feat: implement command to convert currencies (#98)

apps/barry/src/modules/general/commands/chatinput/convert/currency/index.ts

@@ -0,0 +1,244 @@
+import { type APIApplicationCommandOptionChoice, MessageFlags } from "@discordjs/core";
+import { type ApplicationCommandInteraction, SlashCommand, SlashCommandOptionBuilder } from "@barry/core";
+import type GeneralModule from "../../../../index.js";
+
+import { fetch } from "undici";
+import config from "../../../../../../config.js";
+
+/**
+ * Represents the options for the "/convert currency" command.
+ */
+export interface CurrencyOptions {
+    /**
+     * The amount to convert.
+     */
+    amount: number;
+
+    /**
+     * The currency to convert from.
+     */
+    from: string;
+
+    /**
+     * The currency to convert to.
+     */
+    to: string;
+}
+
+/**
+ * Represents the result of the API request.
+ */
+export interface CurrencyResult {
+    /**
+     * The amount that was converted.
+     */
+    amount: number;
+
+    /**
+     * The currency that was converted from.
+     */
+    base: string;
+
+    /**
+     * The date the data was last updated.
+     */
+    date: string;
+
+    /**
+     * The rates for each currency.
+     */
+    rates: Record<string, number>;
+}
+
+/**
+ * Represents the names of each currency.
+ */
+const currencyNames: Record<string, string> = {
+    "AUD": "Australian Dollar",
+    "BGN": "Bulgarian Lev",
+    "BRL": "Brazilian Real",
+    "CAD": "Canadian Dollar",
+    "CHF": "Swiss Franc",
+    "CNY": "Chinese Renminbi Yuan",
+    "CZK": "Czech Koruna",
+    "DKK": "Danish Krone",
+    "EUR": "Euro",
+    "GBP": "British Pound",
+    "HKD": "Hong Kong Dollar",
+    "HUF": "Hungarian Forint",
+    "IDR": "Indonesian Rupiah",
+    "ILS": "Israeli New Sheqel",
+    "INR": "Indian Rupee",
+    "ISK": "Icelandic Króna",
+    "JPY": "Japanese Yen",
+    "KRW": "South Korean Won",
+    "MXN": "Mexican Peso",
+    "MYR": "Malaysian Ringgit",
+    "NOK": "Norwegian Krone",
+    "NZD": "New Zealand Dollar",
+    "PHP": "Philippine Peso",
+    "PLN": "Polish Złoty",
+    "RON": "Romanian Leu",
+    "SEK": "Swedish Krona",
+    "SGD": "Singapore Dollar",
+    "THB": "Thai Baht",
+    "TRY": "Turkish Lira",
+    "USD": "United States Dollar",
+    "ZAR": "South African Rand"
+};
+
+/**
+ * Represents the aliases of each currency.
+ */
+const currencyAliases: Record<string, string[]> = {
+    "AUD": ["A$", "AU$", "AUS$", "AUS $"],
+    "BGN": ["ЛВ"],
+    "BRL": ["R$"],
+    "CAD": ["C$", "CA$", "CAN$", "CAN $"],
+    "CHF": ["FR", "SFR", "CHF"],
+    "CNY": ["¥", "CN¥", "CN ¥"],
+    "CZK": ["KČ"],
+    "DKK": ["KR"],
+    "EUR": ["€"],
+    "GBP": ["£"],
+    "HKD": ["HK$", "HKD"],
+    "HUF": ["FT"],
+    "IDR": ["RP"],
+    "ILS": ["₪"],
+    "INR": ["₹"],
+    "ISK": ["KR"],
+    "JPY": ["¥", "JP¥", "JP ¥", "YEN", "圓", "円"],
+    "KRW": ["₩"],
+    "MXN": ["MEX$", "MEX $"],
+    "MYR": ["RM"],
+    "NOK": ["KR"],
+    "NZD": ["NZ$", "NZD"],
+    "PHP": ["₱"],
+    "PLN": ["ZŁ"],
+    "RON": ["LEI"],
+    "SEK": ["KR"],
+    "SGD": ["S$", "SGD"],
+    "THB": ["฿"],
+    "TRY": ["₺"],
+    "USD": ["$", "US$", "US $"],
+    "ZAR": ["R"]
+};
+
+/**
+ * Represents a slash command for converting currency.
+ */
+export default class extends SlashCommand<GeneralModule> {
+    /**
+     * Represents a slash command for converting currency.
+     *
+     * @param module The module this command belongs to.
+     */
+    constructor(module: GeneralModule) {
+        super(module, {
+            name: "currency",
+            description: "Converts currency from one to another.",
+            options: {
+                amount: SlashCommandOptionBuilder.number({
+                    description: "The amount to convert.",
+                    minimum: 0,
+                    required: true
+                }),
+                from: SlashCommandOptionBuilder.string({
+                    description: "The currency to convert from.",
+                    required: true,
+                    autocomplete: (value) => this.predictCurrency(value)
+                }),
+                to: SlashCommandOptionBuilder.string({
+                    description: "The currency to convert to.",
+                    required: true,
