TravBot-v3/src/core/command.ts

752 lines
32 KiB
TypeScript

import {
Collection,
Client,
Message,
TextChannel,
DMChannel,
NewsChannel,
Guild,
User,
GuildMember,
GuildChannel,
Channel
} from "discord.js";
import {getChannelByID, getGuildByID, getMessageByID, getUserByID, SendFunction} from "./libd";
import {hasPermission, getPermissionLevel, getPermissionName} from "./permissions";
import {getPrefix} from "./interface";
import {parseVars, requireAllCasesHandledFor} from "../lib";
/**
* ===[ Command Types ]===
* SUBCOMMAND - Any specifically-defined keywords / string literals.
* CHANNEL - <#...>
* ROLE - <@&...>
* EMOTE - <::ID> (The previous two values, animated and emote name respectively, do not matter at all for finding the emote.)
* MESSAGE - Available by using the built-in "Copy Message Link" or "Copy ID" buttons. https://discordapp.com/channels/<Guild ID>/<Channel ID>/<Message ID> or <Channel ID>-<Message ID> (automatically searches all guilds for the channel ID).
* USER - <@...> and <@!...>
* ID - Any number with 17-19 digits. Only used as a redirect to another subcommand type.
* NUMBER - Any valid number via the Number() function, except for NaN and Infinity (because those can really mess with the program).
* ANY - Generic argument case.
* NONE - No subcommands exist.
*/
// RegEx patterns used for identifying/extracting each type from a string argument.
// The reason why \d{17,} is used is because the max safe number for JS numbers is 16 characters when stringified (decimal). Beyond that are IDs.
const patterns = {
channel: /^<#(\d{17,})>$/,
role: /^<@&(\d{17,})>$/,
emote: /^<a?:.*?:(\d{17,})>$/,
// The message type won't include <username>#<tag>. At that point, you may as well just use a search usernames function. Even then, tags would only be taken into account to differentiate different users with identical usernames.
messageLink: /^https?:\/\/(?:ptb\.|canary\.)?discord(?:app)?\.com\/channels\/(?:\d{17,}|@me)\/(\d{17,})\/(\d{17,})$/,
messagePair: /^(\d{17,})-(\d{17,})$/,
user: /^<@!?(\d{17,})>$/,
id: /^(\d{17,})$/
};
// Maybe add a guild redirect... somehow?
type ID = "channel" | "role" | "emote" | "message" | "user" | "guild";
// Callbacks don't work with discriminated unions:
// - https://github.com/microsoft/TypeScript/issues/41759
// - https://github.com/microsoft/TypeScript/issues/35769
// Therefore, there won't by any type narrowing on channel or guild of CommandMenu until this is fixed.
// Otherwise, you'd have to define channelType for every single subcommand, which would get very tedious.
// Just use type assertions when you specify a channel type.
export enum CHANNEL_TYPE {
ANY,
GUILD,
DM
}
interface CommandMenu {
readonly args: any[];
readonly client: Client;
readonly message: Message;
readonly channel: TextChannel | DMChannel | NewsChannel;
readonly guild: Guild | null;
readonly author: User;
// According to the documentation, a message can be part of a guild while also not having a
// member object for the author. This will happen if the author of a message left the guild.
readonly member: GuildMember | null;
readonly send: SendFunction;
}
interface CommandOptionsBase {
readonly description?: string;
readonly usage?: string;
readonly permission?: number;
readonly nsfw?: boolean;
readonly channelType?: CHANNEL_TYPE;
}
// Also, contrary to what you might think, channel pings do still work in DM channels.
