//
//  EPTabBarController.swift
//  YuMi
//
//  Created by AI on 2025-10-09.
//  Copyright © 2025 YuMi. All rights reserved.
//

import UIKit
import SnapKit

/// EP 系列 TabBar 控制器
/// 悬浮设计 + 液态玻璃效果，只包含 Moment 和 Mine 两个 Tab
@objc class EPTabBarController: UITabBarController {
    
    // MARK: - Properties
    
    /// 全局事件管理器
    private var globalEventManager: GlobalEventManager?
    
    /// 是否已登录
    private var isLoggedIn: Bool = false
    
    /// 自定义悬浮 TabBar 容器
    private var customTabBarView: UIView!
    
    /// 毛玻璃背景视图
    private var tabBarBackgroundView: UIVisualEffectView!
    
    /// Tab 按钮数组
    private var tabButtons: [UIButton] = []
    
    // MARK: - Lifecycle
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 测试域名配置
        #if DEBUG
        APIConfig.testEncryption()
        #endif
        
        // 隐藏原生 TabBar
        self.tabBar.isHidden = true
        
        // 设置 delegate 以完全控制切换行为
        self.delegate = self
        
        // ✅ 启动时验证 ticket（与 OC 版本保持一致）
        performAutoLogin()
        
        setupCustomFloatingTabBar()
        setupGlobalManagers()
        setupInitialViewControllers()
        
        NSLog("[EPTabBarController] 悬浮 TabBar 初始化完成")
    }
    
    deinit {
        globalEventManager?.removeAllDelegates()
        NSLog("[EPTabBarController] 已释放")
    }
    
    // MARK: - Setup
    
    /// 设置自定义悬浮 TabBar
    private func setupCustomFloatingTabBar() {
        // 创建悬浮容器
        customTabBarView = UIView()
        customTabBarView.translatesAutoresizingMaskIntoConstraints = false
        customTabBarView.backgroundColor = .clear
        view.addSubview(customTabBarView)
        
        // 液态玻璃/毛玻璃效果
        let effect: UIVisualEffect
        if #available(iOS 26.0, *) {
            // iOS 26+ 使用液态玻璃（Material）
            effect = UIGlassEffect()
        } else {
            // iOS 13-17 使用毛玻璃
            effect = UIBlurEffect(style: .systemMaterial)
        }
        
        tabBarBackgroundView = UIVisualEffectView(effect: effect)
        tabBarBackgroundView.translatesAutoresizingMaskIntoConstraints = false
        tabBarBackgroundView.layer.cornerRadius = 28
        tabBarBackgroundView.layer.masksToBounds = true
        
        // 添加边框
        tabBarBackgroundView.layer.borderWidth = 0.5
        tabBarBackgroundView.layer.borderColor = UIColor.white.withAlphaComponent(0.2).cgColor
        
        customTabBarView.addSubview(tabBarBackgroundView)
        
        // 简化的布局约束（类似 Masonry 风格）
        customTabBarView.snp.makeConstraints { make in
            make.leading.equalTo(view).offset(16)
            make.trailing.equalTo(view).offset(-16)
            make.bottom.equalTo(view.safeAreaLayoutGuide).offset(-12)
            make.height.equalTo(64)
        }
        
        tabBarBackgroundView.snp.makeConstraints { make in
            make.edges.equalTo(customTabBarView)
        }
        
        // 添加 Tab 按钮
        setupTabButtons()
        
