//
//  KBSkinDetailVC.m
//  keyBoard
//
//  皮肤详情页（UICollectionView 实现）
//  结构：
//  - Section0：顶部大卡片（上图，下方左右两段文案）
//  - Section1：标签容器 cell（内部再嵌套一个 collectionView 以展示 Cute/Fresh 等标签）
//  - Section2：区块标题 cell（例如 “Recommended Skin”）
//  - Section3：推荐皮肤 2 列网格（使用已有 KBSkinCardCell）
//

#import "KBSkinDetailVC.h"
#import <Masonry/Masonry.h>
#import "UIColor+Extension.h"
#import "UICollectionViewLeftAlignedLayout.h"
#import "KBSkinDetailHeaderCell.h"
#import "KBSkinTagsContainerCell.h"
#import "KBSkinCardCell.h"    // 已有的 皮肤卡片 cell（用作 2 列网格）
#import "KBSkinSectionTitleCell.h"

static NSString * const kHeaderCellId = @"kHeaderCellId";
static NSString * const kTagsContainerCellId = @"kTagsContainerCellId";
static NSString * const kSectionTitleCellId = @"kSectionTitleCellId";
static NSString * const kGridCellId = @"kGridCellId"; // 直接复用 KBSkinCardCell

typedef NS_ENUM(NSInteger, KBSkinDetailSection) {
    KBSkinDetailSectionHeader = 0,
    KBSkinDetailSectionTags,
    KBSkinDetailSectionTitle,
    KBSkinDetailSectionGrid,
    KBSkinDetailSectionCount
};

@interface KBSkinDetailVC () <UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>
@property (nonatomic, strong) UICollectionView *collectionView; // 主列表
@property (nonatomic, copy) NSArray<NSString *> *tags;           // 标签数据
@property (nonatomic, copy) NSArray<NSDictionary *> *gridData;   // 底部网格数据
@end

@implementation KBSkinDetailVC

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];

    // 简单数据（演示）
    self.tags = @[ @"Cute", @"Fresh", @"Cute", @"Fresh", @"Cute", @"Fresh" ];
    self.gridData = @[
        @{ @"title": @"Dopamine" }, @{ @"title": @"Dopamine" },
        @{ @"title": @"Dopamine" }, @{ @"title": @"Dopamine" },
        @{ @"title": @"Dopamine" }, @{ @"title": @"Dopamine" },
    ];

    [self.view addSubview:self.collectionView];
    [self.collectionView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.view);
    }];
}

#pragma mark - UICollectionView DataSource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return KBSkinDetailSectionCount;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    switch (section) {
        case KBSkinDetailSectionHeader: return 1; // 顶部大卡片
        case KBSkinDetailSectionTags:   return 1; // 标签容器
        case KBSkinDetailSectionTitle:  return 1; // 标题
        case KBSkinDetailSectionGrid:   return self.gridData.count; // 2 列网格
    }
    return 0;
}

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    switch (indexPath.section) {
        case KBSkinDetailSectionHeader: {
            KBSkinDetailHeaderCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kHeaderCellId forIndexPath:indexPath];
            [cell configWithTitle:@"Dopamine" right:@"Download: 1 Million"];
            return cell;
        }
        case KBSkinDetailSectionTags: {
            KBSkinTagsContainerCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kTagsContainerCellId forIndexPath:indexPath];
            [cell configWithTags:self.tags];
            return cell;
        }
        case KBSkinDetailSectionTitle: {
            KBSkinSectionTitleCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kSectionTitleCellId forIndexPath:indexPath];
            [cell config:@"Recommended Skin"];
            return cell;
        }
        case KBSkinDetailSectionGrid: {
            KBSkinCardCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kGridCellId forIndexPath:indexPath];
            NSDictionary *d = self.gridData[indexPath.item];
            [cell configWithTitle:d[@"title"] imageURL:nil price:@"20"];
            return cell;
        }
    }
    return [UICollectionViewCell new];
}

#pragma mark - UICollectionView DelegateFlowLayout

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat W = collectionView.bounds.size.width;
    CGFloat insetLR = 16.0;
    CGFloat contentW = W - insetLR * 2;
    switch (indexPath.section) {
        case KBSkinDetailSectionHeader: {
            // 高度 = 图片 0.58W + 文案与上下留白（≈56）
            CGFloat h = contentW * 0.58 + 56;
            return CGSizeMake(contentW, h);
        }
        case KBSkinDetailSectionTags: {
            CGFloat h = [KBSkinTagsContainerCell heightForTags:self.tags width:W];
            return CGSizeMake(contentW, h);
        }
        case KBSkinDetailSectionTitle: {
            return CGSizeMake(contentW, 44);
        }
        case KBSkinDetailSectionGrid: {
            // 2 列
            CGFloat spacing = 12.0;
            CGFloat itemW = floor((contentW - spacing) / 2.0);
            CGFloat itemH = itemW * 0.75 + 56; // 参考 KBSkinCardCell 内部布局
            return CGSizeMake(itemW, itemH);
        }
    }
    return CGSizeZero;
}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    return UIEdgeInsetsMake(12, 16, 12, 16);
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    return 12.0;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
    // 网格区需要这个间距，其它区也保持统一
    return 12.0;
}

#pragma mark - Lazy

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        UICollectionViewFlowLayout *layout = [UICollectionViewFlowLayout new];
        layout.scrollDirection = UICollectionViewScrollDirectionVertical;
        _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
        _collectionView.backgroundColor = [UIColor whiteColor];
        _collectionView.dataSource = self;
        _collectionView.delegate = self;

        // 注册 cell
        [_collectionView registerClass:KBSkinDetailHeaderCell.class forCellWithReuseIdentifier:kHeaderCellId];
        [_collectionView registerClass:KBSkinTagsContainerCell.class forCellWithReuseIdentifier:kTagsContainerCellId];
        [_collectionView registerClass:KBSkinSectionTitleCell.class forCellWithReuseIdentifier:kSectionTitleCellId];
        [_collectionView registerClass:KBSkinCardCell.class forCellWithReuseIdentifier:kGridCellId];
    }
    return _collectionView;
}

@end