import { json, error } from '@sveltejs/kit';
import type { RequestHandler } from './$types';
import { sql } from '$lib/server/db';

/** GET /api/entities/:entityId — Hent entitet med edge-count */
export const GET: RequestHandler = async ({ params, locals }) => {
	if (!locals.workspace || !locals.user) error(401);

	const [entity] = await sql`
		SELECT e.id, e.name, e.type, e.aliases, e.avatar_url,
			n.created_at, n.updated_at,
			(SELECT COUNT(*) FROM graph_edges ge
			 WHERE ge.source_id = e.id OR ge.target_id = e.id) AS edge_count
		FROM entities e
		JOIN nodes n ON n.id = e.id
		WHERE e.id = ${params.entityId} AND n.workspace_id = ${locals.workspace.id}
	`;
	if (!entity) error(404, 'Entitet ikke funnet');

	return json(entity);
};

/** PATCH /api/entities/:entityId — Oppdater entitet */
export const PATCH: RequestHandler = async ({ params, request, locals }) => {
	if (!locals.workspace || !locals.user) error(401);

	const updates = await request.json();

	const [existing] = await sql`
		SELECT e.id FROM entities e
		JOIN nodes n ON n.id = e.id
		WHERE e.id = ${params.entityId} AND n.workspace_id = ${locals.workspace.id}
	`;
	if (!existing) error(404, 'Entitet ikke funnet');

	if (updates.type) {
		const validTypes = ['person', 'organisasjon', 'sted', 'tema', 'konsept'];
		if (!validTypes.includes(updates.type)) {
			error(400, `type må være en av: ${validTypes.join(', ')}`);
		}
	}

	const [updated] = await sql`
		UPDATE entities SET
			name = COALESCE(${updates.name?.trim() ?? null}, name),
			type = COALESCE(${updates.type ?? null}, type),
			aliases = CASE WHEN ${updates.aliases !== undefined} THEN ${updates.aliases ?? []} ELSE aliases END,
			avatar_url = CASE WHEN ${updates.avatar_url !== undefined} THEN ${updates.avatar_url ?? null} ELSE avatar_url END
		WHERE id = ${params.entityId}
		RETURNING id, name, type, aliases, avatar_url,
			(SELECT created_at FROM nodes WHERE id = entities.id) AS created_at,
			(SELECT updated_at FROM nodes WHERE id = entities.id) AS updated_at
	`;

	return json(updated);
};

/** DELETE /api/entities/:entityId — Slett entitet */
export const DELETE: RequestHandler = async ({ params, locals }) => {
	if (!locals.workspace || !locals.user) error(401);

	const [entity] = await sql`
		SELECT e.id FROM entities e
		JOIN nodes n ON n.id = e.id
		WHERE e.id = ${params.entityId} AND n.workspace_id = ${locals.workspace.id}
	`;
	if (!entity) error(404, 'Entitet ikke funnet');

	// Slett node (cascader til entities + graph_edges)
	await sql`DELETE FROM nodes WHERE id = ${params.entityId}`;

	return new Response(null, { status: 204 });
};