//
//  KBAICommentView.m
//  keyBoard
//
//  Created by Mac on 2026/1/16.
//

#import "KBAICommentView.h"
#import "KBAICommentFooterView.h"
#import "KBAICommentHeaderView.h"
#import "KBAICommentInputView.h"
#import "KBAICommentModel.h"
#import "KBAIReplyCell.h"
#import "KBAIReplyModel.h"
#import "KBCommentModel.h"
#import "AiVM.h"
#import "KBUserSessionManager.h"
#import "KBUser.h"
#import <MJExtension/MJExtension.h>
#import <Masonry/Masonry.h>
#import <MJRefresh/MJRefresh.h>

static NSString *const kCommentHeaderIdentifier = @"CommentHeader";
static NSString *const kReplyCellIdentifier = @"ReplyCell";
static NSString *const kCommentFooterIdentifier = @"CommentFooter";

@interface KBAICommentView () <UITableViewDataSource, UITableViewDelegate>

@property(nonatomic, strong) UIVisualEffectView *blurBackgroundView;
@property(nonatomic, strong) UIView *headerView;
@property(nonatomic, strong) UILabel *titleLabel;
@property(nonatomic, strong) UIButton *closeButton;
@property(nonatomic, strong) BaseTableView *tableView;
@property(nonatomic, strong) KBAICommentInputView *inputView;

@property(nonatomic, strong) NSMutableArray<KBAICommentModel *> *comments;

/// Pagination params
@property(nonatomic, assign) NSInteger currentPage;
@property(nonatomic, assign) NSInteger pageSize;
@property(nonatomic, assign) BOOL isLoading;
@property(nonatomic, assign) BOOL hasMoreData;

/// Keyboard height
@property(nonatomic, assign) CGFloat keyboardHeight;
/// Bottom constraint for input view
@property(nonatomic, strong) MASConstraint *inputBottomConstraint;

/// Current reply target (top-level comment)
@property(nonatomic, weak) KBAICommentModel *replyToComment;
/// Current reply target (reply)
@property(nonatomic, weak) KBAIReplyModel *replyToReply;

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

@end

@implementation KBAICommentView

#pragma mark - Local Model Builders

- (NSString *)currentUserName {
  KBUser *user = [KBUserSessionManager shared].currentUser;
  if (user.nickName.length > 0) {
    return user.nickName;
  }
  return KBLocalized(@"Me");
}

- (NSString *)currentUserId {
  KBUser *user = [KBUserSessionManager shared].currentUser;
  return user.userId ?: @"";
}

- (NSString *)currentUserAvatarUrl {
  KBUser *user = [KBUserSessionManager shared].currentUser;
  return user.avatarUrl ?: @"";
}

- (NSString *)generateTempIdString {
  long long ms = (long long)([[NSDate date] timeIntervalSince1970] * 1000.0);
  // Use negative values to avoid colliding with server IDs
  long long tmp = -ms;
  return [NSString stringWithFormat:@"%lld", tmp];
}

- (KBAICommentModel *)buildLocalNewCommentWithText:(NSString *)text
                                        serverItem:(KBCommentItem *_Nullable)serverItem
                                        tableWidth:(CGFloat)tableWidth {
  KBAICommentModel *comment = [[KBAICommentModel alloc] init];
  NSString *cid = nil;
  if (serverItem && serverItem.commentId > 0) {
    cid = [NSString stringWithFormat:@"%ld", (long)serverItem.commentId];
  } else {
    cid = [self generateTempIdString];
  }
  comment.commentId = cid;
  comment.userId = [self currentUserId];
  comment.userName = [self currentUserName];
  comment.avatarUrl = [self currentUserAvatarUrl];
  comment.content = text ?: @"";
  comment.likeCount = 0;
  comment.liked = NO;
  comment.createTime = [[NSDate date] timeIntervalSince1970];
  comment.replies = @[];
  comment.cachedHeaderHeight =
      [comment calculateHeaderHeightWithMaxWidth:tableWidth];
  return comment;
}

- (KBAIReplyModel *)buildLocalNewReplyWithText:(NSString *)text
                                    serverItem:(KBCommentItem *_Nullable)serverItem
                                replyToUserName:(NSString *)replyToUserName
                                    tableWidth:(CGFloat)tableWidth {
  KBAIReplyModel *reply = [[KBAIReplyModel alloc] init];
  NSString *rid = nil;
  if (serverItem && serverItem.commentId > 0) {
    rid = [NSString stringWithFormat:@"%ld", (long)serverItem.commentId];
  } else {
    rid = [self generateTempIdString];
  }
  reply.replyId = rid;
  reply.userId = [self currentUserId];
  reply.userName = [self currentUserName];
  reply.avatarUrl = [self currentUserAvatarUrl];
  reply.content = text ?: @"";
  reply.replyToUserName = replyToUserName ?: @"";
  reply.likeCount = 0;
  reply.liked = NO;
  reply.createTime = [[NSDate date] timeIntervalSince1970];
  reply.cachedCellHeight = [reply calculateCellHeightWithMaxWidth:tableWidth];
  return reply;
}

