major revamp of http client functionalit

lib/utils/dtmf-collector.js

@@ -0,0 +1,42 @@
+class DtmfEntry {
+  constructor(key, time) {
+    this.key = key;
+    this.time = time;
+  }
+}
+
+/**
+ * @classdesc Represents an object that collects dtmf key entries and
+ * reports when a match is detected
+ */
+class DtmfCollector {
+  constructor({logger, patterns, interDigitTimeout}) {
+    this.logger = logger;
+    this.patterns = patterns;
+    this.idt = interDigitTimeout || 3000;
+    this.buffer = [];
+  }
+
+  keyPress(key) {
+    const now = Date.now();
+
+    // age out previous entries if interdigit timer has elapsed
+    const lastDtmf = this.buffer.pop();
+    if (lastDtmf) {
+      if (now - lastDtmf.time < this.idt) this.buffer.push(lastDtmf);
+      else {
+        this.buffer = [];
+      }
+    }
+    // add new entry
+    this.buffer.push(new DtmfEntry(key, now));
+
+    // check for a match
+    const collectedDigits = this.buffer
+      .map((entry) => entry.key)
+      .join('');
+    return this.patterns.find((pattern) => collectedDigits.endsWith(pattern));
+  }
+}
+
+module.exports = DtmfCollector;