cocoaui: fetch lyrics from lyrics.ovh

Author: Oleksiy-Yakovenko

plugins/cocoaui/DesignMode/Widgets/Lyrics/LyricsViewController.m

@@ -7,11 +7,16 @@
 //
 
 #import "LyricsViewController.h"
+#import "Weakify.h"
 
 extern DB_functions_t *deadbeef;
 
+static NSString * const lyricsNotAvailableString = @"Lyrics Not Available";
+
 @interface LyricsViewController ()
 
+@property (nonatomic) NSCache<NSString *, NSString *> *lyricsCache;
+
 @property (unsafe_unretained) IBOutlet NSTextView *textView;
 
 @end
@@ -27,52 +32,132 @@ - (void)dealloc {
 
 - (void)viewDidLoad {
     [super viewDidLoad];
+    self.lyricsCache = [NSCache new];
     [self update];
 }
 
-- (void)update {
-    NSString *lyrics = @"Lyrics Not Available";
+- (NSString *)parseLyricsFromData:(NSData *)data response:(NSURLResponse *)response {
+    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
+
+    if (data == nil || httpResponse.statusCode != 200 || ![response.MIMEType isEqualToString:@"application/json"]) {
+        return nil;
+    }
+
+    id object = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
+    if (![object isKindOfClass:NSDictionary.class]) {
+        return nil;
+    }
+
+    NSDictionary *dict = object;
+    NSString *lyrics = dict[@"lyrics"];
+    if (![lyrics isKindOfClass:NSString.class]) {
+        return nil;
+    }
+
+    return lyrics;
+}
+
+- (void)fetchFromLyricsOvh {
     NSString *artist;
     NSString *title;
-    if (self.track != NULL) {
-        // get lyrics from tags
-        deadbeef->pl_lock();
-
-        // A bit of a hack since deadbeef stores multiline values as 0-separated lines.
-        DB_metaInfo_t *meta = deadbeef->pl_meta_for_key(self.track, "lyrics");
-        if (meta != NULL) {
-            size_t buffer_size = 100000;
-            char *lyrics_buffer = malloc(100000);
-            *lyrics_buffer = 0;
-
-            size_t value_size = meta->valuesize;
-            if (value_size > buffer_size - 1) {
-                value_size = buffer_size - 1;
-            }
-            memcpy(lyrics_buffer, meta->value, value_size);
-            char *p = lyrics_buffer;
-            for (size_t i = 0; i <= value_size; i++, p++) {
-                if (*p == 0) {
-                    *p = '\n';
-                }
-            }
-            lyrics_buffer[value_size] = 0;
-            lyrics = @(lyrics_buffer);
-            free(lyrics_buffer);
-        }
 
-        const char *str = deadbeef->pl_find_meta (self.track, "artist");
-        if (str != NULL) {
-            artist = @(str);
-        }
-        str = deadbeef->pl_find_meta (self.track, "title");
-        if (str != NULL) {
-            title = @(str);
-        }
+    ddb_playItem_t *track = self.track;
+    deadbeef->pl_item_ref (track);
 
