/*
	Fosscord: A FOSS re-implementation and extension of the Discord.com backend.
	Copyright (C) 2023 Fosscord and Fosscord 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 { WebSocket, Payload } from "@fosscord/gateway";
import {
	checkToken,
	Intents,
	Member,
	ReadyEventData,
	User,
	Session,
	EVENTEnum,
	Config,
	PublicMember,
	PublicUser,
	PrivateUserProjection,
	ReadState,
	Application,
	emitEvent,
	SessionsReplace,
	PrivateSessionProjection,
	MemberPrivateProjection,
	PresenceUpdateEvent,
	UserSettings,
	IdentifySchema,
	DefaultUserGuildSettings,
	UserGuildSettings,
	ReadyGuildDTO,
	Guild,
} from "@fosscord/util";
import { Send } from "../util/Send";
import { CLOSECODES, OPCODES } from "../util/Constants";
import { genSessionId } from "../util/SessionUtils";
import { setupListener } from "../listener/listener";
// import experiments from "./experiments.json";
const experiments: any = [];
import { check } from "./instanceOf";
import { Recipient } from "@fosscord/util";

// TODO: user sharding
// TODO: check privileged intents, if defined in the config
// TODO: check if already identified

export async function onIdentify(this: WebSocket, data: Payload) {
	clearTimeout(this.readyTimeout);
	// TODO: is this needed now that we use `json-bigint`?
	if (typeof data.d?.client_state?.highest_last_message_id === "number")
		data.d.client_state.highest_last_message_id += "";
	check.call(this, IdentifySchema, data.d);

	const identify: IdentifySchema = data.d;

	try {
		const { jwtSecret } = Config.get().security;
		var { decoded } = await checkToken(identify.token, jwtSecret); // will throw an error if invalid
	} catch (error) {
		console.error("invalid token", error);
		return this.close(CLOSECODES.Authentication_failed);
	}
	this.user_id = decoded.id;
	let session_id = this.session_id;

	const [user, read_states, members, recipients, session, application] =
		await Promise.all([
			User.findOneOrFail({
				where: { id: this.user_id },
				relations: ["relationships", "relationships.to", "settings"],
				select: [...PrivateUserProjection, "relationships"],
			}),
			ReadState.find({ where: { user_id: this.user_id } }),
			Member.find({
				where: { id: this.user_id },
				select: MemberPrivateProjection,
				relations: [
					"guild",
					"guild.channels",
					"guild.emojis",
					"guild.emojis.user",
					"guild.roles",
					"guild.stickers",
					"user",
					"roles",
				],
			}),
			Recipient.find({
				where: { user_id: this.user_id, closed: false },
				relations: [
					"channel",
					"channel.recipients",
					"channel.recipients.user",
				],
				// TODO: public user selection
			}),
			// save the session and delete it when the websocket is closed
			Session.create({
				user_id: this.user_id,
				session_id: session_id,
				// TODO: check if status is only one of: online, dnd, offline, idle
				status: identify.presence?.status || "offline", //does the session always start as online?
				client_info: {
					//TODO read from identity
					client: "desktop",
					os: identify.properties?.os,
					version: 0,
				},
				activities: [],
			}).save(),
			Application.findOne({ where: { id: this.user_id } }),
		]);

	if (!user) return this.close(CLOSECODES.Authentication_failed);
	if (!user.settings) {
		user.settings = new UserSettings();
		await user.settings.save();
	}

	if (!identify.intents) identify.intents = BigInt("0x6ffffffff");
	this.intents = new Intents(identify.intents);
	if (identify.shard) {
		this.shard_id = identify.shard[0];
		this.shard_count = identify.shard[1];
		if (
			this.shard_count == null ||
			this.shard_id == null ||
			this.shard_id >= this.shard_count ||
			this.shard_id < 0 ||
			this.shard_count <= 0
		) {
			console.log(identify.shard);
			return this.close(CLOSECODES.Invalid_shard);
		}
	}
	var users: PublicUser[] = [];

	const merged_members = members.map((x: Member) => {
		return [
			{
				...x,
				roles: x.roles.map((x) => x.id),
				settings: undefined,
				guild: undefined,
			},
		];
	}) as PublicMember[][];
	let guilds = members.map((x) => ({ ...x.guild, joined_at: x.joined_at }));

	const pending_guilds: typeof guilds = [];
	// @ts-ignore
	guilds = guilds.map((guild) => {
		if (user.bot) {
			pending_guilds.push(guild);
			return { id: guild.id, unavailable: true };
		}

		return guild;
	});

