//
//  SellyCallPiPManager.m
//  SellyCloudSDK_Example
//
//  Created by Caleb on 19/11/25.
//  Copyright © 2025 Caleb. All rights reserved.
//

#import "SellyCallPiPManager.h"
#import <AVKit/AVKit.h>
#import <AVFoundation/AVFoundation.h>

@interface SellyCallPiPManager ()

@property (nonatomic, weak) UIView *renderView;

@property (nonatomic, strong) AVSampleBufferDisplayLayer *pipSampleBufferLayer;
@property (nonatomic, strong) AVPictureInPictureController *pipController;
@property (nonatomic, strong) dispatch_queue_t pipQueue;
@property (nonatomic, assign, readwrite) BOOL pipPossible;
@property (nonatomic, assign, readwrite) BOOL pipActive;

@end

@implementation SellyCallPiPManager

- (instancetype)initWithRenderView:(UIView *)renderView {
    self = [super init];
    if (self) {
        _renderView = renderView;
    }
    return self;
}

- (void)setupIfNeeded {
    if (@available(iOS 15.0, *)) {
        if (![AVPictureInPictureController isPictureInPictureSupported]) {
            self.pipPossible = NO;
            return;
        }
        
        self.pipQueue = dispatch_queue_create("com.sellycloud.pip.queue", DISPATCH_QUEUE_SERIAL);
        
        // SampleBuffer layer（你可以决定要不要加到 renderView 上显示）
        self.pipSampleBufferLayer = [[AVSampleBufferDisplayLayer alloc] init];
        self.pipSampleBufferLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
        
        if (self.renderView) {
            self.pipSampleBufferLayer.frame = self.renderView.bounds;
            [self.renderView.layer addSublayer:self.pipSampleBufferLayer];
        }
        
        // PiP content source
        AVPictureInPictureControllerContentSource *source =
        [[AVPictureInPictureControllerContentSource alloc] initWithSampleBufferDisplayLayer:self.pipSampleBufferLayer
                                                                            playbackDelegate:self];
        
        self.pipController = [[AVPictureInPictureController alloc] initWithContentSource:source];
        self.pipController.delegate = self;
        
        self.pipPossible = (self.pipController != nil);
    } else {
        self.pipPossible = NO;
    }
}

- (void)togglePiP {
    if (@available(iOS 15.0, *)) {
        if (!self.pipController || !self.pipController.isPictureInPicturePossible) {
            NSLog(@"[PiP] not possible");
            return;
        }
        
        if (!self.pipController.isPictureInPictureActive) {
            [self.pipController startPictureInPicture];
        } else {
            [self.pipController stopPictureInPicture];
        }
    }
}

#pragma mark - Feed frame

- (void)feedVideoFrame:(SellyRTCVideoFrame *)frame {
    if (!self.pipSampleBufferLayer || !frame.pixelBuffer) return;
    if (!self.pipPossible) return;
    
    CMSampleBufferRef sb = [self createSampleBufferFromVideoFrame:frame];
    if (!sb) return;
    
    dispatch_async(self.pipQueue, ^{
        if (self.pipSampleBufferLayer.status == AVQueuedSampleBufferRenderingStatusFailed) {
            NSLog(@"[PiP] display layer failed: %@",
                  self.pipSampleBufferLayer.error);
            [self.pipSampleBufferLayer flushAndRemoveImage];
        }
        [self.pipSampleBufferLayer enqueueSampleBuffer:sb];
        CFRelease(sb);
    });
}

- (CMSampleBufferRef)createSampleBufferFromVideoFrame:(SellyRTCVideoFrame *)videoData {
    if (!videoData || !videoData.pixelBuffer) {
        return nil;
    }
    
    CVPixelBufferRef pixelBuffer = videoData.pixelBuffer;
    
    CMVideoFormatDescriptionRef videoInfo = NULL;
    OSStatus status = CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault,
                                                                   pixelBuffer,
                                                                   &videoInfo);
    if (status != noErr || !videoInfo) {
        return nil;
    }
    
    CMTime pts;
    if (videoData.timestamp > 0) {
        // 假设 timestamp 是 ns
        pts = CMTimeMake(videoData.timestamp, 1000000000);
    } else {
        CFTimeInterval t = CACurrentMediaTime();
        int64_t ms = (int64_t)(t * 1000);
        pts = CMTimeMake(ms, 1000);
    }
    
    CMSampleTimingInfo timingInfo;
    timingInfo.duration = kCMTimeInvalid;
    timingInfo.decodeTimeStamp = kCMTimeInvalid;
    timingInfo.presentationTimeStamp = pts;
    
    CMSampleBufferRef sampleBuffer = NULL;
    status = CMSampleBufferCreateReadyWithImageBuffer(kCFAllocatorDefault,
                                                      pixelBuffer,
                                                      videoInfo,
                                                      &timingInfo,
                                                      &sampleBuffer);
    CFRelease(videoInfo);
    
    if (status != noErr) {
        if (sampleBuffer) {
            CFRelease(sampleBuffer);
        }
        return nil;
    }
    
    // 标记立即显示
    CFArrayRef attachments = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, YES);
    if (attachments && CFArrayGetCount(attachments) > 0) {
        CFMutableDictionaryRef attachment =
        (CFMutableDictionaryRef)CFArrayGetValueAtIndex(attachments, 0);
        CFDictionarySetValue(attachment,
                             kCMSampleAttachmentKey_DisplayImmediately,
                             kCFBooleanTrue);
    }
    
    return sampleBuffer; // 调用方 CFRelease
}

#pragma mark - AVPictureInPictureSampleBufferPlaybackDelegate

- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController
                        setPlaying:(BOOL)playing {
    NSLog(@"[PiP] setPlaying = %d", playing);
}

- (CMTimeRange)pictureInPictureControllerTimeRangeForPlayback:(AVPictureInPictureController *)pictureInPictureController {
    return CMTimeRangeMake(kCMTimeZero, CMTimeMake(INT64_MAX, 1000));
}

- (BOOL)pictureInPictureControllerIsPlaybackPaused:(AVPictureInPictureController *)pictureInPictureController {
    return NO;
}

- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController
          didTransitionToRenderSize:(CMVideoDimensions)newRenderSize {
    NSLog(@"[PiP] render size = %d x %d", newRenderSize.width, newRenderSize.height);
}

- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController
                    skipByInterval:(CMTime)skipInterval
                 completionHandler:(void (^)(void))completionHandler {
    if (completionHandler) {
        completionHandler();
    }
}

- (BOOL)pictureInPictureControllerShouldProhibitBackgroundAudioPlayback:(AVPictureInPictureController *)pictureInPictureController {
    return NO;
}

- (void)invalidatePlaybackState {
    // 实时流一般不用
}

#pragma mark - AVPictureInPictureControllerDelegate

- (void)pictureInPictureControllerWillStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
    NSLog(@"[PiP] will start");
    self.pipActive = YES;
}

- (void)pictureInPictureControllerDidStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
    NSLog(@"[PiP] did start");
    self.pipActive = YES;
}

- (void)pictureInPictureControllerDidStopPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
    NSLog(@"[PiP] did stop");
    self.pipActive = NO;
}

@end