using System.Text.Json;
using Microsoft.Extensions.Logging.Abstractions;
using ZB.MOM.WW.ScadaBridge.Commons.Messages.Artifacts;
using ZB.MOM.WW.ScadaBridge.Commons.Messages.Health;
using ZB.MOM.WW.ScadaBridge.SiteRuntime.Persistence;
using ZB.MOM.WW.ScadaBridge.TestSupport;

namespace ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests.Persistence;

/// <summary>
/// Site-secrets artifact deploy: site-local <c>deployed_secrets</c>
/// (LocalDb-replicated ciphertext) and <c>mirrored_secrets</c> (node-local ledger) stores.
/// </summary>
/// <remarks>
/// Backed by a real temp-file LocalDb: <see cref="SiteStorageService"/> takes an
/// <c>ILocalDb</c> rather than a connection string, and LocalDb has no in-memory mode.
/// </remarks>
public class DeployedSecretsStorageTests : IAsyncLifetime, IDisposable
{
    private readonly TestLocalDb _localDb;
    private SiteStorageService _storage = null!;

    /// <summary>Initializes the test class and creates the backing storage.</summary>
    public DeployedSecretsStorageTests()
    {
        _localDb = TestLocalDb.CreateTemp("deployed-secrets");
    }

    /// <summary>Prepares the fixture before the tests run.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    public async Task InitializeAsync()
    {
        _storage = new SiteStorageService(_localDb.Db, NullLogger<SiteStorageService>.Instance);
        await _storage.InitializeAsync();
    }

    /// <summary>Releases the resources used by this instance asynchronously.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    public Task DisposeAsync() => Task.CompletedTask;

    /// <summary>Releases the resources used by this instance.</summary>
    public void Dispose()
    {
        var path = _localDb.Path;
        _localDb.Dispose();
        TestLocalDb.DeleteFiles(path);
    }

    // ── deployed_secrets: full-set upsert / soft-delete reconciliation ──

    /// <summary>Verifies that an upsert is treated as the full set and marks absent rows as removed.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Upsert_IsFullSet_MarksAbsentRowsRemoved()
    {
        var s = _storage;
        await s.UpsertDeployedSecretsAsync([Art("A", 1), Art("B", 1)], "d1");
        var (applied, removed) = await s.UpsertDeployedSecretsAsync([Art("A", 2)], "d2");

        Assert.Equal(["A"], applied);
        Assert.Equal(["B"], removed);

        var rows = await s.GetDeployedSecretsAsync();
        Assert.Equal(2, rows.Single(r => r.Name == "A").Secret.Revision);
        Assert.True(rows.Single(r => r.Name == "B").IsRemoved);
    }

    /// <summary>Verifies that the first upsert applies every row and removes nothing.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Upsert_FirstCall_AppliesEveryRow_AndRemovesNothing()
    {
        var (applied, removed) = await _storage.UpsertDeployedSecretsAsync(
            [Art("A", 1), Art("B", 1)], "d1");

        Assert.Equal(["A", "B"], applied);
        Assert.Empty(removed);
    }

    /// <summary>Verifies that a removed row is not reported as removed again when the set is re-applied.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Upsert_ReAppliedRow_IsNotReportedAsRemovedTwice()
    {
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1), Art("B", 1)], "d1");
        var (_, removedFirst) = await _storage.UpsertDeployedSecretsAsync([Art("A", 2)], "d2");
        Assert.Equal(["B"], removedFirst);

        // B stays removed and is not re-reported as "newly" removed on a later call that
        // still omits it.
        var (_, removedSecond) = await _storage.UpsertDeployedSecretsAsync([Art("A", 3)], "d3");
        Assert.Empty(removedSecond);
    }

    /// <summary>Verifies that a removed row can be re-applied and flips back to not removed.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Upsert_RowThatWasRemoved_CanBeReAppliedAndFlipsBackToNotRemoved()
    {
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1), Art("B", 1)], "d1");
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1)], "d2"); // B removed

        var (applied, removed) = await _storage.UpsertDeployedSecretsAsync(
            [Art("A", 1), Art("B", 2)], "d3");

        Assert.Equal(["A", "B"], applied);
        Assert.Empty(removed);

        var rows = await _storage.GetDeployedSecretsAsync();
        var b = rows.Single(r => r.Name == "B");
        Assert.False(b.IsRemoved);
        Assert.Equal(2, b.Secret.Revision);
    }

