MedicalInsurance/Helper/JsonMapper.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using PTMedicalInsurance.Common;
using PTMedicalInsurance.Variables;
using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;

namespace PTMedicalInsurance.Helper
{
    /// <summary>
    /// 将json转换为实体对象
    /// </summary>
    public class JsonMapper
    {

        const string ArrayPattern = "[]";

        private string jsonConfig;

        private string configFile;

        private JsonMappingSetting setting;


        public JsonMapper(string name)
        {
            configFile = Global.curEvt.path + "/config/" + name + ".json";
            reload();
        }

        public void reload()
        {
            // 加载字段映射配置
            if (File.Exists(configFile))
            {
                jsonConfig = File.ReadAllText(configFile);

                setting = JsonHelper.toObject<JsonMappingSetting>(JObject.Parse(jsonConfig));
            }
            else
            {
                setting = new JsonMappingSetting();
            }
        }

        /// <summary>
        /// 获取入参映射
        /// </summary>
        /// <returns></returns>
        public List<FieldMapping> GetInputMapping()
        {
            return setting.Input??new List<FieldMapping>();
        }
        /// <summary>
        /// 设置入参
        /// </summary>
        /// <param name="value"></param>
        public void SetInputMapping(List<FieldMapping> value)
        {
            setting.Input = value;
        }
        /// <summary>
        /// 获取出参映射
        /// </summary>
        /// <returns></returns>
        public List<FieldMapping> GetOutputMapping()
        {
            return setting.Output ?? new List<FieldMapping>();
        }
        /// <summary>
        /// 设置出参
        /// </summary>
        /// <param name="value"></param>
        public void SetOutputMapping(List<FieldMapping> value)
        {
            setting.Output = value;
        }
        /// <summary>
        /// 获取转换类
        /// </summary>
        /// <returns></returns>
        private ConvertMapping GetConverter()
        {
            return setting.Convert??new ConvertMapping();
        }

        /// <summary>
        /// 根据实体类获取Json
        /// </summary>
        /// <param name="typeName"></param>
        /// <returns></returns>
        private string GetConvertJson(string typeName)
        {
            if (!string.IsNullOrEmpty(typeName))
            {
                if (typeName.IndexOf(".")<1)
                {
                    typeName = "PTMedicalInsurance.Entity.Local." + typeName;
                }
                Type type = Type.GetType(typeName);
                if (type != null)
                {
                    Object obj = Activator.CreateInstance(type);
                    return JsonHelper.toJsonString(obj, false);
                }
            }
            return string.Empty;
        }

        /// <summary>
        /// 将参数方向对调
        /// </summary>
        public void ChangeDirection(List<FieldMapping> mappings)
        {
            mappings.ForEach((map) =>
            {
                if (!string.IsNullOrEmpty(map.Source) && !string.IsNullOrEmpty(map.Target))
                {
                    string orgin = map.Target;
                    map.Target = map.Source;
                    map.Source = orgin;
                }
            });
        }


        /// <summary>
        /// 入参实例JSON
        /// </summary>
        /// <returns></returns>
        public string GetInputJson()
        {
            return GetConvertJson(GetConverter()?.Input);
        }
        /// <summary>
        /// 出参实例JSON
        /// </summary>
        /// <returns></returns>
        public string GetOutputJson()
        {
            return GetConvertJson(GetConverter()?.Output);
        }

        /// <summary>
        /// Json字段映射
        /// </summary>
        /// <param name="jObject"></param>
        /// <returns></returns>
        private JObject MapJson(string key,JObject jSource)
        {
            JObject jObject = new JObject();
            if(string.IsNullOrEmpty(jsonConfig) || string.IsNullOrEmpty(key))
            {
                return jSource;
            }

            List<FieldMapping> fieldMappings = "input".Equals(key) ? GetInputMapping() : GetOutputMapping() ;

            if (fieldMappings != null)
            {
                // 对于每一个字段映射信息
                foreach (var fieldMapping in fieldMappings)
                {
                    // 使用JToken.SelectToken来获取源路径对应的值
                    dynamic value = new JValue("");
                    string nameKey = fieldMapping.Source;
                    string expression = fieldMapping.Expression;

                    if (!string.IsNullOrEmpty(nameKey))
                    {
                        nameKey = nameKey.Split(",".ToCharArray())[0];  //多对一忽略后面的

                        if (fieldMapping.Child != null)
                        {
                            //数组映射
                            nameKey = nameKey.Replace(ArrayPattern, "");
                        }
                        else
                        {
                            if (nameKey.Contains(ArrayPattern))
                            {
                                //数组映射对象时，取第一个
                                nameKey = nameKey.Replace(ArrayPattern, "[0]");
                            }
                        }
                        value = jSource.SelectToken(nameKey);
                    }
                    else if (fieldMapping.Value != null)
                    {
                        // 支持固定值
                        value = new JValue(fieldMapping.Value);
                    }

