/**
 * Demo-mode auto-reply rules: "if you hear X, answer Y".
 *
 * Matching is normalized — uppercased, with spaces and punctuation stripped —
 * so a rule typed as "U OK?" still fires on a decoded "U OK" or "UOK". Antenna
 * Morse won't reliably carry punctuation, so we never require an exact match.
 *
 * Pure module (no DOM/audio) so the matching logic is unit-tested directly.
 */

export function normalizePhrase(s) {
    return String(s).toUpperCase().replace(/[^A-Z0-9]/g, "");
}

/** Default conversation for the two-robot demo (short = fewer antenna taps). */
export const DEFAULT_RULES = [
    { input: "U OK", output: "Y" },
    { input: "SOS", output: "WTF" },
];

/**
 * Find the first rule whose (normalized) input equals the (normalized)
 * decoded text. Returns the rule or null.
 */
export function matchRule(text, rules) {
    const n = normalizePhrase(text);
    if (!n) return null;
    return (rules || []).find(
        (r) => r && r.input && r.output && normalizePhrase(r.input) === n,
    ) || null;
}