//
//  PDFPageEditViewController.m
//  PDFReader
//
//  Copyright © 2014-2022 PDF Technologies, Inc. All Rights Reserved.
//
//  The PDF Reader Sample applications are licensed with a modified BSD license.
//  Please see License for details. This notice may not be removed from this file.
//

#import "PDFPageEditViewController.h"
#import "PDFPageEditCell.h"
#import <MessageUI/MFMailComposeViewController.h>
#import "PDFPageEditAddViewController.h"

@interface PDFPageEditViewController () <UICollectionViewDelegate,UICollectionViewDataSource>

@property (nonatomic,assign) IBOutlet UICollectionView *collectionView;

@property (nonatomic,assign) IBOutlet UIToolbar *toolbar;

@property (nonatomic,retain) NSMutableArray *pages;

@end


@implementation PDFPageEditViewController

#pragma mark - Init Methods

- (instancetype)init {
    if (self = [super init]) {
        
    }
    return self;
}

- (void)dealloc {
    [_pages release];
    [super dealloc];
}

#pragma mark - UIViewController Methods

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // Do any additional setup after loading the view.
    [self setEditing:NO animated:NO];
    
    self.pages = [NSMutableArray array];
    NSURL *documentURL = [self.pdfViewController.pdfView.document documentURL];
    CGPDFDocumentRef documentRef = CGPDFDocumentCreateWithURL((CFURLRef)documentURL);
    if ([self.pdfViewController.pdfView.document password]) {
        CGPDFDocumentUnlockWithPassword(documentRef, [[self.pdfViewController.pdfView.document password] UTF8String]);
    }
    NSInteger pagesCount = CGPDFDocumentGetNumberOfPages(documentRef);
    for (int i = 0; i < pagesCount; i++) {
        CGPDFPageRef pageRef = CGPDFDocumentGetPage(documentRef, i+1);
        PDFEditPage *page = [[PDFEditPage alloc] initWithPageRef:pageRef];
        [self.pages addObject:page];
        [page release];
    }
    CGPDFDocumentRelease(documentRef);
    
    [self.collectionView registerClass:[PDFPageEditCell class] forCellWithReuseIdentifier:@"PDFPageEditCell"];
    self.collectionView.alwaysBounceVertical = YES;
    
    UILongPressGestureRecognizer *longGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)];
    [self.collectionView addGestureRecognizer:longGesture];
    [longGesture release];
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    
    NSInteger pageIndex = [self.pdfViewController.pdfView currentPageIndex];
    NSIndexPath *indexPath = [NSIndexPath indexPathForItem:pageIndex inSection:0];
    [self.collectionView selectItemAtIndexPath:indexPath
                                      animated:NO
                                scrollPosition:UICollectionViewScrollPositionCenteredVertically];
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    
    NSInteger pageIndex = [self.pdfViewController.pdfView currentPageIndex];
    NSIndexPath *indexPath = [NSIndexPath indexPathForItem:pageIndex inSection:0];
    [self.collectionView scrollToItemAtIndexPath:indexPath
                                atScrollPosition:UICollectionViewScrollPositionCenteredVertically
                                        animated:YES];
}

- (void)updateTitle {
    if (self.isEditing) {
        NSInteger count = [self.collectionView indexPathsForSelectedItems].count;
        self.title = [NSString stringWithFormat:@"%@ %ld",NSLocalizedString(@"Selected:", nil), (long)count];
    } else {
        self.title = nil;
    }
}

- (void)reloadDataVisibleCells {
    for (PDFPageEditCell *cell in [self.collectionView visibleCells]) {
        NSIndexPath *indexPath = [self.collectionView indexPathForCell:cell];
        cell.textLabel.text = [NSString stringWithFormat:@"%@",@(indexPath.item+1)];
    }
}

#pragma mark - Button Actions

- (void)setEditing:(BOOL)editing animated:(BOOL)animated {
    [super setEditing:editing animated:animated];
    if (editing) {
        self.collectionView.allowsMultipleSelection = YES;
        
        UIBarButtonItem *selectAllItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"selectall.png"] style:UIBarButtonItemStylePlain target:self action:@selector(buttonItemClicked_SelectAll:)];
        if (UIUserInterfaceIdiomPad == UI_USER_INTERFACE_IDIOM()) {
            NSMutableArray *items = [NSMutableArray array];
            [self.toolbar.items enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(UIBarButtonItem * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
                if (obj.target) {
                    [items addObject:obj];
                }
            }];
            [items addObject:selectAllItem];
            [self.navigationItem setRightBarButtonItems:items animated:animated];
        } else {
            [UIView animateWithDuration:animated ? 0.3 : 0.0 animations:^{
                self.toolbar.alpha = 1.0;
            }];
            
            [self.navigationItem setLeftBarButtonItems:@[selectAllItem] animated:animated];
            
            UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(buttonItemClicked_Done:)];
            [self.navigationItem setRightBarButtonItems:@[doneItem] animated:animated];
            [doneItem release];
        }
        [selectAllItem release];
    } else {
        self.collectionView.allowsMultipleSelection = NO;
        [UIView animateWithDuration:animated ? 0.3 : 0.0 animations:^{
            self.toolbar.alpha = 0.0;
        }];
        
        UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(buttonItemClicked_Done:)];
        [self.navigationItem setLeftBarButtonItems:@[doneItem] animated:animated];
        [doneItem release];
        
        UIBarButtonItem *editItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:self action:@selector(buttonItemClicked_Edit:)];
        [self.navigationItem setRightBarButtonItems:@[editItem] animated:animated];
        [editItem release];
    }
    [self updateTitle];
}

- (void)buttonItemClicked_Done:(id)sender {
    if (self.isEditing) {
        [self setEditing:NO animated:YES];
    } else {
        [self dismissViewControllerAnimated:YES completion:^{
            [self.pdfViewController.pdfView.document writeToURL:self.pdfViewController.pdfView.document.documentURL];
            [self.pdfViewController loadDocumentWithFilePath:self.pdfViewController.filePath completion:nil];
        }];
    }
}

- (void)buttonItemClicked_Edit:(id)sender {
    [self setEditing:YES animated:YES];
}

- (void)buttonItemClicked_SelectAll:(id)sender {
    BOOL isSelectAll = NO;
    if ([self.collectionView indexPathsForSelectedItems].count != [self.collectionView numberOfItemsInSection:0]) {
        isSelectAll = YES;
    }
    for (int i=0; i<[self.collectionView numberOfItemsInSection:0]; i++) {
        NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
        if (isSelectAll) {
            [self.collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionNone];
        } else {
            [self.collectionView deselectItemAtIndexPath:indexPath animated:YES];
        }
    }
    [self updateTitle];
}

- (IBAction)buttonItemClicked_Add:(id)sender {
    PDFPageEditAddViewController *vc = [[PDFPageEditAddViewController alloc] init];
    vc.callback = ^(PDFEditPage *page) {
        NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.pdfViewController.pdfView.currentPageIndex+1
                                                     inSection:0];
        [self.pages insertObject:page atIndex:indexPath.item];
        [self.collectionView insertItemsAtIndexPaths:@[indexPath]];
        if (page.imagePath) {
            [self.pdfViewController.pdfView.document insertPage:page.size withImage:page.imagePath atIndex:indexPath.item];
        } else {
            [self.pdfViewController.pdfView.document insertPage:page.size atIndex:indexPath.item];
        }
        [self reloadDataVisibleCells];
    };
    [vc showViewController:self inBarButtonItem:sender];
    [vc release];
}

- (IBAction)buttonItemClicked_Extract:(id)sender {
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    NSString *fileName = self.pdfViewController.pdfView.document.documentURL.lastPathComponent.stringByDeletingPathExtension;
    NSString *filePath = [NSString stringWithFormat:@"%@/%@_Pages.pdf",path,fileName];
    NSMutableIndexSet *indexSet = [NSMutableIndexSet indexSet];
    for (NSIndexPath *indexPath in [self.collectionView indexPathsForSelectedItems]) {
        [indexSet addIndex:indexPath.item];
    }
    
    CPDFDocument *document = [[[CPDFDocument alloc] init] autorelease];
    [document importPages:indexSet fromDocument:self.pdfViewController.pdfView.document atIndex:0];
    [document writeToURL:[NSURL fileURLWithPath:filePath]];
    
    NSString *message = [NSString stringWithFormat:NSLocalizedString(@"This file has been saved in:'Documents/'", nil)];
    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"OK", nil)
                                                           style:UIAlertActionStyleCancel
                                                         handler:nil];
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Successfully!", nil)
                                                                   message:message
                                                            preferredStyle:UIAlertControllerStyleAlert];
    [alert addAction:cancelAction];
    [self presentViewController:alert animated:YES completion:nil];
}

- (IBAction)buttonItemClicked_Rotate:(id)sender {
    NSMutableIndexSet *indexSet = [NSMutableIndexSet indexSet];
    for (NSIndexPath *indexPath in [self.collectionView indexPathsForSelectedItems]) {
        PDFPageEditCell *cell = (PDFPageEditCell *)[self.collectionView cellForItemAtIndexPath:indexPath];
        PDFEditPage *page = [self.pages objectAtIndex:indexPath.item];
        page.rotation += 90;
        if (page.rotation == 360) {
            page.rotation = 0;
        }
        cell.page = page;
        [indexSet addIndex:indexPath.item];
        
        CPDFPage *pPage = [self.pdfViewController.pdfView.document pageAtIndex:indexPath.item];
        pPage.rotation += 90;
    }
}

- (IBAction)buttonItemClicked_Mail:(id)sender {
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    NSString *fileName = self.pdfViewController.pdfView.document.documentURL.lastPathComponent.stringByDeletingPathExtension;
    NSString *filePath = [NSString stringWithFormat:@"%@/%@_Pages.pdf",path,fileName];
    NSMutableIndexSet *indexSet = [NSMutableIndexSet indexSet];
    for (NSIndexPath *indexPath in [self.collectionView indexPathsForSelectedItems]) {
        [indexSet addIndex:indexPath.item];
    }
    
