// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.ClearScript.JavaScript;
using Microsoft.ClearScript.V8;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace Microsoft.ClearScript.Test
{
    // ReSharper disable once PartialTypeWithSinglePart

    [TestClass]
    [SuppressMessage("Microsoft.Design", "CA1001:TypesThatOwnDisposableFieldsShouldBeDisposable", Justification = "Test classes use TestCleanupAttribute for deterministic teardown.")]
    public partial class ExtensionsTest : ClearScriptTest
    {
        #region setup / teardown

        private ScriptEngine engine;

        [TestInitialize]
        public void TestInitialize()
        {
            BaseTestInitialize();
            engine = new V8ScriptEngine(V8ScriptEngineFlags.EnableDebugging);
            engine.AddHostType(typeof(Extensions));
            engine.AddHostType(typeof(JavaScriptExtensions));
        }

        [TestCleanup]
        public void TestCleanup()
        {
            engine.Dispose();
            BaseTestCleanup();
        }

        #endregion

        #region test methods

        // ReSharper disable InconsistentNaming

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_ToHostType()
        {
            engine.Script.ClrMath = typeof(Math).ToHostType(engine);
            Assert.AreEqual(Math.PI, engine.Evaluate("ClrMath.PI"));

            engine.Script.randomType = typeof(Random);
            Assert.IsInstanceOfType(engine.Evaluate("new (randomType.ToHostType())"), typeof(Random));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_ToRestrictedHostObject()
        {
            IConvertible convertible = 123;
            engine.Script.convertible = convertible.ToRestrictedHostObject(engine);
            Assert.AreEqual(TypeCode.Int32, engine.Evaluate("convertible.GetTypeCode()"));

            engine.AddHostType(typeof(IConvertible));
            Assert.AreEqual(TypeCode.Int32, engine.Evaluate("Extensions.ToRestrictedHostObject(IConvertible, 456).GetTypeCode()"));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise()
        {
            engine.Script.promise = Task.FromResult(Math.PI).ToPromise(engine);
            engine.Execute("(async function () { result = await promise; })()"); 
            Assert.AreEqual(Math.PI, engine.Script.result);

            engine.Script.task = Task.FromResult(Math.E);
            engine.Execute("(async function () { result = await task.ToPromise(); })()");
            Assert.AreEqual(Math.E, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise_Faulted()
        {
            const string message = "No task for you!";
            var task = Task.FromException<double>(new UnauthorizedAccessException(message));

            engine.Script.promise = task.ToPromise(engine);
            engine.Execute("(async function () { try { result = await promise; } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);

            engine.Script.task = task;
            engine.Execute("(async function () { try { result = await task.ToPromise(); } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise_Canceled()
        {
            var message = new TaskCanceledException().Message;
            var task = Task.FromCanceled<double>(new CancellationToken(true));

            engine.Script.promise = task.ToPromise(engine);
            engine.Execute("(async function () { try { result = await promise; } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);

            engine.Script.task = task;
            engine.Execute("(async function () { try { result = await task.ToPromise(); } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise_NoResult()
        {
            engine.Script.promise = RunAsTask(() => engine.Script.result = Math.PI).ToPromise(engine);
            engine.Execute("(async function () { await promise; })()");
            Assert.AreEqual(Math.PI, engine.Script.result);

            engine.Script.task = RunAsTask(() => engine.Script.result = Math.E);
            engine.Execute("(async function () { await task.ToPromise(); })()");
            Assert.AreEqual(Math.E, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise_NoResult_Faulted()
        {
            const string message = "No task for you!";
            var task = Task.FromException(new UnauthorizedAccessException(message));

            engine.Script.promise = task.ToPromise(engine);
            engine.Execute("(async function () { try { result = await promise; } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);

            engine.Script.task = task;
            engine.Execute("(async function () { try { result = await task.ToPromise(); } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToPromise_NoResult_Canceled()
        {
            var message = new TaskCanceledException().Message;
            var task = Task.FromCanceled(new CancellationToken(true));

            engine.Script.promise = task.ToPromise(engine);
            engine.Execute("(async function () { try { result = await promise; } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);

            engine.Script.task = task;
            engine.Execute("(async function () { try { result = await task.ToPromise(); } catch (exception) { result = exception.hostException.InnerException.InnerException.Message; } })()");
            Assert.AreEqual(message, engine.Script.result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToTask()
        {
            engine.AddHostType(typeof(Task));
            Assert.AreEqual(Math.PI, EvaluateAsync("(async function () { await Task.Delay(100).ToPromise(); return Math.PI; })()").Result);
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extensions_JavaScript_ToTask_Fail()
        {
            engine.AddHostType(typeof(Task));
            TestUtil.AssertException<ScriptEngineException>(() => EvaluateAsync("(async function () { await Task.Delay(100).ToPromise(); throw new Error('Unauthorized'); })()").Wait());
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Generator()
        {
            engine.Execute("foo = (function* () { yield 'This'; yield 'is'; yield 'not'; yield 'a'; yield 'drill!'; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_GenericObject()
        {
            engine.Execute("foo = { 'This': 1, 'is': 2, 'not': 3, 'a': 4, 'drill!': 5 }");
            TestUtil.AssertException<ArgumentException>(() => string.Join(" ", engine.Global["foo"].ToEnumerable()));