#pragma mark - Lifecycle

- (instancetype)initWithFrame:(CGRect)frame {
  self = [super initWithFrame:frame];
  if (self) {
    self.comments = [NSMutableArray array];
    self.currentPage = 1;
    self.pageSize = 20;
    self.hasMoreData = YES;
    [self setupUI];
    [self setupKeyboardObservers];
  }
  return self;
}

- (void)dealloc {
  [[NSNotificationCenter defaultCenter] removeObserver:self];
}

#pragma mark - UI Setup

- (void)setupUI {
  // Make background transparent so blur effect is visible
  self.backgroundColor = [UIColor clearColor];
  self.layer.cornerRadius = 12;
  self.layer.maskedCorners = kCALayerMinXMinYCorner | kCALayerMaxXMinYCorner;
  self.clipsToBounds = YES;

  // Add blur background (bottom-most layer)
  [self addSubview:self.blurBackgroundView];
  [self.blurBackgroundView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.edges.equalTo(self);
  }];

  [self addSubview:self.headerView];
  [self.headerView addSubview:self.titleLabel];
  [self.headerView addSubview:self.closeButton];
  [self addSubview:self.tableView];
  [self addSubview:self.inputView];

  [self.headerView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.left.right.equalTo(self);
    make.height.mas_equalTo(50);
  }];

  [self.titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {
    make.center.equalTo(self.headerView);
  }];

  [self.closeButton mas_makeConstraints:^(MASConstraintMaker *make) {
    make.right.equalTo(self.headerView).offset(-16);
    make.centerY.equalTo(self.headerView);
    make.width.height.mas_equalTo(25);
  }];

  [self.inputView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.left.right.equalTo(self).inset(12);
    make.height.mas_equalTo(52);
    self.inputBottomConstraint =
        make.bottom.equalTo(self).offset(-KB_SafeAreaBottom());
  }];

  [self.tableView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(self.headerView.mas_bottom);
    make.left.right.equalTo(self);
    make.bottom.equalTo(self.inputView.mas_top);
  }];

  // Load more on pull-up
  __weak typeof(self) weakSelf = self;
  MJRefreshAutoNormalFooter *footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }
    [strongSelf loadMoreComments];
  }];
  footer.stateLabel.hidden = YES;
  footer.backgroundColor = [UIColor clearColor];
  footer.automaticallyHidden = YES;
  self.tableView.mj_footer = footer;
}

#pragma mark - Keyboard Observers

- (void)setupKeyboardObservers {
  [[NSNotificationCenter defaultCenter]
      addObserver:self
         selector:@selector(keyboardWillShow:)
             name:UIKeyboardWillShowNotification
           object:nil];
  [[NSNotificationCenter defaultCenter]
      addObserver:self
         selector:@selector(keyboardWillHide:)
             name:UIKeyboardWillHideNotification
           object:nil];
}

- (void)keyboardWillShow:(NSNotification *)notification {
  CGRect keyboardFrame =
      [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
  NSTimeInterval duration =
      [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey]
          doubleValue];

  self.keyboardHeight = keyboardFrame.size.height;

  [self.inputBottomConstraint uninstall];
  [self.inputView mas_updateConstraints:^(MASConstraintMaker *make) {
    self.inputBottomConstraint =
        make.bottom.equalTo(self).offset(-self.keyboardHeight);
  }];

  [UIView animateWithDuration:duration
                   animations:^{
                     [self layoutIfNeeded];
                   }];
}

- (void)keyboardWillHide:(NSNotification *)notification {
  NSTimeInterval duration =
      [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey]
          doubleValue];

  self.keyboardHeight = 0;

  [self.inputBottomConstraint uninstall];
  [self.inputView mas_updateConstraints:^(MASConstraintMaker *make) {
    self.inputBottomConstraint =
        make.bottom.equalTo(self).offset(-KB_SafeAreaBottom());
  }];

  [UIView animateWithDuration:duration
                   animations:^{
                     [self layoutIfNeeded];
                   }];
}

#pragma mark - Data Loading

- (void)loadComments {
  if (self.isLoading) {
    return;
  }

  self.currentPage = 1;
  self.hasMoreData = YES;
  [self.tableView.mj_footer resetNoMoreData];

  [self fetchCommentsAtPage:self.currentPage append:NO];
}

- (void)loadMoreComments {
  if (self.isLoading) {
    [self.tableView.mj_footer endRefreshing];
    return;
  }

  if (!self.hasMoreData) {
    [self.tableView.mj_footer endRefreshingWithNoMoreData];
    return;
  }

  NSInteger nextPage = self.currentPage + 1;
  [self fetchCommentsAtPage:nextPage append:YES];
}

