/*
	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
	Copyright (C) 2023 Spacebar and Spacebar Contributors

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published
	by the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import { route } from "@spacebar/api";
import {
	Channel,
	ChannelModifySchema,
	ChannelReorderSchema,
	ChannelUpdateEvent,
	Guild,
	emitEvent,
} from "@spacebar/util";
import { Request, Response, Router } from "express";
const router = Router({ mergeParams: true });

router.get(
	"/",
	route({
		responses: {
			201: {
				body: "APIChannelArray",
			},
		},
	}),
	async (req: Request, res: Response) => {
		const { guild_id } = req.params;
		const channels = await Channel.find({ where: { guild_id } });

		for await (const channel of channels) {
			channel.position = await Channel.calculatePosition(
				channel.id,
				guild_id,
				channel.guild,
			);
		}
		channels.sort((a, b) => a.position - b.position);

		res.json(channels);
	},
);

router.post(
	"/",
	route({
		requestBody: "ChannelModifySchema",
		permission: "MANAGE_CHANNELS",
		responses: {
			201: {
				body: "Channel",
			},
			400: {
				body: "APIErrorResponse",
			},
			403: {
				body: "APIErrorResponse",
			},
		},
	}),
	async (req: Request, res: Response) => {
		// creates a new guild channel https://discord.com/developers/docs/resources/guild#create-guild-channel
		const { guild_id } = req.params;
		const body = req.body as ChannelModifySchema;

		const channel = await Channel.createChannel(
			{ ...body, guild_id },
			req.user_id,
		);
		channel.position = await Channel.calculatePosition(
			channel.id,
			guild_id,
			channel.guild,
		);

		res.status(201).json(channel);
	},
);

router.patch(
	"/",
	route({
		requestBody: "ChannelReorderSchema",
		permission: "MANAGE_CHANNELS",
		responses: {
			204: {},
			400: {
				body: "APIErrorResponse",
			},
			403: {
				body: "APIErrorResponse",
			},
		},
	}),
	async (req: Request, res: Response) => {
		// changes guild channel position
		const { guild_id } = req.params;
		let body = req.body as ChannelReorderSchema;

		const guild = await Guild.findOneOrFail({
			where: { id: guild_id },
			select: { channel_ordering: true },
		});

		body = body.sort((a, b) => {
			const apos =
				a.position ||
				(a.parent_id
					? guild.channel_ordering.findIndex(
							(_) => _ === a.parent_id,
						) + 1
					: 0);
			const bpos =
				b.position ||
				(b.parent_id
					? guild.channel_ordering.findIndex(
							(_) => _ === b.parent_id,
						) + 1
					: 0);
			return apos - bpos;
		});

		// The channels not listed for this query
		const notMentioned = guild.channel_ordering.filter(
			(x) => !body.find((c) => c.id == x),
		);

		const withParents = body.filter((x) => x.parent_id !== undefined);
		const withPositions = body.filter((x) => x.position !== undefined);
		// You can't do it with Promise.all or the way this is being done is super incorrect
		for await (const opt of withPositions) {
			const channel = await Channel.findOneOrFail({
				where: { id: opt.id },
			});

			notMentioned.splice(opt.position as number, 0, channel.id);
			channel.position = notMentioned.findIndex((_) => _ === channel.id);

			await emitEvent({
				event: "CHANNEL_UPDATE",
				data: channel,
				channel_id: channel.id,
				guild_id,
			} as ChannelUpdateEvent);
		}
		// Due to this also being able to change the order, this needs to be done in order
		// have to do the parents after the positions
		for await (const opt of withParents) {
			const [channel, parent] = await Promise.all([
				Channel.findOneOrFail({
					where: { id: opt.id },
				}),
				opt.parent_id
					? Channel.findOneOrFail({
							where: { id: opt.parent_id },
							select: {
								permission_overwrites: true,
								id: true,
							},
						})
					: null,
			]);

			if (opt.lock_permissions && parent)
				await Channel.update(
					{ id: channel.id },
					{ permission_overwrites: parent.permission_overwrites },
				);
			if (parent && opt.position === undefined) {
				const parentPos = notMentioned.indexOf(parent.id);
				notMentioned.splice(parentPos + 1, 0, channel.id);
				channel.position = (parentPos + 1) as number;
			}
			channel.parent = parent || undefined;
			channel.parent_id = parent?.id || null;
			await channel.save();

			await emitEvent({
				event: "CHANNEL_UPDATE",
				data: channel,
				channel_id: channel.id,
				guild_id,
			} as ChannelUpdateEvent);
		}

		await Guild.update(
			{ id: guild_id },
			{ channel_ordering: notMentioned },
		);

		return res.sendStatus(204);
	},
);

export default router;