using Microsoft.AspNetCore.DataProtection;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Migrations;
using Microsoft.EntityFrameworkCore.Migrations.Operations;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Instances;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Templates;
using ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Migrations;

namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests.Migrations;

public class MediumPersistenceSqlTests : IClassFixture<MsSqlMigrationFixture>
{
    private readonly MsSqlMigrationFixture _fixture;
    public MediumPersistenceSqlTests(MsSqlMigrationFixture fixture) => _fixture = fixture;

    [SkippableFact]
    public async Task RealSql_GlobalNameRaceAndLegacyCredentialUpgrade()
    {
        Skip.IfNot(_fixture.Available, _fixture.SkipReason);
        var options = new DbContextOptionsBuilder<ScadaBridgeDbContext>().UseSqlServer(_fixture.ConnectionString).Options;
        var protection = new EphemeralDataProtectionProvider();
        await using var db = new ScadaBridgeDbContext(options, protection);
        var a = new Site("Medium A", "medium-a"); var b = new Site("Medium B", "medium-b");
        var template = new Template("Medium template");
        db.AddRange(a, b, template);
        await db.SaveChangesAsync();
        async Task<bool> Insert(int site)
        {
            await using var attempt = new ScadaBridgeDbContext(options, protection);
            attempt.Instances.Add(new Instance("global-medium-pump") { SiteId = site, TemplateId = template.Id });
            try { await attempt.SaveChangesAsync(); return true; }
            catch (InstanceNameConflictException) { return false; }
        }
        var race = await Task.WhenAll(Insert(a.Id), Insert(b.Id));
        Assert.Single(race, success => success);
        Assert.Single(race, success => !success);
        await db.Database.ExecuteSqlRawAsync(
            "INSERT INTO DataConnections (SiteId, Name, Protocol, PrimaryConfiguration, BackupConfiguration, FailoverRetryCount) VALUES ({0}, 'legacy-medium', 'OpcUa', {1}, {2}, 3)",
            a.Id, """{"password":"sql-primary-secret"}""", """{"password":"sql-backup-secret"}""");
        await DataConnectionSecretUpgrade.UpgradeAsync(db);
        await DataConnectionSecretUpgrade.UpgradeAsync(db);
        var protectedRow = await db.DataConnections.SingleAsync(c => c.Name == "legacy-medium");
        Assert.Contains("sql-primary-secret", protectedRow.PrimaryConfiguration);
        Assert.Contains("sql-backup-secret", protectedRow.BackupConfiguration);

        using var connection = _fixture.OpenConnection();
        using var raw = connection.CreateCommand();
        raw.CommandText = "SELECT PrimaryConfiguration FROM DataConnections WHERE Name = 'legacy-medium'";
        Assert.DoesNotContain("sql-primary-secret", (string)(await raw.ExecuteScalarAsync())!);
        raw.CommandText = "SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='DataConnections' AND COLUMN_NAME IN ('PrimaryConfiguration','BackupConfiguration') AND CHARACTER_MAXIMUM_LENGTH=-1";
        Assert.Equal(2, (int)(await raw.ExecuteScalarAsync())!);

        // A pre-upgrade conflict is rejected explicitly; the transaction restores the index.
        using var transaction = connection.BeginTransaction();
        using var legacy = connection.CreateCommand();
        legacy.Transaction = transaction;
        legacy.CommandText = "DROP INDEX IX_Instances_UniqueName ON Instances";
        await legacy.ExecuteNonQueryAsync();
        legacy.CommandText = "INSERT INTO Instances (UniqueName, TemplateId, SiteId, State) VALUES ('global-medium-pump', @template, @site, 'NotDeployed')";
        legacy.Parameters.AddWithValue("@template", template.Id);
        legacy.Parameters.AddWithValue("@site", a.Id);
        await legacy.ExecuteNonQueryAsync();
        var builder = new MigrationBuilder("Microsoft.EntityFrameworkCore.SqlServer");
        new ProbeMigration().Apply(builder);
        legacy.CommandText = builder.Operations.OfType<SqlOperation>().First().Sql;
        var denied = await Assert.ThrowsAsync<SqlException>(() => legacy.ExecuteNonQueryAsync());
        Assert.Equal(51002, denied.Number);
        transaction.Rollback();
    }

    private sealed class ProbeMigration : EnforceGlobalInstanceNamesAndProtectProtocolConfiguration
    {
        public void Apply(MigrationBuilder builder) => base.Up(builder);
    }
}