keyboard/keyBoard/Class/Search/VC/KBSearchVC.m

//
//  KBSearchVC.m
//  keyBoard
//
//  Created by Mac on 2025/11/7.
//

#import "KBSearchVC.h"
#import "KBSearchBarView.h"
#import "KBSearchSectionHeader.h"
#import "KBTagCell.h"
#import "KBSkinCardCell.h"

static NSString * const kTagCellId = @"KBTagCell";
static NSString * const kSkinCellId = @"KBSkinCardCell";
static NSString * const kHeaderId  = @"KBSearchSectionHeader";

typedef NS_ENUM(NSInteger, KBSearchSection) {
    KBSearchSectionHistory = 0,
    KBSearchSectionRecommend = 1,
};

@interface KBSearchVC ()<UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>
// 顶部搜索栏（封装的 View）
@property (nonatomic, strong) KBSearchBarView *searchBarView;
// 列表
@property (nonatomic, strong) UICollectionView *collectionView;
@property (nonatomic, strong) UICollectionViewFlowLayout *flowLayout;

// 数据
@property (nonatomic, strong) NSMutableArray<NSString *> *historyWords;   // 历史搜索
@property (nonatomic, strong) NSArray<NSDictionary *> *recommendItems;    // 推荐数据（title/price）
@end

@implementation KBSearchVC

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

    // UI
    [self.view addSubview:self.searchBarView];
    [self.view addSubview:self.collectionView];

    // 布局 - Masonry
    [self.searchBarView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.view.mas_top).offset(KB_NAV_TOTAL_HEIGHT + 8);
        make.left.equalTo(self.view).offset(16);
        make.right.equalTo(self.view).offset(-16);
        make.height.mas_equalTo(40);
    }];

    [self.collectionView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.searchBarView.mas_bottom).offset(12);
        make.left.right.bottom.equalTo(self.view);
    }];

    // 初始化测试数据
    self.historyWords = [@[@"果冻橙", @"芒果", @"有机水果卷心菜", @"水果萝卜", @"熟冻帝王蟹", @"赣南脐橙"] mutableCopy];
    self.recommendItems = @[
        @{@"title":@"Dopamine", @"price":@"20"},
        @{@"title":@"Dopamine", @"price":@"20"},
        @{@"title":@"Dopamine", @"price":@"20"},
        @{@"title":@"Dopamine", @"price":@"20"},
        @{@"title":@"Dopamine", @"price":@"20"},
        @{@"title":@"Dopamine", @"price":@"20"},
    ];

    [self.collectionView reloadData];
}

#pragma mark - Private

/// 执行搜索：简单将关键字加入历史
- (void)performSearch:(NSString *)kw {
    NSString *trim = [kw stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    if (trim.length == 0) { return; }
    // 去重插入到最前
    [self.historyWords removeObject:trim];
    [self.historyWords insertObject:trim atIndex:0];
    [self.collectionView reloadData];
}

/// 清空历史
- (void)clearHistory {
    [self.historyWords removeAllObjects];
    [self.collectionView reloadData];
}

#pragma mark - UICollectionViewDataSource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 2; // 历史 + 推荐
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    if (section == KBSearchSectionHistory) {
        return self.historyWords.count; // 无历史则为 0
    }
    return self.recommendItems.count;
}

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == KBSearchSectionHistory) {
        KBTagCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kTagCellId forIndexPath:indexPath];
        [cell config:self.historyWords[indexPath.item]];
        return cell;
    }
    KBSkinCardCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kSkinCellId forIndexPath:indexPath];
    NSDictionary *it = self.recommendItems[indexPath.item];
    [cell configWithTitle:it[@"title"] imageURL:nil price:it[@"price"]];
    return cell;
}

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
    if (kind == UICollectionElementKindSectionHeader) {
        KBSearchSectionHeader *header = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:kHeaderId forIndexPath:indexPath];
        if (indexPath.section == KBSearchSectionHistory) {
            // 当没有历史时，外部通过 sizeForHeader 返回 0，这里仍设置但不会显示
            [header configWithTitle:@"Historical Search" showTrash:self.historyWords.count > 0];
            __weak typeof(self) weakSelf = self;
            header.onTapTrash = ^{ [weakSelf clearHistory]; };
        } else {
            [header configWithTitle:@"Recommended Skin" showTrash:NO];
        }
        return header;
    }
    return [UICollectionReusableView new];
}

#pragma mark - UICollectionViewDelegateFlowLayout

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat width = collectionView.bounds.size.width;
    if (indexPath.section == KBSearchSectionHistory) {
        NSString *t = self.historyWords[indexPath.item];
        return [KBTagCell sizeForText:t];
    }
    // 两列卡片
    CGFloat inset = 16;     // 左右间距
    CGFloat spacing = 12;   // 列间距
    CGFloat w = floor((width - inset*2 - spacing) / 2.0);
    // 高度：封面 0.75w + 标题 + 价格 + 边距，近似定高
    CGFloat h = w*0.75 + 8 + 20 + 10 + 6 + 8; // 估算
    return CGSizeMake(w, h);
}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    if (section == KBSearchSectionHistory) {
        return UIEdgeInsetsMake(8, 16, 12, 16);
    }
    return UIEdgeInsetsMake(8, 16, 20, 16);
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
    return section == KBSearchSectionHistory ? 8 : 12;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    return section == KBSearchSectionHistory ? 8 : 16;
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
    // 当历史记录为空时，header 高度为 0，从而不显示标题与垃圾桶
    if (section == KBSearchSectionHistory) {
        return self.historyWords.count == 0 ? CGSizeZero : CGSizeMake(collectionView.bounds.size.width, 40);
    }
    return CGSizeMake(collectionView.bounds.size.width, 40);
}

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == KBSearchSectionHistory) {
        NSString *kw = self.historyWords[indexPath.item];
        [self.searchBarView updateKeyword:kw];
        [self performSearch:kw];
    }
}

#pragma mark - Lazy

- (KBSearchBarView *)searchBarView {
    if (!_searchBarView) {
        _searchBarView = [[KBSearchBarView alloc] init];
        _searchBarView.placeholder = @"Themes";
        __weak typeof(self) weakSelf = self;
        _searchBarView.onSearch = ^(NSString * _Nonnull keyword) {
            [weakSelf performSearch:keyword];
        };
    }
    return _searchBarView;
}

- (UICollectionViewFlowLayout *)flowLayout {
    if (!_flowLayout) {
        _flowLayout = [[UICollectionViewFlowLayout alloc] init];
        _flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
        _flowLayout.sectionHeadersPinToVisibleBounds = NO;
    }
    return _flowLayout;
}

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:self.flowLayout];
        _collectionView.backgroundColor = [UIColor whiteColor];
        _collectionView.dataSource = self;
        _collectionView.delegate = self;
        // 注册 cell & header
        [_collectionView registerClass:KBTagCell.class forCellWithReuseIdentifier:kTagCellId];
        [_collectionView registerClass:KBSkinCardCell.class forCellWithReuseIdentifier:kSkinCellId];
        [_collectionView registerClass:KBSearchSectionHeader.class forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:kHeaderId];
    }
    return _collectionView;
}

@end