namespace TestClearScriptPerformanceAndNesting
{
    // Some poor-man's performance measurements between
    // ClearScript's V8, ClearScript's JScript (Microsoft Active Scripting)
    // and Jint.
    //
    // Related to
    // https://clearscript.codeplex.com/discussions/554734
    //
    // If you like it, please also visit http://www.zeta-producer.com for
    // a Windows-based offline Desktop CMS.

    using System;
    using System.Diagnostics;
    using Jint;
    using Microsoft.ClearScript;
    using Microsoft.ClearScript.V8;
    using Microsoft.ClearScript.Windows;

    internal static class Program
    {
        private const int LoopCount = 2000;

        private static void Main()
        {
            var sw9 = Run9(); Console.WriteLine(sw9.Elapsed);
            var sw7 = Run7(); Console.WriteLine(sw7.Elapsed);
            var sw8 = Run8(); Console.WriteLine(sw8.Elapsed);
            var sw6 = Run6(); Console.WriteLine(sw6.Elapsed);
            var sw5 = Run5(); Console.WriteLine(sw5.Elapsed);
            var sw4 = Run4(); Console.WriteLine(sw4.Elapsed);
            var sw3 = Run3(); Console.WriteLine(sw3.Elapsed);
            var sw1 = Run1(); Console.WriteLine(sw1.Elapsed);
            var sw2 = Run2(); Console.WriteLine(sw2.Elapsed);

            Console.WriteLine();
            Console.WriteLine();
            Console.WriteLine();
            Console.WriteLine("-");
            Console.WriteLine("ClearScript JScript one interpreter per loop : {0}.", sw1.Elapsed);
            Console.WriteLine("ClearScript JScript two interpreters per loop: {0}.", sw2.Elapsed);
            Console.WriteLine("ClearScript JScript one interpreter          : {0}.", sw6.Elapsed);
            Console.WriteLine("-");
            Console.WriteLine("ClearScript V8 one interpreter per loop      : {0}.", sw7.Elapsed);
            Console.WriteLine("ClearScript V8 two interpreters per loop     : {0}.", sw8.Elapsed);
            Console.WriteLine("ClearScript V8 one interpreter               : {0}.", sw9.Elapsed);
            Console.WriteLine("-");
            Console.WriteLine("Jint two interpreters per loop               : {0}.", sw3.Elapsed);
            Console.WriteLine("Jint one interperter per loop                : {0}.", sw4.Elapsed);
            Console.WriteLine("Jint one interpreter                         : {0}.", sw5.Elapsed);
            Console.WriteLine();
            Console.WriteLine();
        }

        private static Stopwatch Run1()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                using (var engine = new JScriptEngine())
                {
                    engine.AddHostObject(@"host", new HostFunctions1(engine));
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run6()
        {
            var sw = new Stopwatch();
            sw.Start();
            using (var engine = new JScriptEngine())
            {
                for (var i = 0; i < LoopCount; i++)
                {
                    engine.AddHostObject(@"host", new HostFunctions1(engine));
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run2()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                using (var engine = new JScriptEngine())
                {
                    engine.AddHostObject(@"host", new HostFunctions2());
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run7()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                using (var engine = new V8ScriptEngine())
                {
                    engine.AddHostObject(@"host", new HostFunctions1(engine));
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run9()
        {
            var sw = new Stopwatch();
            sw.Start();
            using (var engine = new V8ScriptEngine())
            {
                for (var i = 0; i < LoopCount; i++)
                {
                    engine.AddHostObject(@"host", new HostFunctions1(engine));
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run8()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                using (var engine = new V8ScriptEngine())
                {
                    engine.AddHostObject(@"host", new HostFunctions5());
                    Trace.WriteLine(engine.Evaluate(@"host.RunIt()"));
                }
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run3()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                var engine = new Engine();
                engine.SetValue(@"host", new HostFunctions3());
                Trace.WriteLine(engine.Execute(@"host.RunIt()").GetCompletionValue().ToObject());
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run4()
        {
            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < LoopCount; i++)
            {
                var engine = new Engine();
                engine.SetValue(@"host", new HostFunctions4(engine));
                Trace.WriteLine(engine.Execute(@"host.RunIt()").GetCompletionValue().ToObject());
            }
            sw.Stop();
            return sw;
        }

        private static Stopwatch Run5()
        {
            var sw = new Stopwatch();
            sw.Start();
            var engine = new Engine();
            for (var i = 0; i < LoopCount; i++)
            {
                engine.SetValue(@"host", new HostFunctions4(engine));
                Trace.WriteLine(engine.Execute(@"host.RunIt()").GetCompletionValue().ToObject());
            }
            sw.Stop();
            return sw;
        }
    }

    public sealed class HostFunctions1
    {
        private readonly ScriptEngine _engine;

        public HostFunctions1(ScriptEngine engine)
        {
            _engine = engine;
        }

        public object RunIt()
        {
            return _engine.Evaluate(@"1+2");
        }
    }

    public sealed class HostFunctions2
    {
        public object RunIt()
        {
            using (var engine = new JScriptEngine())
            {
                return engine.Evaluate(@"1+2");
            }
        }
    }

    public sealed class HostFunctions5
    {
        public object RunIt()
        {
            using (var engine = new V8ScriptEngine())
            {
                return engine.Evaluate(@"1+2");
            }
        }
    }

    public sealed class HostFunctions3
    {
        public object RunIt()
        {
            var engine = new Engine();
            return engine.Execute(@"1+2").GetCompletionValue();
        }
    }

    public sealed class HostFunctions4
    {
        private readonly Engine _engine;

        public HostFunctions4(Engine engine)
        {
            _engine = engine;
        }

        public object RunIt()
        {
            return _engine.Execute(@"1+2").GetCompletionValue();
        }
    }
}