//
//  FullImageViewController.m
//  Signal
//
//  Created by Dylan Bourgeois on 11/11/14.
//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
//

#import "FullImageViewController.h"
#import "DJWActionSheet+OWS.h"
#import "UIUtil.h"

#define kImageViewCornerRadius 5.0f

#define kMinZoomScale 1.0f
#define kMaxZoomScale 8.0f
#define kTargetDoubleTapZoom 3.0f

#define kBackgroundAlpha 0.6f

@interface FullImageViewController () <UIScrollViewDelegate, UIGestureRecognizerDelegate>

@property (nonatomic, strong) UIView *backgroundView;

@property (nonatomic, strong) UIScrollView *scrollView;

@property (nonatomic, strong) UIImageView *imageView;

@property (nonatomic, strong) UITapGestureRecognizer *singleTap;
@property (nonatomic, strong) UITapGestureRecognizer *doubleTap;

@property (nonatomic, strong) UIButton *shareButton;

@property CGRect originRect;
@property BOOL isPresenting;

@property TSAttachmentStream *attachment;
@property TSInteraction      *interaction;

@end

@implementation FullImageViewController


- (instancetype)initWithAttachment:(TSAttachmentStream*)attachment fromRect:(CGRect)rect forInteraction:(TSInteraction*)interaction {
    self = [super initWithNibName:nil bundle:nil];
    
    if  (self) {
        self.attachment      = attachment;
        self.imageView.image = self.image;
        self.originRect      = rect;
        self.interaction     = interaction;
    }
    
    return self;
}

- (UIImage*)image{
    return self.attachment.image;
}

- (void)viewDidLoad {
    [super viewDidLoad];

    [self initializeBackground];
    [self initializeScrollView];
    [self initializeImageView];
    [self initializeGestureRecognizers];
    
    [self populateImageView:self.image];
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}


#pragma mark - Initializers

- (void)initializeBackground
{
    self.imageView.backgroundColor      = [UIColor colorWithWhite:0 alpha:kBackgroundAlpha];
    self.view.backgroundColor           = [UIColor colorWithWhite:0 alpha:kBackgroundAlpha];
    self.view.autoresizingMask          = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.backgroundView                 = [[UIView alloc] initWithFrame:CGRectInset(self.view.bounds, -512, -512)];
    self.backgroundView.backgroundColor = [UIColor colorWithWhite:0 alpha:kBackgroundAlpha];
    
    [self.view addSubview:self.backgroundView];
}

- (void)initializeScrollView
{
    self.scrollView                  = [[UIScrollView alloc] initWithFrame:self.view.bounds];
    self.scrollView.delegate         = self;
    self.scrollView.zoomScale        = 1.0f;
    self.scrollView.maximumZoomScale = kMaxZoomScale;
    self.scrollView.scrollEnabled    = NO;
    [self.view addSubview:self.scrollView];
}

- (void)initializeImageView
{
    self.imageView                              = [[UIImageView alloc]initWithFrame:self.originRect];
    self.imageView.layer.cornerRadius           = kImageViewCornerRadius;
    self.imageView.contentMode                  = UIViewContentModeScaleAspectFill;
    self.imageView.userInteractionEnabled       = YES;
    self.imageView.clipsToBounds                = YES;
    self.imageView.layer.allowsEdgeAntialiasing = YES;
    [self.scrollView addSubview:self.imageView];

}

- (void)populateImageView:(UIImage*)image
{
    if (image) {
        self.imageView.image = image;
    }
}

- (void)initializeGestureRecognizers
{
    self.doubleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(imageDoubleTapped:)];
    self.doubleTap.numberOfTapsRequired = 2;
    
    self.singleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(imageSingleTapped:)];
    [self.singleTap requireGestureRecognizerToFail:self.doubleTap];
    
    self.singleTap.delegate = self;
    self.doubleTap.delegate = self;

    [self.view addGestureRecognizer:self.singleTap];
    [self.view addGestureRecognizer:self.doubleTap];
}

- (void) initializeShareButton
{
    CGFloat buttonRadius = 50.0f;
    CGFloat x = 14.0f;
    CGFloat y = self.view.bounds.size.height - buttonRadius - 10.0f;
    
    self.shareButton = [[UIButton alloc]initWithFrame:CGRectMake(x, y, buttonRadius, buttonRadius)];
    [self.shareButton addTarget:self action:@selector(shareButtonTapped:) forControlEvents:UIControlEventTouchUpInside];
    [self.shareButton setImage:[UIImage imageNamed:@"savephoto"] forState:UIControlStateNormal];
    