- (void)fetchCommentsAtPage:(NSInteger)page append:(BOOL)append {
  if (self.companionId <= 0) {
    NSLog(@"[KBAICommentView] companionId is not set, cannot load comments");
    [self showEmptyState];
    [self.tableView.mj_footer endRefreshing];
    return;
  }

  self.isLoading = YES;
  
  __weak typeof(self) weakSelf = self;
  [self.aiVM fetchCommentsWithCompanionId:self.companionId
                                   pageNum:page
                                  pageSize:self.pageSize
                                completion:^(KBCommentPageModel *pageModel, NSError *error) {
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }

    strongSelf.isLoading = NO;
    
    if (error) {
      NSLog(@"[KBAICommentView] Failed to load comments: %@", error.localizedDescription);
      dispatch_async(dispatch_get_main_queue(), ^{
        if (append) {
          [strongSelf.tableView.mj_footer endRefreshing];
        } else {
          [strongSelf showEmptyStateWithError];
        }
      });
      return;
    }
    
    dispatch_async(dispatch_get_main_queue(), ^{
      [strongSelf updateCommentsWithPageModel:pageModel append:append];
    });
  }];
}

/// Update comments (convert backend KBCommentPageModel to UI KBAICommentModel)
- (void)updateCommentsWithPageModel:(KBCommentPageModel *)pageModel append:(BOOL)append {
  if (!pageModel) {
    NSLog(@"[KBAICommentView] pageModel is nil");
    // Data is empty, show empty state
    [self showEmptyState];
    [self.tableView.mj_footer endRefreshing];
    return;
  }
  
//  self.totalCommentCount = pageModel.total;

  if (!append) {
    [self.comments removeAllObjects];
  }
  
  // Get tableView width for height calculation
  CGFloat tableWidth = self.tableView.bounds.size.width;
  if (tableWidth <= 0) {
    tableWidth = [UIScreen mainScreen].bounds.size.width;
  }
  
  NSLog(@"[KBAICommentView] Loaded %ld comments, total %ld, page: %ld/%ld", (long)pageModel.records.count, (long)pageModel.total, (long)pageModel.current, (long)pageModel.pages);
  
  for (KBCommentItem *item in pageModel.records) {
    // Convert to KBAICommentModel (via MJExtension)
    // Note: KBCommentItem maps backend field id to commentId via MJExtension.
    // If we directly use mj_keyValues, the dictionary only has commentId and
    // KBAICommentModel/KBAIReplyModel mapping (commentId/replyId -> id) misses it.
    // That would make commentId/replyId empty and break parentId/rootId when replying.
    NSMutableDictionary *itemKV = [[item mj_keyValues] mutableCopy];
    id commentIdVal = itemKV[@"commentId"];
    if (commentIdVal) {
      itemKV[@"id"] = commentIdVal;
      [itemKV removeObjectForKey:@"commentId"];
    }

    id repliesObj = itemKV[@"replies"];
    if ([repliesObj isKindOfClass:[NSArray class]]) {
      NSArray *replies = (NSArray *)repliesObj;
      NSMutableArray *fixedReplies = [NSMutableArray arrayWithCapacity:replies.count];
      for (id obj in replies) {
        if (![obj isKindOfClass:[NSDictionary class]]) {
          continue;
        }
        NSMutableDictionary *replyKV = [((NSDictionary *)obj) mutableCopy];
        id replyCommentIdVal = replyKV[@"commentId"];
        if (replyCommentIdVal) {
          replyKV[@"id"] = replyCommentIdVal;
          [replyKV removeObjectForKey:@"commentId"];
        }
        [fixedReplies addObject:[replyKV copy]];
      }
      itemKV[@"replies"] = [fixedReplies copy];
    }

    KBAICommentModel *comment = [KBAICommentModel mj_objectWithKeyValues:[itemKV copy]];
    
    // Precompute and cache header height
    comment.cachedHeaderHeight = [comment calculateHeaderHeightWithMaxWidth:tableWidth];
    
    // Precompute and cache all reply heights
    for (KBAIReplyModel *reply in comment.replies) {
      reply.cachedCellHeight = [reply calculateCellHeightWithMaxWidth:tableWidth];
    }
    
    [self.comments addObject:comment];
  }
  
  [self updateTitle];
  [self.tableView reloadData];

  // Update pagination state
  self.currentPage = pageModel.current > 0 ? pageModel.current : self.currentPage;
  if (pageModel.pages > 0) {
    self.hasMoreData = pageModel.current < pageModel.pages;
  } else {
    self.hasMoreData = pageModel.records.count >= self.pageSize;
  }

  if (self.hasMoreData) {
    [self.tableView.mj_footer endRefreshing];
  } else {
    [self.tableView.mj_footer endRefreshingWithNoMoreData];
  }
  
  // Toggle empty state based on data
  if (self.comments.count == 0) {
    [self showEmptyState];
  } else {
    [self hideEmptyState];
  }
}