                    // 表达式（全局变量）
                    if ((expression ?? "").Equals("GlobaVariables"))
                    {
                        value = GetExpressionValue(expression, fieldMapping.Source);
                        expression = null;
                    }
                    // 表达式（扩展字段）
                    if ((expression ?? "").Equals("SaveToExpand"))
                    {
                        SetExpression(expression, fieldMapping.Source, value);
                        continue;
                    }

                    // 普通转换
                    if (value != null)
                    {
                        if (fieldMapping.Child != null)
                        {
                            //数组映射,此时的value为array
                            var items = new JArray();
                            foreach (var item in (JArray)value)
                            {
                                var child = MapChildItem((JObject)item, fieldMapping.Child);
                                items.Add(child);
                            }
                            CreateJObjectFromString(jObject, fieldMapping.Target.Replace(ArrayPattern,""), items, 0);
                        }
                        else
                        {
                            ParseAndMap(value, jObject, nameKey, fieldMapping.Target, expression);
                        }
                    }
                }
            }
            return jObject;
        }

        private JObject MapChildItem(JObject itemObject, List<FieldMapping> childs)
        {
            JObject newItem = new JObject();
            foreach (FieldMapping subMapping in childs)
            {
                if (!string.IsNullOrEmpty(subMapping.Value))
                {
                    newItem[subMapping.Target] = subMapping.Value;
                }
                else
                {
                    newItem[subMapping.Target] = itemObject[subMapping.Source];
                }
            }
            return newItem;
        }

        /// <summary>
        ///  映射实体
        /// </summary>
        /// <typeparam name="TSource">源对象</typeparam>
        /// <typeparam name="TTarget">目标对象</typeparam>
        /// <param name="name">名称</param>
        /// <param name="sourceItem">源数据</param>
        /// <returns></returns>
        public TTarget Map<TSource, TTarget>(string key, TSource sourceItem)
        {
            var json = JsonConvert.SerializeObject(sourceItem);

            var jObject = JObject.Parse(json);
            // 映射
            JObject jRet = MapJson(key,jObject);

            // 然后将修改后的JObject再转化到目标类型的对象
            var targetItem = jRet.ToObject<TTarget>();
            return targetItem;
        }
        /// <summary>
        /// 解析对象后转换为JObject
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <typeparam name="TTarget"></typeparam>
        /// <param name="sourceItem"></param>
        /// <returns></returns>
        //[Obsolete("建议使用Map方法")]
        private JObject MapObject<TSource, TTarget>(string key,TSource sourceItem)
        {

            TTarget target = Map<TSource, TTarget>(key,sourceItem);
            var json = JsonConvert.SerializeObject(target);
            return JObject.Parse(json);
        }
        /// <summary>
        /// 入参映射
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <typeparam name="TTarget"></typeparam>
        /// <param name="sourceItem"></param>
        /// <returns></returns>
        public JObject MapRequest<TSource, TTarget>(TSource sourceItem)
        {
            TTarget target = Map<TSource, TTarget>("input",sourceItem);
            var json = JsonConvert.SerializeObject(target);
            return JObject.Parse(json);
        }
        /// <summary>
        /// 出参映射
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <typeparam name="TTarget"></typeparam>
        /// <param name="sourceItem"></param>
        /// <returns></returns>
        public JObject MapResponse<TSource, TTarget>(TSource sourceItem)
        {
            TTarget target = Map<TSource, TTarget>("output", sourceItem);
            var json = JsonConvert.SerializeObject(target);
            return JObject.Parse(json);
        }

        /// <summary>
        /// 解析并映射字段
        /// </summary>
        /// <param name="sourceToken"></param>
        /// <param name="targetObject"></param>
        /// <param name="sourcePath"></param>
        /// <param name="targetPath"></param>
        private void ParseAndMap(JToken sourceToken, JObject targetObject, string sourcePath, string targetPath, string expression = "")
        {
            // 支持映射多个字段
            var targetFields = targetPath.Split(',');
            foreach (var targetField in targetFields) {
                //if (!sourceToken.HasValues && string.IsNullOrEmpty(sourceToken.Value<string>())) continue;
                ParseAndMapField(sourceToken, targetObject, sourcePath, targetField, expression);
            }
        }

        /// <summary>
        /// 解析并映射单个字段
        /// </summary>
        /// <param name="sourceToken"></param>
        /// <param name="targetObject"></param>
        /// <param name="sourcePath"></param>
        /// <param name="targetPath"></param>
        private void ParseAndMapField(JToken value, JObject targetObject, string sourcePath, string targetPath, string expression = "")
        {
            if (string.IsNullOrEmpty(targetPath)) return;
            if (sourcePath !=null && sourcePath.StartsWith(".")) { sourcePath = sourcePath.Substring(1); }
            if (targetPath.StartsWith(".")) { targetPath = targetPath.Substring(1); }

            var targetTokens = targetPath.Split('.');
            var remainingTargetPath = string.Join(".", targetTokens, 0, targetTokens.Length - 1);
            var isArray = remainingTargetPath.Contains(ArrayPattern);
            var remainingTargetTokens = remainingTargetPath.Split(ArrayPattern.ToCharArray());