    [self.view addSubview:self.shareButton];
}

#pragma mark - Gesture Recognizers

- (void)imageDoubleTapped:(UITapGestureRecognizer*)doubleTap
{
    CGPoint tap = [doubleTap locationInView:doubleTap.view];
    CGPoint convertCoord = [self.scrollView convertPoint:tap fromView:doubleTap.view];
    CGRect targetZoomRect;
    UIEdgeInsets targetInsets;
    
    CGSize zoom ;
    
    if (self.scrollView.zoomScale == 1.0f) {
        zoom = CGSizeMake(self.view.bounds.size.width / kTargetDoubleTapZoom, self.view.bounds.size.height / kTargetDoubleTapZoom);
        targetZoomRect = CGRectMake(convertCoord.x - (zoom.width/2.0f), convertCoord.y - (zoom.height/2.0f), zoom.width, zoom.height);
        targetInsets = [self contentInsetForScrollView:kTargetDoubleTapZoom];
    } else {
        zoom = CGSizeMake(self.view.bounds.size.width * self.scrollView.zoomScale, self.view.bounds.size.height * self.scrollView.zoomScale);
        targetZoomRect = CGRectMake(convertCoord.x - (zoom.width/2.0f), convertCoord.y - (zoom.height/2.0f), zoom.width, zoom.height);
        targetInsets = [self contentInsetForScrollView:1.0f];
    }
    
    self.view.userInteractionEnabled = NO;
    
    [CATransaction begin];
    [CATransaction setCompletionBlock:^{
        self.scrollView.contentInset = targetInsets;
        self.view.userInteractionEnabled = YES;
    }];
    [self.scrollView zoomToRect:targetZoomRect animated:YES];
    [CATransaction commit];

}

- (void)imageSingleTapped:(UITapGestureRecognizer*)singleTap
{
    [self dismiss];
}

#pragma mark - Presentation

-(void)presentFromViewController:(UIViewController*)viewController
{
    _isPresenting = YES;
    self.view.userInteractionEnabled = NO;
    [self.view addSubview:self.imageView];
    self.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    self.view.alpha = 0;
    
    [viewController presentViewController:self animated:NO completion:^{
            [UIView animateWithDuration:0.4f
                                  delay:0
                                options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveEaseInOut
                             animations:^(){
                                 self.view.alpha = 1.0f;
                                 self.imageView.frame = [self resizedFrameForImageView:self.image.size];
                                 self.imageView.center = CGPointMake(self.view.bounds.size.width/2.0f, self.view.bounds.size.height/2.0f);
                           } completion:^(BOOL completed){
                                 self.scrollView.frame = self.view.bounds;
                                 [self.scrollView addSubview:self.imageView];
                                 [self updateLayouts];
                                 [self initializeShareButton];
                                 self.view.userInteractionEnabled = YES;
                                 _isPresenting = NO;
                             }];
        [UIUtil modalCompletionBlock]();
    }];

}

- (void)dismiss
{
    self.view.userInteractionEnabled = NO;
    [UIView animateWithDuration:0.4f
                          delay:0
                        options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveEaseInOut
                     animations:^(){
                         self.backgroundView.backgroundColor = [UIColor clearColor];
                         self.scrollView.alpha = 0;
                         self.view.alpha = 0;
                     } completion:^(BOOL completed){
                         [self.presentingViewController dismissViewControllerAnimated:NO completion:nil];
                     }];
}

#pragma mark - Update Layout

- (void)viewDidLayoutSubviews
{
    [self updateLayouts];
}


- (void) updateLayouts
{
    if (_isPresenting) {
        return;
    }
    
    self.scrollView.frame        = self.view.bounds;
    self.imageView.frame         = [self resizedFrameForImageView:self.image.size];
    self.scrollView.contentSize  = self.imageView.frame.size;
    self.scrollView.contentInset = [self contentInsetForScrollView:self.scrollView.zoomScale];
}


#pragma mark - Resizing

- (CGRect)resizedFrameForImageView:(CGSize)imageSize {
    CGRect frame = self.view.bounds;
    CGSize screenSize = CGSizeMake(frame.size.width * self.scrollView.zoomScale, frame.size.height * self.scrollView.zoomScale);
    CGSize targetSize = screenSize;
    
    if ([self isImagePortrait]) {
        if ([self getAspectRatioForCGSize:screenSize] < [self getAspectRatioForCGSize:imageSize]) {
            targetSize.width = screenSize.height / [self getAspectRatioForCGSize:imageSize];
        } else {
            targetSize.height = screenSize.width * [self getAspectRatioForCGSize:imageSize];
        }
    } else {
        if ([self getAspectRatioForCGSize:screenSize] > [self getAspectRatioForCGSize:imageSize]) {
            targetSize.height = screenSize.width * [self getAspectRatioForCGSize:imageSize];
        } else {
            targetSize.width = screenSize.height / [self getAspectRatioForCGSize:imageSize];
        }
    }
    
    frame.size = targetSize;
    frame.origin = CGPointMake(0, 0);
    return frame;
}

