using System.Globalization;
using System.Windows.Data;

namespace CRSim.ScreenSimulator.Converters
{
    public class LocationToStringConverter : IMultiValueConverter
    {
        public string DisplayMode { get; set; } = "normal";
        public string DisplayArrow { get; set; } = "True";
        public string HyphenText { get; set; } = "~";

        /*
        DisplayMode:
            normal: 正常
            less: 简化
            least：极简（适用于廊桥屏幕）

            在least模式下，如果DisplayArrow为True，则显示箭头，否则不显示箭头。
            在least模式下，需要连字符时将会输出HyphenText。
        
        */
        object IMultiValueConverter.Convert(object[] values, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {   
            if (values[0] is int Length && values[1] is int Location)
            {
                if(DisplayMode == "least" && values[2] is string Direction){
                    if(Direction == "left")
                    {   
                        string Arrow = DisplayArrow == "True"? "←" : "";
                        if(values.Length >= 4 && values[3] is string IsClosedInterval){
                            if(IsClosedInterval == "closed"){
                                if(Location < Length)
                                {
                                    return $"{Arrow}1{HyphenText}{Location-1}";
                                }
                                else if(Length == 1)
                                {
                                    return string.Empty;
                                }
                                else
                                {
                                    return $"{Arrow}1{HyphenText}{Length-1}";
                                }
                            }
                        }
                        if(Location <= Length)
                        {
                            return $"{Arrow}1{HyphenText}{Location}";
                        }
                        else if(Length == 1)
                        {
                            return $"{Arrow}1";
                        }
                        else
                        {
                            return $"{Arrow}1{HyphenText}{Length}";
                        }
                    }
                    if(Direction == "right")
                    {
                        string Arrow = DisplayArrow == "True"? "→" : "";
                        if(Location+1 > Length){
                            return string.Empty;
                        }
                        else if(Location+1 == Length)
                        {
                            return $"{Length}{Arrow}";
                        }
                        else{
                            return $"{Location+1}{HyphenText}{Length}{Arrow}";
                        }
                    }
                    return string.Empty;
                }
                if (DisplayMode == "less")
                {
                    if (Location > Length)
                    {
                        return $"当前无车厢，1~{Length}车厢向前。";
                    }
                    if (Location == Length)
                    {
                        return $"当前{Length}车厢，1车厢向前。";
                    }
                    if (Location == 1)
                    {
                        return $"当前1车厢，{Length}车厢向后。";
                    }
                    return $"1车厢向前，{Length}车厢向后。";
                }
                if (DisplayMode == "normal")
                {
                    if (Location > Length)
                    {
                        return $"当前无车，1-{Length}车向前。";
                    }
                    if (Location == Length)
                    {
                        return $"当前{Location}车，1-{Length-1}车向前。";
                    }
                    if (Location == 1)
                    {
                        return $"当前1车，2-{Length}车向后。";
                    }
                    if (Location == Length-1)
                    {
                        return $"当前{Location}车，1-{Location - 1}车向前，{Length}车向后。";
                    }
                    if (Location == 2)
                    {
                        return $"当前2车，1车向前，3-{Length}车向后。";
                    }
                    return $"当前{Location}车，1-{Location - 1}车向前，{Location + 1}-{Length}车向后。";
                }
                return string.Empty;
            }
            return string.Empty;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            // 通常不需要实现 ConvertBack
            return null;
        }
    }
}