// 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.Generic;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.AspNetCore.Mvc.Formatters.Json;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using Xunit;

namespace Microsoft.Extensions.DependencyInjection
{
    public class MvcJsonOptionsExtensionsTests
    {
        [Fact]
        public void UseCamelCasing_WillSet_CamelCasingStrategy_NameStrategy()
        {
            // Arrange
            var options = new MvcJsonOptions();
            options.SerializerSettings.ContractResolver = new DefaultContractResolver()
            {
                NamingStrategy = new DefaultNamingStrategy()
            };
            var expected = typeof(CamelCaseNamingStrategy);

            // Act
            options.UseCamelCasing(processDictionaryKeys: true);
            var resolver = options.SerializerSettings.ContractResolver as DefaultContractResolver;
            var actual = resolver.NamingStrategy;

            // Assert
            Assert.IsType(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_WillNot_OverrideSpecifiedNames()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: true);

            var annotatedFoo = new AnnotatedFoo()
            {
                HelloWorld = "Hello"
            };
            var expected = "{\"HELLO-WORLD\":\"Hello\"}";

            // Act
            var actual = SerializeToJson(options, value: annotatedFoo);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_WillChange_PropertyNames()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: true);
            var foo = new { TestName = "TestFoo", TestValue = 10 };
            var expected = "{\"testName\":\"TestFoo\",\"testValue\":10}";

            // Act
            var actual = SerializeToJson(options, value: foo);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_WillChangeFirstPartBeforeSeparator_InPropertyName()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: true);
            var foo = new { TestFoo_TestValue = "Test" };
            var expected = "{\"testFoo_TestValue\":\"Test\"}";

            // Act
            var actual = SerializeToJson(options, value: foo);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_ProcessDictionaryKeys_WillChange_DictionaryKeys_IfTrue()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: true);
            var dictionary = new Dictionary<string, int>
            {
                ["HelloWorld"] = 1,
                ["HELLOWORLD"] = 2
            };
            var expected = "{\"helloWorld\":1,\"helloworld\":2}";

            // Act
            var actual = SerializeToJson(options, value: dictionary);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_ProcessDictionaryKeys_WillChangeFirstPartBeforeSeparator_InDictionaryKey_IfTrue()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: true);
            var dictionary = new Dictionary<string, int>()
            {
                ["HelloWorld_HelloWorld"] = 1
            };

            var expected = "{\"helloWorld_HelloWorld\":1}";

            // Act
            var actual = SerializeToJson(options, value: dictionary);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_ProcessDictionaryKeys_WillNotChangeDictionaryKeys_IfFalse()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseCamelCasing(processDictionaryKeys: false);
            var dictionary = new Dictionary<string, int>
            {
                ["HelloWorld"] = 1,
                ["HELLO-WORLD"] = 2
            };
            var expected = "{\"HelloWorld\":1,\"HELLO-WORLD\":2}";

            // Act
            var actual = SerializeToJson(options, value: dictionary);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseMemberCasing_WillNotChange_OverrideSpecifiedNames()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseMemberCasing();
            var annotatedFoo = new AnnotatedFoo()
            {
                HelloWorld = "Hello"
            };
            var expected = "{\"HELLO-WORLD\":\"Hello\"}";

            // Act
            var actual = SerializeToJson(options, value: annotatedFoo);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseMemberCasing_WillSet_DefaultNamingStrategy_AsNamingStrategy()
        {
            // Arrange
            var options = new MvcJsonOptions();
            options.SerializerSettings.ContractResolver = new DefaultContractResolver
            {
                NamingStrategy = new CamelCaseNamingStrategy()
            };
            var expected = typeof(DefaultNamingStrategy);

            // Act
            options.UseMemberCasing();
            var resolver = options.SerializerSettings.ContractResolver as DefaultContractResolver;
            var actual = resolver.NamingStrategy;

            // Assert
            Assert.IsType(expected, actual);
        }

        [Fact]
        public void UseMemberCasing_WillNotChange_PropertyNames()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseMemberCasing();
            var foo = new { fooName = "Test", FooValue = "Value" };
            var expected = "{\"fooName\":\"Test\",\"FooValue\":\"Value\"}";

            // Act
            var actual = SerializeToJson(options, value: foo);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseMemberCasing_WillNotChange_DictionaryKeys()
        {
            // Arrange
            var options = CreateDefaultMvcJsonOptions().UseMemberCasing();
            var dictionary = new Dictionary<string, int>()
            {
                ["HelloWorld"] = 1,
                ["helloWorld"] = 2,
                ["HELLO-WORLD"] = 3
            };
            var expected = "{\"HelloWorld\":1,\"helloWorld\":2,\"HELLO-WORLD\":3}";

            // Act
            var actual = SerializeToJson(options, value: dictionary);

            // Assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void UseCamelCasing_WillThrow_IfContractResolver_IsNot_DefaultContractResolver()
        {
            // Arrange
            var options = new MvcJsonOptions();
            options.SerializerSettings.ContractResolver = new FooContractResolver();
            var expectedMessage = Resources.FormatInvalidContractResolverForJsonCasingConfiguration(nameof(FooContractResolver), nameof(DefaultContractResolver));

            // Act & Assert
            var exception = Assert.Throws<InvalidOperationException>(
                () => options.UseCamelCasing(processDictionaryKeys: false));
            Assert.Equal(expectedMessage, actual: exception.Message);
        }

        [Fact]
        public void UseMemberCasing_WillThrow_IfContractResolver_IsNot_DefaultContractResolver()
        {
            // Arrange
            var options = new MvcJsonOptions();
            options.SerializerSettings.ContractResolver = new FooContractResolver();
            var expectedMessage = Resources.FormatInvalidContractResolverForJsonCasingConfiguration(nameof(FooContractResolver), nameof(DefaultContractResolver));

            // Act & Assert
            var exception = Assert.Throws<InvalidOperationException>(
                () => options.UseMemberCasing());
            Assert.Equal(expectedMessage, actual: exception.Message);
        }

        // NOTE: This method was created to make sure to create a different instance of contract resolver as by default
        // MvcJsonOptions uses a static shared instance of resolver which when changed causes other tests to fail.
        private MvcJsonOptions CreateDefaultMvcJsonOptions()
        {
            var options = new MvcJsonOptions();
            options.SerializerSettings.ContractResolver = JsonSerializerSettingsProvider.CreateContractResolver();
            return options;
        }

        private static string SerializeToJson(MvcJsonOptions options, object value)
        {
            return JsonConvert.SerializeObject(
                value: value,
                formatting: Formatting.None,
                settings: options.SerializerSettings);
        }

        private class AnnotatedFoo
        {
            [JsonProperty("HELLO-WORLD")]
            public string HelloWorld { get; set; }
        }

        private class FooContractResolver : IContractResolver
        {
            public JsonContract ResolveContract(Type type)
            {
                throw new NotImplementedException();
            }
        }
    }
}