// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.Extensions.Primitives;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.IntegrationTests
{
    // Integration tests targeting the behavior of the DictionaryModelBinder with other model binders.
    public class DictionaryModelBinderIntegrationTest
    {
        [Fact]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_WithPrefixAndKVP_Success()
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString("?parameter[0].Key=key0&parameter[0].Value=10");
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, int>() { { "key0", 10 } }, model);

            Assert.Equal(2, modelState.Count);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);

            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[0].Key").Value;
            Assert.Equal("key0", entry.AttemptedValue);
            Assert.Equal("key0", entry.RawValue);

            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[0].Value").Value;
            Assert.Equal("10", entry.AttemptedValue);
            Assert.Equal("10", entry.RawValue);
        }

        [Fact]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_WithPrefixAndItem_Success()
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString("?parameter[key0]=10");
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, int>() { { "key0", 10 } }, model);

            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);

            var kvp = Assert.Single(modelState);
            Assert.Equal("parameter[key0]", kvp.Key);
            var entry = kvp.Value;
            Assert.Equal("10", entry.AttemptedValue);
            Assert.Equal("10", entry.RawValue);
        }

        [Fact]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_WithIndex_Success()
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString =
                    new QueryString("?parameter.index=low&parameter[low].Key=key0&parameter[low].Value=10");
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, int>() { { "key0", 10 } }, model);

            // "index" is not stored in ModelState.
            Assert.Equal(2, modelState.Count);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);

            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[low].Key").Value;
            Assert.Equal("key0", entry.AttemptedValue);
            Assert.Equal("key0", entry.RawValue);
            Assert.Equal(ModelValidationState.Valid, entry.ValidationState);

            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[low].Value").Value;
            Assert.Equal("10", entry.AttemptedValue);
            Assert.Equal("10", entry.RawValue);
            Assert.Equal(ModelValidationState.Valid, entry.ValidationState);
        }

        [Theory]
        [InlineData("?prefix[key0]=10")]
        [InlineData("?prefix[0].Key=key0&prefix[0].Value=10")]
        [InlineData("?prefix.index=low&prefix[low].Key=key0&prefix[low].Value=10")]
        [InlineData("?prefix.index=index&prefix[index].Key=key0&prefix[index].Value=10")]
        [InlineData("?prefix.index=index&prefix[index].Key=key0&prefix[index].Value=10&prefix[extra].Key=key4&prefix[extra].Value=5")]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_WithExplicitPrefix_Success(
            string queryString)
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                BindingInfo = new BindingInfo()
                {
                    BinderModelName = "prefix",
                },
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, int>() { { "key0", 10 }, }, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[key0]=10")]
        [InlineData("?[0].Key=key0&[0].Value=10")]
        [InlineData("?index=low&[low].Key=key0&[low].Value=10")]
        [InlineData("?index=index&[index].Key=key0&[index].Value=10")]
        [InlineData("?index=index&[index].Key=key0&[index].Value=10&[extra].Key=key4&[extra].Value=5")]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_EmptyPrefix_Success(string queryString)
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, int>() { { "key0", 10 }, }, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        public static TheoryData<Action<HttpRequest>> ThreeEntryTestData
        {
            get
            {
                var impliedPrefixQueryString = "?parameter[archive]=1&parameter[correlation]=2&parameter[index]=3";
                var noPrefixQueryString = "?[archive]=1&[correlation]=2&[index]=3";
                var reversedNoPrefixQueryString = "?[index]=3&[correlation]=2&[archive]=1";
                var impliedPrefixDictionary = new Dictionary<string, StringValues>
                {
                    { "parameter[archive]", "1" },
                    { "parameter[correlation]", "2" },
                    { "parameter[index]", "3" },
                };
                var reversedImpliedPrefixDictionary = new Dictionary<string, StringValues>
                {
                    { "parameter[index]", "3" },
                    { "parameter[correlation]", "2" },
                    { "parameter[archive]", "1" },
                };
                var longFormDictionary = new Dictionary<string, StringValues>
                {
                    { "parameter[0].Key", "archive" },
                    { "parameter[0].Value", "1" },
                    { "parameter[1].Key", "correlation" },
                    { "parameter[1].Value", "2" },
                    { "parameter[2].Key", "index" },
                    { "parameter[2].Value", "3" },
                };
                var longerFormDictionary = new Dictionary<string, StringValues>
                {
                    { "parameter[indexer].Key", "archive" },
                    { "parameter[indexer].Value", "1" },
                    { "parameter[index].Key", "correlation" },
                    { "parameter.index", new[] { "indexer", "index", "indexes" } },
                    { "parameter[index].Value", "2" },
                    { "parameter[indexes].Key", "index" },
                    { "parameter[indexes].Value", "3" },
                };
                var longestFormDictionary = new Dictionary<string, StringValues>
                {
                    { "parameter[indexer].Key", "archive" },
                    { "parameter[indexer].Value", "1" },
                    { "parameter[index].Key", "correlation" },
                    { "parameter[extra].Key", "index" },
                    { "parameter[extra].Value", "4" },
                    { "parameter.index", new[] { "indexer", "index", "indexes" } },
                    { "parameter[index].Value", "2" },
                    { "parameter[indexes].Key", "index" },
                    { "parameter[indexes].Value", "3" },
                    { "parameter[another].Key", "index" },
                    { "parameter[another].Value", "5" },
                };
                var noPrefixDictionary = new Dictionary<string, StringValues>
                {
                    { "[archive]", "1" },
                    { "[correlation]", "2" },
                    { "[index]", "3" },
                };
                var reversedNoPrefixDictionary = new Dictionary<string, StringValues>
                {
                    { "[index]", "3" },
                    { "[correlation]", "2" },
                    { "[archive]", "1" },
                };

