From 9d4a2a8a598c500c0a221d82e0e5e983a3f3914b Mon Sep 17 00:00:00 2001
From: Harry Rose <harryrose@protonmail.com>
Date: Wed, 11 Mar 2026 17:22:23 +0000
Subject: [PATCH] Improve chapter generation code and extract it into its own
 function

---
 server/models/PodcastEpisode.js | 150 +++++++++++++++++---------------
 1 file changed, 81 insertions(+), 69 deletions(-)

diff --git a/server/models/PodcastEpisode.js b/server/models/PodcastEpisode.js
index 555c348ca..4b334d6ef 100644
--- a/server/models/PodcastEpisode.js
+++ b/server/models/PodcastEpisode.js
@@ -87,76 +87,12 @@ class PodcastEpisode extends Model {
     } else if (rssPodcastEpisode.chapters?.length) {
       podcastEpisode.chapters = rssPodcastEpisode.chapters.map((ch) => ({ ...ch }))
     } else {
-      const timeMarkerRegex = /\b(\d{1,2}):(\d{1,2})(?::(\d{1,2}))?\b/
-      const chapterTitleRegex = /\b\d{1,2}:\d{1,2}(?::\d{1,2})?\b(.+)$/
-
       Logger.debug("Podcast episode doesn't have chapters, attempting to generate them from timestamps", rssPodcastEpisode.title)
-
-      var errorMessage = null
-      var descriptionLines = podcastEpisode.description.split('</p>')
-      var chaptersToPush = []
-
-      for (let i = 0; i < descriptionLines.length; i++) {
-        let line = descriptionLines[i]
-        Logger.debug('Description Line:', line)
-
-        let match = timeMarkerRegex.exec(line)
-        if (match == null) continue
-
-        Logger.debug('Matches:', match)
-
-        let first = match[1]
-        let second = match[2]
-        let third = match[3]
-
-        let hours = 0
-        let minutes = 0
-        let seconds = 0
-
-        // If there's three components then we can assume its hh:mm:ss
-        if (first && second && third) {
-          hours = Number(first)
-          minutes = Number(second)
-          seconds = Number(third)
-        } else if (first && second) // otherwise assume mm:ss
-        {
-          minutes = Number(first)
-          seconds = Number(second)
-        } else {
-          // Unknown timestamp state
-          errorMessage = `Unknown timestamp format in description, line ${line}`
-          break
-        }
-
-        let startTime = seconds + minutes * 60 + hours * 60 * 60
-        let chapterTitleMatch = chapterTitleRegex.exec(line)
-        Logger.debug('Chapter Title Matches:', chapterTitleMatch)
-
-        if (chapterTitleMatch == null && chapterTitleMatch.length >= 2) {
-          // Unknown chapter state
-          errorMessage = `Unable to get chapter title from description, line ${line}`
-          break
-        }
-
-        let chapter = { title: chapterTitleMatch[1].trim(), id: i, start: startTime }
-
-        if (chaptersToPush.length > 0) {
-          chaptersToPush[chaptersToPush.length - 1].end = startTime
-        }
-
-        chaptersToPush.push(chapter)
-
-        Logger.debug('Added chapter', chapter)
-      }
-      if (errorMessage == null) {
-        if (chaptersToPush.length > 0) {
-          chaptersToPush[chaptersToPush.length - 1].end = podcastEpisode.audioFile.duration
-        }
-
-        podcastEpisode.chapters.push(...chaptersToPush)
-        Logger.debug(`Successfully gnerated ${podcastEpisode.chapters.length} chapters`)
-      } else {
-        Logger.error(`Unable generate chapters from podcast description, error '${errorMessage}`)
+      try {
+        let autoGeneratedChapters = PodcastEpisode.autoGenerateChaptersFromTimestamps(podcastEpisode.description, podcastEpisode.audioFile.duration)
+        podcastEpisode.chapters = autoGeneratedChapters
+      } catch (error) {
+        Logger.error(`[PodcastEpisode] createFromRssPodcastEpisode: Failed to auto generate chapters for "${podcastEpisode.title}"`, error)
       }
     }
 
@@ -309,6 +245,82 @@ class PodcastEpisode extends Model {
 
     return json
   }
+
+  /**
+   *
+   * @param {string} podcastDescription
+   * @param {number} audioDurationSecs
+   * @returns {ChapterObject[]}
+   */
+  static autoGenerateChaptersFromTimestamps(podcastDescription, audioDurationSecs) {
+    if (podcastDescription == null) {
+      throw new Error('Description must not be null')
+    }
+
+    if (audioDurationSecs == null) {
+      throw new Error('Audio duration must not be null')
+    }
+
+    const timestampRegex = /\b(\d{1,2}):(\d{1,2})(?::(\d{1,2}))?\b/
+    const chapterTitleRegex = /\b\d{1,2}:\d{1,2}(?::\d{1,2})?\b(?:\s+|\))(.+)$/
+    const descriptionLineSplitRegex = /\<\s*\/\s*p\s*\>|\<\s*br\s*\s*\/\>|\n/
+
+    var descriptionLines = podcastDescription.split(descriptionLineSplitRegex)
+    var newChapters = []
+
+    for (let i = 0; i < descriptionLines.length; i++) {
+      let line = descriptionLines[i]
+
+      let match = timestampRegex.exec(line)
+      if (match == null) continue
+
+      let first = match[1]
+      let second = match[2]
+      let third = match[3]
+
+      let hours = 0
+      let minutes = 0
+      let seconds = 0
+
+      // If there's three components then we can assume its hh:mm:ss
+      if (first && second && third) {
+        hours = Number(first)
+        minutes = Number(second)
+        seconds = Number(third)
+      } else if (first && second) // otherwise assume mm:ss
+      {
+        minutes = Number(first)
+        seconds = Number(second)
+      }
+
+      let startTime = seconds + minutes * 60 + hours * 60 * 60
+      let chapterTitleMatch = chapterTitleRegex.exec(line)
+
+      if (chapterTitleMatch == null || chapterTitleMatch.length < 2) {
+        // Unknown chapter state
+        throw new Error(`Unable to get chapter title from description, line ${line}`)
+      }
+
+      let chapter = { title: chapterTitleMatch[1].trim(), id: newChapters.length + 1, start: startTime }
+
+      if (newChapters.length > 0) {
+        newChapters[newChapters.length - 1].end = startTime
+      }
+
+      newChapters.push(chapter)
+    }
+    if (newChapters.length > 0) {
+      newChapters[newChapters.length - 1].end = audioDurationSecs
+    }
+
+    Logger.debug(`Successfully gnerated ${newChapters.length} chapters`)
+
+    if (newChapters.length == 1) {
+      throw new Error('Only one chapter found, treating as invalid description')
+    }
+
+    return newChapters
+  }
 }
 
 module.exports = PodcastEpisode