Lanu_iOS/Lanu/Views/Main/LNMainTabBar.swift

//
//  LNMainTabBar.swift
//  Lanu
//
//  Created by OneeChan on 2025/12/26.
//

import Foundation
import UIKit
import SnapKit


class LNMainTabBar: UITabBar {
    private let gradientLayer = CAGradientLayer()
    private let container = UIView()
    private var tabBarButtons: [UIView] = []
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        clipsToBounds = false
        
        gradientLayer.colors = [
            UIColor.init(hex: "#F1F2F500").cgColor,
            UIColor.white.cgColor
        ]
        gradientLayer.locations = [0, 1]
        gradientLayer.startPoint = CGPoint(x: 0, y: 0)
        gradientLayer.endPoint = CGPoint(x: 0, y: 1)
        layer.addSublayer(gradientLayer)
        
        container.layer.shadowColor = UIColor.black.withAlphaComponent(0.2).cgColor
        container.layer.shadowOffset = .init(width: 0, height: 2)
        container.layer.shadowRadius = 6
        container.layer.shadowOpacity = 0.8
        container.layer.masksToBounds = false
        addSubview(container)
        container.snp.makeConstraints { make in
            make.horizontalEdges.equalToSuperview().inset(42)
            make.bottom.equalToSuperview().offset(-36)
            make.height.equalTo(60)
        }
        
        let blurEffect = UIBlurEffect(style: .regular)
        let blurView = UIVisualEffectView(effect: blurEffect)
        blurView.layer.cornerRadius = 30
        blurView.clipsToBounds = true
        container.addSubview(blurView)
        blurView.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
        
        let vibrancyEffect = UIVibrancyEffect(blurEffect: blurEffect)
        let vibrancyView = UIVisualEffectView(effect: vibrancyEffect)
        blurView.contentView.addSubview(vibrancyView)
    }
    
    func setupViews() {
        tabBarButtons = subviews.filter { NSStringFromClass($0.classForCoder) == "UITabBarButton" }
        
        for (index, button) in tabBarButtons.enumerated() {
            button.removeFromSuperview()
            container.addSubview(button)
            button.snp.makeConstraints { make in
                make.centerX.equalToSuperview().multipliedBy(CGFloat(2 * index + 1) / CGFloat(tabBarButtons.count))
                make.height.equalToSuperview().offset(-6)
                make.width.equalToSuperview().multipliedBy(1.0 / CGFloat(tabBarButtons.count)).offset(-6)
            }
            
            if let ic = button.subviews.first(where: { $0 is UIImageView }) {
                ic.snp.makeConstraints { make in
                    make.centerY.equalTo(container)
                }
            } else {
                button.snp.makeConstraints { make in
                    make.centerY.equalToSuperview()
                }
            }
        }
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        gradientLayer.frame = .init(x: 0, y: bounds.height - 96, width: bounds.width, height: 96)
    }
    
    // UITabBar 默认会进行坐标转换，导致点击会有偏差响应
    // 这里重新进行点击判断，进行响应修复
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if !isHidden, let button = tabBarButtons.first(where: {
            let frame = $0.convert($0.bounds, to: self)
            return frame.contains(point)
        }) {
            return button
        }
        return frame.contains(point) ? self : nil
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}