import { redirect } from '@sveltejs/kit';
import { createApiClient } from '$lib/api.server';
import type { components } from '$lib/generated/api';

type IncompleteDocumentDTO = components['schemas']['IncompleteDocumentDTO'];
type NotificationDTO = components['schemas']['NotificationDTO'];
type Document = components['schemas']['Document'];

export async function load({ url, fetch }) {
	const q = url.searchParams.get('q') || '';
	const from = url.searchParams.get('from') || '';
	const to = url.searchParams.get('to') || '';
	const senderId = url.searchParams.get('senderId') || '';
	const receiverId = url.searchParams.get('receiverId') || '';
	const tags = url.searchParams.getAll('tag');

	const isDashboard = !q && !from && !to && !senderId && !receiverId && !tags.length;

	const api = createApiClient(fetch);

	try {
		const [docsResult, personsResult] = await Promise.all([
			isDashboard
				? Promise.resolve(null)
				: api.GET('/api/documents/search', {
						params: {
							query: {
								q: q || undefined,
								from: from || undefined,
								to: to || undefined,
								senderId: senderId || undefined,
								receiverId: receiverId || undefined,
								tag: tags.length ? tags : undefined
							}
						}
					}),
			api.GET('/api/persons')
		]);

		if (personsResult.response.status === 401) {
			throw redirect(302, '/login');
		}
		if (docsResult && docsResult.response.status === 401) {
			throw redirect(302, '/login');
		}

		const documents: Document[] = docsResult?.data ?? [];
		const allPersons = (personsResult.data ?? []) as {
			id: string;
			firstName: string;
			lastName: string;
		}[];

		const senderObj = allPersons.find((p) => p.id === senderId);
		const receiverObj = allPersons.find((p) => p.id === receiverId);

		// Dashboard widgets — failures are isolated and don't crash the page
		let mentions: NotificationDTO[] = [];
		let incompleteDocs: IncompleteDocumentDTO[] = [];
		let recentDocs: Document[] = [];

		if (isDashboard) {
			const [mentionsResult, incompleteResult, recentResult] = await Promise.allSettled([
				api.GET('/api/notifications', { params: { query: { size: 5 } } }),
				api.GET('/api/documents/incomplete', { params: { query: { size: 5 } } }),
				api.GET('/api/documents/recent-activity', { params: { query: { size: 5 } } })
			]);

			if (mentionsResult.status === 'fulfilled' && mentionsResult.value.response.ok) {
				mentions = mentionsResult.value.data?.content ?? [];
			}
			if (incompleteResult.status === 'fulfilled' && incompleteResult.value.response.ok) {
				incompleteDocs = incompleteResult.value.data ?? [];
			}
			if (recentResult.status === 'fulfilled' && recentResult.value.response.ok) {
				recentDocs = recentResult.value.data ?? [];
			}
		}

		return {
			isDashboard,
			documents,
			mentions,
			incompleteDocs,
			recentDocs,
			initialValues: {
				senderName: senderObj ? `${senderObj.firstName} ${senderObj.lastName}` : '',
				receiverName: receiverObj ? `${receiverObj.firstName} ${receiverObj.lastName}` : ''
			},
			filters: { q, from, to, senderId, receiverId, tags },
			error: null as string | null
		};
	} catch (e) {
		if ((e as { status?: number }).status) throw e;
		console.error('Error loading data:', e);
		return {
			isDashboard,
			documents: [],
			mentions: [],
			incompleteDocs: [],
			recentDocs: [],
			initialValues: { senderName: '', receiverName: '' },
			filters: { q, from, to, senderId, receiverId, tags },
			error: 'Daten konnten nicht geladen werden.' as string | null
		};
	}
}