export type DeskValueField = { type: string; options?: Record<string, string> };
export type DeskAnswer = string | number | boolean | string[] | null;

export function deskScalar(value: unknown): string {
    if (typeof value === 'string' || typeof value === 'number')
        return String(value);
    if (typeof value === 'boolean') return value ? '1' : '';
    return '';
}

export function deskChoices(value: unknown): string[] {
    return Array.isArray(value) && value.every((v) => typeof v === 'string')
        ? value
        : [];
}

export function deskEmpty(value: unknown): boolean {
    return (
        value === null ||
        value === undefined ||
        (typeof value === 'string' && value.trim() === '') ||
        (Array.isArray(value) && value.length === 0)
    );
}

/** Preserve typed answers and refusals; a master/profile can never supply a consent declaration. */
export function mergeDeskPrefill(
    current: Record<string, DeskAnswer>,
    patch: Record<string, unknown>,
    fields: Record<string, DeskValueField>,
    replace = false,
): Record<string, DeskAnswer> {
    const next = { ...current };
    for (const [key, value] of Object.entries(patch)) {
        const field = fields[key];
        if (
            field?.type === 'consent' ||
            field?.type === 'attachment' ||
            (!replace && !deskEmpty(current[key]))
        )
            continue;
        if (field?.type === 'multiselect') {
            if (
                Array.isArray(value) &&
                value.every(
                    (v) =>
                        typeof v === 'string' &&
                        Object.hasOwn(field.options ?? {}, v),
                )
            )
                next[key] = [...value];
        } else if (
            value === null ||
            typeof value === 'string' ||
            typeof value === 'number' ||
            typeof value === 'boolean'
        )
            next[key] = value;
    }
    return next;
}