+                    autocomplete: (value) => this.predictCurrency(value)
+                })
+            }
+        });
+    }
+
+    /**
+     * Sends a message with the result of the conversion.
+     *
+     * @param interaction The interaction that triggered this command.
+     * @param options The options for this command.
+     */
+    async execute(interaction: ApplicationCommandInteraction, options: CurrencyOptions): Promise<void> {
+        if (!this.isValidCurrency(options.from)) {
+            return interaction.createMessage({
+                content: `${config.emotes.error} \`${options.from}\` is not a valid currency.`,
+                flags: MessageFlags.Ephemeral
+            });
+        }
+
+        if (!this.isValidCurrency(options.to)) {
+            return interaction.createMessage({
+                content: `${config.emotes.error} \`${options.to}\` is not a valid currency.`,
+                flags: MessageFlags.Ephemeral
+            });
+        }
+
+        if (options.from === options.to) {
+            return interaction.createMessage({
+                content: `${config.emotes.error} You can't convert from and to the same currency.`,
+                flags: MessageFlags.Ephemeral
+            });
+        }
+
+        const rate = await this.fetchRate(options.amount, options.from, options.to);
+        await interaction.createMessage({
+            content: `${config.emotes.add} \`${options.amount} ${options.from}\` is \`${rate} ${options.to}\`.`
+        });
+    }
+
+    /**
+     * Fetches the rate for the given currency.
+     *
+     * @param amount The amount to convert.
+     * @param from The currency to convert from.
+     * @param to The currency to convert to.
+     * @returns The rate for the given currency.
+     */
+    async fetchRate(amount: number, from: string, to: string): Promise<number> {
+        const url = new URL("https://api.frankfurter.app/latest");
+        url.searchParams.append("amount", amount.toString());
+        url.searchParams.append("from", from);
+        url.searchParams.append("to", to);
+
+        return fetch(url, { method: "GET" })
+            .then((response) => response.json() as Promise<CurrencyResult>)
+            .then((data) => data.rates[to]);
+    }
+
+    /**
+     * Checks if the given currency is valid.
+     *
+     * @param currency The currency to check.
+     * @returns Whether the given currency is valid.
+     */
+    isValidCurrency(currency: string): boolean {
+        return currency.toUpperCase() in currencyNames;
+    }
+
+    /**
+     * Predicts the currency from the given value.
+     *
+     * @param currency The currency to predict.
+     * @returns The predicted currency.
+     */
+    predictCurrency(currency: string): Array<APIApplicationCommandOptionChoice<string>> {
+        const cleaned = currency.toUpperCase().replace(".", "");
+        if (cleaned in currencyNames) {
+            return [{ name: currencyNames[cleaned], value: cleaned }];
+        }
+
+        const result = [];
+        for (const [key, aliases] of Object.entries(currencyAliases)) {
+            if (aliases.some((a) => a.includes(cleaned)) || currencyNames[key].toUpperCase().includes(cleaned)) {
+                result.push({ name: currencyNames[key], value: key });
+            }
+        }
+
+        return result.slice(0, 25);
+    }
+}

apps/barry/src/modules/general/commands/chatinput/convert/index.ts

@@ -0,0 +1,29 @@
+import type GeneralModule from "../../../index.js";
+
+import { SlashCommand } from "@barry/core";
+import ConvertCurrencyCommand from "./currency/index.js";
+
+/**
+ * Represents a slash command for converting one unit to another.
+ */
+export default class extends SlashCommand<GeneralModule> {
+    /**
+     * Represents a slash command for converting one unit to another.
+     *
+     * @param module The module this command belongs to.
+     */
+    constructor(module: GeneralModule) {
+        super(module, {
+            name: "convert",
+            description: "Converts one unit to another.",
+            children: [ConvertCurrencyCommand]
+        });
+    }
+
+    /**
+     * Executes the '/convert' command. Will throw an error if executed.
+     */
+    execute(): Promise<void> {
+        throw new Error("Parent commands cannot be executed.");
+    }
+}