FLEX/Classes/Core/Controllers/FLEXTableViewController.m

//
//  FLEXTableViewController.m
//  FLEX
//
//  Created by Tanner on 7/5/19.
//  Copyright © 2020 FLEX Team. All rights reserved.
//

#import "FLEXTableViewController.h"
#import "FLEXExplorerViewController.h"
#import "FLEXBookmarksViewController.h"
#import "FLEXTabsViewController.h"
#import "FLEXScopeCarousel.h"
#import "FLEXTableView.h"
#import "FLEXUtility.h"
#import "FLEXResources.h"
#import "UIBarButtonItem+FLEX.h"
#import <objc/runtime.h>
#import "fakes.h"

@interface Block : NSObject
- (void)invoke;
@end

CGFloat const kFLEXDebounceInstant = 0.f;
CGFloat const kFLEXDebounceFast = 0.05;
CGFloat const kFLEXDebounceForAsyncSearch = 0.15;
CGFloat const kFLEXDebounceForExpensiveIO = 0.5;

@interface FLEXTableViewController ()
@property (nonatomic) NSTimer *debounceTimer;
@property (nonatomic) BOOL didInitiallyRevealSearchBar;
@property (nonatomic) UITableViewStyle style;

@property (nonatomic) BOOL hasAppeared;
@property (nonatomic, readonly) UIView *tableHeaderViewContainer;

@property (nonatomic, readonly) BOOL manuallyDeactivateSearchOnDisappear;

@property (nonatomic) UIBarButtonItem *middleToolbarItem;
@property (nonatomic) UIBarButtonItem *middleLeftToolbarItem;
@property (nonatomic) UIBarButtonItem *leftmostToolbarItem;

@end

@implementation FLEXTableViewController
@dynamic tableView;
@synthesize showsShareToolbarItem = _showsShareToolbarItem;
@synthesize tableHeaderViewContainer = _tableHeaderViewContainer;
@synthesize automaticallyShowsSearchBarCancelButton = _automaticallyShowsSearchBarCancelButton;

#pragma mark - Initialization

- (id)init {
#if FLEX_AT_LEAST_IOS13_SDK
    if (@available(iOS 13.0, *)) {
        #if !TARGET_OS_TV
        self = [self initWithStyle:UITableViewStyleInsetGrouped];
        #else
        self = [self initWithStyle:UITableViewStyleGrouped];
        #endif
    } else {
        self = [self initWithStyle:UITableViewStyleGrouped];
    }
#else
    self = [self initWithStyle:UITableViewStyleGrouped];
#endif
    return self;
}

- (id)initWithStyle:(UITableViewStyle)style {
    self = [super initWithStyle:style];
    
    if (self) {
        _searchBarDebounceInterval = kFLEXDebounceFast;
        _showSearchBarInitially = YES;
        _style = style;
        _manuallyDeactivateSearchOnDisappear = ({
            NSProcessInfo.processInfo.operatingSystemVersion.majorVersion < 11;
        });
        
        // We will be our own search delegate if we implement this method
        if ([self respondsToSelector:@selector(updateSearchResults:)]) {
            self.searchDelegate = (id)self;
        }
    }
    
    return self;
}


#pragma mark - Public

- (FLEXWindow *)window {
    return (id)self.view.window;
}

/**
 
 search is handled a bit differently on tvOS and i couldnt get its pardigm to cooperate, thankfully the UISearchController never needs to be visible to actually work its magic.
 since 3D snapshot viewing doesn't exist on tvOS the leftBarButtonItem is the perfect spot to add a 'search' button. this search button will present a new text entry controller
 the alpha on this viewController is decreased to 0.6 to make it possible to view the filtering changes underneath in realtime. The zero rect textfield associated with
 the search button acts as a proxy to transfer the text to our search bar as necessary
 
