//
//  KBPersonaChatCell.m
//  keyBoard
//
//  Created by Kiro on 2026/1/26.
//

#import "KBPersonaChatCell.h"
#import "KBChatTableView.h"
#import "KBAiChatMessage.h"
#import "KBChatHistoryPageModel.h"
#import "AiVM.h"
#import <Masonry/Masonry.h>
#import <SDWebImage/SDWebImage.h>

@interface KBPersonaChatCell () <UITableViewDelegate, UITableViewDataSource>

/// 背景图
@property (nonatomic, strong) UIImageView *backgroundImageView;

/// 头像
@property (nonatomic, strong) UIImageView *avatarImageView;

/// 人设名称
@property (nonatomic, strong) UILabel *nameLabel;

/// 开场白
@property (nonatomic, strong) UILabel *openingLabel;

/// 聊天列表
@property (nonatomic, strong) UITableView *tableView;

/// 聊天消息
@property (nonatomic, strong) NSMutableArray<KBAiChatMessage *> *messages;

/// 是否已加载数据
@property (nonatomic, assign) BOOL hasLoadedData;

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

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

/// 是否还有更多历史消息
@property (nonatomic, assign) BOOL hasMoreHistory;

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

@end

@implementation KBPersonaChatCell

#pragma mark - Lifecycle

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        [self setupUI];
    }
    return self;
}

#pragma mark - 1：控件初始化

- (void)setupUI {
    // 背景图
    [self.contentView addSubview:self.backgroundImageView];
    [self.backgroundImageView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.contentView);
    }];
    
    // 半透明遮罩
    UIView *maskView = [[UIView alloc] init];
    maskView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.3];
    [self.contentView addSubview:maskView];
    [maskView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.contentView);
    }];
    
    // 头像
    [self.contentView addSubview:self.avatarImageView];
    [self.avatarImageView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.contentView).offset(80);
        make.centerX.equalTo(self.contentView);
        make.size.mas_equalTo(CGSizeMake(80, 80));
    }];
    
    // 人设名称
    [self.contentView addSubview:self.nameLabel];
    [self.nameLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.avatarImageView.mas_bottom).offset(12);
        make.centerX.equalTo(self.contentView);
    }];
    
    // 开场白
    [self.contentView addSubview:self.openingLabel];
    [self.openingLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.nameLabel.mas_bottom).offset(8);
        make.left.equalTo(self.contentView).offset(40);
        make.right.equalTo(self.contentView).offset(-40);
    }];
    
    // 聊天列表
    [self.contentView addSubview:self.tableView];
    [self.tableView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.openingLabel.mas_bottom).offset(30);
        make.left.right.bottom.equalTo(self.contentView);
    }];
}

#pragma mark - Setter

- (void)setPersona:(KBPersonaModel *)persona {
    _persona = persona;
    
    // 重置状态
    self.hasLoadedData = NO;
    self.isLoading = NO;
    self.currentPage = 1;
    self.hasMoreHistory = YES;
    self.messages = [NSMutableArray array];
    self.aiVM = [[AiVM alloc] init];
    
    // 设置 UI
    [self.backgroundImageView sd_setImageWithURL:[NSURL URLWithString:persona.coverImageUrl]
                                placeholderImage:[UIImage imageNamed:@"placeholder_bg"]];
    [self.avatarImageView sd_setImageWithURL:[NSURL URLWithString:persona.avatarUrl]
                            placeholderImage:[UIImage imageNamed:@"placeholder_avatar"]];
    self.nameLabel.text = persona.name;
    self.openingLabel.text = persona.shortDesc.length > 0 ? persona.shortDesc : persona.introText;
    
    [self.tableView reloadData];
}

#pragma mark - 2：数据加载

- (void)preloadDataIfNeeded {
    if (self.hasLoadedData || self.isLoading) {
        return;
    }
    
    [self loadChatHistory];
}

- (void)loadChatHistory {
    if (self.isLoading || !self.hasMoreHistory) {
        return;
    }
    
    self.isLoading = YES;
    
    // 使用 persona.personaId 作为 companionId
    NSInteger companionId = self.persona.personaId;
    
    __weak typeof(self) weakSelf = self;
    [self.aiVM fetchChatHistoryWithCompanionId:companionId
                                        pageNum:self.currentPage
                                       pageSize:20
                                     completion:^(KBChatHistoryPageModel *pageModel, NSError *error) {
        weakSelf.isLoading = NO;
        
        if (error) {
            NSLog(@"[KBPersonaChatCell] 加载聊天记录失败：%@", error.localizedDescription);
            
            // 如果是第一次加载失败，显示开场白
            if (weakSelf.currentPage == 1 && weakSelf.persona.introText.length > 0) {
                [weakSelf showOpeningMessage];
            }
            return;
        }
        
        weakSelf.hasLoadedData = YES;
        weakSelf.hasMoreHistory = pageModel.hasMore;
        
        // 转换为 KBAiChatMessage
        NSMutableArray *newMessages = [NSMutableArray array];
        for (KBChatHistoryModel *item in pageModel.records) {
            KBAiChatMessage *message;
            if (item.isUserMessage) {
                message = [KBAiChatMessage userMessageWithText:item.content];
            } else {
                message = [KBAiChatMessage assistantMessageWithText:item.content];
            }
            message.isComplete = YES;
            [newMessages addObject:message];
        }
        
