keyboard/CustomKeyboard/View/KBFunctionBarView.m

//
//  KBFunctionBarView.m
//  CustomKeyboard
//
//  Created by Mac on 2025/10/28.
//  功能 - barview

#import "KBFunctionBarView.h"
#import "Masonry.h"

@interface KBFunctionBarView ()
@property (nonatomic, strong) UIView *leftContainer;   // 左侧按钮容器
@property (nonatomic, strong) UIView *rightContainer;  // 右侧按钮容器
@property (nonatomic, strong) NSArray<UIButton *> *leftButtonsInternal;
@property (nonatomic, strong) NSArray<UIButton *> *rightButtonsInternal;
@end

@implementation KBFunctionBarView

- (instancetype)initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {
        self.backgroundColor = [UIColor clearColor];
        _leftTitles = @[@"ABC"];
        _rightTitles = @[@"Upgrade VIP"];
        [self buildUI];
    }
    return self;
}

#pragma mark - Public

- (NSArray<UIButton *> *)leftButtons { return self.leftButtonsInternal; }
- (NSArray<UIButton *> *)rightButtons { return self.rightButtonsInternal; }


#pragma mark - UI

- (void)buildUI {
    // 左右两个容器，方便分别布局
    [self addSubview:self.leftContainer];
    [self addSubview:self.rightContainer];

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

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

    // 左侧4个等宽按钮
    NSMutableArray<UIButton *> *leftBtns = [NSMutableArray arrayWithCapacity:4];
    UIView *prev = nil;
    for (NSInteger i = 0; i < self.leftTitles.count; i++) {
        UIButton *btn = [self buildButtonWithTitle:(i < self.leftTitles.count ? self.leftTitles[i] : [NSString stringWithFormat:@"L%ld", (long)i])];
        btn.tag = 100 + i;
        [btn addTarget:self action:@selector(onLeftTap:) forControlEvents:UIControlEventTouchUpInside];
        [self.leftContainer addSubview:btn];
        [btn mas_makeConstraints:^(MASConstraintMaker *make) {
            if (prev) {
                make.left.equalTo(prev.mas_right).offset(8);
                make.width.equalTo(prev);
            } else {
                make.left.equalTo(self.leftContainer.mas_left);
            }
            make.top.bottom.equalTo(self.leftContainer);
        }];
        prev = btn;
        [leftBtns addObject:btn];
    }
    [prev mas_makeConstraints:^(MASConstraintMaker *make) {
        make.right.equalTo(self.leftContainer.mas_right);
    }];
    self.leftButtonsInternal = leftBtns.copy;

    // 右侧N个按钮（靠右、两两等宽）
    NSMutableArray<UIButton *> *rightBtns = [NSMutableArray arrayWithCapacity:3];
    for (NSInteger i = 0; i < self.rightTitles.count; i++) {
        UIButton *btn = [self buildButtonWithTitle:(i < self.rightTitles.count ? self.rightTitles[i] : [NSString stringWithFormat:@"R%ld", (long)i])];
        btn.tag = 200 + i;
        [self.rightContainer addSubview:btn];
        [btn addTarget:self action:@selector(onRightTap:) forControlEvents:UIControlEventTouchUpInside];
        [rightBtns addObject:btn];
    }

    // 从右往左链式布局，保证整体靠右；支持 1/2/3... 任意数量
    UIView *prevRight = nil; // 指向右侧已布局的按钮
    for (NSInteger i = rightBtns.count - 1; i >= 0; i--) {
        UIButton *btn = rightBtns[i];
        [btn mas_makeConstraints:^(MASConstraintMaker *make) {
            if (!prevRight) {
                // 最右侧按钮贴右
                make.right.equalTo(self.rightContainer.mas_right);
            } else {
                // 其余按钮紧挨左侧兄弟，且与其等宽
                make.right.equalTo(prevRight.mas_left).offset(-8);
                make.width.equalTo(prevRight);
            }
            make.top.bottom.equalTo(self.rightContainer);
        }];
        prevRight = btn;
    }
    // 最左侧一个不超出容器左边（允许根据内容自然宽度收缩）
    if (prevRight) {
        [prevRight mas_makeConstraints:^(MASConstraintMaker *make) {
            make.left.greaterThanOrEqualTo(self.rightContainer.mas_left);
        }];
    }

    self.rightButtonsInternal = rightBtns.copy;
}

#pragma mark - Actions

- (void)onLeftTap:(UIButton *)sender {
    NSInteger idx = sender.tag - 100;
    if ([self.delegate respondsToSelector:@selector(functionBarView:didTapLeftAtIndex:)]) {
        [self.delegate functionBarView:self didTapLeftAtIndex:idx];
    }
}

- (void)onRightTap:(UIButton *)sender {
    NSInteger idx = sender.tag - 200;
    if ([self.delegate respondsToSelector:@selector(functionBarView:didTapRightAtIndex:)]) {
        [self.delegate functionBarView:self didTapRightAtIndex:idx];
    }
}

- (UIButton *)buildButtonWithTitle:(NSString *)title {
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
    btn.layer.cornerRadius = 18;
    btn.layer.masksToBounds = YES;
    btn.backgroundColor = [UIColor colorWithWhite:1 alpha:0.9];
    btn.titleLabel.font = [UIFont systemFontOfSize:14 weight:UIFontWeightMedium];
    [btn setTitle:title forState:UIControlStateNormal];
    [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    return btn;
}

#pragma mark - Lazy

- (UIView *)leftContainer {
    if (!_leftContainer) {
        _leftContainer = [[UIView alloc] init];
    }
    return _leftContainer;
}

- (UIView *)rightContainer {
    if (!_rightContainer) {
        _rightContainer = [[UIView alloc] init];
    }
    return _rightContainer;
}

@end