-        deadbeef->pl_unlock();
+    deadbeef->pl_lock();
+
+    const char *str = deadbeef->pl_find_meta (self.track, "artist");
+    if (str != NULL) {
+        artist = @(str);
+    }
+    str = deadbeef->pl_find_meta (self.track, "title");
+    if (str != NULL) {
+        title = @(str);
+    }
+
+    deadbeef->pl_unlock();
+
+    if (artist != nil && title != nil) {
+        NSURL *url = [[[NSURL URLWithString:@"https://api.lyrics.ovh/v1"] URLByAppendingPathComponent:artist] URLByAppendingPathComponent:title];
+        NSURLRequest *request = [NSURLRequest requestWithURL:url];
+
+        weakify(self);
+        NSURLSessionDataTask *task = [NSURLSession.sharedSession dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
+            strongify(self);
+
+            NSString *lyrics = [self parseLyricsFromData:data response:response];
+
+            dispatch_async(dispatch_get_main_queue(), ^{
+                [self updateWithLyrics:lyrics track:track];
+            });
+        }];
+        [task resume];
+    }
+}
+
+- (NSString *)currentArtist {
+    NSString *result;
+
+    if (self.track == nil) {
+        return nil;
+    }
+
+    deadbeef->pl_lock();
+
+    const char *str = deadbeef->pl_find_meta (self.track, "artist");
+    if (str != NULL) {
+        result = @(str);
+    }
+
+    deadbeef->pl_unlock();
+    return result;
+}
+
+- (NSString *)currentTitle {
+    if (self.track == nil) {
+        return nil;
+    }
+
+    NSString *result;
+    deadbeef->pl_lock();
+
+    const char *str = deadbeef->pl_find_meta (self.track, "title");
+    if (str != NULL) {
+        result = @(str);
+    }
+
+    deadbeef->pl_unlock();
+    return result;
+}
+
+- (NSString *)currentKey {
+    NSString *artist = [self currentArtist];
+    NSString *title = [self currentTitle];
+
+    return [NSString stringWithFormat:@"artist:%@;title:%@", artist ?: @"null", title ?: @"null"];
+}
+
+- (void)updateWithLyrics:(NSString * _Nullable)lyrics track:(ddb_playItem_t * _Nullable)track {
+    if (track != self.track) {
+        deadbeef->pl_item_unref(track);
+        return;
     }
 
+    if (track != NULL) {
+        deadbeef->pl_item_unref(track);
+        track = NULL;
+    }
+
+    if (lyrics == nil) {
+        lyrics = lyricsNotAvailableString;
+    }
+
+    NSString *key = [self currentKey];
+    [self.lyricsCache setObject:lyrics forKey:key];
+
+    NSString *artist = [self currentArtist];
+    NSString *title = [self currentTitle];
+
     NSMutableParagraphStyle *paragraphStyle = [NSParagraphStyle.defaultParagraphStyle mutableCopy];
     paragraphStyle.alignment = NSTextAlignmentCenter;
 
@@ -86,7 +171,6 @@ - (void)update {
             NSFontAttributeName: headingFont,
             NSParagraphStyleAttributeName: paragraphStyle
         }];
-
     }
 
     NSAttributedString *contentAttributedString = [[NSAttributedString alloc] initWithString:lyrics attributes:@{
@@ -106,6 +190,57 @@ - (void)update {
     self.textView.selectedRange = NSMakeRange(0, 0);
 }
 
+- (void)update {
+    if (self.track == NULL) {
+        return [self updateWithLyrics:nil track:nil];
+    }
+
+    NSString *key = [self currentKey];
+    NSString *cachedLyrics = [self.lyricsCache objectForKey:key];
+    if (cachedLyrics != nil) {
+        if (self.track != nil) {
+            deadbeef->pl_item_ref(self.track);
+        }
+        return [self updateWithLyrics:cachedLyrics track:self.track];
+    }
+
+    deadbeef->pl_lock();
+
+    // A bit of a hack since deadbeef stores multiline values as 0-separated lines.
+    DB_metaInfo_t *meta = deadbeef->pl_meta_for_key(self.track, "lyrics");
+    if (meta == NULL) {
+        deadbeef->pl_unlock();
+        [self fetchFromLyricsOvh];
+        return;
+    }
+
+    // get lyrics from tags
+    size_t buffer_size = 100000;
+    char *lyrics_buffer = malloc(100000);
+    *lyrics_buffer = 0;
+
+    size_t value_size = meta->valuesize;
+    if (value_size > buffer_size - 1) {
+        value_size = buffer_size - 1;
+    }
+    memcpy(lyrics_buffer, meta->value, value_size);
+    char *p = lyrics_buffer;
+    for (size_t i = 0; i <= value_size; i++, p++) {
+        if (*p == 0) {
+            *p = '\n';
+        }
+    }
+    lyrics_buffer[value_size] = 0;
+    NSString *lyrics = @(lyrics_buffer);
+    free(lyrics_buffer);
+    lyrics_buffer = NULL;
+
+    deadbeef->pl_unlock();
+
+    deadbeef->pl_item_ref (self.track);
+    [self updateWithLyrics:lyrics track:self.track];
+}
+
 - (void)setTrack:(ddb_playItem_t *)track {
     if (_track != NULL) {
         deadbeef->pl_item_unref (_track);