From d0007db645c82c8799a23be9dad0c7ade4485b3d Mon Sep 17 00:00:00 2001
From: Matt Svoboda <matt.svoboda@gmail.com>
Date: Tue, 25 Jun 2024 12:12:17 -0700
Subject: [PATCH] Extend Shuffle mpv hook to support shuffle=yes from mpv
 options table

---
 iina/AppDelegate.swift |  4 ++--
 iina/PlayerCore.swift  | 49 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/iina/AppDelegate.swift b/iina/AppDelegate.swift
index 542977abf9..6a67a0d9ca 100644
--- a/iina/AppDelegate.swift
+++ b/iina/AppDelegate.swift
@@ -1165,9 +1165,9 @@ struct CommandLineStatus {
   func applyMPVArguments(to playerCore: PlayerCore) {
     Logger.log("Setting mpv properties from arguments: \(mpvArguments)")
     for argPair in mpvArguments {
-      if argPair.0 == "shuffle" && argPair.1 == "yes" {
+      if argPair.0 == MPVOption.PlaybackControl.shuffle && argPair.1 == "yes" {
         // Special handling for this one
-        Logger.log("Found \"shuffle\" request in command-line args. Adding mpv hook to shuffle playlist")
+        Logger.log("Found \"shuffle\" request in command-line args. Adding mpv hook for shuffling playlist")
         playerCore.addShufflePlaylistHook()
         continue
       }
diff --git a/iina/PlayerCore.swift b/iina/PlayerCore.swift
index b2b91feda5..cb2955fdb0 100644
--- a/iina/PlayerCore.swift
+++ b/iina/PlayerCore.swift
@@ -179,6 +179,7 @@ class PlayerCore: NSObject {
 
   /// For supporting mpv `--shuffle` arg, to shuffle playlist when launching from command line
   @Atomic private var shufflePending = false
+  private var isShuffleHookAlreadyAdded = false
 
   // test seeking
   var triedUsingExactSeekForCurrentFile: Bool = false
@@ -308,6 +309,21 @@ class PlayerCore: NSObject {
     guard !urls.isEmpty else { return 0 }
     let urls = Utility.resolveURLs(urls)
 
+    if Preference.bool(for: .enableAdvancedSettings) {
+      if let userOptions = Preference.value(for: .userOptions) as? [[String]] {
+        for op in userOptions {
+          if op.count == 2, op[0] == MPVOption.PlaybackControl.shuffle && op[1] == "yes" {
+            log("Found shuffle option in user's mpv options. Will add hook for it if not already added", level: .verbose)
+            addShufflePlaylistHook()
+            break
+          }
+        }
+      } else {
+        // If userOptions failed to parse, an error msg will be displayed to the user later
+        log("Failed to read mpv options; skipping check for shuffle option", level: .verbose)
+      }
+    }
+
     // Handle folder URL (to support mpv shuffle, etc), BD folders and m3u / m3u8 files first.
     // For these cases, mpv will load/build the playlist and notify IINA when it can be retrieved.
     if urls.count == 1 {
@@ -1639,17 +1655,36 @@ class PlayerCore: NSObject {
     return GeometryDef.parse(geometry)
   }
 
-  /// Uses an mpv `on_before_start_file` hook to honor mpv's `shuffle` command via IINA CLI.
+  /// Adds an mpv `on_before_start_file` hook (if not already added) to honor mpv's `shuffle` option.
+  ///
+  /// This hook is needed to maintain support for the mpv `shuffle` option while also enabling IINA to filter any opened
+  /// files/directories for playable files, which mpv does not support (see the `openURLs` method).
   ///
   /// There is currently no way to remove an mpv hook once it has been added, so to minimize potential impact and/or side effects
   /// when not in use:
-  /// 1. Only add the mpv hook if `--mpv-shuffle` (or equivalent) is specified. Because this decision only happens at launch,
-  /// there is no risk of adding the hook more than once per player.
-  /// 2. Use `shufflePending` to decide if it needs to run again. Set to `false` after use, and check its value as early as possible.
+  /// 1. Only add the mpv hook if `--mpv-shuffle` (or equivalent) is specified via the IINA CLI or via the user's mpv options (in Advanced prefs).
+  /// 2. Use `isShuffleHookAlreadyAdded` to keep track of whether the hook was already added. It should be added at most once per mpv core.
+  /// 3. Use `shufflePending` to decide if the playlist needs to be shuffled. The hook will run each time an item in the playlist is about to start,
+  /// but we only want to do the shuffle before the start of the first file. So we will only shuffle if `shufflePending` is true, then set
+  /// `shufflePending` to `false` after shuffling.
   func addShufflePlaylistHook() {
-    $shufflePending.withLock{ $0 = true }
+    var mustAddHook = true
+    $shufflePending.withLock{ shufflePending in
+      shufflePending = true
+
+      guard !isShuffleHookAlreadyAdded else {
+        mustAddHook = false
+        return
+      }
+      isShuffleHookAlreadyAdded = true
+    }
+
+    guard mustAddHook else {
+      Logger.log("Will reuse existing on_before_start_file hook for playlist shuffle", level: .verbose)
+      return
+    }
 
-    func callback(next: @escaping () -> Void) {
+    func shuffleCallback(next: @escaping () -> Void) {
       var mustShuffle = false
       $shufflePending.withLock{ shufflePending in
         if shufflePending {
@@ -1673,7 +1708,7 @@ class PlayerCore: NSObject {
       }
     }
 
-    mpv.addHook(MPVHook.onBeforeStartFile, hook: MPVHookValue(withBlock: callback))
+    mpv.addHook(MPVHook.onBeforeStartFile, hook: MPVHookValue(withBlock: shuffleCallback))
   }
 
   // MARK: - Listeners