import { eq } from 'drizzle-orm';
import { Hono } from 'hono';

import { getDb, type CardsDb } from '../db/connection.ts';
import {
	cards,
	decks,
	importJobs,
	mediaRefs,
	reviews,
	studySessions,
	tags,
} from '../db/schema/index.ts';
import { serviceKeyAuth } from '../middleware/service-key.ts';

export type DsgvoDeps = { db?: CardsDb };

/**
 * DSGVO-Endpunkte. Aufgerufen von mana-admin im Verein-DSGVO-
 * Fan-Out (Auskunft Art. 15/20 + Löschung Art. 17).
 *
 * Auth: Service-Key (`X-Service-Key` muss `CARDS_DSGVO_SERVICE_KEY`
 * matchen). Phase F-1: ersetzt durch mana-auth-Service-Key-Lookup.
 */
export function dsgvoRouter(deps: DsgvoDeps = {}): Hono {
	const r = new Hono();
	const dbOf = () => deps.db ?? getDb();

	r.use('*', serviceKeyAuth({ envVar: 'CARDS_DSGVO_SERVICE_KEY' }));

	/**
	 * Voll-Export aller Cards-Daten eines Users. Liefert serialisier-
	 * bares JSON. mana-admin packt das mit den Antworten anderer Apps
	 * in einen ZIP für den User.
	 */
	r.get('/export', async (c) => {
		const userId = c.req.query('user_id');
		if (!userId) return c.json({ error: 'missing_user_id' }, 400);

		const db = dbOf();
		const [decksRows, cardsRows, reviewsRows, sessionsRows, tagsRows, mediaRows, importsRows] =
			await Promise.all([
				db.select().from(decks).where(eq(decks.userId, userId)),
				db.select().from(cards).where(eq(cards.userId, userId)),
				db.select().from(reviews).where(eq(reviews.userId, userId)),
				db.select().from(studySessions).where(eq(studySessions.userId, userId)),
				db.select().from(tags).where(eq(tags.userId, userId)),
				db.select().from(mediaRefs).where(eq(mediaRefs.userId, userId)),
				db.select().from(importJobs).where(eq(importJobs.userId, userId)),
			]);

		return c.json({
			user_id: userId,
			exported_at: new Date().toISOString(),
			app: 'cards',
			app_version: process.env.CARDS_API_VERSION ?? '0.0.0',
			data: {
				decks: decksRows.map((d) => ({ ...d, createdAt: d.createdAt.toISOString(), updatedAt: d.updatedAt.toISOString() })),
				cards: cardsRows.map((x) => ({
					...x,
					createdAt: x.createdAt.toISOString(),
					updatedAt: x.updatedAt.toISOString(),
				})),
				reviews: reviewsRows.map((r) => ({
					...r,
					due: r.due.toISOString(),
					lastReview: r.lastReview ? r.lastReview.toISOString() : null,
				})),
				study_sessions: sessionsRows.map((s) => ({
					...s,
					startedAt: s.startedAt.toISOString(),
					finishedAt: s.finishedAt ? s.finishedAt.toISOString() : null,
				})),
				tags: tagsRows.map((t) => ({ ...t, createdAt: t.createdAt.toISOString() })),
				media_refs: mediaRows.map((m) => ({ ...m, createdAt: m.createdAt.toISOString() })),
				import_jobs: importsRows.map((j) => ({
					...j,
					createdAt: j.createdAt.toISOString(),
					finishedAt: j.finishedAt ? j.finishedAt.toISOString() : null,
				})),
			},
		});
	});

	/**
	 * Vollständige Löschung aller Cards-Daten eines Users. FK-Cascades
	 * räumen automatisch:
	 *   decks → cards → reviews
	 *           cards → media_refs
	 *           cards → card_tags
	 *           decks → tags
	 *           decks → study_sessions
	 * Verbleibend: import_jobs (eigene Tabelle ohne FK) — wird separat gelöscht.
	 */
	r.post('/delete', async (c) => {
		const body = await c.req.json().catch(() => null);
		const userId = (body as { user_id?: string } | null)?.user_id;
		if (!userId) return c.json({ error: 'missing_user_id' }, 400);

		const db = dbOf();
		const [deletedDecks, deletedImports] = await db.transaction(async (tx) => {
			const dd = await tx.delete(decks).where(eq(decks.userId, userId)).returning({ id: decks.id });
			const di = await tx
				.delete(importJobs)
				.where(eq(importJobs.userId, userId))
				.returning({ id: importJobs.id });
			return [dd, di];
		});

		return c.json({
			deleted: true,
			user_id: userId,
			counts: {
				decks: deletedDecks.length,
				import_jobs: deletedImports.length,
			},
		});
	});

	return r;
}