    CPDFDocument *document = [[[CPDFDocument alloc] init] autorelease];
    [document importPages:indexSet fromDocument:self.pdfViewController.pdfView.document atIndex:0];
    [document writeToURL:[NSURL fileURLWithPath:filePath]];
    
    MFMailComposeViewController *vc = [[MFMailComposeViewController alloc] init];
    vc.mailComposeDelegate = (id)self;
    [vc addAttachmentData:[NSData dataWithContentsOfFile:filePath]
                 mimeType:[NSString stringWithFormat:@"application/%@",[filePath pathExtension]]
                 fileName:[filePath lastPathComponent]];
    [self presentViewController:vc animated:YES completion:nil];
    [vc release];
}

- (IBAction)buttonItemClicked_Delete:(id)sender {
    NSInteger selectedCount = [self.collectionView indexPathsForSelectedItems].count;
    NSInteger totalCount = [self.collectionView numberOfItemsInSection:0];
    if (selectedCount == totalCount) {
        UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"OK", nil)
                                                               style:UIAlertActionStyleCancel
                                                             handler:nil];
        UIAlertController *alert = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Warning", nil)
                                                                       message:NSLocalizedString(@"Can not delete all pages.", nil)
                                                                preferredStyle:UIAlertControllerStyleAlert];
        [alert addAction:cancelAction];
        [self presentViewController:alert animated:YES completion:nil];
        return;
    }
    
    NSMutableIndexSet *indexSet = [NSMutableIndexSet indexSet];
    for (NSIndexPath *indexPath in [self.collectionView indexPathsForSelectedItems]) {
        [indexSet addIndex:indexPath.item];
    }
    [self.pages removeObjectsAtIndexes:indexSet];
    [self.collectionView deleteItemsAtIndexPaths:[self.collectionView indexPathsForSelectedItems]];
    [self.pdfViewController.pdfView.document removePageAtIndexSet:indexSet];
    [self reloadDataVisibleCells];
}

#pragma mark - UICollectionViewDelegateFlowLayout

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    NSInteger count = 4;
    UICollectionViewFlowLayout *flowLayout = (UICollectionViewFlowLayout *)collectionViewLayout;
    CGFloat width = MIN(self.view.bounds.size.width, self.view.bounds.size.height);
    width -= (count-1)*flowLayout.minimumInteritemSpacing;
    width -= flowLayout.sectionInset.left;
    width -= flowLayout.sectionInset.right;
    width /= count;
    return CGSizeMake(width, width+18);
}

#pragma mark - UICollectionViewDataSource

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return self.pages.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    PDFPageEditCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"PDFPageEditCell" forIndexPath:indexPath];
    cell.backgroundColor = [UIColor clearColor];
    cell.page = self.pages[indexPath.item];
    cell.textLabel.text = [NSString stringWithFormat:@"%@",@(indexPath.item+1)];
    return cell;
}

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    [self updateTitle];
    if (!self.isEditing) {
        [self dismissViewControllerAnimated:YES completion:^{
            [self.pdfViewController.pdfView.document writeToURL:self.pdfViewController.pdfView.document.documentURL];
            [self.pdfViewController loadDocumentWithFilePath:self.pdfViewController.filePath completion:^(BOOL result) {
                if (result) {
                    [self.pdfViewController.pdfView goToPageIndex:indexPath.item animated:NO];
                }
            }];
        }];
    }
}

- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
    [self updateTitle];
}

#pragma mark - UICollectionView Draggable

- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath {
    return YES;
}

- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath {
    if (sourceIndexPath.item != destinationIndexPath.item) {
        CPDFPage *page = [[self.pages objectAtIndex:sourceIndexPath.item] retain];
        [self.pages removeObject:page];
        [self.pages insertObject:page atIndex:destinationIndexPath.item];
        [page release];
        [self.pdfViewController.pdfView.document movePageAtIndex:sourceIndexPath.item withPageAtIndex:destinationIndexPath.item];
        [self reloadDataVisibleCells];
    }
}

- (void)handlelongGesture:(UILongPressGestureRecognizer *)longGesture {
    switch (longGesture.state) {
        case UIGestureRecognizerStateBegan:
        {
            NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:[longGesture locationInView:self.collectionView]];
            if (indexPath == nil) {
                break;
            }
            [self.collectionView beginInteractiveMovementForItemAtIndexPath:indexPath];
            [UIView animateWithDuration:0.2 animations:^{
                [self.collectionView updateInteractiveMovementTargetPosition:[longGesture locationInView:self.collectionView]];
            }];
        }
            break;
        case UIGestureRecognizerStateChanged:
        {
            [self.collectionView updateInteractiveMovementTargetPosition:[longGesture locationInView:self.collectionView]];
        }
            break;
        case UIGestureRecognizerStateEnded:
        {
            [self.collectionView endInteractiveMovement];
        }
            break;
        default:
        {
            [self.collectionView cancelInteractiveMovement];
        }
            break;
    }
}

#pragma mark - MFMailComposeViewControllerDelegate

- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(nullable NSError *)error {
    [controller dismissViewControllerAnimated:YES completion:nil];
}


@end