using System.Collections.ObjectModel;
using System.Diagnostics.CodeAnalysis;
using System.Text.Json;
using System.Text.Json.Serialization;

using FrostFS.SDK.Client.Models.Netmap.Placement;

using Xunit.Abstractions;

namespace FrostFS.SDK.Tests.Unit;

[SuppressMessage("Reliability", "CA2007:Consider calling ConfigureAwait on the awaited task", Justification = "Default Value is correct for tests")]
public class PlacementVectorTests(ITestOutputHelper testOutputHelper)
{
    private static readonly JsonSerializerOptions serializeOptions = new()
    {
        PropertyNameCaseInsensitive = true
    };

    private readonly ITestOutputHelper _testOutputHelper = testOutputHelper;

    [Fact]
    public void PlacementTest()
    {
        var path = ".\\..\\..\\..\\TestData\\PlacementTests";
        Assert.True(Directory.Exists(path));

        var files = Directory.GetFiles(path);

        FrostFsVersion v = new(2, 13);
        var addresses = new string[] { "localhost", "server1" };

        foreach (var file in files.Where(f => f.EndsWith(".json", StringComparison.OrdinalIgnoreCase)))
        {
            //if (!file.EndsWith("selector_invalid.json"))
            //    continue;

            var fileName = file[(file.LastIndexOf("..\\", StringComparison.OrdinalIgnoreCase) + 3)..];
            _testOutputHelper.WriteLine($"Open file {fileName}");

            var str = File.ReadAllText(file);
            Assert.False(string.IsNullOrEmpty(str));

            var testCase = JsonSerializer.Deserialize<TestCase>(str, serializeOptions);

            Assert.NotNull(testCase);
            Assert.NotNull(testCase.Nodes);
            Assert.True(testCase.Nodes.Length > 0);

            _testOutputHelper.WriteLine($"Test case: \"{testCase.Name}\"");

            var nodes = testCase.Nodes
                .Select(n => new FrostFsNodeInfo(v,
                    n.State,
                    addresses.AsReadOnly(),
                    n.Attributes?.ToDictionary(x => x.Key, x => x.Value) ?? [],
                    n.PublicKeyBytes
                    )
                )
                .ToArray()
                .AsReadOnly();

            var netmap = new FrostFsNetmapSnapshot(100, nodes);

            Assert.NotNull(testCase.Tests);

            foreach (var test in testCase.Tests)
            {
                _testOutputHelper.WriteLine($"Start test \"{test.Name}\"");

                var policy = new FrostFsPlacementPolicy(
                    test.Policy!.Unique,
                    test.Policy.ContainerBackupFactor,
                    new Collection<FrostFsSelector>(test.Policy.Selectors?.Select(s => s.Selector).ToList() ?? []),
                    new Collection<FrostFsFilter>(test.Policy.Filters?.Select(f => f.Filter).ToList() ?? []),
                    test.Policy.Replicas?.Select(r => new FrostFsReplica(r.Count, r.Selector)).ToArray() ?? []
                );

                try
                {
                    var result = netmap.ContainerNodes(policy, test.PivotBytes);

                    if (test.Result == null)
                    {
                        if (!string.IsNullOrEmpty(test.Error))
                        {
                            Assert.Fail("Error is expected but has not been thrown");
                        }
                        else
                        {
                            Assert.NotNull(test.Policy?.Replicas);
                            Assert.Equal(result.Length, test.Policy.Replicas.Length);

                            for (int i = 0; i < result.Length; i++)
                            {
                                Assert.Empty(result[i]);
                            }
                        }
                    }
                    else
                    {
                        Assert.Equal(test.Result.Length, result.Length);

                        for (var i = 0; i < test.Result.Length; i++)
                        {
                            Assert.Equal(test.Result[i].Length, result[i].Length);
                            for (var j = 0; j < test.Result[i].Length; j++)
                            {
                                CompareNodes(nodes[test.Result[i][j]].Attributes, result[i][j]);
                            }
                        }