// Role pings, maybe not, but it's not a big deal.
interface CommandOptions extends CommandOptionsBase {
readonly run?: (($: CommandMenu) => Promise<any>) | string;
readonly subcommands?: {[key: string]: NamedCommand};
readonly channel?: Command;
readonly role?: Command;
readonly emote?: Command;
readonly message?: Command;
readonly user?: Command;
readonly guild?: Command; // Only available if an ID is set to reroute to it.
readonly id?: ID;
readonly number?: Command;
readonly any?: Command | RestCommand;
}
interface NamedCommandOptions extends CommandOptions {
readonly aliases?: string[];
readonly nameOverride?: string;
}
interface RestCommandOptions extends CommandOptionsBase {
readonly run?: (($: CommandMenu & {readonly combined: string}) => Promise<any>) | string;
}
interface ExecuteCommandMetadata {
readonly header: string;
readonly args: string[];
permission: number;
nsfw: boolean;
channelType: CHANNEL_TYPE;
symbolicArgs: string[]; // i.e. <channel> instead of <#...>
}
export interface CommandInfo {
readonly type: "info";
readonly command: BaseCommand;
readonly subcommandInfo: Collection<string, BaseCommand>;
readonly keyedSubcommandInfo: Collection<string, BaseCommand>;
readonly permission: number;
readonly nsfw: boolean;
readonly channelType: CHANNEL_TYPE;
readonly args: string[];
readonly header: string;
}
interface CommandInfoError {
readonly type: "error";
readonly message: string;
}
interface CommandInfoMetadata {
permission: number;
nsfw: boolean;
channelType: CHANNEL_TYPE;
args: string[];
usage: string;
readonly originalArgs: string[];
readonly header: string;
}
// An isolated command of just the metadata.
abstract class BaseCommand {
public readonly description: string;
public readonly usage: string;
public readonly permission: number; // -1 (default) indicates to inherit, 0 is the lowest rank, 1 is second lowest rank, and so on.
public readonly nsfw: boolean | null; // null (default) indicates to inherit
public readonly channelType: CHANNEL_TYPE | null; // null (default) indicates to inherit
constructor(options?: CommandOptionsBase) {
this.description = options?.description || "No description.";
this.usage = options?.usage ?? "";
this.permission = options?.permission ?? -1;
this.nsfw = options?.nsfw ?? null;
this.channelType = options?.channelType ?? null;
}
}
// Each Command instance represents a block that links other Command instances under it.
export class Command extends BaseCommand {
// The execute and subcommand properties are restricted to the class because subcommand recursion could easily break when manually handled.
// The class will handle checking for null fields.
private run: (($: CommandMenu) => Promise<any>) | string;
private readonly subcommands: Collection<string, NamedCommand>; // This is the final data structure you'll actually use to work with the commands the aliases point to.
private channel: Command | null;
private role: Command | null;
private emote: Command | null;
private message: Command | null;
private user: Command | null;
private guild: Command | null;
private id: Command | null;
private idType: ID | null;
private number: Command | null;
private any: Command | RestCommand | null;
constructor(options?: CommandOptions) {
super(options);
this.run = options?.run || "No action was set on this command!";
this.subcommands = new Collection(); // Populate this collection after setting subcommands.
this.channel = options?.channel || null;
this.role = options?.role || null;
this.emote = options?.emote || null;
this.message = options?.message || null;
this.user = options?.user || null;
this.guild = options?.guild || null;
this.id = null;
this.idType = options?.id || null;
this.number = options?.number || null;
this.any = options?.any || null;
if (options)
switch (options.id) {
case "channel":
this.id = this.channel;
break;
case "role":
this.id = this.role;
break;
case "emote":
this.id = this.emote;
break;
case "message":
this.id = this.message;
break;
case "user":
this.id = this.user;
break;
case "guild":
this.id = this.guild;
break;
case undefined:
break;
default:
requireAllCasesHandledFor(options.id);
}
if (options?.subcommands) {
const baseSubcommands = Object.keys(options.subcommands);
// Loop once to set the base subcommands.
for (const name in options.subcommands) this.subcommands.set(name, options.subcommands[name]);
// Then loop again to make aliases point to the base subcommands and warn if something's not right.