                return new TheoryData<Action<HttpRequest>>
                {
                    request => request.QueryString = new QueryString(impliedPrefixQueryString),
                    request => request.QueryString = new QueryString(noPrefixQueryString),
                    request => request.QueryString = new QueryString(reversedNoPrefixQueryString),
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(impliedPrefixDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(reversedImpliedPrefixDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(longFormDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(longerFormDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(longestFormDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(noPrefixDictionary);
                    },
                    request =>
                    {
                        request.ContentType = "application/x-www-form-urlencoded";
                        request.Form = new FormCollection(reversedNoPrefixDictionary);
                    },
                };
            }
        }

        [Theory]
        [MemberData(nameof(ThreeEntryTestData))]
        public async Task DictionaryModelBinder_Binds3EntriesOfSimpleType(Action<HttpRequest> updateRequest)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, int>
            {
                { "archive", 1 },
                { "correlation", 2 },
                { "index", 3 },
            };

            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var testContext = ModelBindingTestHelper.GetTestContext(updateRequest);
            var modelState = testContext.ModelState;
            var parameter = new ParameterDescriptor
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>),
            };

            // Act
            var result = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(result.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(result.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [MemberData(nameof(ThreeEntryTestData))]
        public async Task DictionaryModelBinder_Binds3EntriesOfSimpleType_WithJQueryQueryString(
            Action<HttpRequest> updateRequest)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, int>
            {
                { "archive", 1 },
                { "correlation", 2 },
                { "index", 3 },
            };

            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var testContext = ModelBindingTestHelper.GetTestContext(
                updateRequest,
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));
            var modelState = testContext.ModelState;
            var parameter = new ParameterDescriptor
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>),
            };

            // Act
            var result = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(result.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(result.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.True(modelState.IsValid);
        }

        [Fact]
        public async Task DictionaryModelBinder_BindsDictionaryOfSimpleType_NoData()
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, int>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString("?");
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, int>>(modelBindingResult.Model);
            Assert.Empty(model);

            Assert.Empty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        private class Person
        {
            [Range(minimum: 0, maximum: 15, ErrorMessage = "You're out of range.")]
            public int Id { get; set; }

            public override bool Equals(object obj)
            {
                return obj is Person other && Id == other.Id;
            }

            public override int GetHashCode()
            {
                return Id.GetHashCode();
            }

            public override string ToString()
            {
                return $"{{ { Id } }}";
            }
        }

        public static TheoryData<string> ComplexType_ImpliedPrefixData
        {
            get
            {
                return new TheoryData<string>
                {
                    "?[key0].Id=10",
                    "?[0].Key=key0&[0].Value.Id=10",
                    "?index=low&[low].Key=key0&[low].Value.Id=10",
                    "?parameter[key0].Id=10",
                    "?parameter[0].Key=key0&parameter[0].Value.Id=10",
                    "?parameter.index=low&parameter[low].Key=key0&parameter[low].Value.Id=10",
                    "?parameter.index=index&parameter[index].Key=key0&parameter[index].Value.Id=10",
                };
            }
        }

