import type { GuardianInvitationOrigin, InvitedAuthorityScope } from '../../services/RelatedPersonService.tsx';

/**
 * THE ONE SENTENCE AN INVITATION SAYS, AND THE ONE PLACE IT IS WRITTEN.
 *
 * Spencer, 2026-09-01, and the rule underneath it is what makes the copy work rather than the copy
 * itself: **an invitation cannot know which relationship it is, so it says what the person may DO rather
 * than naming what they ARE.**
 *
 * SO THE RELATIONSHIP FIELD IS NOT READ HERE, AND MUST NOT BE ADDED. It is in the payload and it is
 * the one thing forbidden: a spouse, an adult child, a lawyer holding power of attorney and a live-in
 * carer all arrive through this same invitation, **and only one of them is a caregiver.** There is no
 * noun that is true for all of them, so no noun is used.
 *
 * The shipped Family-page copy was the forbidden shape verbatim - *"You've been invited as a
 * `<relationship>` caregiver by `<name>`"* - which is why this exists as a function two surfaces call
 * rather than a string each of them writes.
 */
export const invitationSentence = (
    inviterName: string,
    grantScope: InvitedAuthorityScope | undefined,
    origin?: GuardianInvitationOrigin,
): string => {
    // A staff-witnessed guardian declaration made this invitation, not the child it names, so the child is not its
    // author. The server sends the relationship only from the verified declaration, never from the link label.
    if (origin) {
        const access = grantScope === 'acts-on-their-behalf'
            ? `view ${inviterName}'s account and clinical records, and act on their behalf`
            : grantScope === 'view-only' ? `view ${inviterName}'s account and clinical records` : `access ${inviterName}'s account and clinical records`;
        if (origin.kind === 'unavailable') return `You were invited to ${access}.`;
        const recorder = origin.practiceName ?? `Staff at ${inviterName}'s practice`;
        const role = origin.relationship === 'legal-guardian' ? 'legal guardian' : 'parent';
        return `${recorder} recorded you as ${inviterName}'s ${role}, as you told them in person. Accepting lets you ${access}.`;
    }

    if (grantScope === 'acts-on-their-behalf') {
        return `${inviterName} invited you to view their account and clinical records, and to act on their behalf.`;
    }

    if (grantScope === 'view-only') {
        return `${inviterName} invited you to view their account and clinical records.`;
    }

    /**
     * THE SCOPE IS UNKNOWN, AND THIS SENTENCE NEITHER CLAIMS NOR DENIES THE ACTING HALF.
     *
     * The server answers nothing rather than guessing when it cannot establish the grant. Falling
     * back to the view-only wording here would undo that on the last line: somebody would agree to a
     * read-only view and receive the power to act, having read a sentence we wrote.
     * "access" is true of both grants and enumerates neither. **Understating a consent is the
     * dangerous direction; saying less than you know is not the same as saying something false.**
     */
    return `${inviterName} invited you to access their account and clinical records.`;
};