using Microsoft.Data.SqlClient;
using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer.IntegrationTests;

[Collection(SqlHistorianCollection.Name)]
public sealed class SchemaBootstrapIntegrationTests(SqlHistorianFixture fx)
{
    private SqlServerHistorianOptions Opts(string schema, bool auto = true) => new()
    {
        ConnectionString = fx.ConnectionString, Schema = schema, AutoCreateSchema = auto,
    };

    private static SqlServerSchemaBootstrapper Boot(SqlServerHistorianOptions o) =>
        new(new SqlHistorianConnection(o), o);

    private async Task<long> ScalarAsync(string sql)
    {
        await using var c = new SqlConnection(fx.ConnectionString);
        await c.OpenAsync();
        await using var cmd = c.CreateCommand();
        cmd.CommandText = sql;
        return Convert.ToInt64(await cmd.ExecuteScalarAsync());
    }

    [Fact]
    public async Task Bootstrapping_twice_is_a_no_op_with_one_version_row()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        await Boot(Opts(s)).EnsureAsync(CancellationToken.None);
        await Boot(Opts(s)).EnsureAsync(CancellationToken.None); // fresh instance => re-runs the guarded path
        (await ScalarAsync($"SELECT COUNT(*) FROM [{s}].SchemaVersion")).ShouldBe(1);
        (await ScalarAsync($"SELECT COUNT(*) FROM sys.indexes WHERE name='CX_Event_Time' AND object_id=OBJECT_ID('[{s}].Event')")).ShouldBe(1);
    }

    [Fact]
    public async Task A_re_run_of_the_raw_script_is_idempotent()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        await Boot(Opts(s)).EnsureAsync(CancellationToken.None);
        var script = new StreamReader(typeof(SqlServerSchemaBootstrapper).Assembly.GetManifestResourceStream("Schema.001_initial.sql")!).ReadToEnd();
        await using var c = new SqlConnection(fx.ConnectionString);
        await c.OpenAsync();
        foreach (var b in SqlServerSchemaBootstrapper.SplitBatches(script.Replace("$(Schema)", s)))
        {
            await using var cmd = c.CreateCommand();
            cmd.CommandText = b;
            await cmd.ExecuteNonQueryAsync();
        }
        (await ScalarAsync($"SELECT COUNT(*) FROM [{s}].SchemaVersion")).ShouldBe(1);
    }

    [Fact]
    public async Task Concurrent_bootstrappers_both_succeed_with_one_version_row()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        var tasks = Enumerable.Range(0, 4).Select(_ => Task.Run(() => Boot(Opts(s)).EnsureAsync(CancellationToken.None))).ToArray();
        await Task.WhenAll(tasks);
        (await ScalarAsync($"SELECT COUNT(*) FROM [{s}].SchemaVersion")).ShouldBe(1);
    }

    [Fact]
    public async Task AutoCreateSchema_false_on_an_empty_schema_throws_missing()
    {
        fx.SkipIfUnavailable();
        var ex = await Should.ThrowAsync<HistorianSchemaMissingException>(
            () => Boot(Opts(SqlHistorianFixture.UniqueSchema(), auto: false)).EnsureAsync(CancellationToken.None));
        ex.Message.ShouldContain("missing version 1");
    }

    [Fact]
    public async Task AutoCreateSchema_false_passes_once_the_schema_exists_and_failure_is_not_latched()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        var checker = Boot(Opts(s, auto: false));
        await Should.ThrowAsync<HistorianSchemaMissingException>(() => checker.EnsureAsync(CancellationToken.None));
        await Boot(Opts(s)).EnsureAsync(CancellationToken.None);
        await checker.EnsureAsync(CancellationToken.None); // same instance retries
    }

    [Fact]
    public async Task Concurrent_get_or_create_of_one_new_tag_yields_one_row_and_one_id()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        var o = Opts(s);
        var conn = new SqlHistorianConnection(o);
        var boot = new SqlServerSchemaBootstrapper(conn, o);
        await boot.EnsureAsync(CancellationToken.None);
        // Separate catalogs => no shared cache, so every task really races the MERGE. Several rounds on fresh
        // names, all callers released together, raise the odds of hitting the create window.
        for (var round = 0; round < 10; round++)
        {
            var name = $"Plant/Tag{round}";
            using var start = new ManualResetEventSlim(false);
            var ids = Enumerable.Range(0, 32).Select(_ => Task.Run(async () =>
            {
                var cat = new SqlServerTagCatalog(conn, boot);
                await cat.TryGetTagIdAsync("warm", CancellationToken.None); // opens the pool + bootstrap before the race
                start.Wait();
                return await cat.GetOrCreateTagIdAsync(name, 1, CancellationToken.None);
            })).ToArray();
            await Task.Delay(200);
            start.Set();
            (await Task.WhenAll(ids)).Distinct().Count().ShouldBe(1);
            (await ScalarAsync($"SELECT COUNT(*) FROM [{s}].Tag WHERE Name = N'{name}'")).ShouldBe(1);
        }
        (await new SqlServerTagCatalog(conn, boot).TryGetTagIdAsync("nope", CancellationToken.None)).ShouldBeNull();
    }

    [Fact]
    public async Task Sample_tvp_keeps_sub_millisecond_ticks_end_to_end()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        var o = Opts(s);
        var conn = new SqlHistorianConnection(o);
        var boot = new SqlServerSchemaBootstrapper(conn, o);
        var tagId = await new SqlServerTagCatalog(conn, boot).GetOrCreateTagIdAsync("T", 1, CancellationToken.None);
        var t = new DateTime(2026, 10, 9, 0, 0, 0, DateTimeKind.Utc).AddTicks(1234567);
        await using var c = await conn.OpenAsync(CancellationToken.None);
        await using var cmd = conn.CreateCommand(c,
            $"INSERT {conn.Q("Sample")} (TagId, SourceTimeUtc, ValueKind, NumValue, IntValue, StrValue, StatusCode, ServerTimeUtc) " +
            "SELECT @id, SourceTimeUtc, ValueKind, NumValue, IntValue, StrValue, StatusCode, SYSUTCDATETIME() FROM @rows");
        cmd.Parameters.AddWithValue("@id", tagId);
        conn.AddStructured(cmd, "@rows", "SampleRow",
            SampleRowMapper.ToSampleRecords([new SqlSampleRow(t, ZB.MOM.WW.OtOpcUa.Core.Abstractions.HistorianValue.FromDouble(1), 0u)]));
        await cmd.ExecuteNonQueryAsync();
        await using var q = conn.CreateCommand(c, $"SELECT SourceTimeUtc FROM {conn.Q("Sample")}");
        await using var r = await q.ExecuteReaderAsync();
        (await r.ReadAsync()).ShouldBeTrue();
        SqlHistorianConnection.GetUtc(r, 0).Ticks.ShouldBe(t.Ticks);
    }
}