using System.Diagnostics;
using System.Net;
using System.Net.Http.Headers;
using System.Text.Json;
using Azaion.Missions.E2E.Fixtures;
using Azaion.Missions.E2E.Helpers;
using Npgsql;
using Xunit;

namespace Azaion.Missions.E2E.Tests.Errors;

/// <summary>
/// FT-N-08 — destructive scenario: side-channel DROP TABLE vehicles
/// forces the SUT into the generic catch path; the response must redact
/// internals (statusCode/message envelope), and the unhandled exception
/// must land in the container log within 2s.
/// </summary>
/// <remarks>
/// Owns its own xUnit collection because the DROP corrupts the schema for
/// every other test class. Teardown uses <see cref="ComposeRestartFixture"/>
/// (down -v && up -d) which requires <c>COMPOSE_RESTART_ENABLED=1</c>.
/// When the fixture is disabled (developer inner-loop), the test skips with
/// a clear reason — silent passing is rejected by the contract.
/// </remarks>
[Collection("ErrorEnvelope500")]
[Trait("Category", "Blackbox")]
[Trait("db_access", "seed-or-assert-only")]
public sealed class Error500Tests : TestBase, IClassFixture<ComposeRestartFixture>
{
    private readonly ComposeRestartFixture _restart;

    public Error500Tests(ComposeRestartFixture restart) => _restart = restart;

    [SkippableFact]
    [Trait("Traces", "AC-8.6,AC-10.3")]
    [Trait("max_ms", "5000")]
    public async Task FT_N_08_generic_500_returns_redacted_body_and_logs_unhandled_exception()
    {
        Skip.IfNot(_restart.Enabled,
            "ComposeRestartFixture disabled (COMPOSE_RESTART_ENABLED!=1). " +
            "FT-N-08 is destructive and requires `compose down -v && up -d` " +
            "in teardown to restore the schema.");

        // Arrange — drop the vehicles table; the migrator that runs at
        // missions startup is the only thing that re-creates it.
        DbResetFixture.ResetDatabase(TestEnvironment.DbSideChannel);
        DropVehiclesTable();

        var requestStart = DateTime.UtcNow;
        var token = await Tokens.MintDefaultAsync();

        try
        {
            // Act
            using var http = new HttpRequestMessage(
                HttpMethod.Get, $"/vehicles/{Guid.NewGuid()}");
            http.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token.Jwt);
            using var response = await Missions.SendAsync(http);

            // Assert — body redacts internals.
            await HttpAssertions.AssertStatusAsync(response, HttpStatusCode.InternalServerError)
;
            var raw = await response.Content.ReadAsStringAsync();
            using var doc = JsonDocument.Parse(raw);
            var root = doc.RootElement;
            Assert.Equal(500, root.GetProperty("statusCode").GetInt32());
            Assert.Equal("Internal server error", root.GetProperty("message").GetString());

            // Reject extra keys (no stack leak via key names like 'exception',
            // 'stackTrace', 'inner', etc.).
            HttpAssertions.AssertNoStackLeak(root);

            // Stacktrace must land in the SUT container log.
            var deadline = DateTime.UtcNow.AddSeconds(2);
            var logFound = false;
            while (DateTime.UtcNow < deadline)
            {
                if (DockerLogsContain("missions-sut", "Unhandled exception", requestStart))
                {
                    logFound = true;
                    break;
                }
                await Task.Delay(100);
            }
            Assert.True(logFound,
                "expected 'Unhandled exception' in missions-sut docker logs within 2s of request");
        }
        finally
        {
            // Teardown — full stack restart so subsequent tests start clean.
            _restart.RestartStack();
        }
    }

    private static void DropVehiclesTable()
    {
        using var conn = new NpgsqlConnection(TestEnvironment.DbSideChannel);
        conn.Open();
        using var cmd = conn.CreateCommand();
        cmd.CommandText = "DROP TABLE IF EXISTS vehicles CASCADE;";
        cmd.ExecuteNonQuery();
    }

    private static bool DockerLogsContain(string container, string needle, DateTime sinceUtc)
    {
        var since = sinceUtc.ToString("yyyy-MM-ddTHH:mm:ssZ",
            System.Globalization.CultureInfo.InvariantCulture);
        var psi = new ProcessStartInfo("docker", $"logs --since {since} {container}")
        {
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            UseShellExecute = false
        };
        try
        {
            using var p = Process.Start(psi)
                ?? throw new InvalidOperationException("docker command not available");
            // docker logs interleaves stdout/stderr; ASP.NET Core writes
            // exception text to stderr in default config.
            var stdout = p.StandardOutput.ReadToEnd();
            var stderr = p.StandardError.ReadToEnd();
            p.WaitForExit();
            return stdout.Contains(needle, StringComparison.Ordinal)
                || stderr.Contains(needle, StringComparison.Ordinal);
        }
        catch (System.ComponentModel.Win32Exception)
        {
            // No docker CLI in PATH — surface, do not silently pass.
            throw new InvalidOperationException(
                "docker CLI not available in test container; cannot assert log content for FT-N-08. " +
                "Mount /var/run/docker.sock and install docker-cli in the e2e-consumer image.");
        }
    }
}