using System.Text.Json;
using ZB.MOM.WW.CBDDC.Core;
using ZB.MOM.WW.CBDDC.Core.Storage;

namespace ZB.MOM.WW.CBDDC.Sample.Console.Tests;

public abstract class OplogStoreContractTestBase
{
    [Fact]
    public async Task OplogStore_AppendQueryMergeDrop_AndLastHash_Works()
    {
        await using var harness = await CreateHarnessAsync();
        IOplogStore store = harness.Store;

        var entry1 = CreateOplogEntry("Users", "u1", "node-a", 100, 0, "");
        var entry2 = CreateOplogEntry("Users", "u2", "node-a", 110, 0, entry1.Hash);
        var entry3 = CreateOplogEntry("Users", "u3", "node-a", 120, 1, entry2.Hash);
        var otherNode = CreateOplogEntry("Users", "u4", "node-b", 115, 0, "");

        await store.AppendOplogEntryAsync(entry1);
        await store.AppendOplogEntryAsync(entry2);
        await store.AppendOplogEntryAsync(entry3);
        await store.AppendOplogEntryAsync(otherNode);

        var chainRange = (await store.GetChainRangeAsync(entry1.Hash, entry3.Hash)).ToList();
        chainRange.Select(x => x.Hash).ToList().ShouldBe(new[] { entry2.Hash, entry3.Hash });

        var after = (await store.GetOplogAfterAsync(new HlcTimestamp(100, 0, "node-a"))).ToList();
        after.Select(x => x.Hash).ToList().ShouldBe(new[] { entry2.Hash, otherNode.Hash, entry3.Hash });

        var mergedEntry = CreateOplogEntry("Users", "u5", "node-a", 130, 0, entry3.Hash);
        await store.MergeAsync(new[] { entry2, mergedEntry });

        var exported = (await store.ExportAsync()).ToList();
        exported.Count.ShouldBe(5);
        exported.Count(x => x.Hash == entry2.Hash).ShouldBe(1);

        string? cachedLastNodeAHash = await store.GetLastEntryHashAsync("node-a");
        cachedLastNodeAHash.ShouldBe(entry3.Hash);

        IOplogStore rehydratedStore = harness.ReopenStore();
        string? persistedLastNodeAHash = await rehydratedStore.GetLastEntryHashAsync("node-a");
        persistedLastNodeAHash.ShouldBe(mergedEntry.Hash);

        await rehydratedStore.DropAsync();
        (await rehydratedStore.ExportAsync()).ShouldBeEmpty();
    }

    [Fact]
    public async Task OplogStore_DatasetIsolation_Works()
    {
        await using var harness = await CreateHarnessAsync();
        IOplogStore store = harness.Store;

        var primaryEntry = CreateOplogEntry("Users", "p1", "node-a", 100, 0, "");
        var logsEntry = CreateOplogEntry("Users", "l1", "node-a", 100, 1, "");

        await harness.AppendOplogEntryAsync(primaryEntry, DatasetId.Primary);
        await harness.AppendOplogEntryAsync(logsEntry, DatasetId.Logs);

        var primary = (await harness.ExportAsync(DatasetId.Primary)).ToList();
        var logs = (await harness.ExportAsync(DatasetId.Logs)).ToList();

        primary.Count.ShouldBe(1);
        primary[0].DatasetId.ShouldBe(DatasetId.Primary);

        logs.Count.ShouldBe(1);
        logs[0].DatasetId.ShouldBe(DatasetId.Logs);
    }

    [Fact]
    public async Task OplogStore_GetChainRangeAsync_ReturnsOrderedLinkedRange()
    {
        await using var harness = await CreateHarnessAsync();
        IOplogStore store = harness.Store;

        var entry1 = CreateOplogEntry("Users", "k1", "node1", 1000, 0, "");
        var entry2 = CreateOplogEntry("Users", "k2", "node1", 2000, 0, entry1.Hash);
        var entry3 = CreateOplogEntry("Users", "k3", "node1", 3000, 0, entry2.Hash);

        await store.AppendOplogEntryAsync(entry1);
        await store.AppendOplogEntryAsync(entry2);
        await store.AppendOplogEntryAsync(entry3);

        var range = (await store.GetChainRangeAsync(entry1.Hash, entry3.Hash)).ToList();

        range.Count.ShouldBe(2);
        range[0].Hash.ShouldBe(entry2.Hash);
        range[1].Hash.ShouldBe(entry3.Hash);
    }

    protected abstract Task<IOplogStoreContractHarness> CreateHarnessAsync();

    protected static OplogEntry CreateOplogEntry(
        string collection,
        string key,
        string nodeId,
        long wall,
        int logic,
        string previousHash)
    {
        return new OplogEntry(
            collection,
            key,
            OperationType.Put,
            JsonSerializer.SerializeToElement(new { key }),
            new HlcTimestamp(wall, logic, nodeId),
            previousHash);
    }
}

public interface IOplogStoreContractHarness : IAsyncDisposable
{
    IOplogStore Store { get; }

    IOplogStore ReopenStore();

    Task AppendOplogEntryAsync(OplogEntry entry, string datasetId, CancellationToken cancellationToken = default);

    Task<IEnumerable<OplogEntry>> ExportAsync(string datasetId, CancellationToken cancellationToken = default);
}