        NSLog("[EPTabBarController] 悬浮 TabBar 设置完成")
    }
    
    /// 设置 Tab 按钮
    private func setupTabButtons() {
        let momentButton = createTabButton(
            normalImage: "tab_moment_off",
            selectedImage: "tab_moment_on",
            tag: 0
        )
        
        let mineButton = createTabButton(
            normalImage: "tab_mine_off",
            selectedImage: "tab_mine_on",
            tag: 1
        )
        
        tabButtons = [momentButton, mineButton]
        
        let stackView = UIStackView(arrangedSubviews: tabButtons)
        stackView.axis = .horizontal
        stackView.distribution = .fillEqually
        stackView.spacing = 20
        stackView.translatesAutoresizingMaskIntoConstraints = false
        tabBarBackgroundView.contentView.addSubview(stackView)
        
        stackView.snp.makeConstraints { make in
            make.top.equalTo(tabBarBackgroundView).offset(8)
            make.leading.equalTo(tabBarBackgroundView).offset(20)
            make.trailing.equalTo(tabBarBackgroundView).offset(-20)
            make.bottom.equalTo(tabBarBackgroundView).offset(-8)
        }
        
        // 默认选中第一个
        updateTabButtonStates(selectedIndex: 0)
    }
    
    /// 创建 Tab 按钮
    private func createTabButton(normalImage: String, selectedImage: String, tag: Int) -> UIButton {
        let button = UIButton(type: .custom)
        button.tag = tag
        button.adjustsImageWhenHighlighted = false // 禁用高亮效果，避免闪烁
        
        // 尝试设置自定义图片，如果不存在则使用 SF Symbols
        if let normalImg = UIImage(named: normalImage), let selectedImg = UIImage(named: selectedImage) {
            // 正确设置：分别为 normal 和 selected 状态设置图片
            button.setImage(normalImg, for: .normal)
            button.setImage(selectedImg, for: .selected)
        } else {
            // 使用 SF Symbols 作为备用
            let fallbackIcons = ["sparkles", "person.circle"]
            let iconName = fallbackIcons[tag]
            let imageConfig = UIImage.SymbolConfiguration(pointSize: 24, weight: .medium)
            let normalIcon = UIImage(systemName: iconName, withConfiguration: imageConfig)
            
            button.setImage(normalIcon, for: .normal)
            button.setImage(normalIcon, for: .selected)
            button.tintColor = .white.withAlphaComponent(0.6)
        }
        
        // 图片渲染模式
        button.imageView?.contentMode = .scaleAspectFit
        
        // 移除标题
        button.setTitle(nil, for: .normal)
        button.setTitle(nil, for: .selected)
        
        // 设置图片大小约束
        button.imageView?.snp.makeConstraints { make in
            make.size.equalTo(28)
        }
        
        button.addTarget(self, action: #selector(tabButtonTapped(_:)), for: .touchUpInside)
        return button
    }
    
    /// Tab 按钮点击事件
    @objc private func tabButtonTapped(_ sender: UIButton) {
        let newIndex = sender.tag
        
        // 如果点击的是当前已选中的 tab，不做任何操作
        if newIndex == selectedIndex {
            return
        }
        
        // 先更新按钮状态
        updateTabButtonStates(selectedIndex: newIndex)
        
        // 禁用 UITabBarController 的默认切换动画，避免闪烁
        UIView.performWithoutAnimation {
            selectedIndex = newIndex
        }
        
        let tabNames = [YMLocalizedString("tab.moment"), YMLocalizedString("tab.mine")]
        NSLog("[EPTabBarController] 选中 Tab: \(tabNames[newIndex])")
    }
    
    /// 更新 Tab 按钮状态
    private func updateTabButtonStates(selectedIndex: Int) {
        // 禁用按钮交互，避免快速点击
        tabButtons.forEach { $0.isUserInteractionEnabled = false }
        
        for (index, button) in tabButtons.enumerated() {
            let isSelected = (index == selectedIndex)
            
            // 直接设置 isSelected 属性即可，图片会自动切换
            button.isSelected = isSelected
            
            // SF Symbols 的情况需要手动更新 tintColor
            if button.currentImage?.isSymbolImage == true {
                button.tintColor = isSelected ? .white : .white.withAlphaComponent(0.6)
            }
            
