//
//  JXFavoriteViewController.m
//  AICity
//
//  Created by TogetherWatch on 2025-10-20.
//

#import "JXFavoriteViewController.h"
#import "JXAPIService.h"
#import "JXDrama.h"

// Cell复用标识符
static NSString * const kFavoriteCellIdentifier = @"FavoriteCell";

@interface JXFavoriteViewController () <UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>

#pragma mark - UI组件
@property (nonatomic, strong) UICollectionView *collectionView;
@property (nonatomic, strong) UICollectionViewFlowLayout *flowLayout;
@property (nonatomic, strong) UIRefreshControl *refreshControl;
@property (nonatomic, strong) UIView *emptyView;
@property (nonatomic, strong) UIBarButtonItem *editButton;

#pragma mark - 数据
@property (nonatomic, strong) NSMutableArray<JXDrama *> *favoriteList;
@property (nonatomic, strong) NSMutableSet<NSIndexPath *> *selectedIndexPaths;

#pragma mark - 状态
@property (nonatomic, assign) BOOL isLoading;
@property (nonatomic, assign) BOOL hasMoreData;
@property (nonatomic, assign) NSInteger currentPage;
@property (nonatomic, assign) BOOL isEditMode;

@end

@implementation JXFavoriteViewController

#pragma mark - 初始化

- (instancetype)init {
    self = [super init];
    if (self) {
        _favoriteList = [NSMutableArray array];
        _selectedIndexPaths = [NSMutableSet set];
        _currentPage = 1;
        _hasMoreData = YES;
    }
    return self;
}

#pragma mark - 生命周期

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
    self.title = @"我的收藏";
    
    [self setupUI];
    [self loadFavorites];
}

#pragma mark - UI设置

- (void)setupUI {
    // 编辑按钮
    self.editButton = [[UIBarButtonItem alloc] initWithTitle:@"管理"
                                                       style:UIBarButtonItemStylePlain
                                                      target:self
                                                      action:@selector(handleEdit)];
    self.navigationItem.rightBarButtonItem = self.editButton;
    
    // 创建2列网格布局
    self.flowLayout = [[UICollectionViewFlowLayout alloc] init];
    self.flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
    self.flowLayout.minimumLineSpacing = 12;
    self.flowLayout.minimumInteritemSpacing = 12;
    self.flowLayout.sectionInset = UIEdgeInsetsMake(12, 16, 12, 16);
    
    self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:self.flowLayout];
    self.collectionView.backgroundColor = [UIColor whiteColor];
    self.collectionView.delegate = self;
    self.collectionView.dataSource = self;
    self.collectionView.allowsMultipleSelection = YES;
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:kFavoriteCellIdentifier];
    [self.view addSubview:self.collectionView];
    
    // 下拉刷新
    self.refreshControl = [[UIRefreshControl alloc] init];
    [self.refreshControl addTarget:self action:@selector(handleRefresh) forControlEvents:UIControlEventValueChanged];
    [self.collectionView addSubview:self.refreshControl];
    
    // 空状态
    [self setupEmptyView];
    
    // 约束
    self.collectionView.translatesAutoresizingMaskIntoConstraints = NO;
    [NSLayoutConstraint activateConstraints:@[
        [self.collectionView.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor],
        [self.collectionView.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor],
        [self.collectionView.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor],
        [self.collectionView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor]
    ]];
}

- (void)setupEmptyView {
    self.emptyView = [[UIView alloc] init];
    self.emptyView.hidden = YES;
    [self.view addSubview:self.emptyView];
    
    UILabel *emptyLabel = [[UILabel alloc] init];
    emptyLabel.text = @"暂无收藏\n快去收藏喜欢的短剧吧~";
    emptyLabel.textColor = [UIColor grayColor];
    emptyLabel.font = [UIFont systemFontOfSize:14];
    emptyLabel.textAlignment = NSTextAlignmentCenter;
    emptyLabel.numberOfLines = 0;
    [self.emptyView addSubview:emptyLabel];
    
    self.emptyView.translatesAutoresizingMaskIntoConstraints = NO;
    emptyLabel.translatesAutoresizingMaskIntoConstraints = NO;
    
