import { base } from "$app/paths";
import { authCondition, requiresUser } from "$lib/server/auth";
import { collections } from "$lib/server/database";
import { fail, type Actions, redirect } from "@sveltejs/kit";
import { ObjectId } from "mongodb";

import { z } from "zod";
import { sha256 } from "$lib/utils/sha256";
import sharp from "sharp";
import { parseStringToList } from "$lib/utils/parseStringToList";
import { usageLimits } from "$lib/server/usageLimits";
import { generateSearchTokens } from "$lib/utils/searchTokens";

const newAsssistantSchema = z.object({
	name: z.string().min(1),
	modelId: z.string().min(1),
	preprompt: z.string().min(1),
	description: z.string().optional(),
	exampleInput1: z.string().optional(),
	exampleInput2: z.string().optional(),
	exampleInput3: z.string().optional(),
	exampleInput4: z.string().optional(),
	avatar: z.instanceof(File).optional(),
	ragLinkList: z.preprocess(parseStringToList, z.string().url().array().max(10)),
	ragDomainList: z.preprocess(parseStringToList, z.string().array()),
	ragAllowAll: z.preprocess((v) => v === "true", z.boolean()),
});

const uploadAvatar = async (avatar: File, assistantId: ObjectId): Promise<string> => {
	const hash = await sha256(await avatar.text());
	const upload = collections.bucket.openUploadStream(`${assistantId.toString()}`, {
		metadata: { type: avatar.type, hash },
	});

	upload.write((await avatar.arrayBuffer()) as unknown as Buffer);
	upload.end();

	// only return the filename when upload throws a finish event or a 10s time out occurs
	return new Promise((resolve, reject) => {
		upload.once("finish", () => resolve(hash));
		upload.once("error", reject);
		setTimeout(() => reject(new Error("Upload timed out")), 10000);
	});
};

export const actions: Actions = {
	default: async ({ request, locals }) => {
		const formData = Object.fromEntries(await request.formData());

		const parse = newAsssistantSchema.safeParse(formData);

		if (!parse.success) {
			// Loop through the errors array and create a custom errors array
			const errors = parse.error.errors.map((error) => {
				return {
					field: error.path[0],
					message: error.message,
				};
			});

			return fail(400, { error: true, errors });
		}

		// can only create assistants when logged in, IF login is setup
		if (!locals.user && requiresUser) {
			const errors = [{ field: "preprompt", message: "Must be logged in. Unauthorized" }];
			return fail(400, { error: true, errors });
		}

		const assistantsCount = await collections.assistants.countDocuments(authCondition(locals));

		if (usageLimits?.assistants && assistantsCount > usageLimits.assistants) {
			const errors = [
				{
					field: "preprompt",
					message: "You have reached the maximum number of assistants. Delete some to continue.",
				},
			];
			return fail(400, { error: true, errors });
		}

		const createdById = locals.user?._id ?? locals.sessionId;

		const newAssistantId = new ObjectId();

		const exampleInputs: string[] = [
			parse?.data?.exampleInput1 ?? "",
			parse?.data?.exampleInput2 ?? "",
			parse?.data?.exampleInput3 ?? "",
			parse?.data?.exampleInput4 ?? "",
		].filter((input) => !!input);

		let hash;
		if (parse.data.avatar && parse.data.avatar.size > 0) {
			let image;
			try {
				image = await sharp(await parse.data.avatar.arrayBuffer())
					.resize(512, 512, { fit: "inside" })
					.jpeg({ quality: 80 })
					.toBuffer();
			} catch (e) {
				const errors = [{ field: "avatar", message: (e as Error).message }];
				return fail(400, { error: true, errors });
			}

			hash = await uploadAvatar(new File([image], "avatar.jpg"), newAssistantId);
		}

		const { insertedId } = await collections.assistants.insertOne({
			_id: newAssistantId,
			createdById,
			createdByName: locals.user?.username ?? locals.user?.name,
			...parse.data,
			exampleInputs,
			avatar: hash,
			createdAt: new Date(),
			updatedAt: new Date(),
			userCount: 1,
			featured: false,
			rag: {
				allowedLinks: parse.data.ragLinkList,
				allowedDomains: parse.data.ragDomainList,
				allowAllDomains: parse.data.ragAllowAll,
			},
			searchTokens: generateSearchTokens(parse.data.name),
		});

		// add insertedId to user settings

		await collections.settings.updateOne(authCondition(locals), {
			$addToSet: { assistants: insertedId },
		});

		throw redirect(302, `${base}/settings/assistants/${insertedId}`);
	},
};