot-text truncate hover:text-copilot-accent transition"
         title="${esc(doc.original_name)}">${esc(doc.original_name)}</a>
      ${doc.indexed
        ? '<span class="text-[10px] text-copilot-success shrink-0" title="Indexed">●</span>'
        : '<span class="text-[10px] text-copilot-warning shrink-0 animate-pulse" title="Indexing…">●</span>'}
      <button data-delete-doc="${doc.id}"
        class="opacity-0 group-hover:opacity-100 text-copilot-muted hover:text-copilot-danger transition shrink-0"
        title="Delete">
        <svg class="w-3.5 h-3.5 pointer-events-none" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
          <path stroke-linecap="round" d="M6 18L18 6M6 6l12 12"/>
        </svg>
      </button>`;
    list.appendChild(li);
  });
}

async function uploadFiles(files) {
  const indicator = $('#doc-uploading');
  indicator.classList.remove('hidden');
  for (const file of files) {
    const fd = new FormData();
    fd.append('file', file);
    await fetch('/api/documents/upload', { method: 'POST', body: fd });
  }
  await loadDocs();
  indicator.classList.add('hidden');
}

// ── URLs ──────────────────────────────────────────────────────────────────────
async function loadUrls() {
  const res = await fetch('/api/context/urls');
  state.urls = await res.json();
  renderUrls();
}

function renderUrls() {
  const list = $('#url-list');
  list.innerHTML = '';
  if (!state.urls.length) {
    list.innerHTML = '<li class="text-xs text-copilot-muted py-1">No URLs yet</li>';
    return;
  }
  state.urls.forEach((u) => {
    const key = `url_${u.id}`;
    const checked = state.selectedContext.has(key);
    const li = document.createElement('li');
    li.className = 'flex items-center gap-2 group py-0.5 hover:bg-copilot-panel rounded px-1';
    li.innerHTML = `
      <input type="checkbox" data-id="${u.id}" data-type="url"
             class="ctx-checkbox accent-[#89b4fa] shrink-0" ${checked ? 'checked' : ''} />
      <span class="flex-1 text-xs text-copilot-text truncate" title="${esc(u.url)}">${esc(u.title)}</span>
      ${u.indexed
        ? '<span class="text-[10px] text-copilot-success shrink-0" title="Indexed">●</span>'
        : '<span class="text-[10px] text-copilot-warning shrink-0 animate-pulse" title="Scraping…">●</span>'}
      <button data-delete-url="${u.id}"
        class="opacity-0 group-hover:opacity-100 text-copilot-muted hover:text-copilot-danger transition shrink-0"
        title="Remove">
        <svg class="w-3.5 h-3.5 pointer-events-none" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
          <path stroke-linecap="round" d="M6 18L18 6M6 6l12 12"/>
        </svg>
      </button>`;
    list.appendChild(li);
  });
}

// ── Sessions ──────────────────────────────────────────────────────────────────
async function loadSessions() {
  const res = await fetch('/api/chat/sessions');
  state.sessions = await res.json();
  renderSessions();
}

function renderSessions() {
  const list = $('#session-list');
  list.innerHTML = '';
  if (!state.sessions.length) {
    list.innerHTML = '<li class="text-xs text-copilot-muted py-1">No chats yet</li>';
    return;
  }
  state.sessions.forEach((s) => {
    const li = document.createElement('li');
    const isActive = s.id === state.activeSessionId;
    li.className = `flex items-center gap-1 group py-0.5 rounded px-1 cursor-pointer
      ${isActive ? 'bg-copilot-panel text-copilot-accent' : 'hover:bg-copilot-panel text-copilot-text'}`;
    li.innerHTML = `
      <span class="flex-1 text-xs truncate">${esc(s.title)}</span>
      <button data-delete-session="${s.id}"
        class="opacity-0 group-hover:opacity-100 text-copilot-muted hover:text-copilot-danger transition shrink-0"
        title="Delete chat">
        <svg class="w-3.5 h-3.5 pointer-events-none" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
          <path stroke-linecap="round" d="M6 18L18 6M6 6l12 12"/>
        </svg>
      </button>`;
    li.addEventListener('click', (e) => {
      if (e.target.closest('[data-delete-session]')) return;
      selectSession(s.id, s.title);
    });
    list.appendChild(li);
  });
}

async function selectSession(id, title) {
  state.activeSessionId = id;
  $('#chat-title').textContent = title;
  $('#empty-state').classList.add('hidden');
  renderSessions();
  const res = await fetch(`/api/chat/sessions/${id}/messages`);
  const msgs = await res.json();
  chat.renderHistory(msgs);
}