            // 选中状态缩放动画
            UIView.animate(withDuration: 0.2, delay: 0, options: [.curveEaseOut], animations: {
                button.transform = isSelected ? CGAffineTransform(scaleX: 1.1, y: 1.1) : .identity
            })
        }
        
        // 延迟恢复按钮交互
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.25) {
            self.tabButtons.forEach { $0.isUserInteractionEnabled = true }
        }
    }
    
    /// 设置全局管理器
    private func setupGlobalManagers() {
        globalEventManager = GlobalEventManager.shared()
        globalEventManager?.setupSDKDelegates()
        
        // TODO: v0.2 版本暂时禁用房间最小化视图（无房间功能）
        // 后续版本可通过 Build Configuration 或版本号判断是否启用
        /*
        if let containerView = view {
            globalEventManager?.setupRoomMiniView(on: containerView)
        }
        */
        
        // 注册社交分享回调
        globalEventManager?.registerSocialShareCallback()
        
        NSLog("[EPTabBarController] 全局管理器设置完成（v0.2 - 无 MiniRoom）")
    }
    
    /// 设置初始 ViewController（未登录状态）
    private func setupInitialViewControllers() {
        // TODO: 暂时使用空白页面占位
        let blankVC1 = UIViewController()
        blankVC1.view.backgroundColor = .white
        blankVC1.tabBarItem = createTabBarItem(
            title: YMLocalizedString("tab.moment"),
            normalImage: "tab_moment_normal",
            selectedImage: "tab_moment_selected"
        )
        
        let blankVC2 = UIViewController()
        blankVC2.view.backgroundColor = .white
        blankVC2.tabBarItem = createTabBarItem(
            title: YMLocalizedString("tab.mine"),
            normalImage: "tab_mine_normal",
            selectedImage: "tab_mine_selected"
        )
        
        viewControllers = [blankVC1, blankVC2]
        selectedIndex = 0
        
        NSLog("[EPTabBarController] 初始 ViewControllers 设置完成")
    }
    
    /// 创建 TabBarItem
    /// - Parameters:
    ///   - title: 标题
    ///   - normalImage: 未选中图标名称
    ///   - selectedImage: 选中图标名称
    /// - Returns: UITabBarItem
    private func createTabBarItem(title: String, normalImage: String, selectedImage: String) -> UITabBarItem {
        let item = UITabBarItem(
            title: title,
            image: UIImage(named: normalImage)?.withRenderingMode(.alwaysOriginal),
            selectedImage: UIImage(named: selectedImage)?.withRenderingMode(.alwaysOriginal)
        )
        return item
    }
    
    // MARK: - Public Methods
    
    /// 登录成功后刷新 TabBar
    /// - Parameter isLogin: 是否已登录
    func refreshTabBar(isLogin: Bool) {
        isLoggedIn = isLogin
        
        if isLogin {
            setupLoggedInViewControllers()
        } else {
            setupInitialViewControllers()
        }
        
        NSLog("[EPTabBarController] TabBar 已刷新，登录状态: \(isLogin)")
    }
    
    /// 设置登录后的 ViewControllers
    private func setupLoggedInViewControllers() {
        // 只在 viewControllers 为空或不是正确类型时才创建
        if viewControllers?.count != 2 || 
           !(viewControllers?[0] is UINavigationController) ||
           !(viewControllers?[1] is UINavigationController) {
            
            // 创建动态页
            let momentVC = EPMomentViewController()
            momentVC.title = YMLocalizedString("tab.moment")
            let momentNav = createTransparentNavigationController(
                rootViewController: momentVC,
                tabTitle: YMLocalizedString("tab.moment"),
                normalImage: "tab_moment_normal",
                selectedImage: "tab_moment_selected"
            )
            