/// Show empty state view
- (void)showEmptyState {
  self.tableView.useEmptyDataSet = YES;
  self.tableView.emptyTitleText = KBLocalized(@"No comments yet");
  self.tableView.emptyDescriptionText = KBLocalized(@"Be the first to comment");
  self.tableView.emptyImage = nil;  // Optional: set empty-state image
  self.tableView.emptyVerticalOffset = -50;  // Slight upward offset
  [self.tableView kb_reloadEmptyDataSet];
}

/// Show error empty state view
- (void)showEmptyStateWithError {
  self.tableView.useEmptyDataSet = YES;
  self.tableView.emptyTitleText = KBLocalized(@"Load failed");
  self.tableView.emptyDescriptionText = KBLocalized(@"Tap to retry");
  self.tableView.emptyImage = nil;
  self.tableView.emptyVerticalOffset = -50;
  
  // Tap to reload
  __weak typeof(self) weakSelf = self;
  self.tableView.emptyDidTapView = ^{
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (strongSelf) {
      [strongSelf loadComments];
    }
  };
  
  [self.tableView kb_reloadEmptyDataSet];
}

/// Hide empty state view
- (void)hideEmptyState {
  self.tableView.useEmptyDataSet = NO;
  [self.tableView kb_reloadEmptyDataSet];
}

- (void)updateTitle {
  NSString *countText;
  if (self.totalCommentCount >= 10000) {
    countText = [NSString
        stringWithFormat:KBLocalized(@"%.1fw comments"), self.totalCommentCount / 10000.0];
  } else {
    countText =
        [NSString stringWithFormat:KBLocalized(@"%ld comments"), (long)self.totalCommentCount];
  }
  self.titleLabel.text = countText;
}

#pragma mark - UITableViewDataSource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  return self.comments.count;
}

- (NSInteger)tableView:(UITableView *)tableView
    numberOfRowsInSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  return comment.displayedReplies.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
  KBAIReplyCell *cell =
      [tableView dequeueReusableCellWithIdentifier:kReplyCellIdentifier
                                      forIndexPath:indexPath];

  KBAICommentModel *comment = self.comments[indexPath.section];
  KBAIReplyModel *reply = comment.displayedReplies[indexPath.row];
  [cell configureWithReply:reply];

  __weak typeof(self) weakSelf = self;
  cell.onLikeAction = ^{
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }
    
    // Get comment ID (convert to NSInteger)
    NSInteger commentId = [reply.replyId integerValue];
    
    // Call like API
    [strongSelf.aiVM likeCommentWithCommentId:commentId completion:^(KBCommentLikeResponse * _Nullable response, NSError * _Nullable error) {
      dispatch_async(dispatch_get_main_queue(), ^{
        if (error) {
          NSLog(@"[KBAICommentView] Failed to like reply: %@", error.localizedDescription);
          // TODO: Show error message
          return;
        }
        
        if (response && response.code == 0) {
          // data = true: liked, data = false: unliked
          BOOL isNowLiked = response.data;
          
          // Update model state
          if (isNowLiked) {
            // Like succeeded: like count +1
            reply.liked = YES;
            reply.likeCount = MAX(0, reply.likeCount + 1);
            NSLog(@"[KBAICommentView] Reply liked successfully, ID: %ld", (long)commentId);
          } else {
            // Unlike succeeded: like count -1
            reply.liked = NO;
            reply.likeCount = MAX(0, reply.likeCount - 1);
            NSLog(@"[KBAICommentView] Reply unliked successfully, ID: %ld", (long)commentId);
          }
          
          // Refresh target row
          [strongSelf.tableView reloadRowsAtIndexPaths:@[ indexPath ]
                                      withRowAnimation:UITableViewRowAnimationNone];
        } else {
          NSLog(@"[KBAICommentView] Failed to like reply: %@", response.message ?: @"Unknown error");
          // TODO: Show error message
        }
      });
    }];
  };

  cell.onReplyAction = ^{
    [weakSelf setReplyToComment:comment reply:reply];
  };

  return cell;
}

#pragma mark - UITableViewDelegate

- (UIView *)tableView:(UITableView *)tableView
    viewForHeaderInSection:(NSInteger)section {
  KBAICommentHeaderView *header = [tableView
      dequeueReusableHeaderFooterViewWithIdentifier:kCommentHeaderIdentifier];

  KBAICommentModel *comment = self.comments[section];
  [header configureWithComment:comment];

  __weak typeof(self) weakSelf = self;
  header.onLikeAction = ^{
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }
    
    // Get comment ID (convert to NSInteger)
    NSInteger commentId = [comment.commentId integerValue];
    
    // Call like API
    [strongSelf.aiVM likeCommentWithCommentId:commentId completion:^(KBCommentLikeResponse * _Nullable response, NSError * _Nullable error) {
      dispatch_async(dispatch_get_main_queue(), ^{
        if (error) {
          NSLog(@"[KBAICommentView] Failed to like top-level comment: %@", error.localizedDescription);
          // TODO: Show error message
          return;
        }
        
        if (response && response.code == 0) {
          // data = true: liked, data = false: unliked
          BOOL isNowLiked = response.data;
          
