//
//  KBGuideVC.m
//  keyBoard
//
//  Created by Mac on 2025/10/29.
//

#import "KBGuideVC.h"
#import "KBGuideTopCell.h"
#import "KBGuideKFCell.h"
#import "KBGuideUserCell.h"
#import "KBPermissionViewController.h"
#import "KBKeyboardPermissionManager.h"
#import "KBKeyboardMaskView.h"

typedef NS_ENUM(NSInteger, KBGuideItemType) {
    KBGuideItemTypeTop = 0,   // 顶部固定卡片
    KBGuideItemTypeUser,      // 我方消息
    KBGuideItemTypeKF         // 客服回复
};

@interface KBGuideVC () <UITableViewDelegate, UITableViewDataSource, UITextFieldDelegate, UIGestureRecognizerDelegate>

@property (nonatomic, strong) BaseTableView *tableView;     // 列表（继承 BaseTableView）
@property (nonatomic, strong) UIView *inputBar;             // 底部输入容器
@property (nonatomic, strong) UITextField *textField;       // 输入框
@property (nonatomic, strong) MASConstraint *inputBarBottom;// 输入栏底部约束
@property (nonatomic, strong) UITapGestureRecognizer *bgTap;// 点击空白收起键盘

@property (nonatomic, strong) NSMutableArray<NSDictionary *> *items; // 数据源 [{type, text}]
/// 权限引导页作为子控制器（用于“同时隐藏”）
@property (nonatomic, strong, nullable) KBPermissionViewController *permVC;
/// 记录上一次的输入法标识，避免重复提示
@property (nonatomic, copy, nullable) NSString *kb_lastInputModeIdentifier;

/// 当当前系统键盘不是自家键盘时展示的蒙层（带返回箭头 + GIF）
@property (nonatomic, strong, nullable) KBKeyboardMaskView *kbKeyboardMaskView;

/// 最近一次已知的键盘高度（用于初次展示蒙层时的 GIF 位置计算）
@property (nonatomic, assign) CGFloat kb_currentKeyboardHeight;
@property (nonatomic, strong) UIImageView *bgImageView;  // 全屏背景图

@end

@implementation KBGuideVC

- (void)viewDidLoad {
    [super viewDidLoad];
//    self.view.backgroundColor = [UIColor colorWithWhite:0.96 alpha:1.0];
    self.view.backgroundColor = UIColor.clearColor;
    self.kb_navView.backgroundColor = [UIColor clearColor];
    self.bgImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"my_bg_icon"]];
    self.bgImageView.contentMode = UIViewContentModeScaleAspectFill;
    [self.view insertSubview:self.bgImageView belowSubview:self.kb_navView];
    [self.bgImageView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.view);
    }];

    [self.view addSubview:self.tableView];
    [self.view addSubview:self.inputBar];

    [self.inputBar addSubview:self.textField];

    [self.tableView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.bottom.equalTo(self.view);
        make.top.mas_equalTo(KB_NAV_TOTAL_HEIGHT);
    }];

    [self.inputBar mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.height.mas_equalTo(52);
        // 底部跟随键盘变化
            self.inputBarBottom = make.bottom.equalTo(self.view.mas_safeAreaLayoutGuideBottom);
      
    }];

    [self.textField mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(self.inputBar).offset(12);
        make.right.equalTo(self.inputBar).offset(-12);
        make.centerY.equalTo(self.inputBar);
        make.height.mas_equalTo(36);
    }];

    // 初始只有固定 Top
    [self.items addObject:@{ @"type": @(KBGuideItemTypeTop), @"text": @"" }];
    [self.tableView reloadData];

    // 键盘监听
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(kb_keyboardWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];

    // 点击空白收起键盘（不干扰 cell 的点击/滚动）
    self.bgTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(kb_didTapBackground)];
    self.bgTap.cancelsTouchesInView = NO;
    self.bgTap.delegate = self;
    [self.tableView addGestureRecognizer:self.bgTap];

    // 监听应用回到前台/变为活跃：用于从设置返回时再次校验权限
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(kb_checkKeyboardPermission) name:UIApplicationDidBecomeActiveNotification object:nil];