    [NSLayoutConstraint activateConstraints:@[
        [self.emptyView.centerXAnchor constraintEqualToAnchor:self.view.centerXAnchor],
        [self.emptyView.centerYAnchor constraintEqualToAnchor:self.view.centerYAnchor],
        
        [emptyLabel.centerXAnchor constraintEqualToAnchor:self.emptyView.centerXAnchor],
        [emptyLabel.centerYAnchor constraintEqualToAnchor:self.emptyView.centerYAnchor]
    ]];
}

#pragma mark - 数据加载

- (void)loadFavorites {
    if (self.isLoading) {
        return;
    }
    
    self.isLoading = YES;
    
    // TODO: 调用API获取收藏列表
    // 暂时使用示例数据
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        self.isLoading = NO;
        [self.refreshControl endRefreshing];
        
        // 示例数据
        if (self.currentPage == 1) {
            self.favoriteList = [@[] mutableCopy];
        }
        
        [self.collectionView reloadData];
        self.emptyView.hidden = (self.favoriteList.count > 0);
        self.editButton.enabled = (self.favoriteList.count > 0);
    });
}

- (void)loadMoreFavorites {
    if (!self.hasMoreData || self.isLoading) {
        return;
    }
    
    self.currentPage++;
    [self loadFavorites];
}

- (void)handleRefresh {
    self.currentPage = 1;
    self.hasMoreData = YES;
    [self loadFavorites];
}

#pragma mark - 编辑模式

- (void)handleEdit {
    self.isEditMode = !self.isEditMode;
    
    if (self.isEditMode) {
        // 进入编辑模式
        self.editButton.title = @"取消";
        
        // 显示底部工具栏
        [self showBottomToolbar];
        
    } else {
        // 退出编辑模式
        self.editButton.title = @"管理";
        [self.selectedIndexPaths removeAllObjects];
        [self.collectionView reloadData];
        
        // 隐藏底部工具栏
        [self hideBottomToolbar];
    }
}

- (void)showBottomToolbar {
    UIToolbar *toolbar = [[UIToolbar alloc] init];
    toolbar.frame = CGRectMake(0, self.view.bounds.size.height - 44, self.view.bounds.size.width, 44);
    toolbar.tag = 999;
    
    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    UIBarButtonItem *deleteButton = [[UIBarButtonItem alloc] initWithTitle:@"删除"
                                                                     style:UIBarButtonItemStylePlain
                                                                    target:self
                                                                    action:@selector(handleBatchDelete)];
    deleteButton.tintColor = [UIColor systemRedColor];
    
    toolbar.items = @[flexSpace, deleteButton, flexSpace];
    [self.view addSubview:toolbar];
}

- (void)hideBottomToolbar {
    UIView *toolbar = [self.view viewWithTag:999];
    [toolbar removeFromSuperview];
}

- (void)handleBatchDelete {
    if (self.selectedIndexPaths.count == 0) {
        return;
    }
    
    NSString *message = [NSString stringWithFormat:@"确定要取消收藏选中的%lu部短剧吗？", (unsigned long)self.selectedIndexPaths.count];
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"批量取消收藏"
                                                                   message:message
                                                            preferredStyle:UIAlertControllerStyleAlert];
    
    [alert addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil]];
    [alert addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDestructive handler:^(UIAlertAction *action) {
        [self performBatchDelete];
    }]];
    
    [self presentViewController:alert animated:YES completion:nil];
}

- (void)performBatchDelete {
    // 按索引降序排序，从后往前删除
    NSArray *sortedIndexPaths = [[self.selectedIndexPaths allObjects] sortedArrayUsingComparator:^NSComparisonResult(NSIndexPath *obj1, NSIndexPath *obj2) {
        return [@(obj2.item) compare:@(obj1.item)];
    }];
    
    for (NSIndexPath *indexPath in sortedIndexPaths) {
        if (indexPath.item < self.favoriteList.count) {
            [self.favoriteList removeObjectAtIndex:indexPath.item];
        }
    }
    