          // Update model state
          if (isNowLiked) {
            // Like succeeded: like count +1
            comment.liked = YES;
            comment.likeCount = MAX(0, comment.likeCount + 1);
            NSLog(@"[KBAICommentView] Top-level comment liked successfully, ID: %ld", (long)commentId);
          } else {
            // Unlike succeeded: like count -1
            comment.liked = NO;
            comment.likeCount = MAX(0, comment.likeCount - 1);
            NSLog(@"[KBAICommentView] Top-level comment unliked successfully, ID: %ld", (long)commentId);
          }
          
          // Refresh target section
          [strongSelf.tableView reloadSections:[NSIndexSet indexSetWithIndex:section]
                              withRowAnimation:UITableViewRowAnimationNone];
        } else {
          NSLog(@"[KBAICommentView] Failed to like top-level comment: %@", response.message ?: @"Unknown error");
          // TODO: Show error message
        }
      });
    }];
  };

  header.onReplyAction = ^{
    [weakSelf setReplyToComment:comment reply:nil];
  };

  return header;
}

- (UIView *)tableView:(UITableView *)tableView
    viewForFooterInSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  KBAIReplyFooterState state = [comment footerState];

  // Return empty view when there are no replies
  if (state == KBAIReplyFooterStateHidden) {
    return nil;
  }

  KBAICommentFooterView *footer = [tableView
      dequeueReusableHeaderFooterViewWithIdentifier:kCommentFooterIdentifier];
  [footer configureWithComment:comment];

  __weak typeof(self) weakSelf = self;
  footer.onAction = ^{
    [weakSelf handleFooterActionForSection:section];
  };

  return footer;
}

- (CGFloat)tableView:(UITableView *)tableView
    heightForHeaderInSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  return comment.cachedHeaderHeight;
}

- (CGFloat)tableView:(UITableView *)tableView
    heightForRowAtIndexPath:(NSIndexPath *)indexPath {
  KBAICommentModel *comment = self.comments[indexPath.section];
  KBAIReplyModel *reply = comment.displayedReplies[indexPath.row];
  return reply.cachedCellHeight;
}

- (CGFloat)tableView:(UITableView *)tableView
    heightForFooterInSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  KBAIReplyFooterState state = [comment footerState];

  if (state == KBAIReplyFooterStateHidden) {
    return CGFLOAT_MIN;
  }
  return 30;
}

#pragma mark - Footer Actions

/// Number of replies loaded each time
static NSInteger const kRepliesLoadCount = 5;

- (void)handleFooterActionForSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  KBAIReplyFooterState state = [comment footerState];

  switch (state) {
  case KBAIReplyFooterStateExpand:
  case KBAIReplyFooterStateLoadMore: {
    [self loadMoreRepliesForSection:section];
    break;
  }
  case KBAIReplyFooterStateCollapse: {
    [self collapseRepliesForSection:section];
    break;
  }
  default:
    break;
  }
}

- (void)loadMoreRepliesForSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  NSInteger currentCount = comment.displayedReplies.count;

  // Load more replies
  [comment loadMoreReplies:kRepliesLoadCount];

  // Calculate newly inserted rows
  NSInteger newCount = comment.displayedReplies.count;
  NSMutableArray *insertIndexPaths = [NSMutableArray array];
  for (NSInteger i = currentCount; i < newCount; i++) {
    [insertIndexPaths addObject:[NSIndexPath indexPathForRow:i
                                                   inSection:section]];
  }

  // Insert rows (do not refresh header to avoid avatar flicker)
  [self.tableView beginUpdates];
  if (insertIndexPaths.count > 0) {
    [self.tableView insertRowsAtIndexPaths:insertIndexPaths
                          withRowAnimation:UITableViewRowAnimationAutomatic];
  }
  [self.tableView endUpdates];

  // Manually refresh footer
  KBAICommentFooterView *footerView =
      (KBAICommentFooterView *)[self.tableView footerViewForSection:section];
  if (footerView) {
    [footerView configureWithComment:comment];
  }
}

- (void)collapseRepliesForSection:(NSInteger)section {
  KBAICommentModel *comment = self.comments[section];
  NSInteger rowCount = comment.displayedReplies.count;

  // Calculate rows to delete
  NSMutableArray *deleteIndexPaths = [NSMutableArray array];
  for (NSInteger i = 0; i < rowCount; i++) {
    [deleteIndexPaths addObject:[NSIndexPath indexPathForRow:i
                                                   inSection:section]];
  }

  // Collapse all replies
  [comment collapseReplies];

  // Delete rows (do not refresh header to avoid avatar flicker)
  [self.tableView beginUpdates];
  if (deleteIndexPaths.count > 0) {
    [self.tableView deleteRowsAtIndexPaths:deleteIndexPaths
                          withRowAnimation:UITableViewRowAnimationAutomatic];
  }
  [self.tableView endUpdates];

