import { base } from '$app/paths';
import { SHARE_BASE_URL } from '$env/static/private';
import { collections } from '$lib/server/database.js';
import type { SharedConversation } from '$lib/types/SharedConversation.js';
import { sha256 } from '$lib/utils/sha256.js';
import { error } from '@sveltejs/kit';
import { ObjectId } from 'mongodb';
import { nanoid } from 'nanoid';

export async function POST({ params, url, locals }) {
	const conversation = await collections.conversations.findOne({
		_id: new ObjectId(params.id),
		sessionId: locals.sessionId
	});

	if (!conversation) {
		throw error(404, 'Conversation not found');
	}

	const hash = await sha256(JSON.stringify(conversation.messages));

	const existingShare = await collections.sharedConversations.findOne({ hash });

	if (existingShare) {
		return new Response(
			JSON.stringify({
				url: url.origin + `${base}/r/${existingShare._id}`
			}),
			{ headers: { 'Content-Type': 'application/json' } }
		);
	}

	const shared: SharedConversation = {
		_id: nanoid(7),
		createdAt: new Date(),
		messages: conversation.messages,
		hash,
		updatedAt: new Date(),
		title: conversation.title
	};

	await collections.sharedConversations.insertOne(shared);

	return new Response(
		JSON.stringify({
			url: (SHARE_BASE_URL || `${url.origin}${base}`) + `/r/${shared._id}`
		}),
		{ headers: { 'Content-Type': 'application/json' } }
	);
}