TravBot-v3/src/commands/utility/react.ts

import {NamedCommand, RestCommand} from "onion-lasers";
import {Message, Channel, TextChannel} from "discord.js";
import {processEmoteQuery} from "./modules/emote-utils";

export default new NamedCommand({
    aliases: ["r"],
    description:
        "Reacts to the a previous message in your place. You have to react with the same emote before the bot removes that reaction.",
    usage: 'react <emotes...> (<distance / message ID / "Copy ID" / "Copy Message Link">)',
    run: "You need to enter some emotes first.",
    any: new RestCommand({
        async run({send, message, channel, guild, client, args}) {
            let target: Message | undefined;
            let distance = 1;

            if (message.reference) {
                // If the command message is a reply to another message, use that as the react target.
                target = await channel.messages.fetch(message.reference.messageID!);
            }
            // handles reacts by message id/distance
            else if (args.length >= 2) {
                const last = args[args.length - 1]; // Because this is optional, do not .pop() unless you're sure it's a message link indicator.
                const URLPattern = /^(?:https:\/\/discord.com\/channels\/(\d{17,})\/(\d{17,})\/(\d{17,}))$/;
                const copyIDPattern = /^(?:(\d{17,})-(\d{17,}))$/;

                // https://discord.com/channels/<Guild ID>/<Channel ID>/<Message ID> ("Copy Message Link" Button)
                if (URLPattern.test(last)) {
                    const match = URLPattern.exec(last)!;
                    const guildID = match[1];
                    const channelID = match[2];
                    const messageID = match[3];
                    let tmpChannel: Channel | undefined = channel;

                    if (guild?.id !== guildID) {
                        try {
                            guild = await client.guilds.fetch(guildID);
                        } catch {
                            return send(`\`${guildID}\` is an invalid guild ID!`);
                        }
                    }

                    if (tmpChannel.id !== channelID) tmpChannel = guild.channels.cache.get(channelID);
                    if (!tmpChannel) return send(`\`${channelID}\` is an invalid channel ID!`);

                    if (message.id !== messageID) {
                        try {
                            target = await (tmpChannel as TextChannel).messages.fetch(messageID);
                        } catch {
                            return send(`\`${messageID}\` is an invalid message ID!`);
                        }
                    }

                    args.pop();
                }
                // <Channel ID>-<Message ID> ("Copy ID" Button)
                else if (copyIDPattern.test(last)) {
                    const match = copyIDPattern.exec(last)!;
                    const channelID = match[1];
                    const messageID = match[2];
                    let tmpChannel: Channel | undefined = channel;

                    if (tmpChannel.id !== channelID) tmpChannel = guild?.channels.cache.get(channelID);
                    if (!tmpChannel) return send(`\`${channelID}\` is an invalid channel ID!`);

                    if (message.id !== messageID) {
                        try {
                            target = await (tmpChannel as TextChannel).messages.fetch(messageID);
                        } catch {
                            return send(`\`${messageID}\` is an invalid message ID!`);
                        }
                    }

                    args.pop();
                }
                // <Message ID>
                else if (/^\d{17,}$/.test(last)) {
                    try {
                        target = await channel.messages.fetch(last);
                    } catch {
                        return send(`No valid message found by the ID \`${last}\`!`);
                    }

                    args.pop();
                }
                // The entire string has to be a number for this to match. Prevents leaCheeseAmerican1 from triggering this.
                else if (/^\d+$/.test(last)) {
                    distance = parseInt(last);

                    if (distance >= 0 && distance <= 99) args.pop();
                    else return send("Your distance must be between 0 and 99!");
                }
            }

            if (!target) {
                // Messages are ordered from latest to earliest.
                // You also have to add 1 as well because fetchMessages includes your own message.
                target = (
                    await message.channel.messages.fetch({
                        limit: distance + 1
                    })
                ).last();
            }

            for (const emote of processEmoteQuery(args, false)) {
                // Even though the bot will always grab *some* emote, the user can choose not to keep that emote there if it isn't what they want
                const reaction = await target!.react(emote);

                // This part is called with a promise because you don't want to wait 5 seconds between each reaction.
                setTimeout(() => {
                    // This reason for this null assertion is that by the time you use this command, the client is going to be loaded.
                    reaction.users.remove(client.user!);
                }, 5000);
            }

            return;
        }
    })
});