using System.Linq;
using UnityEngine;

namespace DDD.MVVM
{
    /// <summary>
    /// 불린 값을 반전시키는 컨버터
    /// 예: true → false, false → true
    /// </summary>
    public class InvertBoolConverter : IValueConverter
    {
        public object Convert(object value)
        {
            return value is bool boolValue ? !boolValue : false;
        }

        public object ConvertBack(object value)
        {
            return Convert(value); // 반전은 양방향 동일
        }
    }

    /// <summary>
    /// 아이템 개수를 텍스트로 변환하는 컨버터
    /// 예: 5 → "아이템 수: 5"
    /// </summary>
    public class ItemCountConverter : IValueConverter
    {
        public object Convert(object value)
        {
            if (value is int count)
                return $"아이템 수: {count}";
            return "아이템 수: 0";
        }

        public object ConvertBack(object value)
        {
            if (value is string str && str.StartsWith("아이템 수: "))
            {
                var countStr = str.Substring("아이템 수: ".Length);
                return int.TryParse(countStr, out var count) ? count : 0;
            }
            return 0;
        }
    }

    /// <summary>
    /// null 또는 빈 값을 불린으로 변환하는 컨버터
    /// 예: null → false, "" → false, "text" → true
    /// </summary>
    public class IsNullOrEmptyConverter : IValueConverter
    {
        public object Convert(object value)
        {
            if (value == null) return true;
            if (value is string str) return string.IsNullOrEmpty(str);
            return false;
        }

        public object ConvertBack(object value)
        {
            return value is bool boolValue && !boolValue ? "" : null;
        }
    }

    /// <summary>
    /// 숫자를 백분율 텍스트로 변환하는 컨버터
    /// 예: 0.75f → "75%"
    /// </summary>
    public class PercentageConverter : IValueConverter
    {
        public object Convert(object value)
        {
            if (value is float floatValue)
                return $"{(floatValue * 100):F0}%";
            if (value is double doubleValue)
                return $"{(doubleValue * 100):F0}%";
            return "0%";
        }

        public object ConvertBack(object value)
        {
            if (value is string str && str.EndsWith("%"))
            {
                var percentStr = str.Substring(0, str.Length - 1);
                if (float.TryParse(percentStr, out var percent))
                    return percent / 100f;
            }
            return 0f;
        }
    }

    /// <summary>
    /// 열거형을 문자열로 변환하는 컨버터
    /// </summary>
    public class EnumToStringConverter : IValueConverter
    {
        public object Convert(object value)
        {
            return value?.ToString() ?? string.Empty;
        }

        public object ConvertBack(object value)
        {
            // 역변환은 타입 정보가 필요하므로 기본 구현만 제공
            return value;
        }
    }

    /// <summary>
    /// 컬렉션의 개수를 확인하는 컨버터
    /// 예: List<T>(5개) → true, List<T>(0개) → false
    /// </summary>
    public class CollectionHasItemsConverter : IValueConverter
    {
        public object Convert(object value)
        {
            if (value is System.Collections.ICollection collection)
                return collection.Count > 0;
            if (value is System.Collections.IEnumerable enumerable)
                return enumerable.Cast<object>().Any();
            return false;
        }

        public object ConvertBack(object value)
        {
            return value; // 역변환 불가
        }
    }

    /// <summary>
    /// 색상 투명도 조절 컨버터
    /// 불린 값에 따라 알파값을 조절
    /// </summary>
    public class AlphaConverter : IValueConverter
    {
        public float EnabledAlpha { get; set; } = 1.0f;
        public float DisabledAlpha { get; set; } = 0.5f;

        public object Convert(object value)
        {
            if (value is bool boolValue)
                return boolValue ? EnabledAlpha : DisabledAlpha;
            return EnabledAlpha;
        }

        public object ConvertBack(object value)
        {
            if (value is float alpha)
                return Mathf.Approximately(alpha, EnabledAlpha);
            return true;
        }
    }

    /// <summary>
    /// InventoryCategoryType을 한국어로 변환하는 컨버터
    /// </summary>
    public class InventoryCategoryConverter : IValueConverter
    {
        public object Convert(object value)
        {
            if (value is InventoryCategoryType category)
            {
                return category switch
                {
                    InventoryCategoryType.Food => "음식",
                    InventoryCategoryType.Drink => "음료",
                    InventoryCategoryType.Ingredient => "재료",
                    InventoryCategoryType.Cookware => "조리도구",
                    InventoryCategoryType.Special => "특수",
                    _ => "전체"
                };
            }
            return "전체";
        }

        public object ConvertBack(object value)
        {
            if (value is string str)
            {
                return str switch
                {
                    "음식" => InventoryCategoryType.Food,
                    "음료" => InventoryCategoryType.Drink,
                    "재료" => InventoryCategoryType.Ingredient,
                    "조리도구" => InventoryCategoryType.Cookware,
                    "특수" => InventoryCategoryType.Special,
                    _ => InventoryCategoryType.Food
                };
            }
            return InventoryCategoryType.Food;
        }
    }

    /// <summary>
    /// 가격을 통화 형식으로 변환하는 컨버터
    /// 예: 1000 → "1,000원"
    /// </summary>
    public class CurrencyConverter : IValueConverter
    {
        public string CurrencySymbol { get; set; } = "원";

        public object Convert(object value)
        {
            if (value is int intValue)
                return $"{intValue:N0}{CurrencySymbol}";
            if (value is float floatValue)
                return $"{floatValue:N0}{CurrencySymbol}";
            return $"0{CurrencySymbol}";
        }

        public object ConvertBack(object value)
        {
            if (value is string str && str.EndsWith(CurrencySymbol))
            {
                var numberStr = str.Substring(0, str.Length - CurrencySymbol.Length).Replace(",", "");
                if (int.TryParse(numberStr, out var number))
                    return number;
            }
            return 0;
        }
    }
}