// This shouldn't be a problem because I'm hoping that JS stores these as references that point to the same object.
for (const name in options.subcommands) {
const subcmd = options.subcommands[name];
subcmd.name = name;
const aliases = subcmd.aliases;
for (const alias of aliases) {
if (baseSubcommands.includes(alias))
console.warn(
`"${alias}" in subcommand "${name}" was attempted to be declared as an alias but it already exists in the base commands! (Look at the next "Loading Command" line to see which command is affected.)`
);
else if (this.subcommands.has(alias))
console.warn(
`Duplicate alias "${alias}" at subcommand "${name}"! (Look at the next "Loading Command" line to see which command is affected.)`
);
else this.subcommands.set(alias, subcmd);
}
}
}
}
// Go through the arguments provided and find the right subcommand, then execute with the given arguments.
// Will return null if it successfully executes, string if there's an error (to let the user know what it is).
//
// Calls the resulting subcommand's execute method in order to make more modular code, basically pushing the chain of execution to the subcommand.
// For example, a numeric subcommand would accept args of [4] then execute on it.
//
// Because each Command instance is isolated from others, it becomes practically impossible to predict the total amount of subcommands when isolating the code to handle each individual layer of recursion.
// Therefore, if a Command is declared as a rest type, any typed args that come at the end must be handled manually.
public async execute(args: string[], menu: CommandMenu, metadata: ExecuteCommandMetadata): Promise<string | null> {
// Update inherited properties if the current command specifies a property.
// In case there are no initial arguments, these should go first so that it can register.
if (this.permission !== -1) metadata.permission = this.permission;
if (this.nsfw !== null) metadata.nsfw = this.nsfw;
if (this.channelType !== null) metadata.channelType = this.channelType;
// Take off the leftmost argument from the list.
const param = args.shift();
// If there are no arguments left, execute the current command. Otherwise, continue on.
if (param === undefined) {
const error = canExecute(menu, metadata);
if (error) return error;
if (typeof this.run === "string") {
// Although I *could* add an option in the launcher to attach arbitrary variables to this var string...
// I'll just leave it like this, because instead of using var strings for user stuff, you could just make "run" a template string.
await menu.send(
parseVars(
this.run,
{
author: menu.author.toString(),
prefix: getPrefix(menu.guild),
command: `${metadata.header} ${metadata.symbolicArgs.join(", ")}`
},
"???"
)
);
} else {
// Then capture any potential errors.
try {
await this.run(menu);
} catch (error) {
const errorMessage = error.stack ?? error;
console.error(`Command Error: ${metadata.header} (${metadata.args.join(", ")})\n${errorMessage}`);
return `There was an error while trying to execute that command!\`\`\`${errorMessage}\`\`\``;
}
}
return null;
}
// Resolve the value of the current command's argument (adding it to the resolved args),
// then pass the thread of execution to whichever subcommand is valid (if any).
const isMessageLink = patterns.messageLink.test(param);
const isMessagePair = patterns.messagePair.test(param);
if (this.subcommands.has(param)) {
metadata.symbolicArgs.push(param);
return this.subcommands.get(param)!.execute(args, menu, metadata);
} else if (this.channel && patterns.channel.test(param)) {
const id = patterns.channel.exec(param)![1];
const channel = await getChannelByID(id);
if (typeof channel !== "string") {
if (channel instanceof TextChannel || channel instanceof DMChannel) {
metadata.symbolicArgs.push("<channel>");
menu.args.push(channel);
return this.channel.execute(args, menu, metadata);
} else {
return `\`${id}\` is not a valid text channel!`;
}
} else {
return channel;
}
} else if (this.role && patterns.role.test(param)) {
const id = patterns.role.exec(param)![1];
if (!menu.guild) {
return "You can't use role parameters in DM channels!";
}
const role = menu.guild.roles.cache.get(id);
if (role) {
metadata.symbolicArgs.push("<role>");
menu.args.push(role);
return this.role.execute(args, menu, metadata);
} else {
return `\`${id}\` is not a valid role in this server!`;
}
} else if (this.emote && patterns.emote.test(param)) {
const id = patterns.emote.exec(param)![1];
const emote = menu.client.emojis.cache.get(id);
if (emote) {
metadata.symbolicArgs.push("<emote>");
menu.args.push(emote);
return this.emote.execute(args, menu, metadata);
} else {
return `\`${id}\` isn't a valid emote!`;
}
} else if (this.message && (isMessageLink || isMessagePair)) {
let channelID = "";
let messageID = "";
if (isMessageLink) {
const result = patterns.messageLink.exec(param)!;
channelID = result[1];
messageID = result[2];
} else if (isMessagePair) {
const result = patterns.messagePair.exec(param)!;
channelID = result[1];
messageID = result[2];
}
const message = await getMessageByID(channelID, messageID);
if (typeof message !== "string") {
metadata.symbolicArgs.push("<message>");
menu.args.push(message);
return this.message.execute(args, menu, metadata);
} else {
return message;
}
} else if (this.user && patterns.user.test(param)) {
const id = patterns.user.exec(param)![1];
const user = await getUserByID(id);
if (typeof user !== "string") {
metadata.symbolicArgs.push("<user>");
menu.args.push(user);
return this.user.execute(args, menu, metadata);
} else {
return user;
}
} else if (this.id && this.idType && patterns.id.test(param)) {
metadata.symbolicArgs.push("<id>");
const id = patterns.id.exec(param)![1];
// Probably modularize the findXByY code in general in libd.
