//
//  KBVipPay.m
//  keyBoard
//
//  Created by Mac on 2025/11/14.
//

#import "KBVipPay.h"
#import "KBVipPayHeaderView.h"
#import "KBVipSubscribeCell.h"
#import "KBVipReviewListCell.h"

static NSString * const kKBVipHeaderId = @"kKBVipHeaderId";
static NSString * const kKBVipSubscribeCellId = @"kKBVipSubscribeCellId";
static NSString * const kKBVipReviewListCellId = @"kKBVipReviewListCellId";

@interface KBVipPay () <UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>
@property (nonatomic, strong) UICollectionView *collectionView;   // 主列表（竖向滚动）
@property (nonatomic, strong) NSArray<NSDictionary *> *plans;     // 订阅方案数组
@property (nonatomic, assign) NSInteger selectedIndex;            // 当前选中的方案索引
@property (nonatomic, strong) UIButton *closeButton;            // 当前选中的方案索引
@property (nonatomic, strong) UIImageView *bgImageView;  // 全屏背景图
// Header 自适应测量
@property (nonatomic, strong) KBVipPayHeaderView *sizingHeader;
@property (nonatomic, assign) CGFloat headerHeight;

@end

@implementation KBVipPay

- (void)viewDidLoad {
    [super viewDidLoad];
    // 标题与导航样式
//    self.kb_titleLabel.text = @"VIP";
//    self.kb_navView.backgroundColor = [UIColor clearColor];
    self.view.backgroundColor = [UIColor colorWithHex:0xF6F7FB];
    self.kb_enableCustomNavBar = NO;
    self.bgImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"pay_vipbg_icon"]];
    self.bgImageView.contentMode = UIViewContentModeScaleAspectFill;
    [self.view addSubview:self.bgImageView];
    [self.bgImageView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.top.right.equalTo(self.view);
        make.height.mas_equalTo(224);
    }];
    // 初始化数据（简单演示）
    self.plans = @[
        @{@"title":@"Monthly Subscription", @"price":@"$4.49", @"strike":@"$4.49"},
        @{@"title":@"Monthly Subscription", @"price":@"$4.49", @"strike":@"$4.49"},
        @{@"title":@"Monthly Subscription", @"price":@"$4.49", @"strike":@"$4.49"},
    ];
    self.selectedIndex = 1; // 默认选中第二项
    
    // 组装主列表
    [self.view addSubview:self.collectionView];
    [self.collectionView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.bottom.equalTo(self.view);
        make.top.equalTo(self.view).offset(0);
    }];
    [self.view addSubview:self.closeButton];
    [self.closeButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.view).offset(KB_NAV_TOTAL_HEIGHT - 30);
        make.left.equalTo(self.view).offset(15);
        make.width.height.mas_equalTo(36);
    }];
    
    // 预计算 Header 高度（由内部约束决定）
    self.headerHeight = [self kb_calcHeaderHeightForWidth:KB_SCREEN_WIDTH];
    [self.collectionView reloadData];
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    // 首次进入，确保订阅项保持选中态（避免首屏仅显示 Header，待滚动出现时没有选中样式）
    NSIndexPath *ip = [NSIndexPath indexPathForItem:self.selectedIndex inSection:1];
    if (!ip) { return; }
    // 系统层面也置为选中
    [self.collectionView selectItemAtIndexPath:ip animated:NO scrollPosition:UICollectionViewScrollPositionNone];
    // 若此时 cell 不可见，willDisplay 再兜底
    KBVipSubscribeCell *cell = (KBVipSubscribeCell *)[self.collectionView cellForItemAtIndexPath:ip];
    if (cell) { [cell applySelected:YES animated:NO]; }
}

#pragma mark - Header Height Calc
- (CGFloat)kb_calcHeaderHeightForWidth:(CGFloat)width {
    if (width <= 0) { width = KB_SCREEN_WIDTH; }
    if (!self.sizingHeader) {
        self.sizingHeader = [[KBVipPayHeaderView alloc] initWithFrame:CGRectMake(0, 0, width, 1)];
    }
    // 更新目标宽度并触发布局
    self.sizingHeader.bounds = CGRectMake(0, 0, width, self.sizingHeader.bounds.size.height);
    [self.sizingHeader setNeedsLayout];
    [self.sizingHeader layoutIfNeeded];
    CGSize size = [self.sizingHeader systemLayoutSizeFittingSize:CGSizeMake(width, UILayoutFittingCompressedSize.height)
                                  withHorizontalFittingPriority:UILayoutPriorityRequired
                                        verticalFittingPriority:UILayoutPriorityFittingSizeLevel];
    return MAX(1, ceil(size.height));
}

#pragma mark - Action
- (void)onTapClose{
    [self.navigationController popViewControllerAnimated:true];
}

#pragma mark - UICollectionView DataSource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    // 0：头部；1：订阅选项；2：底部横滑好评
    return 3;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    if (section == 1) { return self.plans.count; }
    if (section == 2) { return 1; }
    return 0; // 头部仅使用 header
}