        [Theory]
        [MemberData(nameof(ComplexType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithImpliedPrefix(string queryString)
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, Person> { { "key0", new Person { Id = 10 } }, }, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[key0][Id]=10")] // Both key segments will be rewritten.
        [InlineData("?[0][Key]=key0&[0][Value][Id]=10")]
        [InlineData("?parameter[key0][Id]=10")]
        [InlineData("?parameter[0][Key]=key0&parameter[0][Value][Id]=10")]
        [MemberData(nameof(ComplexType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithImpliedPrefixAndJQuery(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, Person> { { "key0", new Person { Id = 10 } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory after default factories.
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[key0][Id]=10")] // Both key segments will be rewritten.
        [InlineData("?[0][Key]=key0&[0][Value][Id]=10")]
        [InlineData("?parameter[key0][Id]=10")]
        [InlineData("?parameter[0][Key]=key0&parameter[0][Value][Id]=10")]
        [MemberData(nameof(ComplexType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithImpliedPrefixAndJQueryFirst(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, Person> { { "key0", new Person { Id = 10 } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory before default factories.
                options => options.ValueProviderFactories.Insert(0, new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[42][Id]=10")] // Only Id segment will be rewritten.
        [InlineData("?parameter[42][Id]=10")]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithImpliedPrefixIntegralKeysAndJQuery(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, Person> { { "42", new Person { Id = 10 } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory after default factories.
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[42][Id]=10")] // Only Id segment will be rewritten.
        [InlineData("?parameter[42][Id]=10")]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithImpliedPrefixIntegralKeysAndJQueryFirst(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, Person> { { "42", new Person { Id = 10 } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory before default factories.
                options => options.ValueProviderFactories.Insert(0, new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        public static TheoryData<string> ComplexType_ExplicitPrefixData
        {
            get
            {
                return new TheoryData<string>
                {
                    "?prefix[key0].Id=10",
                    "?prefix[0].Key=key0&prefix[0].Value.Id=10",
                    "?prefix.index=low&prefix[low].Key=key0&prefix[low].Value.Id=10",
                    "?prefix.index=index&prefix[index].Key=key0&prefix[index].Value.Id=10",
                };
            }
        }

        [Theory]
        [MemberData(nameof(ComplexType_ExplicitPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithExplicitPrefix(
            string queryString)
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                BindingInfo = new BindingInfo()
                {
                    BinderModelName = "prefix",
                },
                ParameterType = typeof(Dictionary<string, Person>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, Person> { { "key0", new Person { Id = 10 } }, }, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?prefix[key0][Id]=10")]
        [MemberData(nameof(ComplexType_ExplicitPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_WithExplicitPrefixAndJQuery(
            string queryString)
        {
            // Arrange
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory after default factories.
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));

            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                BindingInfo = new BindingInfo()
                {
                    BinderModelName = "prefix",
                },
                ParameterType = typeof(Dictionary<string, Person>)
            };

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, Person> { { "key0", new Person { Id = 10 } }, }, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[key0].Id=100")]
        [InlineData("?[0].Key=key0&[0].Value.Id=100")]
        [InlineData("?index=low&[low].Key=key0&[low].Value.Id=100")]
        [InlineData("?parameter[key0].Id=100")]
        [InlineData("?parameter[0].Key=key0&parameter[0].Value.Id=100")]
        [InlineData("?parameter.index=low&parameter[low].Key=key0&parameter[low].Value.Id=100")]
        [InlineData("?parameter.index=index&parameter[index].Key=key0&parameter[index].Value.Id=100")]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_ImpliedPrefix_FindsValidationErrors(
            string queryString)
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Equal(new Dictionary<string, Person> { { "key0", new Person { Id = 100 } }, }, model);