// Because this part is pretty much a whole bunch of copy pastes.
switch (this.idType) {
case "channel":
const channel = await getChannelByID(id);
if (typeof channel !== "string") {
if (channel instanceof TextChannel || channel instanceof DMChannel) {
metadata.symbolicArgs.push("<channel>");
menu.args.push(channel);
return this.id.execute(args, menu, metadata);
} else {
return `\`${id}\` is not a valid text channel!`;
}
} else {
return channel;
}
case "role":
if (!menu.guild) {
return "You can't use role parameters in DM channels!";
}
const role = menu.guild.roles.cache.get(id);
if (role) {
menu.args.push(role);
return this.id.execute(args, menu, metadata);
} else {
return `\`${id}\` isn't a valid role in this server!`;
}
case "emote":
const emote = menu.client.emojis.cache.get(id);
if (emote) {
menu.args.push(emote);
return this.id.execute(args, menu, metadata);
} else {
return `\`${id}\` isn't a valid emote!`;
}
case "message":
const message = await getMessageByID(menu.channel, id);
if (typeof message !== "string") {
menu.args.push(message);
return this.id.execute(args, menu, metadata);
} else {
return message;
}
case "user":
const user = await getUserByID(id);
if (typeof user !== "string") {
menu.args.push(user);
return this.id.execute(args, menu, metadata);
} else {
return user;
}
case "guild":
const guild = getGuildByID(id);
if (typeof guild !== "string") {
menu.args.push(guild);
return this.id.execute(args, menu, metadata);
} else {
return guild;
}
default:
requireAllCasesHandledFor(this.idType);
}
} else if (this.number && !Number.isNaN(Number(param)) && param !== "Infinity" && param !== "-Infinity") {
metadata.symbolicArgs.push("<number>");
menu.args.push(Number(param));
return this.number.execute(args, menu, metadata);
} else if (this.any instanceof Command) {
metadata.symbolicArgs.push("<any>");
menu.args.push(param);
return this.any.execute(args, menu, metadata);
} else if (this.any instanceof RestCommand) {
metadata.symbolicArgs.push("<...>");
args.unshift(param);
menu.args.push(...args);
return this.any.execute(args.join(" "), menu, metadata);
} else {
metadata.symbolicArgs.push(`"${param}"`);
return `No valid command sequence matching \`${metadata.header} ${metadata.symbolicArgs.join(
" "
)}\` found.`;
}
// Note: Do NOT add a return statement here. In case one of the other sections is missing
// a return statement, there'll be a compile error to catch that.
}
// What this does is resolve the resulting subcommand as well as the inherited properties and the available subcommands.
public resolveInfo(args: string[], header: string): CommandInfo | CommandInfoError {
return this.resolveInfoInternal(args, {
permission: 0,
nsfw: false,
channelType: CHANNEL_TYPE.ANY,
header,
args: [],
usage: "",
originalArgs: [...args]
});
}
private resolveInfoInternal(args: string[], metadata: CommandInfoMetadata): CommandInfo | CommandInfoError {
// Update inherited properties if the current command specifies a property.