            // 创建我的页
            let mineVC = EPMineViewController()
            mineVC.title = YMLocalizedString("tab.mine")
            let mineNav = createTransparentNavigationController(
                rootViewController: mineVC,
                tabTitle: YMLocalizedString("tab.mine"),
                normalImage: "tab_mine_normal",
                selectedImage: "tab_mine_selected"
            )
            
            viewControllers = [momentNav, mineNav]
            NSLog("[EPTabBarController] 登录后 ViewControllers 创建完成 - Moment & Mine")
        }
        
        selectedIndex = 0
    }
    
    /// 创建透明导航控制器（统一配置）
    /// - Parameters:
    ///   - rootViewController: 根视图控制器
    ///   - tabTitle: TabBar 标题
    ///   - normalImage: 未选中图标
    ///   - selectedImage: 选中图标
    /// - Returns: 配置好的 UINavigationController
    private func createTransparentNavigationController(
        rootViewController: UIViewController,
        tabTitle: String,
        normalImage: String,
        selectedImage: String
    ) -> UINavigationController {
        let nav = UINavigationController(rootViewController: rootViewController)
        nav.navigationBar.isTranslucent = true
        nav.navigationBar.setBackgroundImage(UIImage(), for: .default)
        nav.navigationBar.shadowImage = UIImage()
        nav.view.backgroundColor = .clear
        nav.tabBarItem = createTabBarItem(
            title: tabTitle,
            normalImage: normalImage,
            selectedImage: selectedImage
        )
        
        // 设置 delegate 以监听页面切换
        nav.delegate = self
        
        return nav
    }
    
    // MARK: - TabBar Visibility Control
    
    /// 显示悬浮 TabBar
    private func showCustomTabBar(animated: Bool = true) {
        guard customTabBarView.isHidden else { return }
        
        if animated {
            customTabBarView.isHidden = false
            customTabBarView.alpha = 0
            customTabBarView.transform = CGAffineTransform(translationX: 0, y: 20)
            
            UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseOut) {
                self.customTabBarView.alpha = 1
                self.customTabBarView.transform = .identity
            }
        } else {
            customTabBarView.isHidden = false
            customTabBarView.alpha = 1
        }
    }
    
    /// 隐藏悬浮 TabBar
    private func hideCustomTabBar(animated: Bool = true) {
        guard !customTabBarView.isHidden else { return }
        
        if animated {
            UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseIn, animations: {
                self.customTabBarView.alpha = 0
                self.customTabBarView.transform = CGAffineTransform(translationX: 0, y: 20)
            }) { _ in
                self.customTabBarView.isHidden = true
                self.customTabBarView.transform = .identity
            }
        } else {
            customTabBarView.isHidden = true
            customTabBarView.alpha = 0
        }
    }
}

// MARK: - UITabBarControllerDelegate

extension EPTabBarController: UITabBarControllerDelegate {
    
    override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
        NSLog("[EPTabBarController] 选中 Tab: \(item.title ?? "Unknown")")
    }
    
    /// 禁用系统默认的切换动画
    func tabBarController(_ tabBarController: UITabBarController, 
                         animationControllerForTransitionFrom fromVC: UIViewController, 
                         to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        // 返回 nil 表示不使用动画
        return nil
    }
    
    /// 完全控制是否允许切换
    func tabBarController(_ tabBarController: UITabBarController, 
                         shouldSelect viewController: UIViewController) -> Bool {
        // 允许切换，但通过返回 nil 的 animationController 来禁用动画
        return true
    }
}

// MARK: - UINavigationControllerDelegate

extension EPTabBarController: UINavigationControllerDelegate {
    
    func navigationController(_ navigationController: UINavigationController, 
                            willShow viewController: UIViewController, 
                            animated: Bool) {
        
        // 判断是否是根页面（一级页面）
        let isRootViewController = navigationController.viewControllers.count == 1
        
        if isRootViewController {
            // 一级页面：显示 TabBar
            showCustomTabBar(animated: animated)
            NSLog("[EPTabBarController] 显示 TabBar - 根页面")
        } else {
            // 二级及以上页面：隐藏 TabBar
            hideCustomTabBar(animated: animated)
            NSLog("[EPTabBarController] 隐藏 TabBar - 子页面 (层级: \(navigationController.viewControllers.count))")
        }
    }
}

