using SQLInsight.Core.Data;

namespace SQLInsight.Core.Tests;

public class ConfigurationFingerprintTests
{
    private static readonly DateTimeOffset At = new(2026, 10, 2, 8, 0, 0, TimeSpan.Zero);

    [Fact]
    public void Changed_added_and_removed_items_are_listed()
    {
        ConfigurationItem[] before =
        [
            new("sp_configure", "max degree of parallelism", "0"),
            new("Trace flag", "1222", "til"),
            new("Tjenestekonto", "SQL Server (MSSQLSERVER)", @"NT Service\MSSQLSERVER"),
        ];
        ConfigurationItem[] after =
        [
            new("sp_configure", "max degree of parallelism", "1"),
            new("Trace flag", "3226", "til"),
            new("Tjenestekonto", "SQL Server (MSSQLSERVER)", @"NT Service\MSSQLSERVER"),
        ];

        var changes = ConfigurationFingerprint.Diff(before, after, At);

        Assert.Equal(3, changes.Count);
        Assert.Contains(new ConfigurationChange("sp_configure", "max degree of parallelism", "0", "1", At), changes);
        Assert.Contains(new ConfigurationChange("Trace flag", "3226", null, "til", At), changes);
        Assert.Contains(new ConfigurationChange("Trace flag", "1222", "til", null, At), changes);
    }

    [Fact]
    public void Same_setup_has_no_changes() =>
        Assert.Empty(ConfigurationFingerprint.Diff([new("Instans", "Collation", "Danish_Norwegian_CI_AS")], [new("Instans", "Collation", "Danish_Norwegian_CI_AS")], At));

    [Fact]
    public void Fingerprint_covers_options_flags_services_and_instance_settings()
    {
        var instance = new InstanceConfigurationSnapshot
        {
            CapturedAt = At,
            ProductVersion = "16.0.4135.4",
            ProductLevel = "RTM",
            Collation = "Danish_Norwegian_CI_AS",
            Services = [new ServiceInfo("SQL Server (MSSQLSERVER)", @"KUNDE\svc-sql", "Automatic", "Running", true)],
            InstantFileInitialization = true,
            TempdbFiles = [new TempdbFile("tempdev", "ROWS", 8, "64 MB", "ubegrænset"), new TempdbFile("temp2", "ROWS", 8, "64 MB", "ubegrænset"), new TempdbFile("templog", "LOG", 8, "64 MB", "ubegrænset")],
        };

        var items = ConfigurationFingerprint.Items(instance, [new ConfigurationOption("max server memory (MB)", 8192, 8192)], [1222]);

        Assert.Contains(new ConfigurationItem("sp_configure", "max server memory (MB)", "8192"), items);
        Assert.Contains(new ConfigurationItem("Trace flag", "1222", "til"), items);
        Assert.Contains(new ConfigurationItem("Tjenestekonto", "SQL Server (MSSQLSERVER)", @"KUNDE\svc-sql"), items);
        Assert.Contains(new ConfigurationItem("Instans", "Version", "16.0.4135.4 RTM"), items);
        Assert.Contains(new ConfigurationItem("Tempdb", "Antal datafiler", "2"), items);
        Assert.Contains(new ConfigurationItem("Hukommelse", "Instant File Initialization", "til"), items);
        Assert.DoesNotContain(items, i => i.Name == "Lock Pages in Memory"); // unknown on this build: not part of the fingerprint
    }

    [Theory]
    [InlineData("cost threshold for parallelism", 5L)]
    [InlineData("max server memory (MB)", 2147483647L)]
    [InlineData("default trace enabled", 1L)]
    [InlineData("an option nobody knows", null)]
    public void Defaults_are_known_for_the_documented_options(string option, long? expected) =>
        Assert.Equal(expected, ConfigurationFingerprint.DefaultValue(option));
}