// ============================================================
// app.favicon.js — FAVICONS module (extracted from app.js, §3.1)
// ============================================================
//
// Website favicon fetch/cache (opt-in, via the Delphi DuckDuckGo proxy).
// faviconHost() is a pure URL→validated-hostname function (unit-tested);
// the rest are api/Bridge/render calls. Pure declarations, no top-level
// side effects → loads BEFORE app.js. Uses state, api, Bridge, render via
// shared global scope at call time.
//
// ============================================================
// FAVICONS (opt-in, cached server-side as base64 data URI)
// ============================================================

// Extract a usable host from entry.site (we accept anything user-typed).
// Returns '' for values that don't look like real hostnames — common case
// is users storing a brand label ("Gitea", "Work GitHub") to help the
// autofill matcher. Sending those to DDG would leak meaningless tokens
// without ever producing an icon.
function faviconHost(siteRaw) {
    if (!siteRaw) return '';
    let s = String(siteRaw).trim().toLowerCase();
    s = s.replace(/^https?:\/\//, '').replace(/^www\./, '');
    s = s.split('/')[0].split(':')[0];
    // Validate: dot-separated labels, only hostname-safe chars, TLD ≥ 2
    // LETTERS. Rejects "Gitea", "my work pwd", and raw IPs like "1.2.3.4"
    // (numeric final label fails the [a-z]{2,} TLD rule — no favicon for a
    // bare IP, which is fine). 253-char overall cap mirrors the DNS spec.
    if (!s || s.length > 253) return '';
    if (!/^[a-z0-9.-]+$/.test(s)) return '';
    if (s.indexOf('.') < 1) return '';
    if (!/\.[a-z]{2,}$/.test(s)) return '';
    if (s.startsWith('.') || s.endsWith('.')) return '';
    if (s.indexOf('..') >= 0) return '';
    return s;
}

// Save the icon for one entry via the dedicated endpoint (no full PUT,
// no re-encryption). Fire-and-forget: failures are silent so a flaky
// network doesn't break the user's flow.
async function saveEntryIcon(entryId, dataUri) {
    try {
        const r = await fetch(API + '/entries/' + entryId + '/icon', {
            method: 'POST',
            headers: authHeaders({ 'Content-Type': 'application/json' }),
            body: JSON.stringify({ icon_b64: dataUri || '' }),
        });
        if (!r.ok) {
            // Surface the server's reason so silent persistence failures
            // (size cap, auth) stop being invisible bugs.
            let msg = 'HTTP ' + r.status;
            try { const b = await r.json(); if (b && b.error) msg = b.error; }
            catch (_) {}
            toast('Icon NOT saved: ' + msg, 'error');
        }
    } catch (e) {
        toast('Icon save failed: ' + (e && e.message || e), 'error');
    }
}

// Fetch + save the favicon for one entry. Updates state.entries in-place
// so the next render() picks it up. No-op if the entry already has one.
// opts: { force: bypass "already has icon" skip, manual: bypass the global
// faviconsEnabled toggle (for explicit user actions like the Refresh button) }
async function ensureEntryFavicon(entry, opts) {
    opts = opts || {};
    if (!Bridge.active) return;
    if (!opts.manual && !state.faviconsEnabled) return;
    if (!opts.force && entry.icon_b64) return;
    const host = faviconHost(entry.site);
    if (!host) return;
    const dataUri = await Bridge.fetchFavicon(host);
    if (!dataUri) return;
    entry.icon_b64 = dataUri;
    await saveEntryIcon(entry.id, dataUri);
    // Full render() — patching the avatar in place is fragile because
    // the avatar also contains the checkbox overlay.
    render();
}

// Backfill: walk state.entries, fetch missing icons one at a time so we
// don't hammer the upstream. Used by the "Refresh icons" button.
async function backfillFavicons(force) {
    if (!Bridge.active) return;
    const all     = state.entries;
    const eligible = all.filter(e => faviconHost(e.site));
    const skipped  = all.length - eligible.length;
    const targets  = eligible.filter(e => force || !e.icon_b64);
    if (targets.length === 0) {
        if (skipped > 0) {
            toast('No icons to fetch — ' + skipped +
                  ' entries have a non-domain site (e.g. "Gitea")', 'warning');
        } else {
            toast('No icons to fetch');
        }
        return;
    }
    toast('Fetching ' + targets.length + ' icon' + (targets.length === 1 ? '' : 's') + '…');
    let ok = 0;
    for (const e of targets) {
        // Explicit user action — bypass the global toggle so the buttons
        // work even when "Fetch website icons" is OFF (the toggle only
        // gates auto-fetch on save).
        await ensureEntryFavicon(e, { force: !!force, manual: true });
        if (e.icon_b64) ok++;
    }
    toast('Fetched ' + ok + ' / ' + targets.length + ' icons');
    render();
}

async function clearAllFavicons() {
    try {
        await fetch(API + '/entries/icons/all', {
            method: 'DELETE',
            headers: authHeaders(),
        });
    } catch (e) {
        toast('Failed to clear icons', 'error');
        return;
    }
    state.entries.forEach(e => { e.icon_b64 = null; });
    render();
    toast('Cached icons cleared');
}