// MARK: - Auto Login & Ticket Validation

extension EPTabBarController {
    
    /// 自动登录：验证 ticket 有效性（与 OC MainPresenter.autoLogin 保持一致）
    private func performAutoLogin() {
        // 1. 检查账号信息
        guard let accountModel = AccountInfoStorage.instance().getCurrentAccountInfo() else {
            NSLog("[EPTabBarController] ⚠️ 账号信息不存在，跳转到登录页")
            handleTokenInvalid()
            return
        }
        
        // 2. 检查 uid 和 access_token
        let uid = accountModel.uid
        let accessToken = accountModel.access_token
        
        guard !uid.isEmpty, !accessToken.isEmpty else {
            NSLog("[EPTabBarController] ⚠️ uid 或 access_token 为空，跳转到登录页")
            handleTokenInvalid()
            return
        }
        
        // 3. 检查 ticket 是否已存在（内存缓存）
        let existingTicket = AccountInfoStorage.instance().getTicket() ?? ""
        if !existingTicket.isEmpty {
            NSLog("[EPTabBarController] ✅ Ticket 已存在，自动登录成功")
            return
        }
        
        // 4. Ticket 不存在，请求新的 ticket
        NSLog("[EPTabBarController] 🔄 Ticket 不存在，正在请求...")
        let loginService = EPLoginService()
        
        loginService.requestTicket(accessToken: accessToken) { ticket in
            NSLog("[EPTabBarController] ✅ Ticket 请求成功: \(ticket)")
            AccountInfoStorage.instance().saveTicket(ticket)
        } failure: { [weak self] code, msg in
            NSLog("[EPTabBarController] ❌ Ticket 请求失败 (\(code)): \(msg)")
            
            // ⚠️ Ticket 失败，强制退出登录（与 OC MainPresenter 保持一致）
            DispatchQueue.main.async {
                self?.handleTokenInvalid()
            }
        }
    }
    
    /// 处理 Token 失效：清空数据并跳转到登录页
    private func handleTokenInvalid() {
        NSLog("[EPTabBarController] ⚠️ Token 失效，清空账号数据...")
        
        // 1. 清空账号信息
        AccountInfoStorage.instance().saveAccountInfo(nil)
        AccountInfoStorage.instance().saveTicket("")
        
        // 2. 跳转到登录页
        DispatchQueue.main.async {
            let loginVC = EPLoginViewController()
            let nav = BaseNavigationController(rootViewController: loginVC)
            nav.modalPresentationStyle = .fullScreen
            
            // 获取 keyWindow（iOS 13+ 兼容）
            if #available(iOS 13.0, *) {
                for scene in UIApplication.shared.connectedScenes {
                    if let windowScene = scene as? UIWindowScene,
                       windowScene.activationState == .foregroundActive,
                       let window = windowScene.windows.first(where: { $0.isKeyWindow }) {
                        window.rootViewController = nav
                        window.makeKeyAndVisible()
                        break
                    }
                }
            } else {
                if let window = UIApplication.shared.keyWindow {
                    window.rootViewController = nav
                    window.makeKeyAndVisible()
                }
            }
            
            NSLog("[EPTabBarController] ✅ 已跳转到登录页")
        }
    }
}

// MARK: - OC Compatibility

extension EPTabBarController {
    
    /// OC 兼容：创建实例的工厂方法
    @objc static func create() -> EPTabBarController {
        return EPTabBarController()
    }
    
    /// OC 兼容：刷新 TabBar 方法
    @objc func refreshTabBarWithIsLogin(_ isLogin: Bool) {
        refreshTabBar(isLogin: isLogin)
    }
}