// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Generic;
using FluentAssertions;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Hosting.Testing;
using Microsoft.Extensions.Options;
using Xunit;
 
namespace Microsoft.Extensions.AmbientMetadata.Test;
 
public class ConfigurationBindingQuirkBehaviorTests
{
    [Theory]
    [InlineData("ambientmetadata:build")]
    [InlineData("customSection:ambientmetadata:build")]
    public void GivenMetadata_RegistersOptions_HostBuilder(string sectionName)
    {
        // When configuration is not available, values are initialized to the default value of string?, which is null
        var defaultMetadata = new BuildMetadata();
 
        using var host = CreateUsingHostBuilder(sectionName);
 
        // We get a BuildMetadata instance with null values for all its properties, despite using empty strings in the configuration
        // Related issue: https://github.com/dotnet/runtime/issues/62532
        host.Services.GetRequiredService<IOptions<BuildMetadata>>().Value.Should().BeEquivalentTo(defaultMetadata);
    }
 
    [Theory]
    [InlineData("ambientmetadata:build")]
    [InlineData("customSection:ambientmetadata:build")]
    public void GivenMetadata_RegistersOptions_HostApplicationBuilder(string sectionName)
    {
        // When configuration is not available, values are initialized to an empty string
        var metadataWithEmptyStrings = new BuildMetadata
        {
            BuildId = string.Empty,
            BuildNumber = string.Empty,
            SourceBranchName = string.Empty,
            SourceVersion = string.Empty
        };
 
        using var host = CreateUsingHostApplicationBuilder(sectionName);
 
        // We get a BuildMetadata instance with all properties populated with empty strings, as expected
        host.Services.GetRequiredService<IOptions<BuildMetadata>>().Value.Should().BeEquivalentTo(metadataWithEmptyStrings);
    }
 
    private static IConfigurationBuilder ConfigureInMemoryCollection(IConfigurationBuilder configuration, string sectionName)
    {
        return configuration.AddInMemoryCollection(new Dictionary<string, string?>
        {
            { $"{sectionName}:BuildId", string.Empty },
            { $"{sectionName}:BuildNumber", string.Empty },
            { $"{sectionName}:SourceBranchName", string.Empty },
            { $"{sectionName}:SourceVersion", string.Empty }
        });
    }
 
    private static IHost CreateUsingHostBuilder(string sectionName)
    {
        return FakeHost.CreateBuilder()
            .ConfigureHostConfiguration(configBuilder =>
            {
                _ = ConfigureInMemoryCollection(configBuilder, sectionName);
            })
            .ConfigureServices((context, services) =>
            {
                _ = services.AddBuildMetadata(context.Configuration.GetSection(sectionName));
            })
            .Build();
    }
 
    private static IHost CreateUsingHostApplicationBuilder(string sectionName)
    {
        var hostBuilder = Host.CreateEmptyApplicationBuilder(new());
        _ = ConfigureInMemoryCollection(hostBuilder.Configuration, sectionName);
        _ = hostBuilder.Services.AddBuildMetadata(hostBuilder.Configuration.GetSection(sectionName));
        return hostBuilder.Build();
    }
}