- (UIEdgeInsets)contentInsetForScrollView:(CGFloat)targetZoomScale {
    UIEdgeInsets inset = UIEdgeInsetsZero;
    
    CGSize boundsSize = self.scrollView.bounds.size;
    CGSize contentSize = self.image.size;
    CGSize minSize;
    
    if ([self isImagePortrait]) {
        if ([self getAspectRatioForCGSize:boundsSize] < [self getAspectRatioForCGSize:contentSize]) {
            minSize.height = boundsSize.height;
            minSize.width = minSize.height / [self getAspectRatioForCGSize:contentSize];
        } else {
            minSize.width = boundsSize.width;
            minSize.height = minSize.width * [self getAspectRatioForCGSize:contentSize];
        }
    } else {
        if ([self getAspectRatioForCGSize:boundsSize] > [self getAspectRatioForCGSize:contentSize]) {
            minSize.width = boundsSize.width;
            minSize.height =  minSize.width * [self getAspectRatioForCGSize:contentSize];
        } else {
            minSize.height = boundsSize.height;
            minSize.width = minSize.height / [self getAspectRatioForCGSize:contentSize];
        }
    }
    
    CGSize finalSize = self.view.bounds.size;

    minSize.width *= targetZoomScale;
    minSize.height *= targetZoomScale;
    
    if (minSize.height > finalSize.height && minSize.width > finalSize.width) {
        inset = UIEdgeInsetsZero;
    } else {
        CGFloat dy = boundsSize.height - minSize.height;
        CGFloat dx = boundsSize.width - minSize.width;
        
        dy = (dy > 0) ? dy : 0;
        dx = (dx > 0) ? dx : 0;
        
        inset.top    = dy/2.0f;
        inset.bottom = dy/2.0f;
        inset.left   = dx/2.0f;
        inset.right  = dx/2.0f;
    }
    return inset;
}

#pragma mark - UIScrollViewDelegate

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return self.imageView;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
 
    scrollView.contentInset = [self contentInsetForScrollView:scrollView.zoomScale];
    
    if (self.scrollView.scrollEnabled == NO) {
        self.scrollView.scrollEnabled = YES;
    }
}

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale {
    self.scrollView.scrollEnabled = (scale > 1);
    self.scrollView.contentInset = [self contentInsetForScrollView:scale];
}

#pragma mark - Utility

- (BOOL)isImagePortrait
{
    return ([self getAspectRatioForCGSize:self.image.size] > 1.0f);
}

- (CGFloat)getAspectRatioForCGSize:(CGSize)size
{
    return size.height / size.width;
}

#pragma mark - Actions

-(void)shareButtonTapped:(UIButton*)sender
{
    [DJWActionSheet showInView:self.view withTitle:nil cancelButtonTitle:NSLocalizedString(@"TXT_CANCEL_TITLE", @"") destructiveButtonTitle:NSLocalizedString(@"TXT_DELETE_TITLE", @"") otherButtonTitles:@[NSLocalizedString(@"CAMERA_ROLL_SAVE_BUTTON", @""), NSLocalizedString(@"CAMERA_ROLL_COPY_BUTTON", @"")] tapBlock:^(DJWActionSheet *actionSheet, NSInteger tappedButtonIndex) {
        if (tappedButtonIndex == actionSheet.cancelButtonIndex) {

        } else if (tappedButtonIndex == actionSheet.destructiveButtonIndex){
            __block TSInteraction *interaction = [self interaction];
            [self dismissViewControllerAnimated:YES completion:^{
                [interaction remove];
            }];
            
        } else {
            switch (tappedButtonIndex) {
                case 0:
                    UIImageWriteToSavedPhotosAlbum(self.image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
                    break;
                case 1:
                    [[UIPasteboard generalPasteboard] setImage:self.image];
                    break;
                default:
                    DDLogWarn(@"Illegal Action sheet field #%ld <%s>",(long)tappedButtonIndex, __PRETTY_FUNCTION__);
                    break;
            }
        }
    }];
}

#pragma mark - Saving images to Camera Roll

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error
  contextInfo:(void *)contextInfo
{
    if (error)
    {
        DDLogWarn(@"There was a problem saving <%@> to camera roll from %s ", error.localizedDescription ,__PRETTY_FUNCTION__);
    }
}

@end