Lanu_iOS/Lanu/Common/Views/Base/LNViewController.swift

//
//  LNViewController.swift
//  Lanu
//
//  Created by OneeChan on 2025/11/6.
//

import Foundation
import UIKit
import SnapKit
import Combine


class LNViewController: UIViewController {
    let backButton = UIButton()
    
    var showNavigationBar = true
    var enableDragBack = true
    var navigationBarColor: UIColor = .white {
        didSet {
            guard let navBar = navigationController?.navigationBar else { return }
            navBar.standardAppearance.backgroundColor = navigationBarColor
            navBar.scrollEdgeAppearance?.backgroundColor = navigationBarColor
            navBar.compactAppearance?.backgroundColor = navigationBarColor
        }
    }
    var customBack: (() -> Void)?
    
    let fakeNaviBgView = UIView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .white
        edgesForExtendedLayout = []
//        hidesBottomBarWhenPushed = true
        
        let buttonImage: UIImage? = .init(systemName: "chevron.backward")?.withRenderingMode(.alwaysTemplate)
        backButton.contentHorizontalAlignment = .center
        backButton.setImage(buttonImage, for: .normal)
        backButton.tintColor = .black
        backButton.addAction(UIAction(handler: { [weak self] _ in
            guard let self else { return }
            if let customBack {
                customBack()
            } else {
                navigationController?.popViewController(animated: true)
            }
        }), for: .touchUpInside)
        backButton.snp.makeConstraints { make in
            make.width.height.equalTo(24)
        }
        navigationItem.leftBarButtonItem = UIBarButtonItem(customView: backButton)
        
        view.addSubview(fakeNaviBgView)
        fakeNaviBgView.snp.makeConstraints { make in
            make.horizontalEdges.equalToSuperview()
            make.bottom.equalTo(view.snp.top)
            make.height.equalTo(UIView.navigationBarHeight + UIView.statusBarHeight)
        }
        view.publisher(for: \.frame).removeDuplicates().sink
        { [weak self] newValue in
            guard let self else { return }
            if newValue.origin.y > fakeNaviBgView.bounds.height {
                fakeNaviBgView.snp.updateConstraints { make in
                    make.height.equalTo(newValue.origin.y)
                }
            }
        }.store(in: &bag)
    }
    
    func setRightButton(_ view: UIView?) {
        if let view {
            navigationItem.rightBarButtonItem = UIBarButtonItem(customView: view)
        } else {
            navigationItem.rightBarButtonItem = nil
        }
    }
    
    func setTitleView(_ contentView: UIView) {
        navigationItem.titleView = contentView
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        navigationController?.setNavigationBarHidden(!showNavigationBar, animated: animated)
        
        if showNavigationBar,
           let navBar = navigationController?.navigationBar {
            navBar.backgroundColor = .clear
            
            let appearance = UINavigationBarAppearance()
            appearance.configureWithTransparentBackground()
            appearance.backgroundColor = navigationBarColor // 导航栏背景色
            appearance.shadowColor = .clear // 去除底部阴影线
            
            navBar.scrollEdgeAppearance = appearance // 滚动到顶部时的外观（如列表顶部）
            navBar.standardAppearance = appearance   // 常规状态的外观
            navBar.compactAppearance = appearance
        }
        
        fakeNaviBgView.backgroundColor = view.backgroundColor
    }
}