/* ObsiGate — Offline Integration Module
 * Ties together: IndexedDB, offline search, sync queue, UI indicator
 */
import { OfflineDB, NetworkStatus } from './offline-db.js';
import { state } from './state.js';
import { showToast } from './ui.js';

/* ── Init ── */
export async function initOffline() {
  NetworkStatus.init();

  // Open DB early
  try {
    await OfflineDB.open();
    console.log('[Offline] IndexedDB ready');
  } catch (e) {
    console.warn('[Offline] IndexedDB not available:', e);
  }

  NetworkStatus.onChange((online) => {
    updateOfflineIndicator();
    if (online) {
      syncPendingChanges();
      showToast(t('offline.reconnected'), 'info');
    } else {
      showToast(t('offline.mode_offline'), 'warning');
    }
  });

  updateOfflineIndicator();
}

/* ── UI Indicator ── */
function updateOfflineIndicator() {
  const badge = document.getElementById('offline-badge');
  if (!badge) return;

  if (!NetworkStatus.isOnline) {
    // Build or show indicator
    badge.innerHTML = replaceLucideIcon(badge, 'wifi-off',
      '<i data-lucide="wifi-off" style="width:14px;height:14px"></i>');
    badge.title = 'Mode hors-ligne';
    badge.style.display = 'flex';
    badge.className = 'header-icon offline-indicator offline';

    // Add pending count if any
    OfflineDB.getPendingCount().then(count => {
      if (count > 0) {
        const span = badge.querySelector('.offline-pending') || document.createElement('span');
        span.className = 'offline-pending';
        span.textContent = String(count);
        if (!badge.contains(span)) badge.appendChild(span);
      }
    });
  } else {
    badge.style.display = 'none';
    badge.className = 'header-icon offline-indicator';
  }
}

function replaceLucideIcon(container, iconName, html) {
  const existing = container.querySelector('i[data-lucide]');
  if (existing && existing.getAttribute('data-lucide') === iconName) return container.innerHTML;
  return html;
}

/* ── Sync File Index from Server ── */
export async function syncFileIndexFromServer() {
  if (!NetworkStatus.isOnline) {
    console.log('[Offline] Skipping index sync — offline');
    return;
  }
  try {
    // Use a wildcard query to get recent files and populate offline index
    const resp = await fetch('/api/search/advanced?q=**&vault=all&limit=200');
    if (!resp.ok) {
      console.warn('[Offline] Index sync failed — API returned', resp.status);
      return;
    }
    const data = await resp.json();
    const files = (data.results || []).map(r => ({
      vault: r.vault,
      path: r.path,
      title: r.title,
      tags: r.tags || [],
      snippet: r.snippet || '',
      modified: r.modified || '',
      tokens: []
    }));
    if (files.length > 0) {
      await OfflineDB.syncFileIndex(files);
      console.log('[Offline] Index synced:', files.length, 'files');
    }
  } catch (e) {
    console.warn('[Offline] Index sync failed:', e.message);
  }
}

/* ── Cache File When Viewed ── */
export async function cacheViewedFile(vault, path, content, modified) {
  if (!vault || !path) return;
  try {
    await OfflineDB.putFileContent(vault, path, content, modified);
    await OfflineDB.pruneContentCache(50);
  } catch (e) {
    console.warn('[Offline] Cache file failed:', e);
  }
}

/* ── Offline Search ── */
export async function searchOffline(query, vaultFilter) {
  try {
    return await OfflineDB.searchFileIndex(query, vaultFilter || state.currentVault);
  } catch (e) {
    console.error('[Offline] Search failed:', e);
    return [];
  }
}

/* ── Get Cached File ── */
export async function getCachedFile(vault, path) {
  try {
    return await OfflineDB.getFileContent(vault, path);
  } catch (e) {
    return null;
  }
}

/* ── Pending Changes Queue ── */
let _syncing = false;

export async function queueOfflineSave(vault, path, content) {
  try {
    const id = await OfflineDB.addPending({ vault, path, content, action: 'save' });
    updateOfflineIndicator();
    console.log('[Offline] Queued save:', vault, path, 'id=', id);
    return id;
  } catch (e) {
    console.error('[Offline] Queue save failed:', e);
    return null;
  }
}

export async function syncPendingChanges() {
  if (!NetworkStatus.isOnline || _syncing) return;
  _syncing = true;

  try {
    const pending = await OfflineDB.getAllPending();
    if (pending.length === 0) {
      _syncing = false;
      return;
    }

    console.log('[Offline] Syncing', pending.length, 'pending changes...');

    for (const entry of pending) {
      try {
        const resp = await fetch('/api/file/' + encodeURIComponent(entry.vault) + '/write', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ path: entry.path, content: entry.content })
        });

        if (resp.ok) {
          await OfflineDB.removePendingById(entry.id);
          console.log('[Offline] Synced:', entry.vault, entry.path);
        } else if (resp.status === 409) {
          // Conflict — keep in queue for manual resolution
          console.warn('[Offline] Conflict on:', entry.vault, entry.path);
        } else {
          console.error('[Offline] Sync failed for:', entry.vault, entry.path, resp.status);
        }
      } catch (e) {
        console.error('[Offline] Sync error for:', entry.vault, entry.path, e);
        break; // Stop on network error
      }
    }

    const remaining = await OfflineDB.getPendingCount();
    console.log('[Offline] Sync complete. Remaining:', remaining);
    updateOfflineIndicator();

    if (remaining === 0) {
      showToast(t('offline.all_synced'), 'success');
    } else {
      showToast(remaining + ' modification(s) en attente de resolution', 'warning');
    }
  } finally {
    _syncing = false;
  }
}

/* ── Conflict Detection ── */
export async function checkConflict(vault, path, localModified) {
  if (!NetworkStatus.isOnline) return null;

  try {
    const resp = await fetch('/api/file/' + encodeURIComponent(vault) + '/info?path=' + encodeURIComponent(path));
    if (!resp.ok) return null;
    const data = await resp.json();
    if (data.modified && data.modified !== localModified) {
      return { serverModified: data.modified, localModified };
    }
    return null;
  } catch {
    return null;
  }
}