    /// <summary>Verifies that upserting an empty set marks every existing row as removed.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Upsert_EmptySet_MarksEveryExistingRowRemoved()
    {
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1), Art("B", 1)], "d1");

        var (applied, removed) = await _storage.UpsertDeployedSecretsAsync([], "d2");

        Assert.Empty(applied);
        Assert.Equal(["A", "B"], removed.OrderBy(n => n, StringComparer.Ordinal));

        var rows = await _storage.GetDeployedSecretsAsync();
        Assert.All(rows, r => Assert.True(r.IsRemoved));
    }

    /// <summary>Verifies that reading the deployed secrets round-trips every field of the secret artifact.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task GetDeployedSecretsAsync_RoundTripsEveryFieldOfTheSecretArtifact()
    {
        var art = Art("Full", 7);
        await _storage.UpsertDeployedSecretsAsync([art], "dep-full");

        var row = Assert.Single(await _storage.GetDeployedSecretsAsync());

        Assert.Equal("Full", row.Name);
        Assert.Equal("dep-full", row.DeploymentId);
        Assert.False(row.IsRemoved);
        Assert.Equal(art.Name, row.Secret.Name);
        Assert.Equal(art.ContentType, row.Secret.ContentType);
        Assert.Equal(art.Ciphertext, row.Secret.Ciphertext);
        Assert.Equal(art.Nonce, row.Secret.Nonce);
        Assert.Equal(art.Tag, row.Secret.Tag);
        Assert.Equal(art.WrappedDek, row.Secret.WrappedDek);
        Assert.Equal(art.WrapNonce, row.Secret.WrapNonce);
        Assert.Equal(art.WrapTag, row.Secret.WrapTag);
        Assert.Equal(art.KekId, row.Secret.KekId);
        Assert.Equal(art.Revision, row.Secret.Revision);
        Assert.Equal(art.CreatedUtc, row.Secret.CreatedUtc);
        Assert.Equal(art.UpdatedUtc, row.Secret.UpdatedUtc);
        Assert.Equal(art.Description, row.Secret.Description);
    }

    /// <summary>Verifies that reading the deployed secrets includes rows marked as removed.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task GetDeployedSecretsAsync_IncludesRemovedRows()
    {
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1)], "d1");
        await _storage.UpsertDeployedSecretsAsync([], "d2"); // A removed

        var rows = await _storage.GetDeployedSecretsAsync();

        var a = Assert.Single(rows);
        Assert.Equal("A", a.Name);
        Assert.True(a.IsRemoved);
    }

    // ── security: row_json holds only base64 ciphertext, never plaintext ──

    /// <summary>Verifies that the stored row JSON deserializes to a secret artifact with no extra properties.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task RowJson_DeserializesToSecretArtifact_WithNoExtraProperties()
    {
        // Guards against ever widening SecretArtifact (or row_json) with a plaintext
        // field: this walks the RAW stored JSON, not the deserialized object, so a
        // stray extra property would be caught here even though JsonSerializer.Deserialize
        // silently ignores unknown members by default.
        var art = Art("Sec1", 3);
        await _storage.UpsertDeployedSecretsAsync([art], "dep-sec");

        var rowJson = await ReadRawRowJsonAsync("Sec1");

        // SecretArtifact is a record, but records only get member-wise Equals for reference
        // types via THEIR OWN Equals — and Array does not override Equals, so byte[] members
        // compare by reference. Assert.Equal(art, roundTripped) would therefore fail even on
        // a byte-for-byte-identical round trip; compare field-by-field instead.
        var roundTripped = JsonSerializer.Deserialize<SecretArtifact>(rowJson);
        Assert.NotNull(roundTripped);
        Assert.Equal(art.Name, roundTripped!.Name);
        Assert.Equal(art.ContentType, roundTripped.ContentType);
        Assert.Equal(art.Ciphertext, roundTripped.Ciphertext);
        Assert.Equal(art.Nonce, roundTripped.Nonce);
        Assert.Equal(art.Tag, roundTripped.Tag);
        Assert.Equal(art.WrappedDek, roundTripped.WrappedDek);
        Assert.Equal(art.WrapNonce, roundTripped.WrapNonce);
        Assert.Equal(art.WrapTag, roundTripped.WrapTag);
        Assert.Equal(art.KekId, roundTripped.KekId);
        Assert.Equal(art.Revision, roundTripped.Revision);
        Assert.Equal(art.CreatedUtc, roundTripped.CreatedUtc);
        Assert.Equal(art.UpdatedUtc, roundTripped.UpdatedUtc);
        Assert.Equal(art.Description, roundTripped.Description);

