/**
 * Drives endpoints. D0 ships read-only listing; D2 adds the membership API.
 * D3 will add the create-shared-drive flow under the same module.
 *
 * Consumers usually go through the `drives` store (`$lib/stores/drives.svelte`)
 * which dedupes the request and caches the list — touch this module directly
 * only when bypassing the cache is intentional (e.g. an explicit refresh).
 */
import { apiFetch, apiJson } from '$lib/api/client';
import { getCsrfHeaders } from '$lib/api/csrf';
import type { Drive, DriveMember, DriveMemberSubject, DriveRole } from '$lib/api/types';

const JSON_HEADERS = { 'Content-Type': 'application/json' };

/** `GET /api/drives` — every drive the caller can read, default first by convention. */
export function listDrives(): Promise<Drive[]> {
	return apiJson<Drive[]>('/api/drives', { credentials: 'same-origin' });
}

/** `GET /api/drives/{id}/members` — every role grant on the drive. */
export function listDriveMembers(driveId: string): Promise<DriveMember[]> {
	return apiJson<DriveMember[]>(`/api/drives/${encodeURIComponent(driveId)}/members`, {
		credentials: 'same-origin'
	});
}

/**
 * `POST /api/drives/{id}/members` — add a member (or refresh an existing
 * subject's role; the underlying `set_role` is idempotent via UNIQUE
 * `(subject, resource)`).
 *
 * Refused with 405 on personal drives (immutable membership) and 400 if a
 * last-owner demotion would orphan a shared drive.
 */
export async function addDriveMember(
	driveId: string,
	subject: DriveMemberSubject,
	role: DriveRole,
	expiresAt?: string | null
): Promise<DriveMember> {
	const res = await apiFetch(`/api/drives/${encodeURIComponent(driveId)}/members`, {
		method: 'POST',
		headers: { ...JSON_HEADERS, ...getCsrfHeaders() },
		credentials: 'same-origin',
		body: JSON.stringify({ subject, role, expires_at: expiresAt ?? null })
	});
	if (!res.ok) throw new Error(`add member failed: ${res.status}`);
	return (await res.json()) as DriveMember;
}

/**
 * `PATCH /api/drives/{id}/members/{kind}/{sid}` — change a member's role.
 * Same guards as `addDriveMember` apply.
 */
export async function updateDriveMember(
	driveId: string,
	subject: DriveMemberSubject,
	role: DriveRole,
	expiresAt?: string | null
): Promise<DriveMember> {
	const url =
		`/api/drives/${encodeURIComponent(driveId)}/members/` +
		`${encodeURIComponent(subject.type)}/${encodeURIComponent(subject.id)}`;
	const res = await apiFetch(url, {
		method: 'PATCH',
		headers: { ...JSON_HEADERS, ...getCsrfHeaders() },
		credentials: 'same-origin',
		body: JSON.stringify({ role, expires_at: expiresAt ?? null })
	});
	if (!res.ok) throw new Error(`update member failed: ${res.status}`);
	return (await res.json()) as DriveMember;
}

/**
 * `DELETE /api/drives/{id}/members/{kind}/{sid}` — remove a member.
 * Idempotent (removing a non-member returns 204). Refused with 400 if it
 * would leave a shared drive without an owner.
 */
export async function removeDriveMember(
	driveId: string,
	subject: DriveMemberSubject
): Promise<void> {
	const url =
		`/api/drives/${encodeURIComponent(driveId)}/members/` +
		`${encodeURIComponent(subject.type)}/${encodeURIComponent(subject.id)}`;
	const res = await apiFetch(url, {
		method: 'DELETE',
		headers: getCsrfHeaders(),
		credentials: 'same-origin'
	});
	if (!res.ok) throw new Error(`remove member failed: ${res.status}`);
}