/**
 * Hoover — api.js
 *
 * JSON-friendly fetch wrapper with automatic header management.
 * Toast notification system with auto-dismiss.
 * ToastContainer component for rendering queued toasts.
 */

import { h } from './vdom.js';

/**
 * JSON-friendly fetch wrapper.
 *
 * Automatically sets Content-Type for object bodies, parses JSON
 * responses, and normalises the result to { ok, data, error, status }.
 *
 * @param {string} url       – Target URL
 * @param {object} [options] – Fetch options (method, body, headers, …)
 * @returns {Promise<{ok, data, error, status}>}
 */
export async function apiFetch(url, options = {}) {
    const { method = 'GET', body, ...opts } = options;
    const headers = { 'Accept': 'application/json', ...opts.headers };

    if (body && typeof body === 'object' && !(body instanceof FormData)) {
        headers['Content-Type'] = 'application/json';
        options.body = JSON.stringify(body);
    }

    try {
        const res  = await fetch(url, { method, headers, body: options.body, credentials: 'same-origin', ...opts });
        if (res.status === 401) {
            window.location.reload();
            return { ok: false, data: null, error: 'Session expired', status: 401 };
        }
        const json = await res.json();

        if (!res.ok) {
            return { ok: false, data: null, error: json.error || `HTTP ${res.status}`, status: res.status };
        }
        return { ok: json.ok, data: json.ok ? json.data : json, error: null, status: res.status };
    } catch (e) {
        return { ok: false, data: null, error: e.message || 'Network error', status: 0 };
    }
}

/** ─── Toast notifications ────────────────────────────────── */

/** Toast notification queue. Exported for ToastContainer component. */
export const _toasts = [];
const _toastIds = { next: 1 };

/**
 * Show a toast notification.  Auto-dismisses after `duration` ms.
 *
 * @param {string} message   – Toast text
 * @param {string} [type]    – 'info' | 'success' | 'error' | 'warning'
 * @param {number} [duration] – Auto-dismiss timeout in ms (0 = indefinite)
 * @returns {number} id
 */
export function toast(message, type = 'info', duration = 4000) {
    const id = _toastIds.next++;
    _toasts.push({ id, message, type, createdAt: Date.now(), duration });

    if (duration > 0) setTimeout(() => dismissToast(id), duration);
    return id;
}

/**
 * Dismiss a toast by id.
 */
export function dismissToast(id) {
    const idx = _toasts.findIndex(t => t.id === id);
    if (idx !== -1) _toasts.splice(idx, 1);
}

/**
 * Render the queued toast notifications.
 *
 * @returns {VNode} – Toast container (empty text node when no toasts)
 */
export function ToastContainer() {
    if (!_toasts.length) return h('#text', '');

    const clsMap = { info: 'toast-info', success: 'toast-success', error: 'toast-error', warning: 'toast-warning' };

    return h('div', { class: 'toast-container' },
        ..._toasts.map(t =>
            h('div', { class: `toast ${clsMap[t.type] || clsMap.info}`, 'on:click': () => dismissToast(t.id) },
                h('span', null, t.message),
                h('button', { class: 'toast-close', 'on:click': (e) => { e.stopPropagation(); dismissToast(t.id); } }, '\u00d7'),
            ),
        ),
    );
}