feat: $switch function (#663)

src/functions/switch.js

@@ -0,0 +1,46 @@
+const PLACEHOLDER_PATTERN = /\{.*?\}/g
+
+/**
+ * @param {import("..").Data} d
+ */
+module.exports = async d => {
+    const data = d.util.aoiFunc(d)
+    const [value, caseString] = data.inside.splits
+
+    const cases = (caseString.match(PLACEHOLDER_PATTERN) ?? [])
+    .map((v) => {
+        const [type, value, awaitedName] = v.slice(1, -1).split(":")
+        return type === "case" ? { type, value, awaitedName } : { type, awaitedName: value }
+    })
+
+    if (cases.length < 1) {
+        return d.aoiError.fnError(d, "custom", {}, "You must provide cases to evaluate!")
+    }
+
+    const foundCase = cases.find((c) => c.type === "case" && c.value === value)
+    const defaultCase = cases.find((c) => c.type === "default")
+
+    if (foundCase) {
+        const awaitedCommand = d.client.cmd.awaited.find((cmd) => cmd.name.toLowerCase() === foundCase.awaitedName.toLowerCase())
+        if (!awaitedCommand) {
+            return d.aoiError.fnError(d, "custom", {}, `Invalid awaited command name "${foundCase.awaitedName}" provided.`)
+        }
+
+        const result = await d.interpreter(d.client, d.message, d.args, awaitedCommand, d.client.db, true, undefined, d.data)
+        data.result = result.code
+    }
+
+    if (!foundCase && defaultCase) {
+        const awaitedCommand = d.client.cmd.awaited.find((cmd) => cmd.name.toLowerCase() === defaultCase.awaitedName.toLowerCase())
+        if (!awaitedCommand) {
+            return d.aoiError.fnError(d, "custom", {}, `Invalid awaited command name "${defaultCase.awaitedName}" provided.`)
+        }
+
+        const result = await d.interpreter(d.client, d.message, d.args, awaitedCommand, d.client.db, true, undefined, d.data)
+        data.result = result.code
+    }
+
+    return {
+        code: d.util.setCode(data)
+    }
+}