 */

- (void)setShowsSearchBar:(BOOL)showsSearchBar {
    if (_showsSearchBar == showsSearchBar) return;
    _showsSearchBar = showsSearchBar;
    
    if (showsSearchBar) {
        UIViewController *results = self.searchResultsController;
        self.searchController = [[UISearchController alloc] initWithSearchResultsController:results];
        self.searchController.searchBar.placeholder = @"Filter";
        self.searchController.searchResultsUpdater = (id)self;
        self.searchController.delegate = (id)self;
        #if !TARGET_OS_TV
        self.searchController.searchBar.delegate = self;
        self.searchController.dimsBackgroundDuringPresentation = NO;
        #endif
        self.searchController.hidesNavigationBarDuringPresentation = NO;
        /// Not necessary in iOS 13; remove this when iOS 13 is the minimum deployment target
        
        self.automaticallyShowsSearchBarCancelButton = YES;

        #if FLEX_AT_LEAST_IOS13_SDK
        if (@available(iOS 13, *)) {
            self.searchController.automaticallyShowsScopeBar = NO;
        }
        #endif
        [self addSearchController:self.searchController];
    } else {
        // Search already shown and just set to NO, so remove it
        [self removeSearchController:self.searchController];
    }
}

- (void)setShowsCarousel:(BOOL)showsCarousel {
    if (_showsCarousel == showsCarousel) return;
    _showsCarousel = showsCarousel;
    
    if (showsCarousel) {
        _carousel = ({
            __weak __typeof(self) weakSelf = self;

            FLEXScopeCarousel *carousel = [FLEXScopeCarousel new];
            carousel.selectedIndexChangedAction = ^(NSInteger idx) {
                __typeof(self) self = weakSelf;
                [self.searchDelegate updateSearchResults:self.searchText];
            };

            // UITableView won't update the header size unless you reset the header view
            [carousel registerBlockForDynamicTypeChanges:^(FLEXScopeCarousel *carousel) {
                __typeof(self) self = weakSelf;
                [self layoutTableHeaderIfNeeded];
            }];

            carousel;
        });
        [self addCarousel:_carousel];
    } else {
        // Carousel already shown and just set to NO, so remove it
        [self removeCarousel:_carousel];
    }
}

- (NSInteger)selectedScope {
    if (self.searchController.searchBar.showsScopeBar) {
        return self.searchController.searchBar.selectedScopeButtonIndex;
    } else if (self.showsCarousel) {
        return self.carousel.selectedIndex;
    } else {
        return 0;
    }
}

- (void)setSelectedScope:(NSInteger)selectedScope {
    if (self.searchController.searchBar.showsScopeBar) {
        self.searchController.searchBar.selectedScopeButtonIndex = selectedScope;
    } else if (self.showsCarousel) {
        self.carousel.selectedIndex = selectedScope;
    }

    [self.searchDelegate updateSearchResults:self.searchText];
}

- (NSString *)searchText {
    return self.searchController.searchBar.text;
}

- (BOOL)automaticallyShowsSearchBarCancelButton {
#if FLEX_AT_LEAST_IOS13_SDK
    if (@available(iOS 13, *)) {
        return self.searchController.automaticallyShowsCancelButton;
    }
#endif

    return _automaticallyShowsSearchBarCancelButton;
}

- (void)setAutomaticallyShowsSearchBarCancelButton:(BOOL)value {
#if FLEX_AT_LEAST_IOS13_SDK
    if (@available(iOS 13, *)) {
        self.searchController.automaticallyShowsCancelButton = value;
    }
#endif

    _automaticallyShowsSearchBarCancelButton = value;
}

- (void)onBackgroundQueue:(NSArray *(^)(void))backgroundBlock thenOnMainQueue:(void(^)(NSArray *))mainBlock {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSArray *items = backgroundBlock();
        dispatch_async(dispatch_get_main_queue(), ^{
            mainBlock(items);
        });
    });
}

- (void)setsShowsShareToolbarItem:(BOOL)showsShareToolbarItem {
    _showsShareToolbarItem = showsShareToolbarItem;
    if (self.isViewLoaded) {
        [self setupToolbarItems];
    }
}

- (void)disableToolbar {
    #if !TARGET_OS_TV
    self.navigationController.toolbarHidden = YES;
    self.navigationController.hidesBarsOnSwipe = NO;
    self.toolbarItems = nil;
    #endif
}


#pragma mark - View Controller Lifecycle

- (void)loadView {
    self.view = [FLEXTableView style:self.style];
    self.tableView.dataSource = self;
    self.tableView.delegate = self;
    
