using NFluent;
using System.Collections.Generic;
using System.Linq.Dynamic.Core.CustomTypeProviders;
using System.Linq.Dynamic.Core.Exceptions;
using System.Linq.Expressions;
using System.Reflection;
using Xunit;
using User = System.Linq.Dynamic.Core.Tests.Helpers.Models.User;

namespace System.Linq.Dynamic.Core.Tests
{
    public class DynamicExpressionParserTests
    {
        private class MyClass
        {
            public int Foo()
            {
                return 42;
            }
        }

        private class ComplexParseLambda1Result
        {
            public int? Age;
            public int TotalIncome;
        }

        [DynamicLinqType]
        public class ComplexParseLambda3Result
        {
            public int? Age { get; set; }
            public int TotalIncome { get; set; }
        }

        private class TestCustomTypeProvider : AbstractDynamicLinqCustomTypeProvider, IDynamicLinkCustomTypeProvider
        {
            private HashSet<Type> _customTypes;

            public virtual HashSet<Type> GetCustomTypes()
            {
                if (_customTypes != null)
                    return _customTypes;

                _customTypes =
                    new HashSet<Type>(
                        FindTypesMarkedWithDynamicLinqTypeAttribute(new[] {this.GetType().GetTypeInfo().Assembly}));
                return _customTypes;
            }
        }

        [Fact]
        public void ParseLambda_ToList()
        {
            // Arrange
            var testList = User.GenerateSampleModels(51);
            var qry = testList.AsQueryable();

            // Act
            string query = "OrderBy(gg => gg.Income).ToList()";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(qry.GetType(), null, query);
            Delegate del = expression.Compile();
            IEnumerable<dynamic> result = del.DynamicInvoke(qry) as IEnumerable<dynamic>;

            var expected = qry.OrderBy(gg => gg.Income).ToList();

            // Assert
            Check.That(result).IsNotNull();
            Check.That(result).HasSize(expected.Count);
            Check.That(result.ToArray()[0]).Equals(expected[0]);
        }

        [Fact]
        public void ParseLambda_Complex_1()
        {
            // Arrange
            var testList = User.GenerateSampleModels(51);
            var qry = testList.AsQueryable();

            var externals = new Dictionary<string, object>
            {
                { "Users", qry }
            };

            // Act
            string query = "Users.GroupBy(x => new { x.Profile.Age }).OrderBy(gg => gg.Key.Age).Select(j => new (j.Key.Age, j.Sum(k => k.Income) As TotalIncome))";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(null, query, externals);
            Delegate del = expression.Compile();
            IEnumerable<dynamic> result = del.DynamicInvoke() as IEnumerable<dynamic>;

            var expected = qry.GroupBy(x => new { x.Profile.Age }).OrderBy(gg => gg.Key.Age).Select(j => new { j.Key.Age, TotalIncome = j.Sum(k => k.Income) }).Select(c => new ComplexParseLambda1Result { Age = c.Age, TotalIncome = c.TotalIncome }).Cast<dynamic>().ToArray();

            // Assert
            Check.That(result).IsNotNull();
            Check.That(result).HasSize(expected.Length);
            Check.That(result.ToArray()[0]).Equals(expected[0]);
        }

        [Fact]
        public void ParseLambda_Complex_2()
        {
            // Arrange
            var testList = User.GenerateSampleModels(51);
            var qry = testList.AsQueryable();

            // Act
            string query = "GroupBy(x => new { x.Profile.Age }, it).OrderBy(gg => gg.Key.Age).Select(j => new (j.Key.Age, j.Sum(k => k.Income) As TotalIncome))";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(qry.GetType(), null, query);
            Delegate del = expression.Compile();
            IEnumerable<dynamic> result = del.DynamicInvoke(qry) as IEnumerable<dynamic>;

            var expected = qry.GroupBy(x => new { x.Profile.Age }, x => x).OrderBy(gg => gg.Key.Age).Select(j => new { j.Key.Age, TotalIncome = j.Sum(k => k.Income) }).Select(c => new ComplexParseLambda1Result { Age = c.Age, TotalIncome = c.TotalIncome }).Cast<dynamic>().ToArray();

            // Assert
            Check.That(result).IsNotNull();
            Check.That(result).HasSize(expected.Length);
            Check.That(result.ToArray()[0]).Equals(expected[0]);
        }

        [Fact]
        public void ParseLambda_Complex_3()
        {
            GlobalConfig.CustomTypeProvider = new TestCustomTypeProvider();

            // Arrange
            var testList = User.GenerateSampleModels(51);
            var qry = testList.AsQueryable();

            var externals = new Dictionary<string, object>
            {
                { "Users", qry }
            };

