#import <MultipeerConnectivity/MultipeerConnectivity.h>
/*
    1. 註冊一個廣告  告訴別人  我的裝置是可以被發現
    2. 掃描藍芽裝置   需要實現代理方法
    3. 使用一個MCSession物件儲存當前會話   需要實現代理方法
    4. 使用MCSession 物件 傳送和接收資料
 */
#define SERVICE_TYPE @"xmg"
@interface ViewController ()<MCBrowserViewControllerDelegate,UINavigationControllerDelegate,UIImagePickerControllerDelegate,MCSessionDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *showImg;

// 儲存會話
@property (nonatomic, strong)MCSession *m_session;

/** 傳送廣告 */
@property (nonatomic, strong) MCAdvertiserAssistant *assistant;

/** 當前連線到的裝置 */
@property (nonatomic, strong) MCPeerID *peerId;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 初始化 會話
    // 獲取裝置的名字
    NSString *displayName = [UIDevice currentDevice].name;
    // 裝置的id
    MCPeerID *perrID = [[MCPeerID alloc]initWithDisplayName:displayName];
    self.m_session = [[MCSession alloc]initWithPeer:perrID];
    self.m_session.delegate = self;
}

// click events
- (IBAction)connect:(id)sender {
    MCBrowserViewController *browser = [[MCBrowserViewController alloc]initWithServiceType:SERVICE_TYPE session:self.m_session];
    browser.delegate = self;
    [self presentViewController:browser animated:YES completion:nil];
    
}
- (IBAction)selecte:(id)sender {
    UIImagePickerController *imgPicker = [[UIImagePickerController alloc]init];
    imgPicker.delegate = self;
    imgPicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    [self presentViewController:imgPicker animated:YES completion:nil];
    
}
- (IBAction)sendImage:(id)sender {
    if (!self.showImg.image)   return;
    
    // 傳送資料
    [self.m_session sendData:UIImagePNGRepresentation(self.showImg.image) toPeers:@[self.peerId] withMode:MCSessionSendDataUnreliable error:nil];
    
    NSLog(@"===%@" ,self.m_session);
    
}
// 設定可被發現
- (IBAction)found:(id)sender {
    UISwitch *s = (UISwitch *)sender;
    if (s.isOn) {
        // 註冊廣告  可能一個app 傳送了多個廣告,  所以需要給光繫結唯一標示
        self.assistant = [[MCAdvertiserAssistant alloc]initWithServiceType:SERVICE_TYPE discoveryInfo:nil session:self.m_session];
        
        [self.assistant start];
    }
}

#pragma mark - 會話的代理方法
// 接收到的資料
- (void)session:(MCSession *)session didReceiveData:(NSData *)data fromPeer:(MCPeerID *)peerID
{
    dispatch_async(dispatch_get_main_queue(), ^{
        self.showImg.image = [UIImage imageWithData:data];
    });
}

- (void)session:(MCSession *)session peer:(MCPeerID *)peerID didChangeState:(MCSessionState)state
{
    
}

#pragma mark - 掃描裝置的代理
// 連線成功
- (void)browserViewControllerDidFinish:(MCBrowserViewController *)browserViewController
{
    NSLog(@"%s  %d",__func__,__LINE__);
    [browserViewController dismissViewControllerAnimated:YES completion:nil];
}

// 退出連線
- (void)browserViewControllerWasCancelled:(MCBrowserViewController *)browserViewController
{
    
}

// 連線哪個裝置
- (BOOL)browserViewController:(MCBrowserViewController *)browserViewController
      shouldPresentNearbyPeer:(MCPeerID *)peerID
            withDiscoveryInfo:(nullable NSDictionary<NSString *, NSString *> *)info
{
    NSLog(@"%s  %d",__func__,__LINE__);
    self.peerId = peerID;
    return YES;
}


#pragma mark - imageDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    self.showImg.image = info[UIImagePickerControllerOriginalImage];
    [picker dismissViewControllerAnimated:YES completion:nil];
}
@end