interface PhoneNumberDisplayProps {
    phoneNumber: string;
    className?: string;
}

export const formatPhoneNumber = (value: string): string => {
    if (!value) return '';

    // Remove all non-digit characters
    const cleaned = ('' + value).replace(/\D/g, '');

    // Match a 10-digit phone number, with or without the +1 country code
    const match = cleaned.replace(/^1(?=\d{10}$)/, '').match(/^(\d{3})(\d{3})(\d{4})$/);

    if (match) {
        return `(${match[1]}) ${match[2]}-${match[3]}`;
    }

    return value;
};

export const usePhoneNumber = (value: string): string => {
    return formatPhoneNumber(value);
};

export const formatPhoneNumberForInput = (value: string): string => {
    if (!value) return '';

    // Remove all non-digit characters
    const cleaned = ('' + value).replace(/\D/g, '');

    // Format as XXX-XXX-XXXX for input display
    const match = cleaned.match(/^(\d{3})(\d{3})(\d{4})$/);

    if (match) {
        return `${match[1]}-${match[2]}-${match[3]}`;
    }

    return cleaned;
};

export const isValidPhoneNumber = (value: string): boolean => {
    if (!value) return false;

    // Remove all non-digit characters
    const cleaned = ('' + value).replace(/\D/g, '');

    // Check if it's a 10-digit number
    return /^\d{10}$/.test(cleaned);
};

/**
 * Normalize a user-entered phone number to E.164 (e.g. "+15551234567").
 * Cognito's standard `phone_number` attribute requires E.164, and E.164 is the
 * canonical form the SMS pipeline and dedup matcher both want. US-centric: a bare
 * 10-digit number is assumed +1. Returns null when the input can't be confidently
 * normalized, so callers can treat it as an invalid phone rather than store garbage.
 */
export const toE164 = (value: string): string | null => {
    if (!value) return null;

    const trimmed = ('' + value).trim();

    // Already E.164 (leading + and a valid country/subscriber number).
    if (/^\+[1-9]\d{1,14}$/.test(trimmed)) return trimmed;

    const digits = trimmed.replace(/\D/g, '');

    if (digits.length === 10) return `+1${digits}`;                        // US national number
    if (digits.length === 11 && digits.startsWith('1')) return `+${digits}`; // US with country code

    return null;
};

export const PhoneNumberDisplay: React.FC<PhoneNumberDisplayProps> = ({
                                                                          phoneNumber,
                                                                          className
                                                                      }) => {
    const formattedPhoneNumber = formatPhoneNumber(phoneNumber);

    return (
        <span className={className}>{formattedPhoneNumber}</span>
    );
};