import {
    Client,
    CommandInteraction,
    Events,
    GatewayIntentBits,
    REST,
    Routes,
} from "discord.js";

import { buttonCommands, slashCommands } from "./commands.ts";

function requireEnv(key: string): string {
    let value = process.env[key];
    if (!value) {
        throw new Error(`Missing ${key} environment variable.`);
    }
    return value;
}

let token = requireEnv("DISCORD_TOKEN");
let clientId = requireEnv("DISCORD_CLIENT_ID");
let guildId = requireEnv("DISCORD_GUILD_ID");

let client = new Client({ intents: [GatewayIntentBits.Guilds] });

let rest = new REST({ version: "10" }).setToken(token);

async function registerSlashCommands() {
    await rest.put(Routes.applicationGuildCommands(clientId, guildId), {
        body: slashCommands.map(command => command.slashCommand.toJSON()),
    });
}

client.once(Events.ClientReady, (readyClient) => {
    console.log(`Logged in as ${readyClient.user.tag}`);
});

client.on(Events.InteractionCreate, async (interaction) => {
    try {
        if (interaction.isChatInputCommand()) {
            for (let command of slashCommands) {
                if (interaction.commandName === command.slashCommand.name) {
                    await command.handler(interaction);
                    break;
                }
            }
        } else if (interaction.isButton()) {
            for (let button of Object.values(buttonCommands)) {
                if (interaction.customId.startsWith(button.prefix)) {
                    let id = interaction.customId.slice(button.prefix.length);
                    await button.handler(interaction, id);
                    break;
                }
            }
        }
    } catch (error) {
        if (error === "done") return;
        if (interaction instanceof CommandInteraction) {
            console.error("Error while handling interaction", error);
            if (interaction.deferred || interaction.replied) {
                await interaction.followUp({
                    content: "Something went wrong! :(",
                    flags: "Ephemeral",
                });
            } else {
                await interaction.reply({
                    content: "Something went wrong! :(",
                    flags: "Ephemeral",
                });
            }
        }
    }
});

try {
    await registerSlashCommands();
    await client.login(token);
} catch (error) {
    console.error("Discord bot failed to start", error);
    process.exit(1);
}