JavascriptInterfaceWrap

// ReSharper disable once CheckNamespace
namespace JsLab.JsApi
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Reflection;

    public class JsApiBase : Java.Lang.Object
    {
        private readonly string _jsBindName;

        [AttributeUsage(AttributeTargets.Method)]
        protected sealed class JsApiAttribute : Attribute
        {
        }

        // ReSharper disable UnusedAutoPropertyAccessor.Local
        // ReSharper disable once ClassNeverInstantiated.Local
        private sealed class InvokeRequestModel
        {
            public string MethodName { get; set; }
            public object[] Arguments { get; set; }
        }

        private sealed class InvokeResponseModel
        {
            public bool Success { get; set; }
            public Exception Exception { get; set; }
            public object Result { get; set; }
        }

        // ReSharper restore UnusedAutoPropertyAccessor.Local

        protected JsApiBase(string jsBindName)
        {
            _jsBindName = jsBindName;
        }

        public string GenerateFunctionStub()
        {
            var methods = GetType().GetMethods()
                .Where(p => p.IsDefined(typeof(JsApiAttribute), true))
                .ToArray();

            var list = new List<string>(methods.Length);

            // ReSharper disable once LoopCanBeConvertedToQuery
            foreach (var method in methods)
            {
                var argList = string.Join(",", method.GetParameters().Select((p, i) => "p" + i + "_" + p.Name));

                var line1 =
                    $"{method.Name}:function({argList})" + "{" +
                    "var arg={" + $"MethodName:'{method.Name}',Arguments:[{argList}]" + "};" +
                    "var argson=JSON.stringify(arg);" +
                    $"return JSON.parse({_jsBindName}.InvokeInterface(argson));" +
                    "}";

                //TODO: Async version with callback

                list.Add(line1);
            }

            return "{" + string.Join(",", list) + "}";
        }

        [Export]
#if !Android22
        [JavascriptInterface]
#endif
        // ReSharper disable once UnusedMember.Global
        public string InvokeInterface(string json)
        {
            var r = new InvokeResponseModel();

            try
            {
#if Android22
                var im = fastJSON.JSON.ToObject<InvokeRequestModel>(json);
#else
                var im = Newtonsoft.Json.JsonConvert.DeserializeObject<InvokeRequestModel>(json);
#endif
                r.Result = GetType().InvokeMember(im.MethodName, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance, null, this, im.Arguments);
                r.Success = true;
            }
            catch (Exception ex)
            {
                r.Success = false;
                r.Exception = ex;
            }

#if Android22
            return fastJSON.JSON.ToJSON(r);
#else
            return Newtonsoft.Json.JsonConvert.SerializeObject(r);
#endif
        }
    }
}