using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using ZB.MOM.WW.LocalDb;

namespace ZB.MOM.WW.ScadaBridge.Host.Tests;

/// <summary>
/// Pins that a site node creates the directory holding <c>LocalDb:Path</c> before the
/// database is opened.
/// </summary>
/// <remarks>
/// <para>
/// This guarantee used to live in <c>StoreAndForwardStorage.EnsureDatabaseDirectoryExists</c>,
/// which created the parent directory for its own SQLite file. LocalDb Phase 2 moved that
/// file into the consolidated database — but the LocalDb library does <b>not</b> create the
/// directory, and <c>SqliteLocalDb</c> opens the file eagerly in its constructor, so a
/// missing directory is a hard boot failure ("SQLite Error 14: unable to open database
/// file") rather than a degraded start.
/// </para>
/// <para>
/// This is not hypothetical: the default site configuration points at the <i>relative</i>
/// path <c>./data/site-localdb.db</c>, so any site node whose working directory has no
/// <c>data/</c> subdirectory hits it. The docker rig escapes only because its volume mount
/// creates <c>/app/data</c> — which is exactly the kind of coincidence that hides a defect
/// until a bare-metal or fresh deployment.
/// </para>
/// </remarks>
public class SiteLocalDbDirectoryTests
{
    [Fact]
    public void SiteRegistration_CreatesTheLocalDbDirectory_WhenItDoesNotExist()
    {
        var root = Path.Combine(Path.GetTempPath(), "localdb-dir-test-" + Guid.NewGuid().ToString("N"));
        var dbPath = Path.Combine(root, "nested", "site-localdb.db");
        Assert.False(Directory.Exists(root));

        try
        {
            var config = new ConfigurationBuilder()
                .AddInMemoryCollection(new Dictionary<string, string?>
                {
                    ["LocalDb:Path"] = dbPath,
                })
                .Build();

            // The registration path under test. Resolving ILocalDb is what actually opens
            // the file, so this fails with SQLite Error 14 if the directory step regresses.
            var services = new ServiceCollection();
            SiteLocalDbDirectory.Ensure(config);
            services.AddZbLocalDb(config);

            using var provider = services.BuildServiceProvider();
            using var scope = provider.CreateScope();
            var db = scope.ServiceProvider.GetRequiredService<ILocalDb>();

            Assert.NotNull(db);
            Assert.True(Directory.Exists(Path.GetDirectoryName(dbPath)!));
            Assert.True(File.Exists(dbPath));
        }
        finally
        {
            SqliteConnectionPoolCleanup();
            if (Directory.Exists(root))
                Directory.Delete(root, recursive: true);
        }
    }

    private static void SqliteConnectionPoolCleanup() =>
        Microsoft.Data.Sqlite.SqliteConnection.ClearAllPools();
}