    _shareToolbarItem = FLEXBarButtonItemSystem(Action, self, @selector(shareButtonPressed:));
    _bookmarksToolbarItem = [UIBarButtonItem
        flex_itemWithImage:FLEXResources.bookmarksIcon target:self action:@selector(showBookmarks)
    ];
    _openTabsToolbarItem = [UIBarButtonItem
        flex_itemWithImage:FLEXResources.openTabsIcon target:self action:@selector(showTabSwitcher)
    ];
    
    self.leftmostToolbarItem = UIBarButtonItem.flex_fixedSpace;
    self.middleLeftToolbarItem = UIBarButtonItem.flex_fixedSpace;
    self.middleToolbarItem = UIBarButtonItem.flex_fixedSpace;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag;
    
    // Toolbar
    #if !TARGET_OS_TV
    self.navigationController.toolbarHidden = NO;
    self.navigationController.hidesBarsOnSwipe = YES;
    #endif
    // On iOS 13, the root view controller shows it's search bar no matter what.
    // Turning this off avoids some weird flash the navigation bar does when we
    // toggle navigationItem.hidesSearchBarWhenScrolling on and off. The flash
    // will still happen on subsequent view controllers, but we can at least
    // avoid it for the root view controller
    if (@available(iOS 13, *)) {
        if (self.navigationController.viewControllers.firstObject == self) {
            _showSearchBarInitially = NO;
        }
    }
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    
    // When going back, make the search bar reappear instead of hiding
    if (@available(iOS 11.0, *)) {
        if ((self.pinSearchBar || self.showSearchBarInitially) && !self.didInitiallyRevealSearchBar) {
            #if !TARGET_OS_TV
            self.navigationItem.hidesSearchBarWhenScrolling = NO;
            #endif
        }
    }
    #if TARGET_OS_TV
    UIEdgeInsets insets = self.tableView.contentInset;
    insets.top+=20;
    self.tableView.contentInset = insets;
    #endif
    [self setupToolbarItems];
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    // Allow scrolling to collapse the search bar, only if we don't want it pinned
    if (@available(iOS 11.0, *)) {
        if (self.showSearchBarInitially && !self.pinSearchBar && !self.didInitiallyRevealSearchBar) {
            // All this mumbo jumbo is necessary to work around a bug in iOS 13 up to 13.2
            // wherein quickly toggling navigationItem.hidesSearchBarWhenScrolling to make
            // the search bar appear initially results in a bugged search bar that
            // becomes transparent and floats over the screen as you scroll
            [UIView animateWithDuration:0.2 animations:^{
                #if !TARGET_OS_TV
                self.navigationItem.hidesSearchBarWhenScrolling = YES;
                #endif
                [self.navigationController.view setNeedsLayout];
                [self.navigationController.view layoutIfNeeded];
            }];
        }
    }

    // We only want to reveal the search bar when the view controller first appears.
    self.didInitiallyRevealSearchBar = YES;
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    
    if (self.manuallyDeactivateSearchOnDisappear && self.searchController.isActive) {
        self.searchController.active = NO;
    }
}

- (void)didMoveToParentViewController:(UIViewController *)parent {
    [super didMoveToParentViewController:parent];
    // Reset this since we are re-appearing under a new
    // parent view controller and need to show it again
    self.didInitiallyRevealSearchBar = NO;
}


#pragma mark - Toolbar, Public

- (void)setupToolbarItems {
    if (!self.isViewLoaded) {
        return;
    }
    #if !TARGET_OS_TV
    self.toolbarItems = @[
        self.leftmostToolbarItem,
        UIBarButtonItem.flex_flexibleSpace,
        self.middleLeftToolbarItem,
        UIBarButtonItem.flex_flexibleSpace,
        self.middleToolbarItem,
        UIBarButtonItem.flex_flexibleSpace,
        self.bookmarksToolbarItem,
        UIBarButtonItem.flex_flexibleSpace,
        self.openTabsToolbarItem,
    ];
    
    for (UIBarButtonItem *item in self.toolbarItems) {
        [item _setWidth:60];
        // This does not work for anything but fixed spaces for some reason
        // item.width = 60;
    }
    #endif
    // Disable tabs entirely when not presented by FLEXExplorerViewController
    UIViewController *presenter = self.navigationController.presentingViewController;
    if (![presenter isKindOfClass:[FLEXExplorerViewController class]]) {
        self.openTabsToolbarItem.enabled = NO;
    }
}