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 1) {
        KBVipSubscribeCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kKBVipSubscribeCellId forIndexPath:indexPath];
        NSDictionary *plan = self.plans[indexPath.item];
        [cell configTitle:plan[@"title"] price:plan[@"price"] strike:plan[@"strike"]];
        [cell applySelected:(indexPath.item == self.selectedIndex) animated:NO];
        return cell;
    } else {
        KBVipReviewListCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kKBVipReviewListCellId forIndexPath:indexPath];
        return cell;
    }
}

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 0 && [kind isEqualToString:UICollectionElementKindSectionHeader]) {
        KBVipPayHeaderView *header = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:kKBVipHeaderId forIndexPath:indexPath];
        return header;
    }
    return [UICollectionReusableView new];
}

#pragma mark - UICollectionView Delegate
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section != 1) { return; }
    if (self.selectedIndex == indexPath.item) { return; }
    NSInteger old = self.selectedIndex;
    self.selectedIndex = indexPath.item;
    
    KBVipSubscribeCell *newCell = (KBVipSubscribeCell *)[collectionView cellForItemAtIndexPath:indexPath];
    [newCell applySelected:YES animated:YES];
    if (old >= 0 && old < self.plans.count) {
        NSIndexPath *oldIP = [NSIndexPath indexPathForItem:old inSection:1];
        KBVipSubscribeCell *oldCell = (KBVipSubscribeCell *)[collectionView cellForItemAtIndexPath:oldIP];
        [oldCell applySelected:NO animated:YES];
    }
}

- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath {
    // 兜底：当订阅项第一次出现在屏幕上，强制同步选中样式
    if (indexPath.section == 1 && [cell isKindOfClass:KBVipSubscribeCell.class]) {
        BOOL sel = (indexPath.item == self.selectedIndex);
        KBVipSubscribeCell *c = (KBVipSubscribeCell *)cell;
        if (sel) {
            [collectionView selectItemAtIndexPath:indexPath animated:NO scrollPosition:UICollectionViewScrollPositionNone];
        }
        [c applySelected:sel animated:NO];
    }
}

#pragma mark - FlowLayout
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat w = KB_SCREEN_WIDTH - 32;
    if (indexPath.section == 1) {
        return CGSizeMake(w, KBFit(75 + 6));
    } else {
        return CGSizeMake(w, 140);
    }
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
    if (section == 0) {
        // 动态返回测量好的 Header 高度
        CGFloat w = collectionView.bounds.size.width ?: KB_SCREEN_WIDTH;
        if (self.headerHeight <= 1) { self.headerHeight = [self kb_calcHeaderHeightForWidth:w]; }
        return CGSizeMake(w, self.headerHeight);
    }
    return CGSizeZero;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    if (section == 1) { return 14; }
    return 0;
}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    if (section == 1) {
        // 留出顶部间距，避免第一个订阅 cell 的边框被 header 盖住
        return UIEdgeInsetsMake(16, 16, 10, 16);
    } else if (section == 2) {
        return UIEdgeInsetsMake(10, 16, 20, 16);
    }
    return UIEdgeInsetsZero;
}

#pragma mark - Lazy
- (UICollectionView *)collectionView {
    if (!_collectionView) {
        UICollectionViewFlowLayout *layout = [UICollectionViewFlowLayout new];
        layout.scrollDirection = UICollectionViewScrollDirectionVertical;
        // 每次宽度变化时让布局失效，便于 header 重算高度
        layout.sectionHeadersPinToVisibleBounds = NO;
        _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
        _collectionView.backgroundColor = [UIColor clearColor];
        _collectionView.dataSource = self;
        _collectionView.delegate = self;
        _collectionView.alwaysBounceVertical = YES;
        if (@available(iOS 11.0, *)) {
            _collectionView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
        [_collectionView registerClass:KBVipPayHeaderView.class forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:kKBVipHeaderId];
        [_collectionView registerClass:KBVipSubscribeCell.class forCellWithReuseIdentifier:kKBVipSubscribeCellId];
        [_collectionView registerClass:KBVipReviewListCell.class forCellWithReuseIdentifier:kKBVipReviewListCellId];
    }
    return _collectionView;
}


- (UIButton *)closeButton {
    if (!_closeButton) {
        _closeButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [_closeButton setImage:[UIImage imageNamed:@"close_white2_icon"] forState:UIControlStateNormal];
        [_closeButton addTarget:self action:@selector(onTapClose) forControlEvents:UIControlEventTouchUpInside];
    }
    return _closeButton;
}

- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];
    // 宽度变化时重算 Header 高度并刷新布局
    CGFloat w = self.collectionView.bounds.size.width ?: KB_SCREEN_WIDTH;
    CGFloat newH = [self kb_calcHeaderHeightForWidth:w];
    if (fabs(newH - self.headerHeight) > 0.5) {
        self.headerHeight = newH;
        UICollectionViewFlowLayout *layout = (UICollectionViewFlowLayout *)self.collectionView.collectionViewLayout;
        [layout invalidateLayout];
    }
}
@end