using Xunit;

namespace Admin.NET.Plugin.AiDOP.Tests.DataPlatform;

public class MdpSourceIdentityBackfillContractTests
{
    [Fact]
    public void StartupPath_DefersHistoricalBackfillUntilApplicationStarted()
    {
        var aligner = ReadPluginSource("DataPlatform/Schema/MdpSchemaAligner.cs");
        var worker = ReadPluginSource("DataPlatform/Schema/MdpSourceIdentityBackfillWorker.cs");
        var startup = ReadPluginSource("Startup.cs");

        var ensureStart = aligner.IndexOf("public static async Task EnsureSourceIdentityAsync", StringComparison.Ordinal);
        var backfillDeclaration = aligner.IndexOf("public static async Task BackfillProvenSourceAsync", StringComparison.Ordinal);
        Assert.True(ensureStart >= 0 && backfillDeclaration > ensureStart);
        Assert.DoesNotContain(
            "BackfillProvenSourceAsync(",
            aligner[ensureStart..backfillDeclaration],
            StringComparison.Ordinal);

        Assert.Contains("ApplicationStarted.Register", worker, StringComparison.Ordinal);
        Assert.Contains("await started.Task.WaitAsync", worker, StringComparison.Ordinal);
        Assert.Contains("BackfillProvenSourceAsync", worker, StringComparison.Ordinal);
        Assert.Contains("AddHostedService<Admin.NET.Plugin.AiDOP.DataPlatform.Schema.MdpSourceIdentityBackfillWorker>", startup);
    }

    [Fact]
    public void Backfill_BuildsCandidatesPerTableAndFailsClosedOnConflicts()
    {
        var aligner = ReadPluginSource("DataPlatform/Schema/MdpSchemaAligner.cs");

        Assert.Contains("CREATE TEMPORARY TABLE tmp_mdp_proven_source", aligner, StringComparison.Ordinal);
        Assert.Contains("foreach (var table in stgNames)", aligner, StringComparison.Ordinal);
        Assert.Contains("ON DUPLICATE KEY UPDATE", aligner, StringComparison.Ordinal);
        Assert.Contains("g.tenant_id IS NOT NULL", aligner, StringComparison.Ordinal);
        Assert.Contains("x.conflicted=0", aligner, StringComparison.Ordinal);
        Assert.DoesNotContain("var union = string.Join(\" UNION ALL \"", aligner, StringComparison.Ordinal);
    }

    private static string ReadPluginSource(string relativePath)
        => File.ReadAllText(Path.Combine(
            RepoRoot(), "server", "Plugins", "Admin.NET.Plugin.AiDOP",
            relativePath.Replace('/', Path.DirectorySeparatorChar)));

    private static string RepoRoot()
    {
        var dir = new DirectoryInfo(AppContext.BaseDirectory);
        while (dir != null && !Directory.Exists(Path.Combine(dir.FullName, "server")))
            dir = dir.Parent;
        return dir?.FullName ?? throw new DirectoryNotFoundException("Repository root not found.");
    }
}