//
//  KBAIHomeVC.m
//  keyBoard
//
//  Created by Mac on 2026/1/26.
//

#import "KBAIHomeVC.h"
#import "KBPersonaChatCell.h"
#import "KBPersonaModel.h"
#import "KBVoiceInputBar.h"
#import "AiVM.h"
#import <Masonry/Masonry.h>

@interface KBAIHomeVC () <UICollectionViewDelegate, UICollectionViewDataSource, KBVoiceInputBarDelegate>

/// 人设列表容器
@property (nonatomic, strong) UICollectionView *collectionView;

/// 底部语音输入栏
@property (nonatomic, strong) KBVoiceInputBar *voiceInputBar;

/// 人设数据
@property (nonatomic, strong) NSMutableArray<KBPersonaModel *> *personas;

/// 当前页码
@property (nonatomic, assign) NSInteger currentPage;

/// 是否还有更多数据
@property (nonatomic, assign) BOOL hasMore;

/// 是否正在加载
@property (nonatomic, assign) BOOL isLoading;

/// 当前显示的索引
@property (nonatomic, assign) NSInteger currentIndex;

/// 已预加载的索引集合
@property (nonatomic, strong) NSMutableSet<NSNumber *> *preloadedIndexes;

/// AiVM 实例
@property (nonatomic, strong) AiVM *aiVM;

@end

@implementation KBAIHomeVC

#pragma mark - Lifecycle

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.kb_navView.hidden = true;
    // 初始化数据
    self.personas = [NSMutableArray array];
    self.currentPage = 1;
    self.hasMore = YES;
    self.isLoading = NO;
    self.currentIndex = 0;
    self.preloadedIndexes = [NSMutableSet set];
    self.aiVM = [[AiVM alloc] init];
    
    [self setupUI];
    [self loadPersonas];
}

#pragma mark - 1：控件初始化

- (void)setupUI {
    [self.view addSubview:self.collectionView];
    [self.collectionView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.view);
    }];
    
    // 底部语音输入栏
    [self.view addSubview:self.voiceInputBar];
    [self.voiceInputBar mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.bottom.equalTo(self.view);
        make.height.mas_equalTo(150); // 根据实际需要调整高度
    }];
}

#pragma mark - 2：数据加载

- (void)loadPersonas {
    if (self.isLoading) {
        return;
    }
    
    self.isLoading = YES;
    
    __weak typeof(self) weakSelf = self;
    [self.aiVM fetchPersonasWithPageNum:self.currentPage
                               pageSize:10
                             completion:^(KBPersonaPageModel * _Nullable pageModel, NSError * _Nullable error) {
        weakSelf.isLoading = NO;
        
        if (error) {
            NSLog(@"加载人设列表失败：%@", error.localizedDescription);
            // TODO: 显示错误提示
            return;
        }
        
        if (!pageModel || !pageModel.records) {
            NSLog(@"人设列表数据为空");
            return;
        }
        
        // 追加数据
        [weakSelf.personas addObjectsFromArray:pageModel.records];
        weakSelf.hasMore = pageModel.hasMore;
        
        // 刷新 UI
        dispatch_async(dispatch_get_main_queue(), ^{
            [weakSelf.collectionView reloadData];
            
            // 首次加载，预加载前 3 个
            if (weakSelf.currentPage == 1) {
                [weakSelf preloadDataForIndexes:@[@0, @1, @2]];
            }
        });
        
        NSLog(@"加载成功：当前 %ld 条，总共 %ld 条，还有更多：%@",
              weakSelf.personas.count,
              pageModel.total,
              pageModel.hasMore ? @"是" : @"否");
    }];
}

- (void)loadMorePersonas {
    if (!self.hasMore || self.isLoading) {
        return;
    }
    
    self.currentPage++;
    [self loadPersonas];
}

#pragma mark - 3：预加载逻辑

- (void)preloadAdjacentCellsForIndex:(NSInteger)index {
    if (index < 0 || index >= self.personas.count) {
        return;
    }
    
    NSMutableArray *indexesToPreload = [NSMutableArray array];
    
    // 上一个
    if (index > 0) {
        [indexesToPreload addObject:@(index - 1)];
    }
    
    // 当前
    [indexesToPreload addObject:@(index)];
    
    // 下一个
    if (index < self.personas.count - 1) {
        [indexesToPreload addObject:@(index + 1)];
    }
    
