// Copyright 2019 The MediaPipe Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <AVFoundation/AVFoundation.h>
#import <Foundation/Foundation.h>

@class MPPInputSource;

/// A delegate that can receive frames from a source.
@protocol MPPInputSourceDelegate <NSObject>

/// Provides the delegate with a new video frame.
@optional
- (void)processVideoFrame:(CVPixelBufferRef)imageBuffer
               fromSource:(MPPInputSource*)source __deprecated;

/// Provides the delegate with a new video frame.
@optional
- (void)processVideoFrame:(CVPixelBufferRef)imageBuffer
                timestamp:(CMTime)timestamp
               fromSource:(MPPInputSource*)source;

// Provides the delegate with a new depth frame data
@optional
- (void)processDepthData:(AVDepthData*)depthData
               timestamp:(CMTime)timestamp
              fromSource:(MPPInputSource*)source API_AVAILABLE(ios(11.0));

@optional
- (void)videoDidPlayToEnd:(CMTime)timestamp;

@end

/// Abstract class for a video source.
@interface MPPInputSource : NSObject

/// The delegate that receives the frames.
@property(weak, nonatomic, readonly) id<MPPInputSourceDelegate> delegate;

/// The dispatch queue on which to schedule the delegate callback.
@property(nonatomic, readonly) dispatch_queue_t delegateQueue;

/// Whether the source is currently running.
@property(nonatomic, getter=isRunning, readonly) BOOL running;

/// Sets the delegate and the queue on which its callback should be invoked.
- (void)setDelegate:(id<MPPInputSourceDelegate>)delegate queue:(dispatch_queue_t)queue;

/// CoreVideo pixel format for the video frames. Defaults to
/// kCVPixelFormatType_32BGRA.
@property(nonatomic) OSType pixelFormatType;

/// Starts the source.
- (void)start;

/// Stops the source.
- (void)stop;

@end