using System.Text.Json;
using Amazon.SecretsManager;
using Amazon.SecretsManager.Model;
using Api.SeaHavenIndustries.Infrastructure;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using Moq;
using SeaHaven.Services.Configuration;
using SeaHaven.Services.Interfaces;
using Xunit;

namespace Api.SeaHavenIndustries.Tests;

public sealed class WorkOrderWebhookSecretProviderTests
{
    private const string SecretId = "workorder-ingest/shoc-webhook-hmac";

    private static readonly string CurrentKeyset = KeysetDocument(
        ("2026-07-20T00", Hex(64, 'a')));
    private static readonly string RotatedKeyset = KeysetDocument(
        ("2026-08-20T00", Hex(64, 'b')),
        ("2026-07-20T00", Hex(64, 'a')));

    [Fact]
    public async Task Known_key_is_cached_and_callers_receive_independent_secret_copies()
    {
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.Is<GetSecretValueRequest>(r => r.SecretId == SecretId),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(SecretResponse(CurrentKeyset));
        var provider = CreateProvider(client.Object, SecretId);

        var first = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);
        Assert.Equal(WorkOrderWebhookSecretStatus.Found, first.Status);
        Assert.NotNull(first.Secret);
        first.Secret![0] = 0;

        var second = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Found, second.Status);
        Assert.Equal(Hex(64, 'a'), EncodingText(second.Secret!));
        client.Verify(
            c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()),
            Times.Once);
    }

    [Fact]
    public async Task Unknown_key_forces_one_refresh_then_rejects_with_unknown()
    {
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.Is<GetSecretValueRequest>(r => r.SecretId == SecretId),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(SecretResponse(CurrentKeyset));
        var provider = CreateProvider(client.Object, SecretId);

        // Prime the cache with a known key first so the second lookup exercises
        // the refresh-on-unknown path.
        await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        var result = await provider.GetSecretAsync(
            "attacker-controlled-key",
            CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.UnknownKey, result.Status);
        // One prime + exactly one refresh on the unknown kid.
        client.Verify(
            c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()),
            Times.Exactly(2));
    }

    [Fact]
    public async Task Rotation_is_discovered_after_cache_expiry()
    {
        var call = 0;
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(() => ++call == 1 ? SecretResponse(CurrentKeyset) : SecretResponse(RotatedKeyset));
        var provider = CreateProvider(client.Object, SecretId, cacheSeconds: 1);

        var before = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);
        Assert.Equal(Hex(64, 'a'), EncodingText(before.Secret!));

        await Task.Delay(TimeSpan.FromMilliseconds(1100));
        var after = await provider.GetSecretAsync("2026-08-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Found, after.Status);
        Assert.Equal(Hex(64, 'b'), EncodingText(after.Secret!));
    }

    [Fact]
    public async Task Malformed_keyset_returns_unavailable()
    {
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(SecretResponse("not-json"));
        var provider = CreateProvider(client.Object, SecretId);

        var result = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Unavailable, result.Status);
        Assert.Null(result.Secret);
    }

    [Fact]
    public async Task Duplicate_kid_returns_unavailable()
    {
        var duplicate = KeysetDocument(
            ("2026-07-20T00", Hex(64, 'a')),
            ("2026-07-20T00", Hex(64, 'b')));
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(SecretResponse(duplicate));
        var provider = CreateProvider(client.Object, SecretId);

        var result = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Unavailable, result.Status);
    }

    [Fact]
    public async Task Aws_failure_returns_unavailable_without_exposing_the_exception()
    {
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        client.Setup(c => c.GetSecretValueAsync(
                It.IsAny<GetSecretValueRequest>(),
                It.IsAny<CancellationToken>()))
            .ThrowsAsync(new InvalidOperationException("sensitive provider detail"));
        var provider = CreateProvider(client.Object, SecretId);

        var result = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Unavailable, result.Status);
        Assert.Null(result.Secret);
    }

    [Fact]
    public async Task Empty_secret_id_does_not_invoke_aws_and_returns_unavailable()
    {
        var client = new Mock<IAmazonSecretsManager>(MockBehavior.Strict);
        var provider = CreateProvider(client.Object, secretId: "");

        var result = await provider.GetSecretAsync("2026-07-20T00", CancellationToken.None);

        Assert.Equal(WorkOrderWebhookSecretStatus.Unavailable, result.Status);
        client.VerifyNoOtherCalls();
    }

    private static AwsWorkOrderWebhookSecretProvider CreateProvider(
        IAmazonSecretsManager client,
        string secretId,
        int cacheSeconds = 300) =>
        new(
            client,
            new TestOptionsMonitor(new WorkOrderWebhookOptions
            {
                SecretCacheSeconds = cacheSeconds,
                SecretId = secretId
            }),
            TimeProvider.System,
            NullLogger<AwsWorkOrderWebhookSecretProvider>.Instance);

    private static GetSecretValueResponse SecretResponse(string secretString) =>
        new() { SecretString = secretString };

    private static string KeysetDocument(params (string Kid, string Secret)[] keys)
    {
        using var buffer = new MemoryStream();
        using var writer = new Utf8JsonWriter(buffer);
        writer.WriteStartObject();
        writer.WritePropertyName("keys");
        writer.WriteStartArray();
        foreach (var (kid, secret) in keys)
        {
            writer.WriteStartObject();
            writer.WriteString("kid", kid);
            writer.WriteString("secret", secret);
            writer.WriteEndObject();
        }
        writer.WriteEndArray();
        writer.WriteEndObject();
        writer.Flush();
        return System.Text.Encoding.UTF8.GetString(buffer.ToArray());
    }

    private static string Hex(int length, char digit) => new(digit, length);

    private static string EncodingText(byte[] secret) =>
        System.Text.Encoding.UTF8.GetString(secret);

    private sealed class TestOptionsMonitor : IOptionsMonitor<WorkOrderWebhookOptions>
    {
        public TestOptionsMonitor(WorkOrderWebhookOptions currentValue)
        {
            CurrentValue = currentValue;
        }

        public WorkOrderWebhookOptions CurrentValue { get; }

        public WorkOrderWebhookOptions Get(string? name) => CurrentValue;

        public IDisposable? OnChange(
            Action<WorkOrderWebhookOptions, string?> listener) => null;
    }
}