  // Manually refresh footer
  KBAICommentFooterView *footerView =
      (KBAICommentFooterView *)[self.tableView footerViewForSection:section];
  if (footerView) {
    [footerView configureWithComment:comment];
  }
}

#pragma mark - Actions

- (void)closeButtonTapped {
    [self.popView dismiss];
  // Close comment view (handled by outside)
//  [[NSNotificationCenter defaultCenter]
//      postNotificationName:@"KBAICommentViewCloseNotification"
//                    object:nil];
}

#pragma mark - Lazy Loading

- (UIVisualEffectView *)blurBackgroundView {
  if (!_blurBackgroundView) {
    // Create blur effect (43pt blur radius in design)
    // iOS UIBlurEffect has no direct blur-radius API; use system dark style
    UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
    _blurBackgroundView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
    
    // Overlay a semi-transparent black layer to tune tone and opacity
    // Color: #000000, alpha: 0.31
    UIView *darkOverlay = [[UIView alloc] init];
    darkOverlay.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.31];
    [_blurBackgroundView.contentView addSubview:darkOverlay];
    [darkOverlay mas_makeConstraints:^(MASConstraintMaker *make) {
      make.edges.equalTo(_blurBackgroundView);
    }];
  }
  return _blurBackgroundView;
}

- (UIView *)headerView {
  if (!_headerView) {
    _headerView = [[UIView alloc] init];
    _headerView.backgroundColor = [UIColor clearColor];
  }
  return _headerView;
}

- (UILabel *)titleLabel {
  if (!_titleLabel) {
    _titleLabel = [[UILabel alloc] init];
    _titleLabel.font = [UIFont systemFontOfSize:15 weight:UIFontWeightMedium];
    _titleLabel.textColor = [UIColor whiteColor];
    _titleLabel.text = [NSString stringWithFormat:KBLocalized(@"%ld comments"), (long)0];
  }
  return _titleLabel;
}

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

- (BaseTableView *)tableView {
  if (!_tableView) {
    _tableView = [[BaseTableView alloc] initWithFrame:CGRectZero
                                                style:UITableViewStyleGrouped];
    _tableView.dataSource = self;
    _tableView.delegate = self;
    _tableView.backgroundColor = [UIColor clearColor];
    _tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
    _tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag;
    _tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1, 0.01)];
    
    // Disable empty placeholder by default to avoid showing "No data" while loading
    _tableView.useEmptyDataSet = NO;

    // Register Header/Cell/Footer
    [_tableView registerClass:[KBAICommentHeaderView class]
        forHeaderFooterViewReuseIdentifier:kCommentHeaderIdentifier];
    [_tableView registerClass:[KBAIReplyCell class]
        forCellReuseIdentifier:kReplyCellIdentifier];
    [_tableView registerClass:[KBAICommentFooterView class]
        forHeaderFooterViewReuseIdentifier:kCommentFooterIdentifier];

    // Remove top padding
    if (@available(iOS 15.0, *)) {
      _tableView.sectionHeaderTopPadding = 0;
    }
  }
  return _tableView;
}

- (KBAICommentInputView *)inputView {
  if (!_inputView) {
    _inputView = [[KBAICommentInputView alloc] init];
    _inputView.placeholder = KBLocalized(@"Send A Message");
      _inputView.layer.cornerRadius = 26;
      _inputView.clipsToBounds = true;
    __weak typeof(self) weakSelf = self;
    _inputView.onSend = ^(NSString *text) {
      [weakSelf sendCommentWithText:text];
    };
  }
  return _inputView;
}

#pragma mark - Reply

- (void)setReplyToComment:(KBAICommentModel *)comment
                    reply:(KBAIReplyModel *)reply {
  self.replyToComment = comment;
  self.replyToReply = reply;

  if (reply) {
    // Reply to a second-level comment
    self.inputView.placeholder =
        [NSString stringWithFormat:KBLocalized(@"Reply to @%@"), reply.userName];
  } else if (comment) {
    // Reply to a top-level comment
    self.inputView.placeholder =
        [NSString stringWithFormat:KBLocalized(@"Reply to @%@"), comment.userName];
  } else {
    // New comment
    self.inputView.placeholder = KBLocalized(@"Say something...");
  }

  // Show keyboard
  [self.inputView showKeyboard];
}

- (void)clearReplyTarget {
  self.replyToComment = nil;
  self.replyToReply = nil;
  self.inputView.placeholder = KBLocalized(@"Say something...");
}

#pragma mark - Send Comment

- (void)sendCommentWithText:(NSString *)text {
  if (text.length == 0)
    return;

  CGFloat tableWidth = self.tableView.bounds.size.width;
  if (tableWidth <= 0) {
    tableWidth = [UIScreen mainScreen].bounds.size.width;
  }

  if (self.replyToComment) {
    // Send reply (add second-level comment)
    [self sendReplyWithText:text tableWidth:tableWidth];
  } else {
    // Send top-level comment
    [self sendNewCommentWithText:text tableWidth:tableWidth];
  }

