util(duration): add screen duration util.

Author: narekhovhannisyan

src/util/screen-duration.js

@@ -0,0 +1,61 @@
+/**
+ * @param {Array} trims
+ * @returns {number}
+ * @description Get video trims duration.
+ */
+const _getVideoTrimsDuration = (trims) => {
+  return trims.reduce((acc, elem, index) => {
+    if (index % 2 === 0) {
+      return acc + (trims[index + 1] - elem)
+    }
+    return acc
+  }, 0)
+}
+
+/**
+ * @param {Array} areas
+ * @returns {number}
+ * @description Get screen areas duration.
+ */
+const _getScreenAreasDuration = (areas) => {
+  return areas.reduce((acc, area) => {
+    const videoCropParams = area && area.type === 'video' ? area.videoCropParams : null
+    if (!videoCropParams) return acc
+
+    if (videoCropParams.duration) {
+      return acc + _getVideoTrimsDuration(videoCropParams.trims)
+    }
+
+    return acc
+  }, 0)
+}
+
+/**
+ * @param {Object} screen
+ * @param {Array} screen.areas
+ * @returns {number}
+ * @description Get screen duration.
+ */
+const getScreenDuration = (screen) => {
+  const { characterBasedDuration, selectedDuration, extraVideoSecond, areas, duration } = screen
+
+  // If screen duration is adjustable and have selectedDuration, return selectedDuration
+  if (characterBasedDuration && selectedDuration) {
+    return selectedDuration
+  }
+
+  const extra = extraVideoSecond
+    ? parseInt(extraVideoSecond, 10) || 0
+    : 0
+
+  const videoArea = areas.find((area) => area.type === 'video')
+  const conditionScreenDuration = videoArea
+    ? 0
+    : parseInt(duration, 10) || 0
+
+  return (_getScreenAreasDuration(areas) + extra + conditionScreenDuration)
+}
+
+module.exports = {
+  getScreenDuration
+}