    [self preloadDataForIndexes:indexesToPreload];
}

- (void)preloadDataForIndexes:(NSArray<NSNumber *> *)indexes {
    for (NSNumber *indexNum in indexes) {
        if ([self.preloadedIndexes containsObject:indexNum]) {
            continue;
        }
        
        [self.preloadedIndexes addObject:indexNum];
        
        NSInteger index = [indexNum integerValue];
        if (index >= self.personas.count) {
            continue;
        }
        
        NSIndexPath *indexPath = [NSIndexPath indexPathForItem:index inSection:0];
        KBPersonaChatCell *cell = (KBPersonaChatCell *)[self.collectionView cellForItemAtIndexPath:indexPath];
        
        if (cell) {
            [cell preloadDataIfNeeded];
        }
        
        NSLog(@"预加载第 %ld 个人设", (long)index);
    }
}

#pragma mark - UICollectionViewDataSource

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

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    KBPersonaChatCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"KBPersonaChatCell" forIndexPath:indexPath];
    cell.persona = self.personas[indexPath.item];
    
    // 标记为已预加载
    [self.preloadedIndexes addObject:@(indexPath.item)];
    
    // 直接触发预加载
    [cell preloadDataIfNeeded];
    
    return cell;
}

#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat pageHeight = scrollView.bounds.size.height;
    CGFloat offsetY = scrollView.contentOffset.y;
    NSInteger currentPage = offsetY / pageHeight;
    
    // 滑动超过 30% 就预加载
    if (fmod(offsetY, pageHeight) > pageHeight * 0.3) {
        [self preloadAdjacentCellsForIndex:currentPage + 1];
    } else {
        [self preloadAdjacentCellsForIndex:currentPage];
    }
    
    // 接近底部时加载更多
    if (offsetY + scrollView.bounds.size.height >= scrollView.contentSize.height - pageHeight) {
        [self loadMorePersonas];
    }
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    CGFloat pageHeight = scrollView.bounds.size.height;
    NSInteger currentPage = scrollView.contentOffset.y / pageHeight;
    self.currentIndex = currentPage;
    
    if (currentPage < self.personas.count) {
        NSLog(@"当前在第 %ld 个人设：%@", (long)currentPage, self.personas[currentPage].name);
    }
}

#pragma mark - Lazy Load

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
        layout.scrollDirection = UICollectionViewScrollDirectionVertical;
        layout.minimumLineSpacing = 0;
        layout.minimumInteritemSpacing = 0;
        layout.itemSize = [UIScreen mainScreen].bounds.size;
        
        _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
        _collectionView.pagingEnabled = YES;
        _collectionView.showsVerticalScrollIndicator = NO;
        _collectionView.backgroundColor = [UIColor whiteColor];
        _collectionView.delegate = self;
        _collectionView.dataSource = self;
        [_collectionView registerClass:[KBPersonaChatCell class] forCellWithReuseIdentifier:@"KBPersonaChatCell"];
        
        if (@available(iOS 11.0, *)) {
            _collectionView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
    }
    return _collectionView;
}

- (KBVoiceInputBar *)voiceInputBar {
    if (!_voiceInputBar) {
        _voiceInputBar = [[KBVoiceInputBar alloc] init];
        _voiceInputBar.delegate = self;
        _voiceInputBar.statusText = @"按住按钮开始对话";
    }
    return _voiceInputBar;
}

#pragma mark - KBVoiceInputBarDelegate

- (void)voiceInputBarDidBeginRecording:(KBVoiceInputBar *)inputBar {
    NSLog(@"[KBAIHomeVC] 开始录音");
    inputBar.statusText = @"正在聆听...";
    
    // TODO: 开始录音逻辑
    // 1. 检查登录状态
    // 2. 连接语音识别服务
    // 3. 开始录音
}

- (void)voiceInputBarDidEndRecording:(KBVoiceInputBar *)inputBar {
    NSLog(@"[KBAIHomeVC] 结束录音");
    inputBar.statusText = @"正在识别...";
    
    // TODO: 结束录音逻辑
    // 1. 停止录音
    // 2. 发送音频数据
    // 3. 等待识别结果
}

- (void)voiceInputBarDidCancelRecording:(KBVoiceInputBar *)inputBar {
    NSLog(@"[KBAIHomeVC] 取消录音");
    inputBar.statusText = @"已取消";
    
    // TODO: 取消录音逻辑
    // 1. 停止录音
    // 2. 清理资源
}

@end