// In case there are no initial arguments, these should go first so that it can register.
if (this.permission !== -1) metadata.permission = this.permission;
if (this.nsfw !== null) metadata.nsfw = this.nsfw;
if (this.channelType !== null) metadata.channelType = this.channelType;
if (this.usage !== "") metadata.usage = this.usage;
// Take off the leftmost argument from the list.
const param = args.shift();
// If there are no arguments left, return the data or an error message.
if (param === undefined) {
const keyedSubcommandInfo = new Collection<string, BaseCommand>();
const subcommandInfo = new Collection<string, BaseCommand>();
// Get all the subcommands of the current command but without aliases.
for (const [tag, command] of this.subcommands.entries()) {
// Don't capture duplicates generated from aliases.
if (tag === command.name) {
keyedSubcommandInfo.set(tag, command);
}
}
// Then get all the generic subcommands.
if (this.channel) subcommandInfo.set("<channel>", this.channel);
if (this.role) subcommandInfo.set("<role>", this.role);
if (this.emote) subcommandInfo.set("<emote>", this.emote);
if (this.message) subcommandInfo.set("<message>", this.message);
if (this.user) subcommandInfo.set("<user>", this.user);
if (this.id) subcommandInfo.set(`<id = <${this.idType}>>`, this.id);
if (this.number) subcommandInfo.set("<number>", this.number);
// The special case for a possible rest command.
if (this.any) {
if (this.any instanceof Command) subcommandInfo.set("<any>", this.any);
else subcommandInfo.set("<...>", this.any);
}
return {
type: "info",
command: this,
keyedSubcommandInfo,
subcommandInfo,
...metadata
};
}
const invalidSubcommandGenerator: () => CommandInfoError = () => ({
type: "error",
message: `No subcommand found by the argument list: \`${metadata.originalArgs.join(" ")}\``
});
// Then test if anything fits any hardcoded values, otherwise check if it's a valid keyed subcommand.
if (param === "<channel>") {
if (this.channel) {
metadata.args.push("<channel>");
return this.channel.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<role>") {
if (this.role) {
metadata.args.push("<role>");
return this.role.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<emote>") {
if (this.emote) {
metadata.args.push("<emote>");
return this.emote.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<message>") {
if (this.message) {
metadata.args.push("<message>");
return this.message.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<user>") {
if (this.user) {
metadata.args.push("<user>");
return this.user.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<id>") {
if (this.id) {
metadata.args.push(`<id = <${this.idType}>>`);
return this.id.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<number>") {
if (this.number) {
metadata.args.push("<number>");
return this.number.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<any>") {
if (this.any instanceof Command) {
metadata.args.push("<any>");
return this.any.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (param === "<...>") {
if (this.any instanceof RestCommand) {
metadata.args.push("<...>");
return this.any.resolveInfoFinale(metadata);
} else {
return invalidSubcommandGenerator();
}
} else if (this.subcommands?.has(param)) {
metadata.args.push(param);
return this.subcommands.get(param)!.resolveInfoInternal(args, metadata);
} else {
return invalidSubcommandGenerator();
}
}
}
export class NamedCommand extends Command {
public readonly aliases: string[]; // This is to keep the array intact for parent Command instances to use. It'll also be used when loading top-level aliases.
private originalCommandName: string | null; // If the command is an alias, what's the original name?
constructor(options?: NamedCommandOptions) {
super(options);
this.aliases = options?.aliases || [];
// The name override exists in case a user wants to bypass filename restrictions.
this.originalCommandName = options?.nameOverride ?? null;
}
public get name(): string {
if (this.originalCommandName === null) throw new Error("originalCommandName must be set before accessing it!");
else return this.originalCommandName;
}
public set name(value: string) {
if (this.originalCommandName !== null)
throw new Error(`originalCommandName cannot be set twice! Attempted to set the value to "${value}".`);
else this.originalCommandName = value;
}
public isNameSet(): boolean {
return this.originalCommandName !== null;
}
}
// RestCommand is a declarative version of the common "any: args.join(' ')" pattern, basically the Command version of a rest parameter.