    // 监听输入法切换（系统未公开常量，使用字符串名以兼容不同系统版本）
    NSArray<NSString *> *modeNotiNames = @[ @"UITextInputCurrentInputModeDidChangeNotification",
                                            @"UITextInputCurrentInputModeDidChange" ];
    for (NSString *n in modeNotiNames) {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(kb_inputModeDidChange:) name:n object:nil];
    }

    // 提前创建并铺满权限引导页（默认隐藏），避免后续显示时出现布局进场感
    [self kb_preparePermissionOverlayIfNeeded];

}

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

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    // 每次进入页面都校验一次（包括从其它页面返回）
    [self kb_checkKeyboardPermission];
    // 仅在“权限已满足/引导未显示”时再去判断当前键盘是否为自家扩展
    BOOL permissionReady = (self.permVC && self.permVC.view.hidden == YES);
    if (permissionReady) {
        // 不要在未成为第一响应者时立即判断，避免拿不到 textInputMode 导致“误判不是自己的键盘”
        if (![self.textField isFirstResponder]) {
            [self.textField becomeFirstResponder];
        }
        // 尝试在下一轮主线程循环评估一次；若键盘尚未完全弹出，会在
        // UIKeyboardWillChangeFrame 或输入法切换通知里再次评估
        dispatch_async(dispatch_get_main_queue(), ^{
            [self kb_evaluateCurrentInputModeAndNotifyIfNeeded];
        });
    }
}

/// 校验键盘权限：
/// - 未启用或已启用但拒绝完全访问 => 弹出引导页
/// - 已满足条件且正在展示引导页 => 关闭引导页
- (void)kb_checkKeyboardPermission {
    KBKeyboardPermissionManager *mgr = [KBKeyboardPermissionManager shared];
    BOOL enabled = [mgr isKeyboardEnabled];
    KBFARecord fa = [mgr lastKnownFullAccess];
    BOOL needGuide = (!enabled) || (enabled && fa == KBFARecordDenied);

    [self kb_preparePermissionOverlayIfNeeded];
    BOOL show = needGuide;
    // 同步控制引导页视频的播放/暂停：仅在显示时播放
    self.permVC.view.hidden = !show;
    if (show) {
        [self.permVC kb_resumeGuideVideoIfNeeded];
    } else {
        [self.permVC kb_pauseGuideVideo];
    }
    
    // 若权限已满足（引导未显示），从设置返回时尝试让输入框成为第一响应者，
    // 以便立刻触发键盘挂载并检测是否为自家键盘/是否已开启完全访问
    if (!show) {
        [self kb_tryActivateTextFieldIfReady];
    }
}

/// 提前创建权限引导页覆盖层（仅一次）
- (void)kb_preparePermissionOverlayIfNeeded {
    if (self.permVC) return;
    KBPermissionViewController *guide = [KBPermissionViewController new];
//    guide.modalPresentationStyle = UIModalPresentationFullScreen; // 仅用于内部布局，不会真正 present
    KBWeakSelf;
    guide.backHandler = ^{ [weakSelf.navigationController popViewControllerAnimated:YES]; };
    self.permVC = guide;
    guide.backButton.hidden = true;
    [self addChildViewController:guide];
    [self.view addSubview:guide.view];
//    [guide.view mas_makeConstraints:^(MASConstraintMaker *make) { make.edges.equalTo(self.view); }];
    [guide didMoveToParentViewController:self];
    guide.view.hidden = YES; // 初始隐藏
}

- (void)kb_didTapBackground {
    // 结束编辑，隐藏键盘
    [self.view endEditing:YES];
}


#pragma mark - Actions

// 发送：回车发送一条消息，随后插入固定的客服回复
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    NSString *text = [textField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    if (text.length == 0) { return NO; }

    // 1. 插入我方消息
    [self.items addObject:@{ @"type": @(KBGuideItemTypeUser), @"text": text ?: @"" }];
    // 2. 紧跟一条固定客服消息
    NSString *reply = KBLocalized(@"🎉 If you run into any other issues, tap Online Support to get help~");
    [self.items addObject:@{ @"type": @(KBGuideItemTypeKF), @"text": reply }];