            Assert.NotEmpty(modelState);
            Assert.False(modelState.IsValid);
            Assert.All(modelState, kvp =>
            {
                Assert.NotEqual(ModelValidationState.Unvalidated, kvp.Value.ValidationState);
                Assert.NotEqual(ModelValidationState.Skipped, kvp.Value.ValidationState);
            });

            var entry = Assert.Single(modelState, kvp => kvp.Value.ValidationState == ModelValidationState.Invalid);
            var error = Assert.Single(entry.Value.Errors);
            Assert.Equal("You're out of range.", error.ErrorMessage);
        }

        [Fact]
        public async Task DictionaryModelBinder_BindsDictionaryOfComplexType_NoData()
        {
            // Arrange
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, Person>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString("?");
            });

            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, Person>>(modelBindingResult.Model);
            Assert.Empty(model);

            Assert.Empty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        public static TheoryData<string> CollectionType_ImpliedPrefixData
        {
            get
            {
                return new TheoryData<string>
                {
                    "?[key0]=10&[key0]=11",
                    "?[key0][0]=10&[key0][1]=11",
                    "?[0].Key=key0&[0].Value[0]=10&[0].Value[1]=11",
                    "?index=low&[low].Key=key0&[low].Value[0]=10&[low].Value[1]=11",
                    "?parameter[key0]=10&parameter[key0]=11",
                    "?parameter[key0][0]=10&parameter[key0][1]=11",
                    "?parameter[0].Key=key0&parameter[0].Value[0]=10&parameter[0].Value[1]=11",
                    "?parameter.index=low&parameter[low].Key=key0&parameter[low].Value[0]=10&parameter[low].Value[1]=11",
                    "?parameter.index=index&parameter[index].Key=key0&parameter[index].Value[0]=10&parameter[index].Value[1]=11",
                };
            }
        }

        [Theory]
        [MemberData(nameof(CollectionType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfCollectionType_WithImpliedPrefix(string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string[]> { { "key0", new[] { "10", "11" } } };
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, string[]>)
            };

            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString));
            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, string[]>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [MemberData(nameof(CollectionType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfCollectionType_WithImpliedPrefixAndJQuery(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string[]> { { "key0", new[] { "10", "11" } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory after default factories.
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, string[]>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, string[]>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [MemberData(nameof(CollectionType_ImpliedPrefixData))]
        public async Task DictionaryModelBinder_BindsDictionaryOfCollectionType_WithImpliedPrefixAndJQueryFirst(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string[]> { { "key0", new[] { "10", "11" } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory before default factories.
                options => options.ValueProviderFactories.Insert(0, new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, string[]>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, string[]>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[42]=10&[42]=11")]
        [InlineData("?[42][]=10&[42][]=11")]
        [InlineData("?[42][0]=10&[42][1]=11")]
        [InlineData("?parameter[42]=10&parameter[42]=11")]
        [InlineData("?parameter[42][]=10&parameter[42][]=11")]
        [InlineData("?parameter[42][0]=10&parameter[42][1]=11")]
        public async Task DictionaryModelBinder_BindsDictionaryOfCollectionType_WithImpliedPrefixIntegralKeysAndJQuery(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string[]> { { "42", new[] { "10", "11" } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory after default factories.
                options => options.ValueProviderFactories.Add(new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, string[]>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, string[]>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        [Theory]
        [InlineData("?[42]=10&[42]=11")]
        [InlineData("?[42][]=10&[42][]=11")]
        [InlineData("?[42][0]=10&[42][1]=11")]
        [InlineData("?parameter[42]=10&parameter[42]=11")]
        [InlineData("?parameter[42][]=10&parameter[42][]=11")]
        [InlineData("?parameter[42][0]=10&parameter[42][1]=11")]
        public async Task DictionaryModelBinder_BindsDictionaryOfCollectionType_WithImpliedPrefixIntegralKeysAndJQueryFirst(
            string queryString)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string[]> { { "42", new[] { "10", "11" } } };
            var testContext = ModelBindingTestHelper.GetTestContext(
                request => request.QueryString = new QueryString(queryString),
                // Add JQueryQueryStringValueProviderFactory before default factories.
                options => options.ValueProviderFactories.Insert(0, new JQueryQueryStringValueProviderFactory()));

            var modelState = testContext.ModelState;
            var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext.HttpContext.RequestServices);
            var parameter = new ParameterDescriptor()
            {
                Name = "parameter",
                ParameterType = typeof(Dictionary<string, string[]>)
            };