// This way, you avoid having extra subcommands when using this pattern.
// I'm probably not going to add a transformer function (a callback to automatically handle stuff like searching for usernames).
// I don't think the effort to figure this part out via generics or something is worth it.
export class RestCommand extends BaseCommand {
private run: (($: CommandMenu & {readonly combined: string}) => Promise<any>) | string;
constructor(options?: RestCommandOptions) {
super(options);
this.run = options?.run || "No action was set on this command!";
}
public async execute(
combined: string,
menu: CommandMenu,
metadata: ExecuteCommandMetadata
): Promise<string | null> {
// Update inherited properties if the current command specifies a property.
// In case there are no initial arguments, these should go first so that it can register.
if (this.permission !== -1) metadata.permission = this.permission;
if (this.nsfw !== null) metadata.nsfw = this.nsfw;
if (this.channelType !== null) metadata.channelType = this.channelType;
const error = canExecute(menu, metadata);
if (error) return error;
if (typeof this.run === "string") {
// Although I *could* add an option in the launcher to attach arbitrary variables to this var string...
// I'll just leave it like this, because instead of using var strings for user stuff, you could just make "run" a template string.
await menu.send(
parseVars(
this.run,
{
author: menu.author.toString(),
prefix: getPrefix(menu.guild),
command: `${metadata.header} ${metadata.symbolicArgs.join(", ")}`
},
"???"
)
);
} else {
// Then capture any potential errors.
try {
// Args will still be kept intact. A common pattern is popping some parameters off the end then doing some branching.
// That way, you can still declaratively mark an argument list as continuing while also handling the individual args.
await this.run({...menu, args: menu.args, combined});
} catch (error) {
const errorMessage = error.stack ?? error;
console.error(`Command Error: ${metadata.header} (${metadata.args.join(", ")})\n${errorMessage}`);
return `There was an error while trying to execute that command!\`\`\`${errorMessage}\`\`\``;
}
}
return null;
}
public resolveInfoFinale(metadata: CommandInfoMetadata): CommandInfo {
if (this.permission !== -1) metadata.permission = this.permission;
if (this.nsfw !== null) metadata.nsfw = this.nsfw;
if (this.channelType !== null) metadata.channelType = this.channelType;
if (this.usage !== "") metadata.usage = this.usage;
return {
type: "info",
command: this,
keyedSubcommandInfo: new Collection<string, BaseCommand>(),
subcommandInfo: new Collection<string, BaseCommand>(),
...metadata
};
}
}
// See if there is anything that'll prevent the user from executing the command.
// Returns null if successful, otherwise returns a message with the error.
function canExecute(menu: CommandMenu, metadata: ExecuteCommandMetadata): string | null {
// 1. Does this command specify a required channel type? If so, does the channel type match?
if (
metadata.channelType === CHANNEL_TYPE.GUILD &&
(!(menu.channel instanceof GuildChannel) || menu.guild === null || menu.member === null)
) {
return "This command must be executed in a server.";
} else if (
metadata.channelType === CHANNEL_TYPE.DM &&
(menu.channel.type !== "dm" || menu.guild !== null || menu.member !== null)
) {
return "This command must be executed as a direct message.";
}
// 2. Is this an NSFW command where the channel prevents such use? (DM channels bypass this requirement.)
if (metadata.nsfw && menu.channel.type !== "dm" && !menu.channel.nsfw) {
return "This command must be executed in either an NSFW channel or as a direct message.";
}
// 3. Does the user have permission to execute the command?
if (!hasPermission(menu.author, menu.member, metadata.permission)) {
const userPermLevel = getPermissionLevel(menu.author, menu.member);
return `You don't have access to this command! Your permission level is \`${getPermissionName(
userPermLevel
)}\` (${userPermLevel}), but this command requires a permission level of \`${getPermissionName(
metadata.permission
)}\` (${metadata.permission}).`;
}
return null;
}