using System;
using System.Windows;
using XP.Common.GeneralForm.ViewModels;
using XP.Common.Localization;

namespace XP.Common.GeneralForm.Views
{
    /// <summary>
    /// 通用输入对话框，支持单行文本输入和可选的输入验证
    /// General input dialog with single-line text input and optional validation
    /// </summary>
    public partial class InputDialog : Window
    {
        private readonly InputDialogViewModel _viewModel;

        /// <summary>
        /// 用户输入的结果，取消时为 null | User input result, null if cancelled
        /// </summary>
        public string? Result { get; private set; }

        /// <summary>
        /// 构造函数 | Constructor
        /// </summary>
        /// <param name="prompt">提示文本 | Prompt text</param>
        /// <param name="title">窗口标题 | Window title</param>
        /// <param name="defaultValue">默认值 | Default value</param>
        /// <param name="validate">可选的验证委托，返回 null 表示通过，返回错误信息则阻止确认 | Optional validation delegate</param>
        public InputDialog(
            string prompt,
            string title,
            string defaultValue = "",
            Func<string, string?>? validate = null)
        {
            _viewModel = new InputDialogViewModel(prompt, title, defaultValue, validate);
            DataContext = _viewModel;

            InitializeComponent();

            // 继承调用方窗口图标 | Inherit caller window icon
            if (Application.Current?.MainWindow != null)
            {
                Icon = Application.Current.MainWindow.Icon;
            }
        }

        /// <summary>
        /// 确定按钮点击事件 | OK button click handler
        /// </summary>
        private void OnOkClick(object sender, RoutedEventArgs e)
        {
            // 执行验证 | Run validation
            if (!_viewModel.Validate())
                return;

            Result = _viewModel.InputText;
            DialogResult = true;
        }

        /// <summary>
        /// 取消按钮点击事件 | Cancel button click handler
        /// </summary>
        private void OnCancelClick(object sender, RoutedEventArgs e)
        {
            Result = null;
            DialogResult = false;
        }

        /// <summary>
        /// 静态便捷方法，显示输入对话框并返回结果 | Static convenience method
        /// </summary>
        /// <param name="prompt">提示文本 | Prompt text</param>
        /// <param name="title">窗口标题 | Window title</param>
        /// <param name="defaultValue">默认值 | Default value</param>
        /// <param name="validate">可选的验证委托 | Optional validation delegate</param>
        /// <param name="owner">父窗口（可选）| Owner window (optional)</param>
        /// <returns>用户输入的值，取消时返回 null | User input, null if cancelled</returns>
        public static string? Show(
            string prompt,
            string title,
            string defaultValue = "",
            Func<string, string?>? validate = null,
            Window? owner = null)
        {
            var dialog = new InputDialog(prompt, title, defaultValue, validate);
            // owner 未指定时自动回退到主窗口，确保对话框有父窗口约束不会被遮挡
            // Fall back to MainWindow if owner not specified, ensuring dialog stays in front
            dialog.Owner = owner ?? Application.Current?.MainWindow;
            dialog.ShowDialog();
            return dialog.Result;
        }
    }
}