/**
 * Batch operations (/api/batch/*). Used for multi-item copy — move and delete
 * already have per-item endpoints the files view loops over, but copy only
 * exists as a batch endpoint on the backend.
 */
import { apiFetch } from '$lib/api/client';
import { getCsrfHeaders } from '$lib/api/csrf';

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

async function post(url: string, body: unknown): Promise<void> {
	const res = await apiFetch(url, {
		method: 'POST',
		credentials: 'same-origin',
		headers: { ...JSON_HEADERS, ...getCsrfHeaders() },
		body: JSON.stringify(body)
	});
	if (!res.ok) {
		const e = (await res.json().catch(() => ({}))) as { error?: string; message?: string };
		throw new Error(e.error || e.message || `${url} failed: ${res.status}`);
	}
}

export function copyFiles(fileIds: string[], targetFolderId: string | null): Promise<void> {
	if (fileIds.length === 0) return Promise.resolve();
	return post('/api/batch/files/copy', { file_ids: fileIds, target_folder_id: targetFolderId });
}

export function copyFolders(folderIds: string[], targetFolderId: string | null): Promise<void> {
	if (folderIds.length === 0) return Promise.resolve();
	return post('/api/batch/folders/copy', {
		folder_ids: folderIds,
		target_folder_id: targetFolderId
	});
}

/**
 * Stream a multi-item selection as a server-built zip (`POST /api/batch/download`
 * — folders included, unlike the legacy per-item loop). The caller names and
 * saves the returned blob.
 */
export async function downloadBatch(fileIds: string[], folderIds: string[]): Promise<Blob> {
	const res = await apiFetch('/api/batch/download', {
		method: 'POST',
		credentials: 'same-origin',
		headers: { ...JSON_HEADERS, ...getCsrfHeaders() },
		body: JSON.stringify({ file_ids: fileIds, folder_ids: folderIds })
	});
	if (!res.ok) {
		const e = (await res.json().catch(() => ({}))) as { error?: string; message?: string };
		throw new Error(e.error || e.message || `batch download failed: ${res.status}`);
	}
	return res.blob();
}