import type { MyProxy } from '../hooks/useMyProxies';
import { effectiveAllowMessaging } from '../components/FhirRelatedPersonDisplay/careAccess.helpers';

interface TeamOnRoster {
    patientId: string;
    members: ReadonlyArray<{ memberRef: string; state: string }>;
}

const mayMessage = (link: MyProxy): boolean =>
    link.careTier ? effectiveAllowMessaging(link.careTier, link.allowMessaging === true) : link.allowMessaging === true;

// Why the viewer may read this team's thread but not write in it, or undefined when nothing here says so.
// Only a viewer on the roster through their own link to the team's patient is judged; the server stays the gate.
export const teamMessagingRefusal = (
    team: TeamOnRoster,
    selfPatientId: string | undefined,
    links: readonly MyProxy[],
): string | undefined => {
    if (!selfPatientId || team.patientId === selfPatientId) return undefined;
    const roster = new Set(team.members.filter((member) => member.state === 'active').map((member) => member.memberRef));
    const through = links.filter((link) => link.subjectPatientId === team.patientId && roster.has(`RelatedPerson/${link.relatedPersonId}`));
    if (through.length === 0 || through.some(mayMessage)) return undefined;
    const name = through[0].subjectName?.trim() || 'The patient';
    return `${name} has not given you permission to send messages, so you can read this conversation but not write in it.`;
};