    // 刷新并滚动到底部
    [self.tableView reloadData];
    [self scrollToBottomAnimated:YES];

    textField.text = @"";
    return YES;
}

- (void)kb_keyboardWillChange:(NSNotification *)note {
    NSDictionary *info = note.userInfo;
    NSTimeInterval duration = [info[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationOptions curve = ([info[UIKeyboardAnimationCurveUserInfoKey] integerValue] << 16);

    CGRect endFrame = [info[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat screenH = UIScreen.mainScreen.bounds.size.height;
    CGFloat kbHeight = MAX(0, screenH - endFrame.origin.y);
    self.kb_currentKeyboardHeight = kbHeight;

    CGFloat safeBtm = 0;
    if (@available(iOS 11.0, *)) { safeBtm = self.view.safeAreaInsets.bottom; }

    // 输入栏距离底部 = -max(kbHeight - 安全区, 0)
    CGFloat offset = -MAX(kbHeight - safeBtm, 0);
    self.inputBarBottom.offset = offset;

    [UIView animateWithDuration:duration delay:0 options:curve animations:^{
        UIEdgeInsets inset = self.tableView.contentInset;
        inset.bottom = 52 + MAX(kbHeight - safeBtm, 0);
        self.tableView.contentInset = inset;
//        self.tableView.scrollIndicatorInsets = inset;
    } completion:^(BOOL finished) {
        [self scrollToBottomAnimated:YES];
        // 键盘位置变化后，尝试检测是否发生了输入法切换
        [self kb_evaluateCurrentInputModeAndNotifyIfNeeded];
    }];

    // 更新蒙层内部 GIF 与键盘的相对位置，保证不被遮挡
    if (self.kbKeyboardMaskView) {
        [self.kbKeyboardMaskView updateForKeyboardHeight:kbHeight
                                               duration:duration
                                                  curve:curve];
    }
}

- (void)scrollToBottomAnimated:(BOOL)animated {
    if (self.items.count == 0) return;
    NSInteger last = self.items.count - 1;
    NSIndexPath *ip = [NSIndexPath indexPathForRow:last inSection:0];
    if (last >= 0) {
        [self.tableView scrollToRowAtIndexPath:ip atScrollPosition:UITableViewScrollPositionBottom animated:animated];
    }
}

#pragma mark - Keyboard Detection

/// 判断当前激活在本页输入框上的系统键盘是否为我方扩展键盘
/// 说明：
/// - 依赖 `UITextField.textInputMode` 获取当前输入法；
/// - 通过 KVC 读取其 `identifier`（系统未公开的属性），再与扩展的 bundle id 比较；
/// - 仅在 `textField` 为第一响应者、且软键盘弹出时才有意义。
- (BOOL)kb_isMyExtensionKeyboardSelected {
    UITextInputMode *mode = self.textField.textInputMode;
    if (!mode) { return NO; }
    NSString *identifier = nil;
    @try {
        // 私有字段：仅用于判断是否为自家扩展；与 App 内其它用法保持一致
        identifier = [mode valueForKey:@"identifier"];
    } @catch (__unused NSException *e) {
        identifier = nil;
    }
    if (![identifier isKindOfClass:[NSString class]]) { return NO; }
    return [identifier rangeOfString:KB_KEYBOARD_EXTENSION_BUNDLE_ID].location != NSNotFound;
}

- (void)kb_inputModeDidChange:(NSNotification *)note {
    // 用户从地球键切换输入法时调用
    [self kb_evaluateCurrentInputModeAndNotifyIfNeeded];
}

/// 读取当前输入法 identifier（可能为 nil）
- (NSString *)kb_currentInputModeIdentifier {
    UITextInputMode *mode = self.textField.textInputMode;
    if (!mode) return nil;
    NSString *identifier = nil;
    @try { identifier = [mode valueForKey:@"identifier"]; } @catch (__unused NSException *e) { identifier = nil; }
    return [identifier isKindOfClass:NSString.class] ? identifier : nil;
}

/// 若输入法发生变化，则立刻提示是否为自家键盘
- (void)kb_evaluateCurrentInputModeAndNotifyIfNeeded {
    // 仅在本页输入框处于编辑状态时判断，避免误触发
    if (![self.textField isFirstResponder]) return;

    // 若权限引导正在显示，不弹提示（未满足前置条件）
    if (self.permVC && self.permVC.view.hidden == NO) return;