  // Clear input and reply target
  [self.inputView clearText];
  [self clearReplyTarget];
}

- (void)sendNewCommentWithText:(NSString *)text tableWidth:(CGFloat)tableWidth {
  NSLog(@"[KBAICommentView] Send top-level comment: %@", text);

  __weak typeof(self) weakSelf = self;
  [self.aiVM addCommentWithCompanionId:self.companionId
                              content:text
                             parentId:nil
                                rootId:nil
                            completion:^(KBCommentItem * _Nullable newItem, NSInteger code, NSError * _Nullable error) {
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }

    dispatch_async(dispatch_get_main_queue(), ^{
      if (error || code != 0) {
        NSLog(@"[KBAICommentView] Failed to send top-level comment: %@", error.localizedDescription ?: @"");
        return;
      }

       // Insert new comment locally at first position; avoid full reload
       KBAICommentModel *localComment =
           [strongSelf buildLocalNewCommentWithText:text
                                         serverItem:newItem
                                         tableWidth:tableWidth];
       [strongSelf.comments insertObject:localComment atIndex:0];
       strongSelf.totalCommentCount += 1;
       [strongSelf updateTitle];
       [strongSelf hideEmptyState];
       if ([strongSelf.delegate respondsToSelector:@selector(commentView:didUpdateTotalCommentCount:)]) {
         [strongSelf.delegate commentView:strongSelf didUpdateTotalCommentCount:strongSelf.totalCommentCount];
       }

       [strongSelf.tableView beginUpdates];
       [strongSelf.tableView
           insertSections:[NSIndexSet indexSetWithIndex:0]
         withRowAnimation:UITableViewRowAnimationAutomatic];
       [strongSelf.tableView endUpdates];

       [strongSelf.tableView setContentOffset:CGPointZero animated:YES];
    });
  }];
  
  // Example code:
  // [self.aiVM sendCommentWithCompanionId:self.companionId
  //                                content:text
  //                             completion:^(KBCommentItem *newItem, NSError *error) {
  //   if (error) {
  //     NSLog(@"[KBAICommentView] Failed to send comment: %@", error.localizedDescription);
  //     return;
  //   }
  //   
  //   // Convert to KBAICommentModel
  //   KBAICommentModel *comment = [KBAICommentModel mj_objectWithKeyValues:[newItem mj_keyValues]];
  //   comment.cachedHeaderHeight = [comment calculateHeaderHeightWithMaxWidth:tableWidth];
  //   
  //   // Insert into array at index 0
  //   [self.comments insertObject:comment atIndex:0];
  //   self.totalCommentCount++;
  //   [self updateTitle];
  //   
  //   // Insert new section
  //   [self.tableView insertSections:[NSIndexSet indexSetWithIndex:0]
  //                 withRowAnimation:UITableViewRowAnimationAutomatic];
  //   
  //   // Scroll to top
  //   [self.tableView setContentOffset:CGPointZero animated:YES];
  // }];
}

- (void)sendReplyWithText:(NSString *)text tableWidth:(CGFloat)tableWidth {
  KBAICommentModel *comment = self.replyToComment;
  if (!comment)
    return;
  
  NSLog(@"[KBAICommentView] Reply to comment %@: %@", comment.commentId, text);

  NSInteger root = [comment.commentId integerValue];
  NSNumber *rootId = @(root);
  NSNumber *parentId = nil;

  if (self.replyToReply && self.replyToReply.replyId.length > 0) {
    parentId = @([self.replyToReply.replyId integerValue]);
  } else {
    parentId = @(root);
  }

  __weak typeof(self) weakSelf = self;
  [self.aiVM addCommentWithCompanionId:self.companionId
                              content:text
                             parentId:parentId
                                rootId:rootId
                            completion:^(KBCommentItem * _Nullable newItem, NSInteger code, NSError * _Nullable error) {
    __strong typeof(weakSelf) strongSelf = weakSelf;
    if (!strongSelf) {
      return;
    }

    dispatch_async(dispatch_get_main_queue(), ^{
      if (error || code != 0) {
        NSLog(@"[KBAICommentView] Failed to send reply: %@", error.localizedDescription ?: @"");
        return;
      }

       NSInteger section = [strongSelf.comments indexOfObject:comment];
       if (section == NSNotFound) {
         return;
       }

       NSInteger oldTotalReplyCount = comment.totalReplyCount;
       BOOL wasFooterHidden = (oldTotalReplyCount == 0);
       BOOL wasFullyExpanded =
           (comment.isRepliesExpanded &&
            comment.displayedReplies.count == oldTotalReplyCount);

       NSString *replyToUserName = @"";
       if (strongSelf.replyToReply && strongSelf.replyToReply.userName.length > 0) {
         replyToUserName = strongSelf.replyToReply.userName;
       } else if (comment.userName.length > 0) {
         replyToUserName = comment.userName;
       }

