From fd138f65caa5c67bd7811576da69f4ed3f29ba65 Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Thu, 17 Aug 2017 18:55:17 +0200
Subject: [PATCH] Add method to find available languages

---
 mediafileinfo.cpp | 35 ++++++++++++++++++++++++++++-------
 mediafileinfo.h   |  2 ++
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/mediafileinfo.cpp b/mediafileinfo.cpp
index 3aebae2..4ea26ee 100644
--- a/mediafileinfo.cpp
+++ b/mediafileinfo.cpp
@@ -810,7 +810,7 @@ bool MediaFileInfo::hasTracksOfType(MediaType type) const
         if(m_singleTrack && m_singleTrack->mediaType() == type) {
             return true;
         } else if(m_container) {
-            for(size_t i = 0, count = m_container->trackCount(); i < count; ++i) {
+            for(size_t i = 0, count = m_container->trackCount(); i != count; ++i) {
                 if(m_container->track(i)->mediaType() == type) {
                     return true;
                 }
@@ -831,15 +831,36 @@ bool MediaFileInfo::hasTracksOfType(MediaType type) const
  */
 ChronoUtilities::TimeSpan MediaFileInfo::duration() const
 {
-    TimeSpan res;
     if(m_container) {
-        res = m_container->duration();
-    } else {
-        for(const AbstractTrack *track : tracks()) {
-            if(track->duration() > res) {
-                res = track->duration();
+        return m_container->duration();
+    } else if(m_singleTrack) {
+        return m_singleTrack->duration();
+    }
+    return TimeSpan();
+}
+
+/*!
+ * \brief Determines the available languages for specified media type (by default MediaType::Audio).
+ *
+ * If \a type is MediaType::Unknown, all media types are considered.
+ *
+ * parseTracks() needs to be called before. Otherwise this
+ * method always returns an empty set.
+ *
+ * \sa parseTracks()
+ */
+unordered_set<string> MediaFileInfo::availableLanguages(MediaType type) const
+{
+    unordered_set<string> res;
+    if(m_container) {
+        for(size_t i = 0, count = m_container->trackCount(); i != count; ++i) {
+            const AbstractTrack *track = m_container->track(i);
+            if((type == MediaType::Unknown || track->mediaType() == type) && !track->language().empty() && track->language() != "und") {
+                res.emplace(track->language());
             }
         }
+    } else if(m_singleTrack && (type == MediaType::Unknown || m_singleTrack->mediaType() == type) && !m_singleTrack->language().empty() && m_singleTrack->language() != "und") {
+        res.emplace(m_singleTrack->language());
     }
     return res;
 }
diff --git a/mediafileinfo.h b/mediafileinfo.h
index 44328f4..20cbff9 100644
--- a/mediafileinfo.h
+++ b/mediafileinfo.h
@@ -7,6 +7,7 @@
 #include "./abstractcontainer.h"
 
 #include <vector>
+#include <unordered_set>
 #include <memory>
 
 namespace Media {
@@ -95,6 +96,7 @@ public:
     std::vector<AbstractTrack *> tracks() const;
     bool hasTracksOfType(Media::MediaType type) const;
     ChronoUtilities::TimeSpan duration() const;
+    std::unordered_set<std::string> availableLanguages(Media::MediaType type = Media::MediaType::Audio) const;
     bool areTracksSupported() const;
     // ... the tags
     ParsingStatus tagsParsingStatus() const;