/*
 * MainWindow.xaml.cs - Better-Seewo 安装向导主窗口逻辑
 * 负责安装步骤管理（Welcome -> Install -> Complete）、页面导航动画、按钮逻辑和关闭确认
 * 作者：雾启工作室
 */

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;

namespace Better_Seewo.Installer
{
    /// <summary>
    /// MainWindow 的交互逻辑 - Fluent Design 风格安装向导主窗口
    /// </summary>
    public partial class MainWindow : Window
    {
        /// <summary>
        /// 页面切换动画时长（毫秒）
        /// </summary>
        private const int PageTransitionDuration = 300;

        /// <summary>
        /// 进度指示器动画时长（毫秒）
        /// </summary>
        private const int DotAnimationDuration = 300;

        /// <summary>
        /// 当前安装步骤索引（0=欢迎页, 1=安装页, 2=完成页）
        /// </summary>
        private int _currentStep = 0;

        /// <summary>
        /// 构造函数，初始化窗口组件
        /// </summary>
        public MainWindow()
        {
            InitializeComponent();

            // 为所有按钮初始化 RenderTransform（用于悬停缩放动画）
            BtnNext.RenderTransform = new ScaleTransform(1.0, 1.0);
            BtnInstall.RenderTransform = new ScaleTransform(1.0, 1.0);
            BtnFinish.RenderTransform = new ScaleTransform(1.0, 1.0);
            BtnBack.RenderTransform = new ScaleTransform(1.0, 1.0);
        }

        /// <summary>
        /// 窗口加载完成事件处理 - 导航到默认欢迎页
        /// </summary>
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            // 导航到欢迎页
            NavigateToPage(new Pages.WelcomePage());
            // 设置按钮状态
            UpdateButtonStates();
        }

        #region ===== 自定义标题栏拖动 =====

        /// <summary>
        /// 标题栏鼠标左键按下 - 实现窗口拖动
        /// </summary>
        private void TitleBar_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            // 如果点击的是按钮区域则不触发拖动
            if (e.Source is Button) return;

            // 调用 DragMove 实现窗口拖动
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                DragMove();
            }
        }

        #endregion

        #region ===== 窗口关闭 =====

        /// <summary>
        /// 关闭按钮点击 - 安装进行中不允许关闭
        /// </summary>
        private void BtnClose_Click(object sender, RoutedEventArgs e)
        {
            // 安装进行中时禁止关闭
            if (App.IsInstalling)
            {
                MessageBox.Show(
                    "安装正在进行中，请等待安装完成后再关闭。",
                    "Better-Seewo 安装程序",
                    MessageBoxButton.OK,
                    MessageBoxImage.Information
                );
                return;
            }

            // 安装已完成或未开始时，确认关闭
            if (App.IsInstallCompleted)
            {
                Application.Current.Shutdown();
                return;
            }

            // 未完成安装时二次确认
            var result = MessageBox.Show(
                "安装尚未完成，确定要退出安装程序吗？",
                "Better-Seewo 安装程序",
                MessageBoxButton.YesNo,
                MessageBoxImage.Question
            );

            if (result == MessageBoxResult.Yes)
            {
                Application.Current.Shutdown();
            }
        }

        #endregion

        #region ===== 按钮事件处理 =====

        /// <summary>
        /// 下一步按钮点击 - 从欢迎页跳转到安装页
        /// </summary>
        private void BtnNext_Click(object sender, RoutedEventArgs e)
        {
            if (_currentStep == 0)
            {
                // 从欢迎页进入安装页
                _currentStep = 1;
                NavigateToPage(new Pages.InstallPage());
                UpdateButtonStates();
                UpdateProgressDots();
            }
        }

        /// <summary>
        /// 安装按钮点击 - 开始执行安装
        /// </summary>
        private void BtnInstall_Click(object sender, RoutedEventArgs e)
        {
            if (ContentFrame.Content is Pages.InstallPage installPage)
            {
                // 标记安装开始
                App.IsInstalling = true;
                App.InstallStartTime = DateTime.Now;

                // 禁用安装按钮，显示返回按钮不可用
                BtnInstall.IsEnabled = false;
                BtnInstall.Content = "正在安装...";
                BtnBack.IsEnabled = false;

                // 启动安装过程
                installPage.StartInstallation();
            }
        }

        /// <summary>
        /// 返回按钮点击 - 返回上一步
        /// </summary>
        private void BtnBack_Click(object sender, RoutedEventArgs e)
        {
            if (_currentStep == 1)
            {
                // 从安装页返回欢迎页
                _currentStep = 0;
                NavigateToPage(new Pages.WelcomePage());
                UpdateButtonStates();
                UpdateProgressDots();
            }
        }

        /// <summary>
        /// 完成按钮点击 - 关闭安装程序
        /// </summary>
        private void BtnFinish_Click(object sender, RoutedEventArgs e)
        {
            Application.Current.Shutdown();
        }

        #endregion

        #region ===== 页面导航 =====

        /// <summary>
        /// 导航到指定页面，带淡出旧页面 -> 新页面从右侧滑入的动画效果
        /// </summary>
        /// <param name="page">要导航到的 Page 实例</param>
        private void NavigateToPage(Page page)
        {
            // 步骤1：淡出当前页面
            var fadeOutAnimation = new DoubleAnimation
            {
                From = 1.0,
                To = 0.0,
                Duration = TimeSpan.FromMilliseconds(PageTransitionDuration / 2),
                EasingFunction = new CubicEase { EasingMode = EasingMode.EaseIn }
            };

            fadeOutAnimation.Completed += (s, e) =>
            {
                // 步骤2：切换到新页面
                ContentFrame.Navigate(page);