        using var document = JsonDocument.Parse(rowJson);
        var propertyNames = document.RootElement.EnumerateObject()
            .Select(p => p.Name)
            .ToHashSet(StringComparer.OrdinalIgnoreCase);

        var expected = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
        {
            nameof(SecretArtifact.Name), nameof(SecretArtifact.ContentType),
            nameof(SecretArtifact.Ciphertext), nameof(SecretArtifact.Nonce),
            nameof(SecretArtifact.Tag), nameof(SecretArtifact.WrappedDek),
            nameof(SecretArtifact.WrapNonce), nameof(SecretArtifact.WrapTag),
            nameof(SecretArtifact.KekId), nameof(SecretArtifact.Revision),
            nameof(SecretArtifact.CreatedUtc), nameof(SecretArtifact.UpdatedUtc),
            nameof(SecretArtifact.Description),
        };

        Assert.Equal(expected, propertyNames);
    }

    /// <summary>Verifies that the stored row JSON encodes every byte-array field as Base64 text.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task RowJson_EncodesEveryByteArrayField_AsBase64Text()
    {
        // byte[] serializes as base64 via System.Text.Json by default. Asserted at the raw
        // JSON level (JsonValueKind.String, not an array of numbers) so a future custom
        // converter that changed the wire shape would be caught here.
        var art = Art("Sec2", 1);
        await _storage.UpsertDeployedSecretsAsync([art], "dep-sec2");

        var rowJson = await ReadRawRowJsonAsync("Sec2");
        using var document = JsonDocument.Parse(rowJson);
        var root = document.RootElement;

        foreach (var byteArrayField in new[]
                 {
                     nameof(SecretArtifact.Ciphertext), nameof(SecretArtifact.Nonce),
                     nameof(SecretArtifact.Tag), nameof(SecretArtifact.WrappedDek),
                     nameof(SecretArtifact.WrapNonce), nameof(SecretArtifact.WrapTag),
                 })
        {
            var property = root.GetProperty(byteArrayField);
            Assert.Equal(JsonValueKind.String, property.ValueKind);

            // Base64.TryFromBase64String throws on malformed input — proves it really is
            // base64 text, not just any string.
            Assert.True(Convert.TryFromBase64String(property.GetString()!, new byte[64], out _));
        }
    }

    private async Task<string> ReadRawRowJsonAsync(string name)
    {
        await using var connection = _storage.CreateConnection();
        await using var command = connection.CreateCommand();
        command.CommandText = "SELECT row_json FROM deployed_secrets WHERE name = @name";
        command.Parameters.AddWithValue("@name", name);
        return (string)(await command.ExecuteScalarAsync())!;
    }

    // ── mirrored_secrets: node-local ledger ──

    /// <summary>Verifies that a mirrored secret that is set can be read back.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task MirroredSecrets_SetThenGet_RoundTrips()
    {
        await _storage.SetMirroredSecretAsync("Sec1", 3);

        var rows = await _storage.GetMirroredSecretsAsync();

        var row = Assert.Single(rows);
        Assert.Equal("Sec1", row.Name);
        Assert.Equal(3, row.Revision);
    }

    /// <summary>Verifies that setting a mirrored secret twice updates the existing entry.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task MirroredSecrets_Set_IsUpsert()
    {
        await _storage.SetMirroredSecretAsync("Sec1", 1);
        await _storage.SetMirroredSecretAsync("Sec1", 2);

        var rows = await _storage.GetMirroredSecretsAsync();

        var row = Assert.Single(rows);
        Assert.Equal(2, row.Revision);
    }

    /// <summary>Verifies that removing a mirrored secret deletes its ledger row.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task MirroredSecrets_Remove_DeletesTheLedgerRow()
    {
        await _storage.SetMirroredSecretAsync("Sec1", 1);

        await _storage.RemoveMirroredSecretAsync("Sec1");

        Assert.Empty(await _storage.GetMirroredSecretsAsync());
    }

    /// <summary>Verifies that removing an unknown mirrored secret name does nothing.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task MirroredSecrets_Remove_OfAnUnknownName_IsANoOp()
    {
        await _storage.RemoveMirroredSecretAsync("NeverMirrored");

