/**
 * Settings — backup / restore configuration.
 */

import { apiKey } from '../core/state.js';
import { API_BASE, fetchWithAuth } from '../core/api.js';
import { Modal } from '../core/modal.js';
import { showToast, showConfirm } from '../core/ui.js';
import { t } from '../core/i18n.js';

// Simple modal (no form / no dirty check needed)
const settingsModal = new Modal('settings-modal');

export function openSettingsModal() {
    document.getElementById('settings-error').style.display = 'none';
    settingsModal.open();
}

export function closeSettingsModal() {
    settingsModal.forceClose();
}

// ─── Backup ────────────────────────────────────────────────

export async function downloadBackup() {
    try {
        const resp = await fetchWithAuth('/system/backup', { timeout: 30000 });
        if (!resp.ok) {
            const err = await resp.json().catch(() => ({}));
            throw new Error(err.detail || `HTTP ${resp.status}`);
        }
        const blob = await resp.blob();
        const disposition = resp.headers.get('Content-Disposition') || '';
        const match = disposition.match(/filename="(.+?)"/);
        const filename = match ? match[1] : 'ledgrab-backup.json';

        const a = document.createElement('a');
        a.href = URL.createObjectURL(blob);
        a.download = filename;
        document.body.appendChild(a);
        a.click();
        a.remove();
        URL.revokeObjectURL(a.href);

        showToast(t('settings.backup.success'), 'success');
    } catch (err) {
        console.error('Backup download failed:', err);
        showToast(t('settings.backup.error') + ': ' + err.message, 'error');
    }
}

// ─── Restore ───────────────────────────────────────────────

export async function handleRestoreFileSelected(input) {
    const file = input.files[0];
    input.value = '';
    if (!file) return;

    const confirmed = await showConfirm(t('settings.restore.confirm'));
    if (!confirmed) return;

    try {
        const formData = new FormData();
        formData.append('file', file);

        const resp = await fetch(`${API_BASE}/system/restore`, {
            method: 'POST',
            headers: { 'Authorization': `Bearer ${apiKey}` },
            body: formData,
        });

        if (!resp.ok) {
            const err = await resp.json().catch(() => ({}));
            throw new Error(err.detail || `HTTP ${resp.status}`);
        }

        const data = await resp.json();
        showToast(data.message || t('settings.restore.success'), 'success');
        settingsModal.forceClose();

        if (data.restart_scheduled) {
            showRestartOverlay();
        }
    } catch (err) {
        console.error('Restore failed:', err);
        showToast(t('settings.restore.error') + ': ' + err.message, 'error');
    }
}

// ─── Restart overlay ───────────────────────────────────────

function showRestartOverlay() {
    const overlay = document.createElement('div');
    overlay.id = 'restart-overlay';
    overlay.style.cssText =
        'position:fixed;inset:0;z-index:100000;display:flex;flex-direction:column;' +
        'align-items:center;justify-content:center;background:rgba(0,0,0,0.85);color:#fff;font-size:1.2rem;';
    overlay.innerHTML =
        '<div class="spinner" style="width:48px;height:48px;border:4px solid rgba(255,255,255,0.3);' +
        'border-top-color:#fff;border-radius:50%;animation:spin 0.8s linear infinite;margin-bottom:1rem;"></div>' +
        `<div id="restart-msg">${t('settings.restore.restarting')}</div>`;

    // Add spinner animation if not present
    if (!document.getElementById('restart-spinner-style')) {
        const style = document.createElement('style');
        style.id = 'restart-spinner-style';
        style.textContent = '@keyframes spin{to{transform:rotate(360deg)}}';
        document.head.appendChild(style);
    }

    document.body.appendChild(overlay);
    pollHealth();
}

function pollHealth() {
    const start = Date.now();
    const maxWait = 30000;
    const interval = 1500;

    const check = async () => {
        if (Date.now() - start > maxWait) {
            const msg = document.getElementById('restart-msg');
            if (msg) msg.textContent = t('settings.restore.restart_timeout');
            return;
        }
        try {
            const resp = await fetch('/health', { signal: AbortSignal.timeout(3000) });
            if (resp.ok) {
                window.location.reload();
                return;
            }
        } catch { /* server still down */ }
        setTimeout(check, interval);
    };
    // Wait a moment before first check to let the server shut down
    setTimeout(check, 2000);
}