cog/Audio/Plugin.h

// Plugins! HOORAY!

#import "AudioChunk.h"

@protocol CogSource <NSObject>
+ (NSArray *)schemes; // http, file, etc

- (NSURL *)url;
- (NSString *)mimeType;

- (BOOL)open:(NSURL *)url;
- (BOOL)seekable;
- (BOOL)seek:(long)position whence:(int)whence;
- (long)tell;
- (long)read:(void *)buffer amount:(long)amount; // reads UP TO amount, returns amount read.
- (void)close;
- (void)dealloc;
@end

@protocol CogVersionCheck <NSObject>
+ (BOOL)shouldLoadForOSVersion:(NSOperatingSystemVersion)version;
@end

@protocol CogContainer <NSObject>
+ (NSArray *)fileTypes; // mp3, ogg, etc
+ (NSArray *)mimeTypes;
+ (float)priority;

+ (NSArray *)urlsForContainerURL:(NSURL *)url;

@optional
+ (NSArray *)dependencyUrlsForContainerURL:(NSURL *)url;
@end

@protocol CogDecoder <NSObject>
@required
+ (NSArray *)mimeTypes;
+ (NSArray *)fileTypes; // mp3, ogg, etc
+ (NSArray *)fileTypeAssociations; // array of NSArray of NSString, where first item in array is the type name, the second is the icon name, and the rest are the extensions
+ (float)priority; // should be 0.0 ... 1.0, higher means you get selected first, should default to 1.0 unless you know a reason why any of your extensions may behave badly, ie. greedily taking over some file type extension without performing any header validation on it

// For KVO
//- (void)setProperties:(NSDictionary *)p;
- (NSDictionary *)properties;
- (NSDictionary *)metadata; // Only to be implemented for dynamic metadata, send events on change

- (AudioChunk *)readAudio;

- (BOOL)open:(id<CogSource>)source;
- (long)seek:(long)frame;
- (void)close;

@optional
- (void)dealloc;

- (BOOL)setTrack:(NSURL *)track;

// These are in NSObject, so as long as you are a subclass of that, you are ok.
- (void)addObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)context;
- (void)removeObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath;
- (void)removeObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath context:(void *)context;

- (BOOL)isSilence;
@end

@protocol CogMetadataReader <NSObject>
+ (NSArray *)fileTypes;
+ (NSArray *)mimeTypes;
+ (float)priority;
+ (NSDictionary *)metadataForURL:(NSURL *)url;
@end

@protocol CogMetadataWriter <NSObject>
//+ (NSArray *)fileTypes;
//+ (NSArray *)mimeTypes;
+ (int)putMetadataInURL:(NSURL *)url tagData:(NSDictionary *)tagData;
@end

@protocol CogPropertiesReader <NSObject>
+ (NSArray *)fileTypes;
+ (NSArray *)mimeTypes;
+ (float)priority;
+ (NSDictionary *)propertiesForSource:(id<CogSource>)source;
@end

@protocol CogPluginController <NSObject>
+ (id<CogPluginController>)sharedPluginController;

- (NSDictionary *)sources;
- (NSDictionary *)containers;
- (NSDictionary *)metadataReaders;

- (NSDictionary *)propertiesReadersByExtension;
- (NSDictionary *)propertiesReadersByMimeType;

- (NSDictionary *)decodersByExtension;
- (NSDictionary *)decodersByMimeType;

- (id<CogSource>)audioSourceForURL:(NSURL *)url;
- (NSArray *)urlsForContainerURL:(NSURL *)url;
- (NSArray *)dependencyUrlsForContainerURL:(NSURL *)url;
- (NSDictionary *)metadataForURL:(NSURL *)url skipCue:(BOOL)skip;
- (NSDictionary *)propertiesForURL:(NSURL *)url skipCue:(BOOL)skip;
- (id<CogDecoder>)audioDecoderForSource:(id<CogSource>)source skipCue:(BOOL)skip;

- (int)putMetadataInURL:(NSURL *)url;
@end

static NSString *guess_encoding_of_string(const char *input) {
	NSString *ret = @"";
	NSData *stringData = [NSData dataWithBytes:input length:strlen(input)];
	[NSString stringEncodingForData:stringData encodingOptions:nil convertedString:&ret usedLossyConversion:nil];
	return ret;
}