	// TODO: Rewrite this. Perhaps a DTO?
	const user_guild_settings_entries = members.map((x) => ({
		...DefaultUserGuildSettings,
		...x.settings,
		guild_id: x.guild.id,
		channel_overrides: Object.entries(
			x.settings.channel_overrides ?? {},
		).map((y) => ({
			...y[1],
			channel_id: y[0],
		})),
	})) as any as UserGuildSettings[];

	const channels = recipients.map((x) => {
		//@ts-ignore
		x.channel.recipients = x.channel.recipients?.map((x) =>
			x.user.toPublicUser(),
		);
		//TODO is this needed? check if users in group dm that are not friends are sent in the READY event
		users = users.concat(x.channel.recipients as unknown as User[]);
		if (x.channel.isDm()) {
			x.channel.recipients = x.channel.recipients!.filter(
				(x) => x.id !== this.user_id,
			);
		}
		return x.channel;
	});

	for (let relation of user.relationships) {
		const related_user = relation.to;
		const public_related_user = {
			username: related_user.username,
			discriminator: related_user.discriminator,
			id: related_user.id,
			public_flags: related_user.public_flags,
			avatar: related_user.avatar,
			bot: related_user.bot,
			bio: related_user.bio,
			premium_since: user.premium_since,
			premium_type: user.premium_type,
			accent_color: related_user.accent_color,
		};
		users.push(public_related_user);
	}

	setImmediate(async () => {
		// run in seperate "promise context" because ready payload is not dependent on those events
		emitEvent({
			event: "SESSIONS_REPLACE",
			user_id: this.user_id,
			data: await Session.find({
				where: { user_id: this.user_id },
				select: PrivateSessionProjection,
			}),
		} as SessionsReplace);
		emitEvent({
			event: "PRESENCE_UPDATE",
			user_id: this.user_id,
			data: {
				user: await User.getPublicUser(this.user_id),
				activities: session.activities,
				client_status: session?.client_info,
				status: session.status,
			},
		} as PresenceUpdateEvent);
	});

	read_states.forEach((s: any) => {
		s.id = s.channel_id;
		delete s.user_id;
		delete s.channel_id;
	});

	const privateUser = {
		avatar: user.avatar,
		mobile: user.mobile,
		desktop: user.desktop,
		discriminator: user.discriminator,
		email: user.email,
		flags: user.flags,
		id: user.id,
		mfa_enabled: user.mfa_enabled,
		nsfw_allowed: user.nsfw_allowed,
		phone: user.phone,
		premium: user.premium,
		premium_type: user.premium_type,
		public_flags: user.public_flags,
		premium_usage_flags: user.premium_usage_flags,
		purchased_flags: user.purchased_flags,
		username: user.username,
		verified: user.verified,
		bot: user.bot,
		accent_color: user.accent_color,
		banner: user.banner,
		bio: user.bio,
		premium_since: user.premium_since,
	};

	const d: ReadyEventData = {
		v: 9,
		application: {
			id: application?.id ?? "",
			flags: application?.flags ?? 0,
		}, //TODO: check this code!
		user: privateUser,
		user_settings: user.settings,
		// @ts-ignore
		guilds: guilds.map((x) => {
			return {
				...new ReadyGuildDTO(x as Guild & { joined_at: Date }).toJSON(),
				guild_hashes: {},
				joined_at: x.joined_at,
			};
		}),
		guild_experiments: [], // TODO
		geo_ordered_rtc_regions: [], // TODO
		relationships: user.relationships.map((x) => x.toPublicRelationship()),
		read_state: {
			entries: read_states,
			partial: false,
			version: 304128,
		},
		user_guild_settings: {
			entries: user_guild_settings_entries,
			partial: false, // TODO partial
			version: 642,
		},
		private_channels: channels,
		session_id: session_id,
		analytics_token: "", // TODO
		connected_accounts: [], // TODO
		consents: {
			personalization: {
				consented: false, // TODO
			},
		},
		country_code: user.settings.locale,
		friend_suggestion_count: 0, // TODO
		// @ts-ignore
		experiments: experiments, // TODO
		guild_join_requests: [], // TODO what is this?
		users: users.filter((x) => x).unique(),
		merged_members: merged_members,
		// shard // TODO: only for user sharding
		sessions: [], // TODO:
	};

	// TODO: send real proper data structure
	await Send(this, {
		op: OPCODES.Dispatch,
		t: EVENTEnum.Ready,
		s: this.sequence++,
		d,
	});

	await Promise.all(
		pending_guilds.map((guild) =>
			Send(this, {
				op: OPCODES.Dispatch,
				t: EVENTEnum.GuildCreate,
				s: this.sequence++,
				d: guild,
			})?.catch(console.error),
		),
	);

	//TODO send READY_SUPPLEMENTAL
	//TODO send GUILD_MEMBER_LIST_UPDATE
	//TODO send SESSIONS_REPLACE
	//TODO send VOICE_STATE_UPDATE to let the client know if another device is already connected to a voice channel

	await setupListener.call(this);

	// console.log(`${this.ipAddress} identified as ${d.user.id}`);
}