using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Data.SqlClient;
using SQLInsight.Collectors.Performance;
using SQLInsight.Core.Data;
using SQLInsight.Core.Instances;
using SQLInsight.Repository;

namespace SQLInsight.IntegrationTests;

/// <summary>Active session sampling against real SQL Server, and the wait type page.</summary>
[Collection(SqlServerTestGroup.Name)]
[Trait("Category", "Integration")]
public class WaitSamplingTests(SqlServerFixture sql)
{
    private async Task<SqlConnection> OpenAsync(string application)
    {
        var connection = new SqlConnection(new SqlConnectionStringBuilder(sql.DatabaseConnectionString(SqlServerFixture.TestDatabase))
        {
            ApplicationName = application,
            CommandTimeout = 120,
        }.ConnectionString);
        await connection.OpenAsync();
        return connection;
    }

    [Fact]
    public async Task A_blocked_session_is_sampled_with_its_wait_type_and_statement_but_the_agent_is_not()
    {
        var table = "WaitSample_" + Guid.NewGuid().ToString("N")[..6];
        await sql.ExecuteAsSaAsync($"USE [{SqlServerFixture.TestDatabase}]; CREATE TABLE dbo.{table} (Id int PRIMARY KEY, Name nvarchar(20)); INSERT dbo.{table} VALUES (1, N'a');");
        await using var holder = await OpenAsync("Lock holder");
        await using var transaction = holder.BeginTransaction();
        await using (var update = new SqlCommand($"UPDATE dbo.{table} SET Name = N'b' WHERE Id = 1;", holder, transaction))
        {
            await update.ExecuteNonQueryAsync();
        }

        await using var user = await OpenAsync("AX32");
        await using var agentLike = await OpenAsync("SQLInsight Pro (test)");
        var blocked = new SqlCommand($"SELECT Name FROM dbo.{table} WHERE Id = 1;", user).ExecuteScalarAsync();
        var ignored = new SqlCommand($"SELECT Name FROM dbo.{table} WHERE Id = 1;", agentLike).ExecuteScalarAsync();
        try
        {
            await using var session = await AgentSession.OpenAsync(sql);
            WaitSampleSnapshot snapshot;
            var attempts = 0;
            do
            {
                await Task.Delay(500);
                snapshot = await session.CollectAsync<WaitSampleSnapshot>(new WaitSamplingCollector());
            }
            while (snapshot.Rows.All(r => r.WaitType != "LCK_M_S") && ++attempts < 20);

            var row = Assert.Single(snapshot.Rows, r => r.WaitType == "LCK_M_S");
            Assert.Equal(1, row.Sessions); // the "SQLInsight Pro" connection waits too, but is the agent's own kind
            Assert.Equal(1, row.BlockedSessions);
            Assert.Equal(SqlServerFixture.TestDatabase, row.DatabaseName);
            Assert.NotNull(row.QueryKey);
            var statement = Assert.Single(snapshot.Statements, s => s.QueryKey == row.QueryKey);
            Assert.Contains(table, statement.Text, StringComparison.Ordinal);

            // The same key as top SQL, so the text and use can be joined.
            Assert.StartsWith("0x", row.QueryKey, StringComparison.Ordinal);
        }
        finally
        {
            await transaction.RollbackAsync();
            await Task.WhenAll(blocked, ignored);
            await sql.ExecuteAsSaAsync($"USE [{SqlServerFixture.TestDatabase}]; DROP TABLE dbo.{table};");
        }
    }

    [Fact]
    public async Task Wait_type_page_shows_the_explanation_trend_and_statements()
    {
        var database = "SQLInsightWait_" + Guid.NewGuid().ToString("N")[..8];
        await sql.ExecuteAsSaAsync($"CREATE DATABASE [{database}];");
        try
        {
            var repository = new InsightRepository(sql.DatabaseConnectionString(database));
            await repository.MigrateAsync();
            var info = new InstanceInfo
            {
                ServerName = "AX01",
                Version = SqlServerVersion.Parse("16.0.4135.4"),
                ProductLevel = "RTM",
                Edition = "Standard Edition",
                EngineEdition = EngineEdition.Standard,
            };
            var now = DateTimeOffset.UtcNow;
            var id = await repository.UpsertInstanceAsync(@"AX01\AX30", info, "SqlClient", false, now);
            for (var i = 0; i < 4; i++)
            {
                await repository.SaveCollectedAsync(id, "wait-sampling", WaitSampling.Aggregate(
                [
                    new WaitingRequest(60 + i, "LCK_M_U", 3000, "AXDB", "0x1234ABCD", "UPDATE NUMBERSEQUENCETABLE SET NEXTREC = @P1", 55),
                    new WaitingRequest(70, "LCK_M_U", 1000, "AXDB", "0x9999", "SELECT 1", 0),
                ], now.AddSeconds(-15 * i)));
            }

            await using var factory = new WebApplicationFactory<Program>().WithWebHostBuilder(b =>
            {
                b.UseEnvironment("Development");
                b.UseSetting("SQLInsight:Repository:ConnectionString", sql.DatabaseConnectionString(database));
                b.UseSetting("SQLInsight:Web:Authentication", "None");
            });
            var client = factory.CreateClient();
            var name = Uri.EscapeDataString(@"AX01\AX30");
            var page = await client.GetStringAsync($"/instanser/{name}/ventetyper/LCK_M_U");
            var text = await client.GetStringAsync($"/instanser/{name}/sql?noegle=0x1234ABCD");
            var unknown = await client.GetStringAsync($"/instanser/{name}/ventetyper/NEW_WAIT_X");

            Assert.Contains("Venter på en lås", page, StringComparison.Ordinal);
            Assert.Contains("NUMBERSEQUENCETABLE", page, StringComparison.Ordinal);
            Assert.Contains("50 %", page, StringComparison.Ordinal);      // 4 of 8 samples
            Assert.Contains("#blocking", page, StringComparison.Ordinal);  // lock waits link to blocking
            Assert.Contains("sql?noegle=0x1234ABCD", page, StringComparison.Ordinal);
            Assert.Contains("UPDATE NUMBERSEQUENCETABLE", text, StringComparison.Ordinal);
            Assert.Contains("uden dansk forklaring", unknown, StringComparison.Ordinal);

            var statements = await repository.GetWaitTypeStatementsAsync(id, "LCK_M_U", now.AddMinutes(-5), now.AddMinutes(1));
            Assert.Equal(4, statements.Single(s => s.QueryKey == "0x1234ABCD").Samples);
        }
        finally
        {
            await sql.ExecuteAsSaAsync($"ALTER DATABASE [{database}] SET SINGLE_USER WITH ROLLBACK IMMEDIATE; DROP DATABASE [{database}];");
        }
    }
}