            // Act
            string query = "Users.GroupBy(x => new { x.Profile.Age }).OrderBy(gg => gg.Key.Age).Select(j => new System.Linq.Dynamic.Core.Tests.DynamicExpressionParserTests+ComplexParseLambda3Result{j.Key.Age, j.Sum(k => k.Income) As TotalIncome})";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(null, query, externals);
            Delegate del = expression.Compile();
            IEnumerable<dynamic> result = del.DynamicInvoke() as IEnumerable<dynamic>;

            var expected = qry.GroupBy(x => new { x.Profile.Age }).OrderBy(gg => gg.Key.Age).Select(j => new ComplexParseLambda3Result { Age = j.Key.Age, TotalIncome = j.Sum(k => k.Income) }).Cast<dynamic>().ToArray();

            // Assert
            Check.That(result).IsNotNull();
            Check.That(result).HasSize(expected.Length);
            Check.That(result.ToArray()[0]).Equals(expected[0]);

            GlobalConfig.CustomTypeProvider = null;
        }

        [Fact]
        public void ParseLambda_Select_1()
        {
            // Arrange
            var testList = User.GenerateSampleModels(51);
            var qry = testList.AsQueryable();

            var externals = new Dictionary<string, object>
            {
                {"Users", qry}
            };

            // Act
            string query = "Users.Select(j => new User(j.Income As Income))";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(null, query, externals);
            Delegate del = expression.Compile();
            object result = del.DynamicInvoke();

            // Assert
            Assert.NotNull(result);
        }

        [Fact]
        public void ParseLambda_Select_2()
        {
            // Arrange
            var testList = User.GenerateSampleModels(5);
            var qry = testList.AsQueryable();

            var externals = new Dictionary<string, object>
            {
                {"Users", qry}
            };

            // Act
            string query = "Users.Select(j => j)";
            LambdaExpression expression = DynamicExpressionParser.ParseLambda(null, query, externals);
            Delegate del = expression.Compile();
            object result = del.DynamicInvoke();

            // Assert
            Assert.NotNull(result);
        }

        // https://github.com/StefH/System.Linq.Dynamic.Core/issues/58
        [Fact]
        public void ParseLambda_4_Issue58()
        {
            var expressionParams = new[]
            {
                Expression.Parameter(typeof (MyClass), "myObj")
            };

            var myClassInstance = new MyClass();
            var invokersMerge = new List<object> { myClassInstance };

            LambdaExpression expression = DynamicExpressionParser.ParseLambda(false, expressionParams, null, "myObj.Foo()");
            Delegate del = expression.Compile();
            object result = del.DynamicInvoke(invokersMerge.ToArray());

            Check.That(result).Equals(42);
        }

        [Fact]
        public void ParseLambda_DuplicateParameterNames_ThrowsException()
        {
            // Arrange
            var parameters = new[]
            {
                Expression.Parameter(typeof(int), "x"),
                Expression.Parameter(typeof(int), "x")
            };

            // Act and Assert
            Check.ThatCode(() => DynamicExpressionParser.ParseLambda(parameters, typeof(bool), "it == 42"))
                .Throws<ParseException>()
                .WithMessage("The identifier 'x' was defined more than once");
        }

        [Fact]
        public void ParseLambda_EmptyParameterList()
        {
            // Arrange
            var pEmpty = new ParameterExpression[] { };

            // Act
            var @delegate = DynamicExpressionParser.ParseLambda(pEmpty, null, "1+2").Compile();
            int? result = @delegate.DynamicInvoke() as int?;

            // Assert
            Check.That(result).Equals(3);
        }

        [Fact]
        public void ParseLambda_ParameterName()
        {
            // Arrange
            var parameters = new[]
            {
                Expression.Parameter(typeof(int), "x")
            };

            // Assert
            var expressionX = DynamicExpressionParser.ParseLambda(parameters, typeof(bool), "x == 42");
            var expressionIT = DynamicExpressionParser.ParseLambda(parameters, typeof(bool), "it == 42");

            // Assert
            Assert.Equal(typeof(bool), expressionX.Body.Type);
            Assert.Equal(typeof(bool), expressionIT.Body.Type);
        }

        [Fact]
        public void ParseLambda_ParameterName_Empty()
        {
            // Arrange
            var parameters = new[]
            {
                Expression.Parameter(typeof(int), "")
            };

            // Assert
            var expression = DynamicExpressionParser.ParseLambda(parameters, typeof(bool), "it == 42");

            // Assert
            Assert.Equal(typeof(bool), expression.Body.Type);
        }

        [Fact]
        public void ParseLambda_ParameterName_Null()
        {
            // Arrange
            var parameters = new[]
            {
                Expression.Parameter(typeof(int), null)
            };

            // Assert
            var expression = DynamicExpressionParser.ParseLambda(parameters, typeof(bool), "it == 42");

            // Assert
            Assert.Equal(typeof(bool), expression.Body.Type);
        }

