using System;
using System.Collections.Generic;
using System.Linq;
using Emby.Server.Implementations.MediaEncoding;
using Jellyfin.Server.Extensions;
using MediaBrowser.Controller.MediaEncoding;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Xunit;

namespace Jellyfin.Server.Tests.HighAvailability;

/// <summary>
/// Which transcode session store was selected is invisible at runtime — the Redis client does not
/// abort on an unreachable server and every call site swallows failures — so the selection is
/// asserted here together with the startup log line that reports it.
/// </summary>
public sealed class TranscodeStoreRegistrationTests
{
    [Fact]
    public void AddTranscodeSessionStore_Should_Select_RedisStore_From_UnprefixedEnvironmentKeyShape()
    {
        var services = new ServiceCollection();
        var logger = new RecordingLogger<TranscodeStoreRegistrationTests>();

        services.AddTranscodeSessionStore(BuildConfiguration("valkey-cheeztv-valkey:6379,abortConnect=false"), logger);

        Assert.Equal(typeof(RedisTranscodeSessionStore), StoreImplementation(services));
        Assert.True(logger.HasEntry(LogLevel.Information, nameof(RedisTranscodeSessionStore)));
    }

    [Fact]
    public void AddTranscodeSessionStore_Should_Select_NullStore_Without_ConnectionString()
    {
        var services = new ServiceCollection();
        var logger = new RecordingLogger<TranscodeStoreRegistrationTests>();

        services.AddTranscodeSessionStore(BuildConfiguration(null), logger);

        Assert.Equal(typeof(NullTranscodeSessionStore), StoreImplementation(services));
        Assert.True(logger.HasEntry(LogLevel.Information, nameof(NullTranscodeSessionStore)));
    }

    [Fact]
    public void AddTranscodeSessionStore_Should_Log_Endpoints_Without_Password()
    {
        var services = new ServiceCollection();
        var logger = new RecordingLogger<TranscodeStoreRegistrationTests>();

        services.AddTranscodeSessionStore(BuildConfiguration("valkey:6379,password=hunter2"), logger);

        var message = Assert.Single(logger.Entries, entry => entry.Level == LogLevel.Information).Message;
        Assert.Contains("valkey:6379", message, StringComparison.Ordinal);
        Assert.DoesNotContain("hunter2", message, StringComparison.Ordinal);
    }

    [Fact]
    public void AddTranscodeSessionStore_Should_Register_ConnectivityProbe_Only_With_Redis()
    {
        var withRedis = new ServiceCollection();
        withRedis.AddTranscodeSessionStore(BuildConfiguration("valkey:6379"), new RecordingLogger<TranscodeStoreRegistrationTests>());

        var withoutRedis = new ServiceCollection();
        withoutRedis.AddTranscodeSessionStore(BuildConfiguration(null), new RecordingLogger<TranscodeStoreRegistrationTests>());

        Assert.Contains(withRedis, descriptor => descriptor.ImplementationType == typeof(TranscodeStoreConnectivityProbe));
        Assert.DoesNotContain(withoutRedis, descriptor => descriptor.ServiceType == typeof(IHostedService));
    }

    [Fact]
    public void AddTranscodeSessionStore_Should_Bind_Options()
    {
        var services = new ServiceCollection();
        var configuration = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                [TranscodeStoreOptions.RedisConnectionStringKey] = "valkey:6379",
                ["Jellyfin:TranscodeStore:LeaseDurationSeconds"] = "45"
            })
            .Build();

        services.AddTranscodeSessionStore(configuration, new RecordingLogger<TranscodeStoreRegistrationTests>());

        using var provider = services.BuildServiceProvider();
        var options = provider.GetRequiredService<IOptions<TranscodeStoreOptions>>().Value;

        Assert.Equal(45, options.LeaseDurationSeconds);
        Assert.Equal("valkey:6379", options.RedisConnectionString);
    }

    private static IConfiguration BuildConfiguration(string? redisConnectionString)
        => new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                [TranscodeStoreOptions.RedisConnectionStringKey] = redisConnectionString
            })
            .Build();

    private static Type? StoreImplementation(IServiceCollection services)
        => services.Single(descriptor => descriptor.ServiceType == typeof(ITranscodeSessionStore)).ImplementationType;
}