            //var value = sourceToken.SelectToken(sourcePath);

            // 抵达路径顶点
            if (targetTokens.Length == 1)
            {
                targetObject.Add(targetTokens[0], value);
                return;
            }
            // 处理数组类型的映射
            if (isArray)
            {
                if (value is JValue) {
                    // 将固定数据给数组中的第一个对象
                    var newItem = (targetObject[targetTokens[0]] ?? new JObject()) as JObject;
                    CreateJObjectFromString(newItem, targetPath, (JValue)value,1,expression);
                    targetObject[targetTokens[0]] = newItem;
                }
                //if (value is JArray)
                //{
                //    string[] childPath = sourcePath.Split(ArrayPattern.ToCharArray());
                //    string[] destPath = targetPath.Split(ArrayPattern.ToCharArray());
                //    string arrayKey = targetTokens[0].Split(ArrayPattern.ToCharArray())[0];
                //    var newItem = (targetObject[arrayKey] ?? new JArray()) as JArray;
                //    //CreateJObjectFromString(newItem, targetPath, null,0);
                //    foreach (var item in ((JArray)value).Children<JObject>())
                //    {
                //        var childItem = new JObject();
                //        ParseAndMapField(item.SelectToken(childPath[2].Substring(1)), childItem, childPath[2], destPath[2]); // 递归处理嵌套路径
                //        newItem.Add(childItem);
                //    }
                //    targetObject[arrayKey] = newItem;
                //}
            }
            else if (targetTokens.Length > 1) {
                // 对象层级
                string nameKey = targetTokens[0];
                int index = 1; //不包含根节点
                if (nameKey.Contains("[]"))
                {
                    nameKey = nameKey.Substring(0, nameKey.Length - 2);
                    index = 0;
                }

                var newItem = (targetObject[nameKey] ?? new JObject()) as JObject;
                CreateJObjectFromString(newItem,targetPath,(JValue)value, index, expression);

                targetObject[nameKey] = newItem;

            }
            else // 普通嵌套映射
            {
                var newItem = new JObject();
                ParseAndMapField(value, newItem, sourcePath, remainingTargetPath); // 递归处理嵌套路径
                targetObject.Add(targetTokens[0], newItem);
            }
            targetObject.Remove(sourcePath);
        }

        /// <summary>
        /// 根据层级创建对象
        /// </summary>
        /// <param name="current"></param>
        /// <param name="input"></param>
        /// <param name="value"></param>
        /// <returns></returns>
        private JObject CreateJObjectFromString(JObject current, string input,JToken value,int index = 1,string expression = "")
        {
            var keys = input.Split('.');
            JObject root = current;
            
            for (int i = index; i < keys.Length - 1; i++)
            {
                if (keys[i].EndsWith("[]"))
                {
                    string actualKey = keys[i].Substring(0, keys[i].Length - 2);
                    if (current[actualKey] == null)
                    {
                        current[actualKey] = new JArray { new JObject() };
                    }
                    // 数组的某一条
                    current = (JObject)((JArray)current[actualKey]).Last; ;
                }
                else
                {
                    if (current[keys[i]] == null)
                    {
                        current[keys[i]] = new JObject();
                    }
                    current = (JObject)current[keys[i]];
                }
            }
            if (!string.IsNullOrEmpty(expression)) {
                value = GetExpressionValue(expression, value);
            }
            current[keys[keys.Length - 1]] = value;

            return root;
        }

        private void SetExpression(string method, string key,object value)
        {
            try
            {
                Type type = typeof(ExpressionEvaluator);
                MethodInfo mi = type.GetMethod(method);
                if (mi != null)
                {
                    mi.Invoke(null, new object[] {key,value });
                }
            }
            catch (Exception e)
            { }
        }

        private string GetExpressionValue(string method,object value)
        {
            object objRtn = null;
            try
            {
                Type type = typeof(ExpressionEvaluator);
                MethodInfo mi = type.GetMethod(method);
                if (mi != null)
                {
                    objRtn = mi.Invoke(null, new object[] { value });
                }
            }
            catch (Exception e)
            { }

            return objRtn?.ToString();

        }

        /// <summary>
        /// 保存配置
        /// </summary>
        public void Save()
        {
            jsonConfig = JsonHelper.toJsonString(this.setting);
            if(!string.IsNullOrEmpty(jsonConfig) && !string.IsNullOrEmpty(configFile))
            {
                File.WriteAllText(configFile,jsonConfig);
            }
        }

    }


    public class JsonMappingSetting
    { 
        public List<FieldMapping> Input { set; get; }

        public List<FieldMapping> Output { set; get; }

        public ConvertMapping Convert { set; get; }
    }

    public class FieldMapping
    {
        public string Source { get; set; }
        public string Target { get; set; }
        public string Value { get; set; }
        public string Expression { set; get; }

        public List<FieldMapping> Child { get; set; }

        public FieldMapping()
        { }
    }

    public class ConvertMapping
    { 
        public string Input { set; get; }

        public string Output { set; get; }
    }
}