        [Fact]
        public void ParseLambda_ParameterExpressionMethodCall_ReturnsIntExpression()
        {
            var expression = DynamicExpressionParser.ParseLambda(true,
                new[] { Expression.Parameter(typeof(int), "x") },
                typeof(int),
                "x + 1");
            Assert.Equal(typeof(int), expression.Body.Type);
        }

        [Fact]
        public void ParseLambda_RealNumbers()
        {
            var parameters = new ParameterExpression[0];

            var result1 = DynamicExpressionParser.ParseLambda(parameters, typeof(double), "0.10");
            var result2 = DynamicExpressionParser.ParseLambda(parameters, typeof(double), "0.10d");
            var result3 = DynamicExpressionParser.ParseLambda(parameters, typeof(float), "0.10f");
            var result4 = DynamicExpressionParser.ParseLambda(parameters, typeof(decimal), "0.10m");

            // Assert
            Assert.Equal(0.10d, result1.Compile().DynamicInvoke());
            Assert.Equal(0.10d, result2.Compile().DynamicInvoke());
            Assert.Equal(0.10f, result3.Compile().DynamicInvoke());
            Assert.Equal(0.10m, result4.Compile().DynamicInvoke());
        }

        [Fact]
        public void ParseLambda_StringLiteral_ReturnsBooleanLambdaExpression()
        {
            var expression = DynamicExpressionParser.ParseLambda(new[] { Expression.Parameter(typeof(string), "Property1") }, typeof(Boolean), "Property1 == \"test\"");
            Assert.Equal(typeof(Boolean), expression.Body.Type);
        }

        [Fact]
        public void ParseLambda_StringLiteralEmpty_ReturnsBooleanLambdaExpression()
        {
            var expression = DynamicExpressionParser.ParseLambda(new[] { Expression.Parameter(typeof(string), "Property1") }, typeof(Boolean), "Property1 == \"\"");
            Assert.Equal(typeof(Boolean), expression.Body.Type);
        }

        [Fact]
        public void ParseLambda_StringLiteralEmbeddedQuote_ReturnsBooleanLambdaExpression()
        {
            string expectedRightValue = "\"test \\\"string\"";
            var expression = DynamicExpressionParser.ParseLambda(
                new[] { Expression.Parameter(typeof(string), "Property1") },
                typeof(Boolean),
                string.Format("Property1 == {0}", expectedRightValue));

            string rightValue = ((BinaryExpression)expression.Body).Right.ToString();
            Assert.Equal(typeof(Boolean), expression.Body.Type);
            Assert.Equal(expectedRightValue, rightValue);
        }

        [Fact]
        public void ParseLambda_StringLiteralStartEmbeddedQuote_ReturnsBooleanLambdaExpression()
        {
            string expectedRightValue = "\"\\\"test\"";
            var expression = DynamicExpressionParser.ParseLambda(
                new[] { Expression.Parameter(typeof(string), "Property1") },
                typeof(Boolean),
                string.Format("Property1 == {0}", expectedRightValue));

            string rightValue = ((BinaryExpression)expression.Body).Right.ToString();
            Assert.Equal(typeof(Boolean), expression.Body.Type);
            Assert.Equal(expectedRightValue, rightValue);
        }

        [Fact]
        public void ParseLambda_StringLiteral_MissingClosingQuote()
        {
            string expectedRightValue = "\"test\\\"";

            Assert.Throws<ParseException>(() => DynamicExpressionParser.ParseLambda(
                new[] { Expression.Parameter(typeof(string), "Property1") },
                typeof(Boolean),
                string.Format("Property1 == {0}", expectedRightValue)));
        }

        [Fact]
        public void ParseLambda_StringLiteralEscapedBackslash_ReturnsBooleanLambdaExpression()
        {
            string expectedRightValue = "\"test\\string\"";
            var expression = DynamicExpressionParser.ParseLambda(
                new[] { Expression.Parameter(typeof(string), "Property1") },
                typeof(Boolean),
                string.Format("Property1 == {0}", expectedRightValue));

            string rightValue = ((BinaryExpression)expression.Body).Right.ToString();
            Assert.Equal(typeof(Boolean), expression.Body.Type);
            Assert.Equal(expectedRightValue, rightValue);
        }

        [Fact]
        public void ParseLambda_TupleToStringMethodCall_ReturnsStringLambdaExpression()
        {
            var expression = DynamicExpressionParser.ParseLambda(
                typeof(Tuple<int>),
                typeof(string),
                "it.ToString()");
            Assert.Equal(typeof(string), expression.ReturnType);
        }

        [Fact]
        public void ParseLambda_IllegalMethodCall_ThrowsException()
        {
            Check.ThatCode(() =>
            {
                DynamicExpressionParser.ParseLambda(typeof(IO.FileStream), null, "it.Close()");
            })
            .Throws<ParseException>().WithMessage("Methods on type 'Stream' are not accessible");
        }
    }
}