// ── Context chips ─────────────────────────────────────────────────────────────
function renderContext() {
  const chips = $('#context-chips');
  chips.innerHTML = '';
  state.selectedContext.forEach((item, key) => {
    const chip = document.createElement('span');
    chip.className = 'inline-flex items-center gap-1 bg-copilot-panel border border-copilot-border rounded-full px-2 py-0.5 text-xs text-copilot-accent';
    chip.innerHTML = `${esc(item.name)}
      <button data-remove-ctx="${key}" class="text-copilot-muted hover:text-copilot-danger ml-0.5 leading-none">✕</button>`;
    chips.appendChild(chip);
  });

  const badge = $('#context-badge');
  badge.textContent = state.selectedContext.size
    ? `${state.selectedContext.size} context source${state.selectedContext.size > 1 ? 's' : ''} active`
    : '';
}

// ── Event delegation ──────────────────────────────────────────────────────────
document.addEventListener('change', (e) => {
  if (e.target.matches('.ctx-checkbox')) {
    const { id, type } = e.target.dataset;
    const key = `${type}_${id}`;
    if (e.target.checked) {
      const name =
        type === 'doc'
          ? state.docs.find((d) => d.id == id)?.original_name ?? `Doc ${id}`
          : state.urls.find((u) => u.id == id)?.title ?? `URL ${id}`;
      state.selectedContext.set(key, { id: parseInt(id), type, name });
    } else {
      state.selectedContext.delete(key);
    }
    renderContext();
  }
});

document.addEventListener('click', async (e) => {
  const delDoc = e.target.closest('[data-delete-doc]');
  if (delDoc) {
    const id = delDoc.dataset.deleteDoc;
    await fetch(`/api/documents/${id}`, { method: 'DELETE' });
    state.selectedContext.delete(`doc_${id}`);
    renderContext();
    await loadDocs();
    return;
  }

  const delUrl = e.target.closest('[data-delete-url]');
  if (delUrl) {
    const id = delUrl.dataset.deleteUrl;
    await fetch(`/api/context/urls/${id}`, { method: 'DELETE' });
    state.selectedContext.delete(`url_${id}`);
    renderContext();
    await loadUrls();
    return;
  }

  const delSession = e.target.closest('[data-delete-session]');
  if (delSession) {
    e.stopPropagation();
    const id = delSession.dataset.deleteSession;
    await fetch(`/api/chat/sessions/${id}`, { method: 'DELETE' });
    if (state.activeSessionId == id) {
      state.activeSessionId = null;
      chat.clear();
      $('#chat-title').textContent = 'Select or start a chat';
      $('#empty-state').classList.remove('hidden');
    }
    await loadSessions();
    return;
  }

  const removeCtx = e.target.closest('[data-remove-ctx]');
  if (removeCtx) {
    const key = removeCtx.dataset.removeCtx;
    state.selectedContext.delete(key);
    // Uncheck corresponding checkbox
    const [type, id] = key.split('_');
    const cb = document.querySelector(`.ctx-checkbox[data-id="${id}"][data-type="${type}"]`);
    if (cb) cb.checked = false;
    renderContext();
  }
});

// File upload
$('#file-input').addEventListener('change', (e) => {
  if (e.target.files.length) uploadFiles(Array.from(e.target.files));
  e.target.value = '';
});

// URL add
$('#url-form').addEventListener('submit', async (e) => {
  e.preventDefault();
  const input = $('#url-input');
  const url = input.value.trim();
  if (!url) return;
  input.value = '';
  await fetch('/api/context/urls', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ url }),
  });
  await loadUrls();
});

// New chat
$('#btn-new-chat').addEventListener('click', async () => {
  const res = await fetch('/api/chat/sessions', { method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ title: 'New Chat' }) });
  const session = await res.json();
  state.sessions.unshift(session);
  await loadSessions();
  selectSession(session.id, session.title);
});

// Send message
$('#chat-form').addEventListener('submit', async (e) => {
  e.preventDefault();
  if (!state.activeSessionId) {
    alert('Please start or select a chat first.');
    return;
  }
  const input = $('#chat-input');
  const msg = input.value.trim();
  if (!msg) return;
  input.value = '';
  input.style.height = '42px';

  const contextIds = Array.from(state.selectedContext.values()).map((c) => ({
    id: c.id,
    type: c.type,
  }));

  await chat.send(state.activeSessionId, msg, contextIds);

  // Refresh session title
  await loadSessions();
});

// Auto-grow textarea
$('#chat-input').addEventListener('input', function () {
  this.style.height = '42px';
  this.style.height = Math.min(this.scrollHeight, 160) + 'px';
});

// Submit on Enter (Shift+Enter = newline)
$('#chat-input').addEventListener('keydown', (e) => {
  if (e.key === 'Enter' && !e.shiftKey) {
    e.preventDefault();
    $('#chat-form').dispatchEvent(new Event('submit', { bubbles: true, cancelable: true }));
  }
});

// ── Helpers ───────────────────────────────────────────────────────────────────
function esc(str = '') {
  return String(str)
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

init();