using System;
using System.IO;
using MediaBrowser.Common.Configuration;
using Microsoft.Extensions.Configuration;
using Moq;
using Xunit;

namespace Jellyfin.Server.Tests.HighAvailability;

/// <summary>
/// The fork's own settings live under the <c>Jellyfin:*</c> configuration root and every manifest,
/// chart and document sets them as bare <c>Jellyfin__Section__Key</c> environment variables. The
/// startup configuration the host reads them from must therefore accept that form; when it does not,
/// a correctly set variable is dropped and the feature it configures stays off without any error.
/// </summary>
public sealed class JellyfinSectionConfigurationTests : IDisposable
{
    private const string RedisKey = "Jellyfin:TranscodeStore:RedisConnectionString";
    private const string UnprefixedVariable = "Jellyfin__TranscodeStore__RedisConnectionString";
    private const string PrefixedVariable = "JELLYFIN_Jellyfin__TranscodeStore__RedisConnectionString";
    private const string LeaseUnprefixedVariable = "Jellyfin__TranscodeStore__LeaseDurationSeconds";

    private readonly string _configDirectory;

    public JellyfinSectionConfigurationTests()
    {
        _configDirectory = Directory.CreateTempSubdirectory("jellyfin-config-test").FullName;
        File.WriteAllText(Path.Combine(_configDirectory, "logging.default.json"), "{}");
    }

    public void Dispose()
    {
        Environment.SetEnvironmentVariable(UnprefixedVariable, null);
        Environment.SetEnvironmentVariable(PrefixedVariable, null);
        Environment.SetEnvironmentVariable(LeaseUnprefixedVariable, null);
        Directory.Delete(_configDirectory, true);
    }

    [Fact]
    public void CreateAppConfiguration_Should_Read_UnprefixedVariable()
    {
        Environment.SetEnvironmentVariable(UnprefixedVariable, "valkey-cheeztv-valkey:6379,abortConnect=false");

        var config = CreateConfiguration();

        Assert.Equal("valkey-cheeztv-valkey:6379,abortConnect=false", config[RedisKey]);
    }

    [Fact]
    public void CreateAppConfiguration_Should_Read_UnprefixedNonStringValue()
    {
        Environment.SetEnvironmentVariable(LeaseUnprefixedVariable, "45");

        var config = CreateConfiguration();

        Assert.Equal("45", config["Jellyfin:TranscodeStore:LeaseDurationSeconds"]);
    }

    [Fact]
    public void CreateAppConfiguration_Should_Read_PrefixedVariable()
    {
        Environment.SetEnvironmentVariable(PrefixedVariable, "redis:6379");

        var config = CreateConfiguration();

        Assert.Equal("redis:6379", config[RedisKey]);
    }

    [Fact]
    public void CreateAppConfiguration_Should_Prefer_PrefixedVariable()
    {
        Environment.SetEnvironmentVariable(UnprefixedVariable, "unprefixed:6379");
        Environment.SetEnvironmentVariable(PrefixedVariable, "prefixed:6379");

        var config = CreateConfiguration();

        Assert.Equal("prefixed:6379", config[RedisKey]);
    }

    [Fact]
    public void CreateAppConfiguration_Should_Leave_Key_Unset_Without_Variables()
    {
        var config = CreateConfiguration();

        Assert.Null(config[RedisKey]);
    }

    private IConfiguration CreateConfiguration()
    {
        var appPaths = new Mock<IApplicationPaths>();
        appPaths.Setup(paths => paths.ConfigurationDirectoryPath).Returns(_configDirectory);

        return Program.CreateAppConfiguration(new StartupOptions(), appPaths.Object);
    }
}