    NSString *currId = [self kb_currentInputModeIdentifier];
    if (currId.length == 0) return;
    if ([self.kb_lastInputModeIdentifier isEqualToString:currId]) return; // 去抖
    self.kb_lastInputModeIdentifier = currId;

    BOOL isMine = [currId rangeOfString:KB_KEYBOARD_EXTENSION_BUNDLE_ID].location != NSNotFound;

    // 根据是否为自家键盘，更新遮罩层显示/隐藏
    [self kb_updateKeyboardMaskForIsMyKeyboard:isMine];
}

/// 当权限满足时，尽力激活输入框，从而触发键盘挂载与输入法检测
- (void)kb_tryActivateTextFieldIfReady {
    // 权限未满足或存在覆盖层时不处理
    if (self.permVC && self.permVC.view.hidden == NO) return;
    // 视图未显示到窗口上时不处理（避免早期调用无效）
    if (!self.view.window) return;
    // 若未成为第一响应者，则尝试激活并在下一轮循环评估一次
    if (![self.textField isFirstResponder]) {
        [self.textField becomeFirstResponder];
    }
    dispatch_async(dispatch_get_main_queue(), ^{
        [self kb_evaluateCurrentInputModeAndNotifyIfNeeded];
    });
}

/// 根据当前是否为自家键盘，展示/隐藏键盘指导蒙层
- (void)kb_updateKeyboardMaskForIsMyKeyboard:(BOOL)isMine {
    // 权限引导显示期间不再额外显示键盘蒙层
    if (self.permVC && self.permVC.view.hidden == NO) {
        if (self.kbKeyboardMaskView) {
            self.kbKeyboardMaskView.hidden = YES;
        }
        return;
    }

    BOOL shouldShow = !isMine;

    if (shouldShow) {
        // 按需创建并添加蒙层
        if (!self.kbKeyboardMaskView) {
            KBKeyboardMaskView *mask = [[KBKeyboardMaskView alloc] initWithFrame:self.view.bounds];
            __weak typeof(self) weakSelf = self;
            mask.tapHandler = ^{
                __strong typeof(weakSelf) self = weakSelf;
                if (!self) return;
                // 点击蒙层：在“激活/收起”之间切换 textField 的第一响应状态
                if ([self.textField isFirstResponder]) {
                    // 当前是第一响应者 -> 收起键盘
                    [self.view endEditing:YES];
                } else {
                    // 当前不是第一响应者 -> 激活，弹出键盘
                    [self.textField becomeFirstResponder];
                }
            };
            // 左上角返回按钮：退出当前 KBGuideVC
            [mask.backButton addTarget:self action:@selector(kb_onMaskBack) forControlEvents:UIControlEventTouchUpInside];

            self.kbKeyboardMaskView = mask;

            if (self.permVC && self.permVC.view.superview == self.view) {
                // 确保权限页在最上层，键盘蒙层位于其下方
                [self.view insertSubview:mask belowSubview:self.permVC.view];
            } else {
                [self.view addSubview:mask];
            }
            [mask mas_makeConstraints:^(MASConstraintMaker *make) {
                make.edges.equalTo(self.view);
            }];

            // 创建时立即根据当前键盘高度调整 GIF 位置，避免首次展示被遮挡
            [mask updateForKeyboardHeight:self.kb_currentKeyboardHeight
                                 duration:0
                                    curve:UIViewAnimationOptionCurveEaseInOut];
        }
    }

    if (!self.kbKeyboardMaskView) return;

    BOOL currentlyVisible = !self.kbKeyboardMaskView.hidden && self.kbKeyboardMaskView.alpha > 0.01;
    if (shouldShow == currentlyVisible) return;

    self.kbKeyboardMaskView.hidden = NO;
    CGFloat targetAlpha = shouldShow ? 1.0 : 0.0;
    [UIView animateWithDuration:0.25 animations:^{
        self.kbKeyboardMaskView.alpha = targetAlpha;
    } completion:^(BOOL finished) {
        self.kbKeyboardMaskView.hidden = !shouldShow;
    }];
}

/// 蒙层左上角返回按钮事件：让 KBGuideVC 退出
- (void)kb_onMaskBack {
    [self.navigationController popViewControllerAnimated:YES];
}

