/**
 * Hoover — helpers.js
 *
 * Shared utilities: text escaping, attribute escaping, DOM value helpers,
 * zone parsing, form utilities.
 */

/**
 * Escape text for safe HTML output.
 * Appends the string to a temporary div and reads innerHTML,
 * which safely escapes all HTML special characters.
 */
export function esc(s) {
    const d = document.createElement('div');
    d.append(String(s ?? ''));
    return d.innerHTML;
}

/**
 * Escape a string for safe use in HTML attributes.
 */
export function att_esc(s) {
    return String(s ?? '')
        .replace(/&/g, '&')
        .replace(/"/g, '"')
        .replace(/'/g, ''')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;');
}

/**
 * URL-encode a string.
 */
export const enc = encodeURIComponent;

/**
 * Get the value of a DOM element by ID.
 */
export function $val(id) {
    return document.getElementById(id)?.value;
}

/**
 * Parse zone data from various API response shapes into a flat string array.
 */
export function parseZones(data) {
    let z = data?.active || data?.zones || [];
    if (typeof z === 'object' && !Array.isArray(z))
        z = Object.values(z).map(i => i?.name || i);
    return Array.isArray(z) ? z : [];
}

/**
 * Trigger a browser file download from a Blob.
 *
 * @param {Blob} blob
 * @param {string} filename
 */
/**
 * Format bytes to human-readable string.
 * @param {number} bytes
 */
export function fmtBytes(bytes) {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return (bytes / Math.pow(k, i)).toFixed(i > 0 ? 1 : 0) + ' ' + sizes[i];
}

/**
 * Split a comma-separated string into trimmed, non-empty values.
 * @param {string} [value]
 * @returns {string[]}
 */
export function csvToArr(value) {
    if (!value || !value.trim()) return [];
    return value.split(',').map(s => s.trim()).filter(Boolean);
}

export function downloadBlob(blob, filename) {
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = filename;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}