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

import {
	CardsCreateInputSchema,
	CardsSearchInputSchema,
	cardContentHash,
	subIndexCount,
	subIndexCountForCloze,
} from '@wordeck/domain';

import { makeInitialReviewRows } from '../lib/reviews.ts';

import { getDb, type CardsDb } from '../db/connection.ts';
import { cards, decks, reviews } from '../db/schema/index.ts';
import { authMiddleware, type AuthVars } from '../middleware/auth.ts';
import { ulid } from '../lib/ulid.ts';
import { searchUserCards } from '../lib/search.ts';

const APP_BASE_URL = process.env.WORDECK_PUBLIC_URL ?? 'https://wordeck.com';
const APP_VERSION = process.env.WORDECK_API_VERSION ?? '0.0.0';

export type ToolsDeps = { db?: CardsDb };

/**
 * Tool-Invoke-Endpoint für mana-mcp / Persona-Runner / Claude.
 * Dispatch nach `:name`. Auth: User-JWT (X-User-Id-Header im Dev-Stub).
 *
 * Phase F-1: zusätzlich Service-Key-Pfad für mcp-getriggerte Calls
 * mit user-on-behalf-of-Token.
 */
export function toolsRouter(deps: ToolsDeps = {}): Hono<{ Variables: AuthVars }> {
	const r = new Hono<{ Variables: AuthVars }>();
	const dbOf = () => deps.db ?? getDb();

	r.use('*', authMiddleware);

	r.post('/:name', async (c) => {
		const userId = c.get('userId');
		const name = c.req.param('name');
		const body = await c.req.json().catch(() => null);
		if (body == null) return c.json({ error: 'invalid_json' }, 400);

		switch (name) {
			case 'cards.create': {
				const parsed = CardsCreateInputSchema.safeParse(body);
				if (!parsed.success) {
					return c.json(
						{ error: 'invalid_input', issues: parsed.error.issues.map((i) => i.message) },
						422
					);
				}
				const [deck] = await dbOf()
					.select({ id: decks.id, userId: decks.userId })
					.from(decks)
					.where(eq(decks.id, parsed.data.deck_id))
					.limit(1);
				if (!deck) return c.json({ error: 'deck_not_found' }, 404);
				if (deck.userId !== userId) return c.json({ error: 'deck_not_owned' }, 403);

				// Text-abhängige Sub-Index-Counts identisch zum REST-Pfad
				// (cards.ts POST). Cloze ohne Cluster wird 422.
				let count: number;
				if (parsed.data.type === 'cloze') {
					count = subIndexCountForCloze(parsed.data.fields.text ?? '');
					if (count === 0) {
						return c.json(
							{ error: 'invalid_input', issues: ['cloze.text contains no {{cN::…}} clusters'] },
							422
						);
					}
				} else {
					count = subIndexCount(parsed.data.type);
				}

				const cardId = ulid();
				const now = new Date();
				const contentHash = await cardContentHash({
					type: parsed.data.type,
					fields: parsed.data.fields,
				});
				const [row] = await dbOf().transaction(async (tx) => {
					const [card] = await tx
						.insert(cards)
						.values({
							id: cardId,
							deckId: parsed.data.deck_id,
							userId,
							type: parsed.data.type,
							fields: parsed.data.fields,
							contentHash,
							createdAt: now,
							updatedAt: now,
						})
						.returning();
					const subIndices = Array.from({ length: count }, (_, i) => i);
					const initial = makeInitialReviewRows({ userId, cardId, subIndices, now });
					if (initial.length > 0) await tx.insert(reviews).values(initial);
					return [card];
				});
				return c.json({
					id: row.id,
					deck_id: row.deckId,
					user_id: row.userId,
					type: row.type,
					fields: row.fields,
					content_hash: row.contentHash,
					created_at: row.createdAt.toISOString(),
					updated_at: row.updatedAt.toISOString(),
				});
			}

			case 'cards.search': {
				const parsed = CardsSearchInputSchema.safeParse(body);
				if (!parsed.success) {
					return c.json(
						{ error: 'invalid_input', issues: parsed.error.issues.map((i) => i.message) },
						422
					);
				}
				const max = parsed.data.max_results ?? 30;
				const { hits, tookMs } = await searchUserCards(dbOf(), userId, parsed.data.query, max);
				return c.json({
					query: parsed.data.query,
					results: hits.map((h) => ({
						id: h.id,
						type: 'card' as const,
						title: h.title,
						snippet: h.snippet,
						link: h.link,
						score: h.score,
					})),
					total: hits.length,
					took_ms: tookMs,
					app: 'wordeck',
					app_version: APP_VERSION,
					base_url: APP_BASE_URL,
				});
			}

			default:
				return c.json({ error: 'unknown_tool', name }, 404);
		}
	});

	return r;
}