        Assert.Empty(await _storage.GetMirroredSecretsAsync());
    }

    /// <summary>Verifies that the mirrored-secrets ledger is independent of the deployed secrets.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task MirroredSecrets_IsIndependentOf_DeployedSecrets()
    {
        // mirroring is a separate, node-local action from the site-wide deployed_secrets
        // reconcile — removing a deployed secret must not touch the mirrored ledger, and
        // vice versa. Mirroring/un-mirroring in response to a removal is the caller's job.
        await _storage.UpsertDeployedSecretsAsync([Art("A", 1)], "d1");
        await _storage.SetMirroredSecretAsync("A", 1);

        await _storage.UpsertDeployedSecretsAsync([], "d2"); // A removed from deployed_secrets

        var deployed = Assert.Single(await _storage.GetDeployedSecretsAsync());
        Assert.True(deployed.IsRemoved);

        var mirrored = Assert.Single(await _storage.GetMirroredSecretsAsync());
        Assert.Equal("A", mirrored.Name);
    }

    // ── secret_mirror_status (standby mirror failures) ──

    /// <summary>Verifies that mirror status round-trips with one row per node, ordered by node name.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task SecretMirrorStatus_RoundTrips_OneRowPerNode_OrderedByNodeName()
    {
        var at = new DateTimeOffset(2026, 9, 28, 6, 0, 0, TimeSpan.Zero);
        await _storage.SetSecretMirrorStatusAsync(
            "node-b", [new SecretMirrorFailure("A", "did not decrypt")], at);
        await _storage.SetSecretMirrorStatusAsync("node-a", [], at.AddMinutes(1));

        var rows = await _storage.GetSecretMirrorStatusesAsync();

        Assert.Equal(["node-a", "node-b"], rows.Select(r => r.NodeName));
        Assert.Empty(rows[0].Failures);
        Assert.Equal(at.AddMinutes(1), rows[0].CheckedAtUtc);
        var failure = Assert.Single(rows[1].Failures);
        Assert.Equal(new SecretMirrorFailure("A", "did not decrypt"), failure);
        Assert.Equal(at, rows[1].CheckedAtUtc);
    }

    /// <summary>Verifies that setting the mirror status updates that node's existing row.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task SecretMirrorStatus_Set_UpsertsTheNodesRow()
    {
        var at = new DateTimeOffset(2026, 9, 28, 6, 0, 0, TimeSpan.Zero);
        await _storage.SetSecretMirrorStatusAsync("node-a", [new SecretMirrorFailure("A", "x")], at);
        await _storage.SetSecretMirrorStatusAsync("node-a", [], at.AddHours(1));

        var row = Assert.Single(await _storage.GetSecretMirrorStatusesAsync());
        Assert.Empty(row.Failures);
        Assert.Equal(at.AddHours(1), row.CheckedAtUtc);
    }

    /// <summary>Verifies that an unparseable mirror status row reads as a failure rather than as healthy.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task SecretMirrorStatus_UnparseableRow_ReadsAsAFailure_NotAsHealthy()
    {
        await using (var connection = _storage.CreateConnection())
        await using (var insert = connection.CreateCommand())
        {
            insert.CommandText =
                "INSERT INTO secret_mirror_status (node_name, failures_json, checked_at) VALUES ('node-b', '{not json', '2026-09-28T00:00:00.0000000+00:00')";
            await insert.ExecuteNonQueryAsync();
        }

        var row = Assert.Single(await _storage.GetSecretMirrorStatusesAsync());
        Assert.Equal("node-b", row.NodeName);
        Assert.Single(row.Failures);
    }

    private static SecretArtifact Art(string name, long revision) => new(
        Name: name,
        ContentType: "application/octet-stream",
        Ciphertext: [1, 2, 3, 4, 5],
        Nonce: [10, 11, 12],
        Tag: [20, 21, 22, 23],
        WrappedDek: [30, 31, 32, 33, 34, 35],
        WrapNonce: [40, 41, 42],
        WrapTag: [50, 51, 52, 53],
        KekId: "kek-1",
        Revision: revision,
        CreatedUtc: new DateTimeOffset(2026, 9, 28, 0, 0, 0, TimeSpan.Zero),
        UpdatedUtc: new DateTimeOffset(2026, 9, 28, 1, 0, 0, TimeSpan.Zero),
        Description: "test secret");
}