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            var model = Assert.IsType<Dictionary<string, string[]>>(modelBindingResult.Model);
            Assert.Equal(expectedDictionary, model);

            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
            Assert.True(modelState.IsValid);
        }

        // parameter type, query string, expected type
        public static TheoryData<Type, string, Type> DictionaryTypeData
        {
            get
            {
                return new TheoryData<Type, string, Type>
                {
                    {
                        typeof(IDictionary<string, string>),
                        "?[key0]=hello&[key1]=world",
                        typeof(Dictionary<string, string>)
                    },
                    {
                        typeof(Dictionary<string, string>),
                        "?[key0]=hello&[key1]=world",
                        typeof(Dictionary<string, string>)
                    },
                    {
                        typeof(ClosedGenericDictionary),
                        "?[key0]=hello&[key1]=world",
                        typeof(ClosedGenericDictionary)
                    },
                    {
                        typeof(ClosedGenericKeyDictionary<string>),
                        "?[key0]=hello&[key1]=world",
                        typeof(ClosedGenericKeyDictionary<string>)
                    },
                    {
                        typeof(ExplicitClosedGenericDictionary),
                        "?[key0]=hello&[key1]=world",
                        typeof(ExplicitClosedGenericDictionary)
                    },
                    {
                        typeof(ExplicitDictionary<string, string>),
                        "?[key0]=hello&[key1]=world",
                        typeof(ExplicitDictionary<string, string>)
                    },
                    {
                        typeof(IDictionary<string, string>),
                        "?index=low&index=high&[low].Key=key0&[low].Value=hello&[high].Key=key1&[high].Value=world",
                        typeof(Dictionary<string, string>)
                    },
                    {
                        typeof(Dictionary<string, string>),
                        "?[0].Key=key0&[0].Value=hello&[1].Key=key1&[1].Value=world",
                        typeof(Dictionary<string, string>)
                    },
                    {
                        typeof(ClosedGenericDictionary),
                        "?index=low&index=high&[low].Key=key0&[low].Value=hello&[high].Key=key1&[high].Value=world",
                        typeof(ClosedGenericDictionary)
                    },
                    {
                        typeof(ClosedGenericKeyDictionary<string>),
                        "?[0].Key=key0&[0].Value=hello&[1].Key=key1&[1].Value=world",
                        typeof(ClosedGenericKeyDictionary<string>)
                    },
                    {
                        typeof(ExplicitClosedGenericDictionary),
                        "?index=low&index=high&[low].Key=key0&[low].Value=hello&[high].Key=key1&[high].Value=world",
                        typeof(ExplicitClosedGenericDictionary)
                    },
                    {
                        typeof(ExplicitDictionary<string, string>),
                        "?[0].Key=key0&[0].Value=hello&[1].Key=key1&[1].Value=world",
                        typeof(ExplicitDictionary<string, string>)
                    },
                };
            }
        }

        [Theory]
        [MemberData(nameof(DictionaryTypeData))]
        public async Task DictionaryModelBinder_BindsParameterToExpectedType(
            Type parameterType,
            string queryString,
            Type expectedType)
        {
            // Arrange
            var expectedDictionary = new Dictionary<string, string>
            {
                { "key0", "hello" },
                { "key1", "world" },
            };
            var parameter = new ParameterDescriptor
            {
                Name = "parameter",
                ParameterType = parameterType,
            };

            var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
            var testContext = ModelBindingTestHelper.GetTestContext(request =>
            {
                request.QueryString = new QueryString(queryString);
            });
            var modelState = testContext.ModelState;

            // Act
            var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

            // Assert
            Assert.True(modelBindingResult.IsModelSet);

            Assert.IsType(expectedType, modelBindingResult.Model);

            var model = modelBindingResult.Model as IDictionary<string, string>;
            Assert.NotNull(model); // Guard
            Assert.Equal(expectedDictionary.Keys, model.Keys);
            Assert.Equal(expectedDictionary.Values, model.Values);