                // 步骤3：新页面从右侧滑入 + 淡入
                var translateAnimation = new DoubleAnimation
                {
                    From = 30.0,
                    To = 0.0,
                    Duration = TimeSpan.FromMilliseconds(PageTransitionDuration / 2),
                    EasingFunction = new CubicEase { EasingMode = EasingMode.EaseOut }
                };

                var fadeInAnimation = new DoubleAnimation
                {
                    From = 0.0,
                    To = 1.0,
                    Duration = TimeSpan.FromMilliseconds(PageTransitionDuration / 2),
                    EasingFunction = new CubicEase { EasingMode = EasingMode.EaseOut }
                };

                // 应用水平偏移动画
                ContentFrame.BeginAnimation(
                    FrameworkElement.RenderTransformOriginProperty, null);
                var translateTransform = new TranslateTransform(30, 0);
                ContentFrame.RenderTransform = translateTransform;
                translateTransform.BeginAnimation(TranslateTransform.XProperty, translateAnimation);

                // 应用淡入动画
                ContentFrame.BeginAnimation(OpacityProperty, fadeInAnimation);
            };

            // 应用淡出动画到 Frame
            ContentFrame.BeginAnimation(OpacityProperty, fadeOutAnimation);
        }

        /// <summary>
        /// 根据当前步骤更新按钮的可见性和状态
        /// </summary>
        private void UpdateButtonStates()
        {
            switch (_currentStep)
            {
                case 0: // 欢迎页
                    BtnBack.Visibility = Visibility.Collapsed;
                    BtnNext.Visibility = Visibility.Visible;
                    BtnInstall.Visibility = Visibility.Collapsed;
                    BtnFinish.Visibility = Visibility.Collapsed;
                    BtnNext.IsEnabled = true;
                    BtnNext.Content = "下一步  \uE74E;";
                    break;

                case 1: // 安装页
                    BtnBack.Visibility = Visibility.Visible;
                    BtnBack.IsEnabled = true;
                    BtnNext.Visibility = Visibility.Collapsed;
                    BtnInstall.Visibility = Visibility.Visible;
                    BtnInstall.IsEnabled = true;
                    BtnInstall.Content = "开始安装  \uE74E;";
                    BtnFinish.Visibility = Visibility.Collapsed;
                    break;

                case 2: // 完成页
                    BtnBack.Visibility = Visibility.Collapsed;
                    BtnNext.Visibility = Visibility.Collapsed;
                    BtnInstall.Visibility = Visibility.Collapsed;
                    BtnFinish.Visibility = Visibility.Visible;
                    break;
            }
        }

        /// <summary>
        /// 更新底部进度指示器圆点的颜色，高亮当前步骤
        /// </summary>
        private void UpdateProgressDots()
        {
            // 获取主题中的画刷资源
            var accentBrush = (Brush)FindResource("AccentBrush");
            var borderBrush = (Brush)FindResource("BorderBrush");

            // 更新三个圆点的颜色
            Dot1.Fill = _currentStep >= 0 ? accentBrush : borderBrush;
            Dot2.Fill = _currentStep >= 1 ? accentBrush : borderBrush;
            Dot3.Fill = _currentStep >= 2 ? accentBrush : borderBrush;

            // 为当前圆点播放缩放动画（突出当前步骤）
            var currentDot = _currentStep switch
            {
                0 => Dot1,
                1 => Dot2,
                2 => Dot3,
                _ => Dot1
            };

            AnimateDotScale(currentDot);
        }

        /// <summary>
        /// 为进度指示器圆点播放缩放脉冲动画
        /// </summary>
        private void AnimateDotScale(FrameworkElement dot)
        {
            // 放大到 1.5 倍再缩回 1.0 倍
            var scaleUpAnimation = new DoubleAnimation
            {
                From = 1.0,
                To = 1.5,
                Duration = TimeSpan.FromMilliseconds(DotAnimationDuration),
                EasingFunction = new CubicEase { EasingMode = EasingMode.EaseOut }
            };

            var scaleDownAnimation = new DoubleAnimation
            {
                From = 1.5,
                To = 1.0,
                Duration = TimeSpan.FromMilliseconds(DotAnimationDuration),
                EasingFunction = new CubicEase { EasingMode = EasingMode.EaseIn },
                BeginTime = TimeSpan.FromMilliseconds(DotAnimationDuration)
            };

            // 设置缩放变换中心点
            dot.RenderTransform = new ScaleTransform(1.0, 1.0, 4, 4);

            // 应用缩放动画
            dot.RenderTransform.BeginAnimation(ScaleTransform.ScaleXProperty, scaleUpAnimation);
            dot.RenderTransform.BeginAnimation(ScaleTransform.ScaleXProperty, scaleDownAnimation);
            dot.RenderTransform.BeginAnimation(ScaleTransform.ScaleYProperty, scaleUpAnimation);
            dot.RenderTransform.BeginAnimation(ScaleTransform.ScaleYProperty, scaleDownAnimation);
        }

        /// <summary>
        /// 安装完成后由 InstallPage 调用，切换到完成页
        /// </summary>
        public void OnInstallCompleted()
        {
            // 标记安装完成
            App.IsInstalling = false;
            App.IsInstallCompleted = true;

            // 切换到完成页
            Dispatcher.Invoke(() =>
            {
                _currentStep = 2;
                NavigateToPage(new Pages.CompletePage());
                UpdateButtonStates();
                UpdateProgressDots();
            });
        }

        #endregion
    }
}