using Xunit;
using Moq;
using System.Threading.Tasks;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System.Text.Json;
using allstarr.Models.Domain;
using allstarr.Models.Spotify;
using allstarr.Services.Common;
using allstarr.Models.Settings;

namespace allstarr.Tests;

public class RedisCacheServiceTests
{
    private readonly Mock<ILogger<RedisCacheService>> _mockLogger;
    private readonly IOptions<RedisSettings> _settings;

    public RedisCacheServiceTests()
    {
        _mockLogger = new Mock<ILogger<RedisCacheService>>();
        _settings = Options.Create(new RedisSettings
        {
            Enabled = false, // Disabled for unit tests to avoid requiring actual Redis
            ConnectionString = "localhost:6379"
        });
    }

    private RedisCacheService CreateService(IMemoryCache? memoryCache = null, IOptions<RedisSettings>? settings = null)
    {
        return new RedisCacheService(
            settings ?? _settings,
            _mockLogger.Object,
            memoryCache ?? new MemoryCache(new MemoryCacheOptions()));
    }

    [Fact]
    public void Constructor_InitializesWithSettings()
    {
        // Act
        var service = CreateService();

        // Assert
        Assert.NotNull(service);
        Assert.False(service.IsEnabled); // Should be disabled in tests
    }

    [Fact]
    public void Constructor_WithEnabledSettings_AttemptsConnection()
    {
        // Arrange
        var enabledSettings = Options.Create(new RedisSettings
        {
            Enabled = true,
            ConnectionString = "localhost:6379"
        });

        // Act - Constructor will try to connect but should handle failure gracefully
        var service = CreateService(settings: enabledSettings);

        // Assert - Service should be created even if connection fails
        Assert.NotNull(service);
    }

    [Fact]
    public async Task GetStringAsync_WhenDisabled_ReturnsNull()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.GetStringAsync("test:key");

        // Assert
        Assert.Null(result);
    }

    [Fact]
    public async Task GetAsync_WhenDisabled_ReturnsNull()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.GetAsync<TestObject>("test:key");

        // Assert
        Assert.Null(result);
    }

    [Fact]
    public async Task SetStringAsync_WhenDisabled_ReturnsFalse()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.SetStringAsync("test:key", "test value");

        // Assert
        Assert.False(result);
    }

    [Fact]
    public async Task SetAsync_WhenDisabled_ReturnsFalse()
    {
        // Arrange
        var service = CreateService();
        var testObj = new TestObject { Id = 1, Name = "Test" };

        // Act
        var result = await service.SetAsync("test:key", testObj);

        // Assert
        Assert.False(result);
    }

    [Fact]
    public async Task DeleteAsync_WhenDisabled_ReturnsFalse()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.DeleteAsync("test:key");

        // Assert
        Assert.False(result);
    }

    [Fact]
    public async Task ExistsAsync_WhenDisabled_ReturnsFalse()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.ExistsAsync("test:key");

        // Assert
        Assert.False(result);
    }

    [Fact]
    public async Task DeleteByPatternAsync_WhenDisabled_ReturnsZero()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.DeleteByPatternAsync("test:*");

        // Assert
        Assert.Equal(0, result);
    }

    [Fact]
    public async Task SetStringAsync_WithExpiry_AcceptsTimeSpan()
    {
        // Arrange
        var service = CreateService();
        var expiry = TimeSpan.FromHours(1);

        // Act
        var result = await service.SetStringAsync("test:key", "value", expiry);

        // Assert - Should return false when disabled, but not throw
        Assert.False(result);
    }

    [Fact]
    public async Task SetAsync_WithExpiry_AcceptsTimeSpan()
    {
        // Arrange
        var service = CreateService();
        var testObj = new TestObject { Id = 1, Name = "Test" };
        var expiry = TimeSpan.FromDays(30);

        // Act
        var result = await service.SetAsync("test:key", testObj, expiry);

        // Assert - Should return false when disabled, but not throw
        Assert.False(result);
    }

