Adjusted

2026-09-27 00:12:54 +08:00 · 2026-05-20 13:22:29 +08:00
parent 6907e9bb2d
commit 6a5145f553
26 changed files with 2615 additions and 221 deletions
@@ -0,0 +1,112 @@
+// utils/duration.util.js
+
+const AVG_WORDS_PER_MINUTE = 200;
+
+function stripHtml(html) {
+  // Simple regex strip — no extra dependency needed
+  return (html ?? "").replace(/<[^>]*>/g, " ").replace(/\s+/g, " ").trim();
+}
+
+/**
+ * Estimate seconds for a single lesson block
+ * Block shape: { type: 'text'|'image'|'video', content, word_count, video_duration_seconds }
+ */
+function estimateBlockDuration(block) {
+  const videoDuration = Number(block.video_duration_seconds) || 0;
+
+  // Derive word count from HTML content on the fly
+  const getWordCount = (html) => {
+    const text = stripHtml(html);
+    return text ? text.split(" ").filter(Boolean).length : 0;
+  };
+
+  const readingSecs = (html) =>
+    Math.ceil((getWordCount(html) / AVG_WORDS_PER_MINUTE) * 60);
+
+  switch (block.type) {
+    case "text":
+      return readingSecs(block.content?.body);
+
+    case "image":
+      return 60;
+
+    case "video":
+      return videoDuration;
+
+    case "text-image":
+    case "text_image":
+      return readingSecs(block.content?.body) + 60;
+
+    case "text-video":
+    case "text_video":
+      return readingSecs(block.content?.body) + videoDuration;
+
+    default:
+      return 0;
+  }
+}
+
+/**
+ * Recompute and persist duration_seconds up the chain:
+ * blocks → lesson → unit → course
+ */
+async function recomputeDurations(lessonId) {
+  const Lesson = require("../models/courses/lessons.mdl");
+  const Unit = require("../models/courses/units.mdl");
+  const { Course } = require("../models/courses/courses.mdl");
+  const LessonPage = require("../models/courses/lesson_page.mdl");
+
+  // 1. Lesson duration from blocks
+  const page = await LessonPage.findOne({ where: { lesson_id: lessonId } });
+  const lessonSecs = (page?.blocks ?? []).reduce(
+    (sum, block) => sum + estimateBlockDuration(block), 0
+  );
+
+  // Guard against NaN before DB write
+  const safeLessonSecs = isNaN(lessonSecs) ? 0 : lessonSecs;
+  await Lesson.update({ duration_seconds: safeLessonSecs }, { where: { lesson_id: lessonId } });
+
+  // 2. Unit duration — sum of its lessons
+  const lesson = await Lesson.findOne({ where: { lesson_id: lessonId } });
+  const [unitResult] = await Lesson.sequelize.query(`
+    SELECT COALESCE(SUM(duration_seconds), 0) AS total
+    FROM lessons
+    WHERE unit_id = :unitId AND "deletedAt" IS NULL
+  `, { replacements: { unitId: lesson.unit_id }, type: Lesson.sequelize.QueryTypes.SELECT });
+
+  await Unit.update(
+    { duration_seconds: unitResult.total },
+    { where: { unit_id: lesson.unit_id } }
+  );
+
+  // 3. Course duration — sum of its units
+  const unit = await Unit.findOne({ where: { unit_id: lesson.unit_id } });
+  const [courseResult] = await Lesson.sequelize.query(`
+    SELECT COALESCE(SUM(duration_seconds), 0) AS total
+    FROM units
+    WHERE course_id = :courseId AND "deletedAt" IS NULL
+  `, { replacements: { courseId: unit.course_id }, type: Lesson.sequelize.QueryTypes.SELECT });
+
+  await Course.update(
+    { duration_seconds: courseResult.total },
+    { where: { course_id: unit.course_id } }
+  );
+}
+
+/**
+ * Format seconds → human readable: "1 hr 10 mins", "45 mins", "30 secs"
+ */
+function formatDuration(seconds) {
+  if (!seconds) return "0 mins";
+  const h = Math.floor(seconds / 3600);
+  const m = Math.floor((seconds % 3600) / 60);
+  const s = seconds % 60;
+
+  const parts = [];
+  if (h) parts.push(`${h} hr`);
+  if (m) parts.push(`${m} min${m !== 1 ? "s" : ""}`);
+  if (!h && !m && s) parts.push(`${s} sec${s !== 1 ? "s" : ""}`);
+  return parts.join(" ");
+}
+
+module.exports = { estimateBlockDuration, recomputeDurations, formatDuration };