refract: file structure

server/classes/Timer.js

@@ -0,0 +1,120 @@
+class Timer {
+  _current = null;
+  _finishAt = null;
+  _startedAt = null;
+  _pausedAt = null;
+  _pausedInterval = null;
+  _pausedTotal = null;
+  state = 'pause';
+
+  constructor() {}
+
+  // call setup separately
+  setupWithSeconds(seconds, autoStart = false) {
+    // aux
+    const now = new Date().getTime();
+
+    // populate targets
+    this._finishAt = now + seconds * 1000;
+
+    // start counting
+    this._startedAt = now;
+
+    if (autoStart) {
+      this.state = 'start';
+    } else {
+      this._pausedAt = now;
+      this._pausedInterval = 0;
+    }
+    this._pausedTotal = 0;
+    this.update();
+  }
+
+  // update()
+  update() {
+    // get current time
+    const now = new Date().getTime();
+
+    // check playstate
+    switch (this.state) {
+      case 'start':
+        // update current timer
+        this._current = this._finishAt + this._pausedTotal - now;
+        break;
+      case 'pause':
+        // update paused time
+        this._pausedInterval = now - this._pausedAt;
+        break;
+      default:
+        console.error('Timer: no playstate on update call', this.state);
+        break;
+    }
+  }
+
+  // helpers
+  static toSeconds(millis) {
+    return Math.floor(Math.max(millis * 0.001), 0);
+  }
+
+  _getExpectedFinish() {
+    return this._finishAt + (this._pausedInterval + this._pausedTotal);
+  }
+
+  // getObject
+  getObject() {
+    this.update();
+    return {
+      currentSeconds: Timer.toSeconds(this._current),
+      expectedFinish: this._getExpectedFinish(),
+      startedAt: this._startedAt,
+    };
+  }
+
+  // current time in seconds
+  getCurrentInSeconds() {
+    // update timeStamp
+    this.update();
+    return Timer.toSeconds(this._current);
+  }
+
+  // playback
+  start() {
+    // do we need to change
+    if (this.state === 'start') return;
+
+    // update start time if needed
+    if (!this._startedAt) {
+      this._startedAt = new Date().getTime();
+    }
+
+    // check if there is paused time
+    if (this._pausedInterval) {
+      this._pausedTotal += this._pausedInterval;
+      this._pausedInterval = null;
+    }
+
+    // change state
+    this.state = 'start';
+  }
+  pause() {
+    // do we need to change
+    if (this.state === 'pause') return;
+
+    // update pause time
+    this._pausedAt = new Date().getTime();
+
+    // change state
+    this.state = 'pause';
+  }
+  stop() {
+    console.log('stop: not yet implemented');
+    return false;
+  }
+  roll() {
+    console.log('roll: not yet implemented');
+    return false;
+  }
+}
+
+
+module.exports = Timer;