            engine.Execute("foo[Symbol.iterator] = function* () { for (const item of Object.keys(foo)) yield item; }");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Array()
        {
            engine.Execute("foo = [ 'This', 'is', 'not', 'a', 'drill!' ]");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Managed_Object()
        {
            engine.Global["bar"] = new PropertyBag { { "This", 1 }, { "is", 2 }, { "not", 3 }, { "a", 4 }, { "drill!", 5 } };
            TestUtil.AssertException<ArgumentException>(() => string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Execute("foo = (function* () { for (const item of Object.keys(bar)) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Managed_Array()
        {
            engine.Global["bar"] = new[] { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Global["bar"] = new object[] { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Managed_List()
        {
            engine.Global["bar"] = new List<string> { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Global["bar"] = new List<object> { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToEnumerable_Managed_ArrayList()
        {
            engine.Global["bar"] = new ArrayList { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["bar"].ToEnumerable()));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", engine.Global["foo"].ToEnumerable()));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Generator()
        {
            engine.Execute("foo = (function* () { yield 'This'; yield 'is'; yield 'not'; yield 'a'; yield 'drill!'; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_AsyncGenerator()
        {
            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo = (async function* () { await delay(1), yield 'This'; await delay(1), yield 'is'; await delay(1), yield 'not'; await delay(1), yield 'a'; await delay(1), yield 'drill!'; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_GenericObject()
        {
            engine.Execute("foo = { 'This': 1, 'is': 2, 'not': 3, 'a': 4, 'drill!': 5 }");
            TestUtil.AssertException<ArgumentException>(() => string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Execute("foo[Symbol.iterator] = function* () { for (const item of Object.keys(foo)) yield item; }");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo[Symbol.asyncIterator] = async function* () { for (const item of Object.keys(foo)) { await delay(1); yield item; } }");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Array()
        {
            engine.Execute("foo = [ 'This', 'is', 'not', 'a', 'drill!' ]");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Managed_Object()
        {
            engine.Global["bar"] = new PropertyBag { { "This", 1 }, { "is", 2 }, { "not", 3 }, { "a", 4 }, { "drill!", 5 } };
            TestUtil.AssertException<ArgumentException>(() => string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Execute("foo = (function* () { for (const item of Object.keys(bar)) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo = (async function* () { for (const item of Object.keys(bar)) { await delay(1); yield item; } })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Managed_Array()
        {
            engine.Global["bar"] = new[] { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Global["bar"] = new object[] { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo = (async function* () { for (const item of bar) { await delay(1); yield item; } })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Managed_List()
        {
            engine.Global["bar"] = new List<string> { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Global["bar"] = new List<object> { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo = (async function* () { for (const item of bar) { await delay(1); yield item; } })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        [TestMethod, TestCategory("Extensions")]
        public void Extension_JavaScript_ToAsyncEnumerable_Managed_ArrayList()
        {
            engine.Global["bar"] = new ArrayList { "This", "is", "not", "a", "drill!" };
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["bar"].ToAsyncEnumerable())));

            engine.Execute("foo = (function* () { for (const item of bar) yield item; })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));

            engine.Global["delay"] = new Func<int, object>(ms => Task.Delay(ms).ToPromise());
            engine.Execute("foo = (async function* () { for (const item of bar) { await delay(1); yield item; } })()");
            Assert.AreEqual("This is not a drill!", string.Join(" ", IterateAsyncEnumerable(engine.Global["foo"].ToAsyncEnumerable())));
        }

        // ReSharper restore InconsistentNaming

        #endregion

        #region miscellaneous

        private static Task RunAsTask(Action action)
        {
            var task = Task.Run(action);
            task.Wait();
            return task;
        }

        private async Task<object> EvaluateAsync(string code)
        {
            return await engine.Evaluate(code).ToTask();
        }

        private static IEnumerable<T> IterateAsyncEnumerable<T>(IAsyncEnumerable<T> asyncEnumerable)
        {
            var asyncEnumerator = asyncEnumerable.GetAsyncEnumerator();
            while (asyncEnumerator.MoveNextAsync().AsTask().Result)
            {
                yield return asyncEnumerator.Current;
            }

            asyncEnumerator.DisposeAsync().AsTask().Wait();
        }

        #endregion
    }
}