    [self.selectedIndexPaths removeAllObjects];
    [self.collectionView reloadData];
    
    // 如果列表为空，退出编辑模式
    if (self.favoriteList.count == 0) {
        [self handleEdit];
        self.emptyView.hidden = NO;
    }
}

#pragma mark - UICollectionViewDataSource

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

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kFavoriteCellIdentifier forIndexPath:indexPath];
    
    // 清除旧内容
    for (UIView *subview in cell.contentView.subviews) {
        [subview removeFromSuperview];
    }
    
    JXDrama *drama = self.favoriteList[indexPath.item];
    
    // 封面图（占位）
    UIView *coverView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, cell.contentView.bounds.size.width, cell.contentView.bounds.size.width * 1.4)];
    coverView.backgroundColor = [UIColor colorWithWhite:0.9 alpha:1.0];
    [cell.contentView addSubview:coverView];
    
    // 标题
    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, coverView.frame.size.height + 8, cell.contentView.bounds.size.width, 40)];
    titleLabel.text = drama.title;
    titleLabel.font = [UIFont systemFontOfSize:14];
    titleLabel.numberOfLines = 2;
    [cell.contentView addSubview:titleLabel];
    
    // 编辑模式：显示选中状态
    if (self.isEditMode) {
        BOOL isSelected = [self.selectedIndexPaths containsObject:indexPath];
        
        UIView *checkmark = [[UIView alloc] initWithFrame:CGRectMake(cell.contentView.bounds.size.width - 30, 10, 24, 24)];
        checkmark.backgroundColor = isSelected ? [UIColor systemBlueColor] : [UIColor colorWithWhite:0.8 alpha:0.8];
        checkmark.layer.cornerRadius = 12;
        [cell.contentView addSubview:checkmark];
        
        if (isSelected) {
            UILabel *checkLabel = [[UILabel alloc] initWithFrame:checkmark.bounds];
            checkLabel.text = @"✓";
            checkLabel.textColor = [UIColor whiteColor];
            checkLabel.font = [UIFont boldSystemFontOfSize:16];
            checkLabel.textAlignment = NSTextAlignmentCenter;
            [checkmark addSubview:checkLabel];
        }
    }
    
    cell.backgroundColor = [UIColor whiteColor];
    cell.layer.cornerRadius = 8;
    
    return cell;
}

#pragma mark - UICollectionViewDelegateFlowLayout

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout *)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat totalWidth = collectionView.bounds.size.width;
    CGFloat spacing = 12;
    CGFloat inset = 16;
    CGFloat availableWidth = totalWidth - (inset * 2) - spacing;
    CGFloat itemWidth = availableWidth / 2;
    CGFloat itemHeight = itemWidth * 1.4 + 60;
    
    return CGSizeMake(itemWidth, itemHeight);
}

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    
    if (self.isEditMode) {
        // 编辑模式：切换选中状态
        if ([self.selectedIndexPaths containsObject:indexPath]) {
            [self.selectedIndexPaths removeObject:indexPath];
        } else {
            [self.selectedIndexPaths addObject:indexPath];
        }
        [collectionView reloadItemsAtIndexPaths:@[indexPath]];
        
    } else {
        // 普通模式：跳转到详情或播放
        JXDrama *drama = self.favoriteList[indexPath.item];
        NSLog(@"[JXFavorite] 点击短剧: %@", drama.title);
        // TODO: 跳转到播放页或详情页
    }
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    // 预加载
    CGFloat offsetY = scrollView.contentOffset.y;
    CGFloat contentHeight = scrollView.contentSize.height;
    CGFloat scrollViewHeight = scrollView.bounds.size.height;
    
    if (offsetY + scrollViewHeight >= contentHeight - 200) {
        [self loadMoreFavorites];
    }
}

@end