using System;
using System.Collections.Generic;
using System.Linq;

namespace LTEMvcApp.Models
{
    /// <summary>
    /// ASN1扩展方法
    /// </summary>
    public static class ASN1Extensions
    {
        /// <summary>
        /// 安全获取字典值
        /// </summary>
        public static T GetValueOrDefault<T>(this Dictionary<string, object> dict, string key, T defaultValue = default(T))
        {
            if (dict != null && dict.ContainsKey(key))
            {
                try
                {
                    return (T)Convert.ChangeType(dict[key], typeof(T));
                }
                catch
                {
                    return defaultValue;
                }
            }
            return defaultValue;
        }

        /// <summary>
        /// 安全获取字典值
        /// </summary>
        public static object GetValueOrDefault(this Dictionary<string, object> dict, string key)
        {
            return dict?.ContainsKey(key) == true ? dict[key] : null;
        }

        /// <summary>
        /// 将对象转换为字典
        /// </summary>
        public static Dictionary<string, object> ToDictionary(this object obj)
        {
            if (obj is Dictionary<string, object> dict)
                return dict;
            
            if (obj is IDictionary<string, object> idict)
                return new Dictionary<string, object>(idict);
            
            return null;
        }

        /// <summary>
        /// 将对象转换为列表
        /// </summary>
        public static List<object> ToList(this object obj)
        {
            if (obj is List<object> list)
                return list;
            
            if (obj is IEnumerable<object> enumerable)
                return enumerable.ToList();
            
            return null;
        }

        /// <summary>
        /// 安全转换为整数
        /// </summary>
        public static int? ToInt32(this object obj)
        {
            if (obj == null) return null;
            
            try
            {
                return Convert.ToInt32(obj);
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 安全转换为字符串
        /// </summary>
        public static string ToSafeString(this object obj)
        {
            return obj?.ToString();
        }

        /// <summary>
        /// 安全转换为布尔值
        /// </summary>
        public static bool? ToBoolean(this object obj)
        {
            if (obj == null) return null;
            
            try
            {
                return Convert.ToBoolean(obj);
            }
            catch
            {
                return null;
            }
        }
    }

    /// <summary>
    /// ASN1工具类
    /// </summary>
    public static class ASN1Utils
    {
        /// <summary>
        /// 创建ASN1对象
        /// </summary>
        public static Dictionary<string, object> CreateASN1Object()
        {
            return new Dictionary<string, object>();
        }

        /// <summary>
        /// 创建ASN1数组
        /// </summary>
        public static List<object> CreateASN1Array()
        {
            return new List<object>();
        }

        /// <summary>
        /// 添加属性到ASN1对象
        /// </summary>
        public static void AddProperty(Dictionary<string, object> obj, string name, object value)
        {
            if (obj == null) return;
            
            if (string.IsNullOrEmpty(name))
            {
                if (obj.ContainsKey(""))
                {
                    var existing = obj[""];
                    if (existing is List<object> list)
                    {
                        list.Add(value);
                    }
                    else
                    {
                        obj[""] = new List<object> { existing, value };
                    }
                }
                else
                {
                    obj[""] = new List<object> { value };
                }
            }
            else
            {
                if (obj.ContainsKey(name))
                {
                    var existing = obj[name];
                    if (existing is List<object> list)
                    {
                        list.Add(value);
                    }
                    else
                    {
                        obj[name] = new List<object> { existing, value };
                    }
                }
                else
                {
                    obj[name] = value;
                }
            }
        }

        /// <summary>
        /// 添加元素到ASN1数组
        /// </summary>
        public static void AddElement(List<object> array, object value)
        {
            array?.Add(value);
        }

        /// <summary>
        /// 深度克隆ASN1对象
        /// </summary>
        public static Dictionary<string, object> DeepClone(Dictionary<string, object> obj)
        {
            if (obj == null) return null;
            
            var result = new Dictionary<string, object>();
            foreach (var kvp in obj)
            {
                if (kvp.Value is Dictionary<string, object> dict)
                {
                    result[kvp.Key] = DeepClone(dict);
                }
                else if (kvp.Value is List<object> list)
                {
                    result[kvp.Key] = DeepCloneList(list);
                }
                else
                {
                    result[kvp.Key] = kvp.Value;
                }
            }
            return result;
        }

        /// <summary>
        /// 深度克隆ASN1数组
        /// </summary>
        public static List<object> DeepCloneList(List<object> list)
        {
            if (list == null) return null;
            
            var result = new List<object>();
            foreach (var item in list)
            {
                if (item is Dictionary<string, object> dict)
                {
                    result.Add(DeepClone(dict));
                }
                else if (item is List<object> subList)
                {
                    result.Add(DeepCloneList(subList));
                }
                else
                {
                    result.Add(item);
                }
            }
            return result;
        }

        /// <summary>
        /// 将ASN1对象转换为JSON字符串
        /// </summary>
        public static string ToJson(Dictionary<string, object> obj, bool prettyPrint = false)
        {
            if (obj == null) return "null";
            
            var settings = new Newtonsoft.Json.JsonSerializerSettings
            {
                Formatting = prettyPrint ? Newtonsoft.Json.Formatting.Indented : Newtonsoft.Json.Formatting.None
            };
            
            return Newtonsoft.Json.JsonConvert.SerializeObject(obj, settings);
        }

        /// <summary>
        /// 从JSON字符串创建ASN1对象
        /// </summary>
        public static Dictionary<string, object> FromJson(string json)
        {
            if (string.IsNullOrEmpty(json)) return null;
            
            try
            {
                return Newtonsoft.Json.JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
            }
            catch
            {
                return null;
            }
        }
    }
}