using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace Melskin.Controls
{
    public class StepBar : ItemsControl
    {
        // 使用 StepProgress 代替 SelectedIndex，允许值范围 0 到 Items.Count
        public static readonly DependencyProperty StepProgressProperty =
            DependencyProperty.Register("StepProgress", typeof(int), typeof(StepBar),
                new FrameworkPropertyMetadata(0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnStepProgressChanged));

        public int StepProgress
        {
            get => (int)GetValue(StepProgressProperty);
            set => SetValue(StepProgressProperty, value);
        }

        public static readonly DependencyProperty OrientationProperty =
            DependencyProperty.Register("Orientation", typeof(Orientation), typeof(StepBar),
                new PropertyMetadata(Orientation.Horizontal));

        public Orientation Orientation
        {
            get => (Orientation)GetValue(OrientationProperty);
            set => SetValue(OrientationProperty, value);
        }

        static StepBar()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(StepBar), new FrameworkPropertyMetadata(typeof(StepBar)));
        }

        private static void OnStepProgressChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is StepBar bar) bar.UpdateItemsStatus();
        }

        protected override DependencyObject GetContainerForItemOverride() => new StepBarItem();
        protected override bool IsItemItsOwnContainerOverride(object item) => item is StepBarItem;

        protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
        {
            base.PrepareContainerForItemOverride(element, item);
            UpdateItemsStatus();
        }

        internal void UpdateItemsStatus()
        {
            for (int i = 0; i < Items.Count; i++)
            {
                if (ItemContainerGenerator.ContainerFromIndex(i) is StepBarItem container)
                {
                    container.Index = i + 1;
                    container.IsLast = (i == Items.Count - 1);
                    container.Orientation = this.Orientation;

                    // 核心逻辑：
                    // i < Progress -> 已完成 (Completed)
                    // i == Progress -> 进行中 (Active)
                    // i > Progress -> 等待 (Waiting)
                    if (i < StepProgress)
                        container.Status = StepStatus.Completed;
                    else if (i == StepProgress)
                        container.Status = StepStatus.Active;
                    else
                        container.Status = StepStatus.Waiting;
                }
            }
        }
    }

    public class StepBarItem : ContentControl
    {
        public static readonly DependencyProperty StatusProperty = DependencyProperty.Register("Status", typeof(StepStatus), typeof(StepBarItem), new PropertyMetadata(StepStatus.Waiting));
        public StepStatus Status { get => (StepStatus)GetValue(StatusProperty); set => SetValue(StatusProperty, value); }

        public static readonly DependencyProperty IndexProperty = DependencyProperty.Register("Index", typeof(int), typeof(StepBarItem), new PropertyMetadata(1));
        public int Index { get => (int)GetValue(IndexProperty); set => SetValue(IndexProperty, value); }

        public static readonly DependencyProperty IsLastProperty = DependencyProperty.Register("IsLast", typeof(bool), typeof(StepBarItem), new PropertyMetadata(false));
        public bool IsLast { get => (bool)GetValue(IsLastProperty); set => SetValue(IsLastProperty, value); }

        public static readonly DependencyProperty OrientationProperty = DependencyProperty.Register("Orientation", typeof(Orientation), typeof(StepBarItem), new PropertyMetadata(Orientation.Horizontal));
        public Orientation Orientation { get => (Orientation)GetValue(OrientationProperty); set => SetValue(OrientationProperty, value); }

        static StepBarItem()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(StepBarItem), new FrameworkPropertyMetadata(typeof(StepBarItem)));
        }

        protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
        {
            base.OnMouseLeftButtonDown(e);
            var parent = ItemsControl.ItemsControlFromItemContainer(this) as StepBar;
            if (parent != null)
            {
                int myIndex = parent.ItemContainerGenerator.IndexFromContainer(this);

                // 点击逻辑：
                // 1. 如果点的是当前正在进行的步 -> 完成这一步，进度+1
                // 2. 如果点的是已经完成的步 -> 回退到那一步
                // 3. 如果点的是还没开始的步 -> 直接跳到那一步
                if (parent.StepProgress == myIndex)
                {
                    parent.StepProgress = myIndex + 1;
                }
                else
                {
                    parent.StepProgress = myIndex;
                }
            }
        }
    }
}

public enum StepStatus
{
    Completed,
    Active,
    Waiting
}