            Assert.True(modelState.IsValid);
            Assert.NotEmpty(modelState);
            Assert.Equal(0, modelState.ErrorCount);
        }

        private class ClosedGenericDictionary : Dictionary<string, string>
        {
        }

        private class ClosedGenericKeyDictionary<TValue> : Dictionary<string, TValue>
        {
        }

        private class ExplicitClosedGenericDictionary : IDictionary<string, string>
        {
            private IDictionary<string, string> _data = new Dictionary<string, string>();

            string IDictionary<string, string>.this[string key]
            {
                get
                {
                    throw new NotImplementedException();
                }

                set
                {
                    _data[key] = value;
                }
            }

            int ICollection<KeyValuePair<string, string>>.Count
            {
                get
                {
                    return _data.Count;
                }
            }

            bool ICollection<KeyValuePair<string, string>>.IsReadOnly
            {
                get
                {
                    return false;
                }
            }

            ICollection<string> IDictionary<string, string>.Keys
            {
                get
                {
                    return _data.Keys;
                }
            }

            ICollection<string> IDictionary<string, string>.Values
            {
                get
                {
                    return _data.Values;
                }
            }

            void ICollection<KeyValuePair<string, string>>.Add(KeyValuePair<string, string> item)
            {
                _data.Add(item);
            }

            void IDictionary<string, string>.Add(string key, string value)
            {
                throw new NotImplementedException();
            }

            void ICollection<KeyValuePair<string, string>>.Clear()
            {
                _data.Clear();
            }

            bool ICollection<KeyValuePair<string, string>>.Contains(KeyValuePair<string, string> item)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<string, string>.ContainsKey(string key)
            {
                throw new NotImplementedException();
            }

            void ICollection<KeyValuePair<string, string>>.CopyTo(KeyValuePair<string, string>[] array, int arrayIndex)
            {
                throw new NotImplementedException();
            }

            IEnumerator IEnumerable.GetEnumerator()
            {
                return _data.GetEnumerator();
            }

            IEnumerator<KeyValuePair<string, string>> IEnumerable<KeyValuePair<string, string>>.GetEnumerator()
            {
                return _data.GetEnumerator();
            }

            bool ICollection<KeyValuePair<string, string>>.Remove(KeyValuePair<string, string> item)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<string, string>.Remove(string key)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<string, string>.TryGetValue(string key, out string value)
            {
                return _data.TryGetValue(key, out value);
            }
        }

        private class ExplicitDictionary<TKey, TValue> : IDictionary<TKey, TValue>
        {
            private IDictionary<TKey, TValue> _data = new Dictionary<TKey, TValue>();

            TValue IDictionary<TKey, TValue>.this[TKey key]
            {
                get
                {
                    throw new NotImplementedException();
                }

                set
                {
                    _data[key] = value;
                }
            }

            int ICollection<KeyValuePair<TKey, TValue>>.Count
            {
                get
                {
                    return _data.Count;
                }
            }

            bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly
            {
                get
                {
                    return false;
                }
            }

            ICollection<TKey> IDictionary<TKey, TValue>.Keys
            {
                get
                {
                    return _data.Keys;
                }
            }

            ICollection<TValue> IDictionary<TKey, TValue>.Values
            {
                get
                {
                    return _data.Values;
                }
            }

            void ICollection<KeyValuePair<TKey, TValue>>.Add(KeyValuePair<TKey, TValue> item)
            {
                _data.Add(item);
            }

            void IDictionary<TKey, TValue>.Add(TKey key, TValue value)
            {
                throw new NotImplementedException();
            }

            void ICollection<KeyValuePair<TKey, TValue>>.Clear()
            {
                _data.Clear();
            }

            bool ICollection<KeyValuePair<TKey, TValue>>.Contains(KeyValuePair<TKey, TValue> item)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<TKey, TValue>.ContainsKey(TKey key)
            {
                throw new NotImplementedException();
            }

            void ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
            {
                throw new NotImplementedException();
            }

            IEnumerator IEnumerable.GetEnumerator()
            {
                return _data.GetEnumerator();
            }

            IEnumerator<KeyValuePair<TKey, TValue>> IEnumerable<KeyValuePair<TKey, TValue>>.GetEnumerator()
            {
                return _data.GetEnumerator();
            }

            bool ICollection<KeyValuePair<TKey, TValue>>.Remove(KeyValuePair<TKey, TValue> item)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<TKey, TValue>.Remove(TKey key)
            {
                throw new NotImplementedException();
            }

            bool IDictionary<TKey, TValue>.TryGetValue(TKey key, out TValue value)
            {
                return _data.TryGetValue(key, out value);
            }
        }
    }
}