                        if (test.Placement?.Result != null && test.Placement.PivotBytes != null)
                        {
                            var placementResult = netmap.PlacementVectors(result, test.Placement.PivotBytes);

                            Assert.Equal(test.Placement.Result.Length, placementResult.Length);

                            for (int i = 0; i < placementResult.Length; i++)
                            {
                                Assert.Equal(test.Placement.Result[i].Length, placementResult[i].Length);
                                for (int j = 0; j < placementResult[i].Length; j++)
                                {
                                    CompareNodes(nodes[test.Placement.Result[i][j]].Attributes, placementResult[i][j]);
                                }
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    if (!string.IsNullOrEmpty(test.Error))
                    {
                        Assert.Contains(test.Error, ex.Message, StringComparison.InvariantCulture);
                    }
                    else
                    {
                        throw;
                    }
                }

                _testOutputHelper.WriteLine($"Done");
            }
        }
    }


    private static void CompareNodes(IReadOnlyDictionary<string, string> attrs, FrostFsNodeInfo nodeInfo)
    {
        Assert.Equal(attrs.Count, nodeInfo.Attributes.Count);
        Assert.True(attrs.OrderBy(k => k.Key).SequenceEqual(nodeInfo.Attributes.OrderBy(x => x.Key)));
    }
}

public class TestCase
{
    public string? Name { get; set; }

    public Node[]? Nodes { get; set; }

    public TestData[]? Tests { get; set; }
}



public class Node
{
    [JsonPropertyName("attributes")]
    public KeyValuePair<string, string>[]? Attributes { get; set; }

    public string? PublicKey { get; set; }

    internal byte[]? PublicKeyBytes => string.IsNullOrEmpty(PublicKey) ? [] : Convert.FromBase64String(PublicKey);

    public string[]? Addresses { get; set; }

    [JsonConverter(typeof(JsonStringEnumConverter<NodeState>))]
    public NodeState State { get; set; } = NodeState.Online;
}

public class TestData
{
    public string? Name { get; set; }

    public PolicyDto? Policy { get; set; }

    public string? Pivot { get; set; }

    public int[][]? Result { get; set; }

    public string? Error { get; set; }

    internal byte[]? PivotBytes => Pivot != null ? Convert.FromBase64String(Pivot) : null;

    public ResultData? Placement { get; set; }
}

public class PolicyDto
{
    public bool Unique { get; set; }

    public uint ContainerBackupFactor { get; set; }

    public FilterDto[]? Filters { get; set; }

    public ReplicaDto[]? Replicas { get; set; }

    public SelectorDto[]? Selectors { get; set; }
}

public class SelectorDto()
{
    public uint Count { get; set; }

    public string? Name { get; set; }

    [JsonConverter(typeof(JsonStringEnumConverter<ClauseValues>))]
    public ClauseValues Clause { get; set; }

    public string? Attribute { get; set; }

    public string? Filter { get; set; }

    public FrostFsSelector Selector => new(Name ?? string.Empty)
    {
        Count = Count,
        Clause = (int)Clause,
        Filter = Filter,
        Attribute = Attribute
    };
}

public class FilterDto
{
    public string? Name { get; set; }

    public string? Key { get; set; }

    [JsonConverter(typeof(JsonStringEnumConverter<Operation>))]
    public Operation Op { get; set; }

    public string? Value { get; set; }

    public FilterDto[]? Filters { get; set; }

    public FrostFsFilter Filter => new(
            Name ?? string.Empty,
            Key ?? string.Empty,
            (int)Op,
            Value ?? string.Empty,
            Filters != null ? [.. Filters.Select(f => f.Filter)] : []);
}

public class ReplicaDto
{
    public uint Count { get; set; }

    public string? Selector { get; set; }
}

public class ResultData
{
    public string? Pivot { get; set; }

    public int[][]? Result { get; set; }

    internal byte[]? PivotBytes => Pivot != null ? Convert.FromBase64String(Pivot) : null;
}

public enum ClauseValues
{
    UNSPECIFIED = 0,
    SAME,
    DISTINCT
}