        // 插入到顶部（历史消息）
        if (weakSelf.currentPage == 1) {
            // 第一页，直接赋值
            weakSelf.messages = newMessages;
        } else {
            // 后续页，插入到顶部
            NSIndexSet *indexSet = [NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, newMessages.count)];
            [weakSelf.messages insertObjects:newMessages atIndexes:indexSet];
        }
        
        // 刷新 UI
        dispatch_async(dispatch_get_main_queue(), ^{
            if (weakSelf.currentPage == 1) {
                [weakSelf.tableView reloadData];
                
                // 滚动到底部（最新消息）
                if (weakSelf.messages.count > 0) {
                    NSIndexPath *lastIndexPath = [NSIndexPath indexPathForRow:weakSelf.messages.count - 1 inSection:0];
                    [weakSelf.tableView scrollToRowAtIndexPath:lastIndexPath
                                              atScrollPosition:UITableViewScrollPositionBottom
                                                      animated:NO];
                }
            } else {
                // 保持滚动位置
                CGFloat oldContentHeight = weakSelf.tableView.contentSize.height;
                [weakSelf.tableView reloadData];
                CGFloat newContentHeight = weakSelf.tableView.contentSize.height;
                CGFloat offsetY = newContentHeight - oldContentHeight;
                [weakSelf.tableView setContentOffset:CGPointMake(0, offsetY) animated:NO];
            }
        });
        
        NSLog(@"[KBPersonaChatCell] 加载成功：第 %ld 页，%ld 条消息，还有更多：%@",
              (long)weakSelf.currentPage,
              (long)newMessages.count,
              pageModel.hasMore ? @"是" : @"否");
    }];
}

- (void)loadMoreHistory {
    if (!self.hasMoreHistory || self.isLoading) {
        return;
    }
    
    self.currentPage++;
    [self loadChatHistory];
}

- (void)showOpeningMessage {
    // 显示开场白作为第一条消息
    KBAiChatMessage *openingMsg = [KBAiChatMessage assistantMessageWithText:self.persona.introText];
    openingMsg.isComplete = YES;
    [self.messages addObject:openingMsg];
    
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tableView reloadData];
    });
}

#pragma mark - UITableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.messages.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
        cell.backgroundColor = [UIColor clearColor];
        cell.textLabel.textColor = [UIColor whiteColor];
        cell.textLabel.numberOfLines = 0;
    }
    
    KBAiChatMessage *message = self.messages[indexPath.row];
    cell.textLabel.text = message.text;
    
    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return UITableViewAutomaticDimension;
}

#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat offsetY = scrollView.contentOffset.y;
    
    // 下拉到顶部，加载历史消息
    if (offsetY <= -50 && !self.isLoading) {
        [self loadMoreHistory];
    }
}

#pragma mark - Lazy Load

- (UIImageView *)backgroundImageView {
    if (!_backgroundImageView) {
        _backgroundImageView = [[UIImageView alloc] init];
        _backgroundImageView.contentMode = UIViewContentModeScaleAspectFill;
        _backgroundImageView.clipsToBounds = YES;
    }
    return _backgroundImageView;
}

- (UIImageView *)avatarImageView {
    if (!_avatarImageView) {
        _avatarImageView = [[UIImageView alloc] init];
        _avatarImageView.contentMode = UIViewContentModeScaleAspectFill;
        _avatarImageView.layer.cornerRadius = 40;
        _avatarImageView.layer.borderWidth = 3;
        _avatarImageView.layer.borderColor = [UIColor whiteColor].CGColor;
        _avatarImageView.clipsToBounds = YES;
    }
    return _avatarImageView;
}

- (UILabel *)nameLabel {
    if (!_nameLabel) {
        _nameLabel = [[UILabel alloc] init];
        _nameLabel.font = [UIFont boldSystemFontOfSize:20];
        _nameLabel.textColor = [UIColor whiteColor];
        _nameLabel.textAlignment = NSTextAlignmentCenter;
    }
    return _nameLabel;
}

- (UILabel *)openingLabel {
    if (!_openingLabel) {
        _openingLabel = [[UILabel alloc] init];
        _openingLabel.font = [UIFont systemFontOfSize:14];
        _openingLabel.textColor = [[UIColor whiteColor] colorWithAlphaComponent:0.9];
        _openingLabel.textAlignment = NSTextAlignmentCenter;
        _openingLabel.numberOfLines = 2;
    }
    return _openingLabel;
}

- (UITableView *)tableView {
    if (!_tableView) {
        _tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
        _tableView.delegate = self;
        _tableView.dataSource = self;
        _tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
        _tableView.backgroundColor = [UIColor clearColor];
        _tableView.showsVerticalScrollIndicator = NO;
        _tableView.estimatedRowHeight = 60;
        _tableView.rowHeight = UITableViewAutomaticDimension;
        
        if (@available(iOS 11.0, *)) {
            _tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
    }
    return _tableView;
}

@end