archived-handler/src/handler/plugins/plugin.ts

//
// Plugins can be inserted on all commands and are emitted
//
// 1.) on ready event, where all commands are loaded.
// 2.) on corresponding observable (command triggers)
//
// The goal of plugins is to organize commands and
// provide extensions to repetitive patterns
// examples include refreshing modules,
// categorizing commands, cooldowns, permissions, etc.
// Plugins are reminiscent of middleware in express.
//

import type { Awaitable, Client } from 'discord.js';
import type { Err, Ok, Result } from 'ts-results';
import type { Module, Override, Wrapper } from '../..';
import type { CommandType } from '../sern';
import type { BaseModule, ModuleDefs } from '../structures/module';


export interface Controller {
    next: () => Ok<void>;
    stop: () => Err<void>;
}

export enum PluginType {
    Command = 0b01,
    Event = 0b10,
}

type executeCmdPlugin = { execute: (wrapper: Wrapper, controller: Controller) => Result<void, void> };

interface BasePlugin extends Override<BaseModule, executeCmdPlugin> {
    type: PluginType;
}

export type CommandPlugin = {
    type: PluginType.Command;
} & Override<BasePlugin,
    {
        execute: (wrapper: Client, module: Module, controller: Controller) => Awaitable<Result<void, void>>;
    }>;

//TODO: rn adding the modType check a little hackish. Find better way to determine the
// module type of the event plugin
export type EventPlugin<T extends CommandType> = {
    type: PluginType.Event;
    modType: T;
} & Override<BasePlugin,
    {
        execute: (event: Parameters<ModuleDefs[T]['execute']>, controller: Controller) => Awaitable<Result<void, void>>;
    }>;

export function plugins(...plug: CommandPlugin[]): CommandPlugin[];
export function plugins<T extends CommandType>(...plug: EventPlugin<T>[]): EventPlugin<T>[];

export function plugins<T extends CommandType>(...plug: CommandPlugin[] | EventPlugin<T>[]) {
    return plug;
}

export function sernModule(mod: Module): Module {
    return mod;
}