#pragma mark - UITableView

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

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSDictionary *it = self.items[indexPath.row];
    KBGuideItemType type = [it[@"type"] integerValue];
    NSString *text = it[@"text"] ?: @"";

    if (type == KBGuideItemTypeTop) {
        KBGuideTopCell *cell = [tableView dequeueReusableCellWithIdentifier:[KBGuideTopCell reuseId]];
        if (!cell) cell = [[KBGuideTopCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[KBGuideTopCell reuseId]];
        return cell;
    } else if (type == KBGuideItemTypeUser) {
        KBGuideUserCell *cell = [tableView dequeueReusableCellWithIdentifier:[KBGuideUserCell reuseId]];
        if (!cell) cell = [[KBGuideUserCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[KBGuideUserCell reuseId]];
        [cell configText:text];
        return cell;
    } else {
        KBGuideKFCell *cell = [tableView dequeueReusableCellWithIdentifier:[KBGuideKFCell reuseId]];
        if (!cell) cell = [[KBGuideKFCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[KBGuideKFCell reuseId]];
        [cell configText:text];
        return cell;
    }
}

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

- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 100;
}

#pragma mark - Lazy

- (BaseTableView *)tableView {
    if (!_tableView) {
        _tableView = [[BaseTableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
        _tableView.delegate = self;
        _tableView.dataSource = self;
        _tableView.separatorStyle = UITableViewCellSeparatorStyleNone; // 无分割线
        _tableView.backgroundColor = [UIColor clearColor];
        _tableView.rowHeight = UITableViewAutomaticDimension;
        _tableView.estimatedRowHeight = 120; // 开启自适应高度
        _tableView.contentInset = UIEdgeInsetsMake(0, 0, 52 + KB_SafeAreaBottom(), 0);
        _tableView.scrollIndicatorInsets = _tableView.contentInset;
    }
    return _tableView;
}

- (UIView *)inputBar {
    if (!_inputBar) {
        _inputBar = [UIView new];
        _inputBar.backgroundColor = [UIColor colorWithWhite:0.96 alpha:1.0];
        UIView *bg = [UIView new];
        bg.backgroundColor = [UIColor whiteColor];
        bg.layer.cornerRadius = 10; bg.layer.masksToBounds = YES;
        [_inputBar addSubview:bg];
        [bg mas_makeConstraints:^(MASConstraintMaker *make) {
            make.left.equalTo(_inputBar).offset(12);
            make.right.equalTo(_inputBar).offset(-12);
            make.top.equalTo(_inputBar).offset(8);
            make.bottom.equalTo(_inputBar).offset(-8);
        }];
    }
    return _inputBar;
}

- (UITextField *)textField {
    if (!_textField) {
        _textField = [UITextField new];
        _textField.delegate = self;
        _textField.returnKeyType = UIReturnKeySend; // 回车发送
        _textField.font = [UIFont systemFontOfSize:15];
        _textField.placeholder = KBLocalized(@"After pasting the conversation in the keyboard, choose a reply style");
        _textField.backgroundColor = [UIColor whiteColor];
        _textField.layer.cornerRadius = 10; _textField.layer.masksToBounds = YES;
        UIView *pad = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 10, 36)];
        _textField.leftView = pad; _textField.leftViewMode = UITextFieldViewModeAlways;
    }
    return _textField;
}

- (NSMutableArray<NSDictionary *> *)items {
    if (!_items) { _items = @[].mutableCopy; }
    return _items;
}

#pragma mark - UIGestureRecognizerDelegate

// 避免点到输入栏触发收起
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    if (gestureRecognizer == self.bgTap) {
        // 1) 点在输入栏区域：不当作“背景点击”
        if ([touch.view isDescendantOfView:self.inputBar]) {
            return NO;
        }
        // 2) 点在任意 cell（包括 KBGuideTopCell）内部：不当作“背景点击”，避免复制时收起键盘
        UIView *v = touch.view;
        while (v && ![v isKindOfClass:UITableViewCell.class]) {
            v = v.superview;
        }
        if (v) { // 找到了 cell
            return NO;
        }
    }
    return YES;
}

// 与其它手势同时识别，避免影响表格滚动/选择
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    return YES;
}

@end