- (void)addToolbarItems:(NSArray<UIBarButtonItem *> *)items {
    if (self.showsShareToolbarItem) {
        // Share button is in the middle, skip middle button
        if (items.count > 0) {
            self.middleLeftToolbarItem = items[0];
        }
        if (items.count > 1) {
            self.leftmostToolbarItem = items[1];
        }
    } else {
        // Add buttons right-to-left
        if (items.count > 0) {
            self.middleToolbarItem = items[0];
        }
        if (items.count > 1) {
            self.middleLeftToolbarItem = items[1];
        }
        if (items.count > 2) {
            self.leftmostToolbarItem = items[2];
        }
    }
    
    [self setupToolbarItems];
}

- (void)setShowsShareToolbarItem:(BOOL)showShare {
    if (_showsShareToolbarItem != showShare) {
        _showsShareToolbarItem = showShare;
        
        if (showShare) {
            // Push out leftmost item
            self.leftmostToolbarItem = self.middleLeftToolbarItem;
            self.middleLeftToolbarItem = self.middleToolbarItem;
            
            // Use share for middle
            self.middleToolbarItem = self.shareToolbarItem;
        } else {
            // Remove share, shift custom items rightward
            self.middleToolbarItem = self.middleLeftToolbarItem;
            self.middleLeftToolbarItem = self.leftmostToolbarItem;
            self.leftmostToolbarItem = UIBarButtonItem.flex_fixedSpace;
        }
    }
    
    [self setupToolbarItems];
}

- (void)shareButtonPressed:(UIBarButtonItem *)sender {

}


#pragma mark - Private

- (void)debounce:(void(^)(void))block {
    [self.debounceTimer invalidate];
    
    self.debounceTimer = [NSTimer
        scheduledTimerWithTimeInterval:self.searchBarDebounceInterval
        target:block
        selector:@selector(invoke)
        userInfo:nil
        repeats:NO
    ];
}

- (void)layoutTableHeaderIfNeeded {
    if (self.showsCarousel) {
        self.carousel.frame = FLEXRectSetHeight(
            self.carousel.frame, self.carousel.intrinsicContentSize.height
        );
    }
    
    self.tableView.tableHeaderView = self.tableView.tableHeaderView;
}

- (void)addCarousel:(FLEXScopeCarousel *)carousel {
    if (@available(iOS 11.0, *)) {
        self.tableView.tableHeaderView = carousel;
    } else {
        carousel.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin;
        
        CGRect frame = self.tableHeaderViewContainer.frame;
        CGRect subviewFrame = carousel.frame;
        subviewFrame.origin.y = 0;
        
        // Put the carousel below the search bar if it's already there
        if (self.showsSearchBar) {
            carousel.frame = subviewFrame = FLEXRectSetY(
                subviewFrame, self.searchController.searchBar.frame.size.height
            );
            frame.size.height += carousel.intrinsicContentSize.height;
        } else {
            frame.size.height = carousel.intrinsicContentSize.height;
        }
        
        self.tableHeaderViewContainer.frame = frame;
        [self.tableHeaderViewContainer addSubview:carousel];
    }
    
    [self layoutTableHeaderIfNeeded];
}

- (void)removeCarousel:(FLEXScopeCarousel *)carousel {
    [carousel removeFromSuperview];
    
    if (@available(iOS 11.0, *)) {
        self.tableView.tableHeaderView = nil;
    } else {
        if (self.showsSearchBar) {
            [self removeSearchController:self.searchController];
            [self addSearchController:self.searchController];
        } else {
            self.tableView.tableHeaderView = nil;
            _tableHeaderViewContainer = nil;
        }
    }
}