       KBAIReplyModel *localReply =
           [strongSelf buildLocalNewReplyWithText:text
                                       serverItem:newItem
                                   replyToUserName:replyToUserName
                                       tableWidth:tableWidth];

       NSArray<KBAIReplyModel *> *oldReplies = comment.replies ?: @[];
       NSMutableArray<KBAIReplyModel *> *newReplies =
           [NSMutableArray arrayWithArray:oldReplies];
       [newReplies addObject:localReply];
       comment.replies = [newReplies copy];

       strongSelf.totalCommentCount += 1;
       [strongSelf updateTitle];
       if ([strongSelf.delegate respondsToSelector:@selector(commentView:didUpdateTotalCommentCount:)]) {
         [strongSelf.delegate commentView:strongSelf didUpdateTotalCommentCount:strongSelf.totalCommentCount];
       }

       // If fully expanded, insert new row directly; otherwise keep displayedReplies as prefix to preserve loadMoreReplies behavior
       if (wasFullyExpanded) {
         [comment.displayedReplies addObject:localReply];
         NSInteger newRowIndex = comment.displayedReplies.count - 1;
         NSIndexPath *indexPath =
             [NSIndexPath indexPathForRow:newRowIndex inSection:section];
         [strongSelf.tableView beginUpdates];
         [strongSelf.tableView insertRowsAtIndexPaths:@[ indexPath ]
                                     withRowAnimation:UITableViewRowAnimationAutomatic];
         [strongSelf.tableView endUpdates];

         KBAICommentFooterView *footerView =
             (KBAICommentFooterView *)[strongSelf.tableView footerViewForSection:section];
         if (footerView) {
           [footerView configureWithComment:comment];
         }
       } else {
         if (wasFooterHidden) {
           [strongSelf.tableView reloadSections:[NSIndexSet indexSetWithIndex:section]
                               withRowAnimation:UITableViewRowAnimationNone];
         } else {
           KBAICommentFooterView *footerView =
               (KBAICommentFooterView *)[strongSelf.tableView footerViewForSection:section];
           if (footerView) {
             [footerView configureWithComment:comment];
           } else {
             [strongSelf.tableView reloadSections:[NSIndexSet indexSetWithIndex:section]
                                 withRowAnimation:UITableViewRowAnimationNone];
           }
         }
       }
    });
  }];
  
  // Example code:
  // NSInteger parentId = [comment.commentId integerValue];
  // [self.aiVM replyCommentWithParentId:parentId
  //                              content:text
  //                           completion:^(KBCommentItem *newItem, NSError *error) {
  //   if (error) {
  //     NSLog(@"[KBAICommentView] Failed to reply comment: %@", error.localizedDescription);
  //     return;
  //   }
  //   
  //   // Convert to KBAIReplyModel
  //   KBAIReplyModel *newReply = [KBAIReplyModel mj_objectWithKeyValues:[newItem mj_keyValues]];
  //   newReply.cachedCellHeight = [newReply calculateCellHeightWithMaxWidth:tableWidth];
  //   
  //   // Append to replies array
  //   NSMutableArray *newReplies = [NSMutableArray arrayWithArray:comment.replies];
  //   [newReplies addObject:newReply];
  //   comment.replies = newReplies;
  //   comment.totalReplyCount = newReplies.count;
  //   
  //   // Find section for this comment
  //   NSInteger section = [self.comments indexOfObject:comment];
  //   if (section == NSNotFound) return;
  //   
  //   // If expanded, append to displayedReplies and insert row
  //   if (comment.isRepliesExpanded) {
  //     NSInteger newRowIndex = comment.displayedReplies.count;
  //     [comment.displayedReplies addObject:newReply];
  //     
  //     NSIndexPath *indexPath = [NSIndexPath indexPathForRow:newRowIndex inSection:section];
  //     [self.tableView insertRowsAtIndexPaths:@[indexPath]
  //                           withRowAnimation:UITableViewRowAnimationAutomatic];
  //     
  //     // Refresh footer
  //     KBAICommentFooterView *footerView = (KBAICommentFooterView *)[self.tableView footerViewForSection:section];
  //     if (footerView) {
  //       [footerView configureWithComment:comment];
  //     }
  //     
  //     // Scroll to new reply
  //     [self.tableView scrollToRowAtIndexPath:indexPath
  //                           atScrollPosition:UITableViewScrollPositionBottom
  //                                   animated:YES];
  //   } else {
  //     // If not expanded, refresh footer to show updated reply count
  //     KBAICommentFooterView *footerView = (KBAICommentFooterView *)[self.tableView footerViewForSection:section];
  //     if (footerView) {
  //       [footerView configureWithComment:comment];
  //     }
  //   }
  // }];
}

- (AiVM *)aiVM {
  if (!_aiVM) {
    _aiVM = [[AiVM alloc] init];
  }
  return _aiVM;
}

@end