    [Fact]
    public void IsEnabled_ReflectsSettings()
    {
        // Arrange
        var disabledService = CreateService();
        
        var enabledSettings = Options.Create(new RedisSettings
        {
            Enabled = true,
            ConnectionString = "localhost:6379"
        });
        var enabledService = CreateService(settings: enabledSettings);

        // Assert
        Assert.False(disabledService.IsEnabled);
        // enabledService.IsEnabled may be false if connection fails, which is expected
    }

    [Fact]
    public async Task GetAsync_DeserializesComplexObjects()
    {
        // Arrange
        var service = CreateService();

        // Act
        var result = await service.GetAsync<ComplexTestObject>("test:complex");

        // Assert
        Assert.Null(result); // Null when disabled
    }

    [Fact]
    public async Task SetAsync_SerializesComplexObjects()
    {
        // Arrange
        var service = CreateService();
        var complexObj = new ComplexTestObject
        {
            Id = 1,
            Name = "Test",
            Items = new System.Collections.Generic.List<string> { "Item1", "Item2" },
            Metadata = new System.Collections.Generic.Dictionary<string, string>
            {
                { "Key1", "Value1" },
                { "Key2", "Value2" }
            }
        };

        // Act
        var result = await service.SetAsync("test:complex", complexObj, TimeSpan.FromHours(1));

        // Assert
        Assert.False(result); // False when disabled
    }

    [Fact]
    public void ConnectionString_IsConfigurable()
    {
        // Arrange
        var customSettings = Options.Create(new RedisSettings
        {
            Enabled = false,
            ConnectionString = "redis-server:6380,password=secret,ssl=true"
        });

        // Act
        var service = CreateService(settings: customSettings);

        // Assert
        Assert.NotNull(service);
    }

    [Fact]
    public async Task SetStringAsync_WhenDisabled_CachesValueInMemory()
    {
        var service = CreateService();

        var setResult = await service.SetStringAsync("test:key", "test value");
        var cachedValue = await service.GetStringAsync("test:key");

        Assert.False(setResult);
        Assert.Equal("test value", cachedValue);
    }

    [Fact]
    public async Task SetAsync_WhenDisabled_CachesSerializedObjectInMemory()
    {
        var service = CreateService();
        var expected = new TestObject { Id = 42, Name = "Tiered" };

        var setResult = await service.SetAsync("test:object", expected);
        var cachedValue = await service.GetAsync<TestObject>("test:object");

        Assert.False(setResult);
        Assert.NotNull(cachedValue);
        Assert.Equal(expected.Id, cachedValue.Id);
        Assert.Equal(expected.Name, cachedValue.Name);
    }

    [Fact]
    public async Task ExistsAsync_WhenValueOnlyExistsInMemory_ReturnsTrue()
    {
        var service = CreateService();

        await service.SetStringAsync("test:key", "test value");

        var exists = await service.ExistsAsync("test:key");

        Assert.True(exists);
    }

    [Fact]
    public async Task DeleteAsync_WhenValueOnlyExistsInMemory_EvictsEntry()
    {
        var service = CreateService();

        await service.SetStringAsync("test:key", "test value");

        var deleted = await service.DeleteAsync("test:key");
        var cachedValue = await service.GetStringAsync("test:key");

        Assert.False(deleted);
        Assert.Null(cachedValue);
    }

    [Fact]
    public async Task DeleteByPatternAsync_WhenValuesOnlyExistInMemory_RemovesMatchingEntries()
    {
        var service = CreateService();

        await service.SetStringAsync("search:one", "1");
        await service.SetStringAsync("search:two", "2");
        await service.SetStringAsync("other:one", "3");

        var deletedCount = await service.DeleteByPatternAsync("search:*");

        Assert.Equal(2, deletedCount);
        Assert.Null(await service.GetStringAsync("search:one"));
        Assert.Null(await service.GetStringAsync("search:two"));
        Assert.Equal("3", await service.GetStringAsync("other:one"));
    }