- (void)addSearchController:(UISearchController *)controller {
#if TARGET_OS_TV
    KBSearchButton *sb = [KBSearchButton buttonWithType:UIButtonTypeSystem];
    sb.searchBar = self.searchController.searchBar;
    UIBarButtonItem *searchButton = [[UIBarButtonItem alloc] initWithCustomView:sb];
    self.navigationItem.leftBarButtonItem = searchButton;
#else
    if (@available(iOS 11.0, *)) {
        self.navigationItem.searchController = controller;
    } else {
        controller.searchBar.autoresizingMask |= UIViewAutoresizingFlexibleBottomMargin;
        [self.tableHeaderViewContainer addSubview:controller.searchBar];
        CGRect subviewFrame = controller.searchBar.frame;
        CGRect frame = self.tableHeaderViewContainer.frame;
        frame.size.width = MAX(frame.size.width, subviewFrame.size.width);
        frame.size.height = subviewFrame.size.height;
        
        // Move the carousel down if it's already there
        if (self.showsCarousel) {
            self.carousel.frame = FLEXRectSetY(
                                               self.carousel.frame, subviewFrame.size.height
                                               );
            frame.size.height += self.carousel.frame.size.height;
        }
        
        self.tableHeaderViewContainer.frame = frame;
        [self layoutTableHeaderIfNeeded];
    }
#endif
}

- (void)removeSearchController:(UISearchController *)controller {
    #if TARGET_OS_TV
    self.navigationItem.leftBarButtonItem = nil;
    #else
    if (@available(iOS 11.0, *)) {
        self.navigationItem.searchController = nil;
    } else {
        [controller.searchBar removeFromSuperview];
        
        if (self.showsCarousel) {
//            self.carousel.frame = FLEXRectRemake(CGPointZero, self.carousel.frame.size);
            [self removeCarousel:self.carousel];
            [self addCarousel:self.carousel];
        } else {
            self.tableView.tableHeaderView = nil;
            _tableHeaderViewContainer = nil;
        }
    }
    #endif
}

- (UIView *)tableHeaderViewContainer {
    if (!_tableHeaderViewContainer) {
        _tableHeaderViewContainer = [UIView new];
        self.tableView.tableHeaderView = self.tableHeaderViewContainer;
    }
    
    return _tableHeaderViewContainer;
}

- (void)showBookmarks {
    UINavigationController *nav = [[UINavigationController alloc]
        initWithRootViewController:[FLEXBookmarksViewController new]
    ];
    [self presentViewController:nav animated:YES completion:nil];
}

- (void)showTabSwitcher {
    UINavigationController *nav = [[UINavigationController alloc]
        initWithRootViewController:[FLEXTabsViewController new]
    ];
    [self presentViewController:nav animated:YES completion:nil];
}


#pragma mark - Search Bar

#pragma mark UISearchResultsUpdating

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController {
    [self.debounceTimer invalidate];
    NSString *text = searchController.searchBar.text;
    
    void (^updateSearchResults)() = ^{
        if (self.searchResultsUpdater) {
            [self.searchResultsUpdater updateSearchResults:text];
        } else {
            [self.searchDelegate updateSearchResults:text];
        }
    };
    
    // Only debounce if we want to, and if we have a non-empty string
    // Empty string events are sent instantly
    if (text.length && self.searchBarDebounceInterval > kFLEXDebounceInstant) {
        [self debounce:updateSearchResults];
    } else {
        updateSearchResults();
    }
}

#if !TARGET_OS_TV
#pragma mark UISearchControllerDelegate

- (void)willPresentSearchController:(UISearchController *)searchController {
    // Manually show cancel button for < iOS 13
    if (!@available(iOS 13, *) && self.automaticallyShowsSearchBarCancelButton) {
        [searchController.searchBar setShowsCancelButton:YES animated:YES];
    }
}

- (void)willDismissSearchController:(UISearchController *)searchController {
    // Manually hide cancel button for < iOS 13
    if (!@available(iOS 13, *) && self.automaticallyShowsSearchBarCancelButton) {
        [searchController.searchBar setShowsCancelButton:NO animated:YES];
    }
}


#pragma mark UISearchBarDelegate

/// Not necessary in iOS 13; remove this when iOS 13 is the deployment target
- (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope {
    [self updateSearchResultsForSearchController:self.searchController];
}
#endif

#pragma mark Table View

/// Not having a title in the first section looks weird with a rounded-corner table view style
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    if (@available(iOS 13, *)) {
        #if !TARGET_OS_TV
        if (self.style == UITableViewStyleInsetGrouped) {
            return @" ";
        }
        #endif
    }

    return nil; // For plain/gropued style
}

@end