From b983a4336b45465c4d8df9f471edd185cbbbe12a Mon Sep 17 00:00:00 2001
From: Jackson Harper <jacksonh@gmail.com>
Date: Tue, 4 Oct 2022 16:35:28 +0800
Subject: [PATCH] Dont try to highlight beyond the last item despite speech
 marks offset data

---
 .../AudioPlayer/ScrollingStackModifier.swift  | 78 +++++++++++++++++++
 .../AudioSession/AudioController.swift        | 15 +++-
 2 files changed, 91 insertions(+), 2 deletions(-)
 create mode 100644 apple/OmnivoreKit/Sources/App/Views/AudioPlayer/ScrollingStackModifier.swift

diff --git a/apple/OmnivoreKit/Sources/App/Views/AudioPlayer/ScrollingStackModifier.swift b/apple/OmnivoreKit/Sources/App/Views/AudioPlayer/ScrollingStackModifier.swift
new file mode 100644
index 000000000..1bce64649
--- /dev/null
+++ b/apple/OmnivoreKit/Sources/App/Views/AudioPlayer/ScrollingStackModifier.swift
@@ -0,0 +1,78 @@
+//
+//  ScrollingStackModifier.swift
+//  ScrollView_Tests
+//
+//  Created by Jean-Marc Boullianne on 8/7/20.
+//
+import SwiftUI
+
+struct ScrollingHStackModifier: ViewModifier {
+    
+    @State private var scrollOffset: CGFloat
+    @State private var dragOffset: CGFloat
+    
+    var items: Int
+    var itemWidth: CGFloat
+    var itemSpacing: CGFloat
+    
+    init(items: Int, itemWidth: CGFloat, itemSpacing: CGFloat) {
+        self.items = items
+        self.itemWidth = itemWidth
+        self.itemSpacing = itemSpacing
+        
+        // Calculate Total Content Width
+        let contentWidth: CGFloat = CGFloat(items) * itemWidth + CGFloat(items - 1) * itemSpacing
+        let screenWidth = UIScreen.main.bounds.width
+        
+        // Set Initial Offset to first Item
+        let initialOffset = (contentWidth/2.0) - (screenWidth/2.0) + ((screenWidth - itemWidth) / 2.0)
+        
+        self._scrollOffset = State(initialValue: initialOffset)
+        self._dragOffset = State(initialValue: 0)
+    }
+    
+    func body(content: Content) -> some View {
+        content
+            .offset(x: scrollOffset + dragOffset, y: 0)
+            .gesture(DragGesture()
+                .onChanged({ event in
+                    dragOffset = event.translation.width
+                })
+                .onEnded({ event in
+                    // Scroll to where user dragged
+                    scrollOffset += event.translation.width
+                    dragOffset = 0
+                    
+                    // Now calculate which item to snap to
+                    let contentWidth: CGFloat = CGFloat(items) * itemWidth + CGFloat(items - 1) * itemSpacing
+                    let screenWidth = UIScreen.main.bounds.width
+                    
+                    // Center position of current offset
+                    let center = scrollOffset + (screenWidth / 2.0) + (contentWidth / 2.0)
+                    
+                    // Calculate which item we are closest to using the defined size
+                    var index = (center - (screenWidth / 2.0)) / (itemWidth + itemSpacing)
+                    
+                    // Should we stay at current index or are we closer to the next item...
+                    if index.remainder(dividingBy: 1) > 0.5 {
+                        index += 1
+                    } else {
+                        index = CGFloat(Int(index))
+                    }
+                    
+                    // Protect from scrolling out of bounds
+                    index = min(index, CGFloat(items) - 1)
+                    index = max(index, 0)
+                    
+                    // Set final offset (snapping to item)
+                    let newOffset = index * itemWidth + (index - 1) * itemSpacing - (contentWidth / 2.0) + (screenWidth / 2.0) - ((screenWidth - itemWidth) / 2.0) + itemSpacing
+                    
+                    // Animate snapping
+                    withAnimation {
+                        scrollOffset = newOffset
+                    }
+                    
+                })
+            )
+    }
+}
diff --git a/apple/OmnivoreKit/Sources/Services/AudioSession/AudioController.swift b/apple/OmnivoreKit/Sources/Services/AudioSession/AudioController.swift
index e2a10681e..75b82a078 100644
--- a/apple/OmnivoreKit/Sources/Services/AudioSession/AudioController.swift
+++ b/apple/OmnivoreKit/Sources/Services/AudioSession/AudioController.swift
@@ -198,6 +198,7 @@ public class AudioController: NSObject, ObservableObject, AVAudioPlayerDelegate
   @Published public var currentAudioIndex: Int = 0
   @Published public var readText: String = ""
   @Published public var unreadText: String = ""
+  @Published public var numberOfSpeechItems: Int = 0
 
   @Published public var itemAudioProperties: LinkedItemAudioProperties?
 
@@ -254,6 +255,8 @@ public class AudioController: NSObject, ObservableObject, AVAudioPlayerDelegate
     player?.removeAllItems()
 
     document = nil
+    numberOfSpeechItems = 0
+
     timer = nil
     player = nil
     observer = nil
@@ -476,7 +479,13 @@ public class AudioController: NSObject, ObservableObject, AVAudioPlayerDelegate
 
   public var textItems: [String]? {
     if let document = self.document {
-      return document.utterances.map(\.text)
+      return document.utterances.map { utterance in
+        if let regex = try? NSRegularExpression(pattern: "<[^>]*>", options: .caseInsensitive) {
+          let modString = regex.stringByReplacingMatches(in: utterance.text, options: [], range: NSRange(location: 0, length: utterance.text.count), withTemplate: "")
+          return modString
+        }
+        return ""
+      }
     }
     return nil
   }
@@ -503,7 +512,7 @@ public class AudioController: NSObject, ObservableObject, AVAudioPlayerDelegate
 
       let idx = item.speechItem.audioIdx
       let currentItem = textItems[idx]
-      let currentReadIndex = currentItem.index(currentItem.startIndex, offsetBy: currentItemOffset)
+      let currentReadIndex = currentItem.index(currentItem.startIndex, offsetBy: max(currentItemOffset, currentItem.count))
       let lastItem = String(currentItem[..<currentReadIndex])
       let lastItemAfter = String(currentItem[currentReadIndex...])
 
@@ -662,7 +671,9 @@ public class AudioController: NSObject, ObservableObject, AVAudioPlayerDelegate
     if let itemID = itemAudioProperties?.itemID {
       Task {
         let document = try? await downloadSpeechFile(itemID: itemID, priority: .high)
+
         DispatchQueue.main.async {
+          self.numberOfSpeechItems = document?.utterances.count ?? 0
           if let document = document {
             self.startStreamingAudio(itemID: itemID, document: document)
           } else {