    [Fact]
    public async Task SetStringAsync_ImageKeysDoNotUseMemoryCache()
    {
        var service = CreateService();

        await service.SetStringAsync("image:test:key", "binary-ish");

        var cachedValue = await service.GetStringAsync("image:test:key");
        var exists = await service.ExistsAsync("image:test:key");

        Assert.Null(cachedValue);
        Assert.False(exists);
    }

    [Fact]
    public async Task SetAsync_WhenSongContainsRawJellyfinMetadata_CachesSerializedValueInMemory()
    {
        var service = CreateService();
        var songs = new List<Song> { CreateLocalSongWithRawJellyfinMetadata() };

        var setResult = await service.SetAsync("test:songs:raw-jellyfin", songs);
        var cachedValue = await service.GetAsync<List<Song>>("test:songs:raw-jellyfin");

        Assert.False(setResult);
        Assert.NotNull(cachedValue);

        var roundTrippedSong = Assert.Single(cachedValue!);
        Assert.True(JellyfinItemSnapshotHelper.TryGetClonedRawItemSnapshot(roundTrippedSong, out var rawItem));
        Assert.Equal("song-1", ((JsonElement)rawItem["Id"]!).GetString());

        var mediaSources = Assert.IsType<JsonElement>(roundTrippedSong.JellyfinMetadata!["MediaSources"]);
        Assert.Equal(JsonValueKind.Array, mediaSources.ValueKind);
        Assert.Equal(2234068710L, mediaSources[0].GetProperty("RunTimeTicks").GetInt64());
    }

    [Fact]
    public async Task SetAsync_WhenMatchedTracksContainRawJellyfinMetadata_CachesSerializedValueInMemory()
    {
        var service = CreateService();
        var matchedTracks = new List<MatchedTrack>
        {
            new()
            {
                Position = 0,
                SpotifyId = "spotify-1",
                SpotifyTitle = "Track",
                SpotifyArtist = "Artist",
                MatchType = "fuzzy",
                MatchedSong = CreateLocalSongWithRawJellyfinMetadata()
            }
        };

        var setResult = await service.SetAsync("test:matched:raw-jellyfin", matchedTracks);
        var cachedValue = await service.GetAsync<List<MatchedTrack>>("test:matched:raw-jellyfin");

        Assert.False(setResult);
        Assert.NotNull(cachedValue);

        var roundTrippedMatch = Assert.Single(cachedValue!);
        Assert.True(
            JellyfinItemSnapshotHelper.TryGetClonedRawItemSnapshot(roundTrippedMatch.MatchedSong, out var rawItem));
        Assert.Equal("song-1", ((JsonElement)rawItem["Id"]!).GetString());

        var mediaSources =
            Assert.IsType<JsonElement>(roundTrippedMatch.MatchedSong.JellyfinMetadata!["MediaSources"]);
        Assert.Equal(JsonValueKind.Array, mediaSources.ValueKind);
        Assert.Equal("song-1", mediaSources[0].GetProperty("Id").GetString());
    }

    private static Song CreateLocalSongWithRawJellyfinMetadata()
    {
        var song = new Song
        {
            Id = "song-1",
            Title = "Track",
            Artist = "Artist",
            Album = "Album",
            IsLocal = true
        };

        using var doc = JsonDocument.Parse("""
            {
              "Id": "song-1",
              "ServerId": "c17d351d3af24c678a6d8049c212d522",
              "RunTimeTicks": 2234068710,
              "MediaSources": [
                {
                  "Id": "song-1",
                  "RunTimeTicks": 2234068710
                }
              ]
            }
            """);

        JellyfinItemSnapshotHelper.StoreRawItemSnapshot(song, doc.RootElement);
        song.JellyfinMetadata ??= new Dictionary<string, object?>();
        song.JellyfinMetadata["MediaSources"] =
            JsonSerializer.Deserialize<object>(doc.RootElement.GetProperty("MediaSources").GetRawText());

        return song;
    }

    private class TestObject
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
    }

    private class ComplexTestObject
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public System.Collections.Generic.List<string> Items { get; set; } = new();
        public System.Collections.Generic.Dictionary<string, string> Metadata { get; set; } = new();
    }
}