using System.Reflection;
using System.Text.RegularExpressions;

namespace SQLInsight.Servers.Tests;

/// <summary>
/// The Windows queries in SQL Scripts/SQLI-WIN-*.sql (comment blocks, for review) are the ones the agent sends, word for
/// word: every query in <see cref="CimQueries"/> is shown in a script, and every script shows at least one of them.
/// </summary>
public sealed partial class ServerScriptTests
{
    private static readonly DateTimeOffset Example = new(2026, 10, 2, 12, 0, 0, TimeSpan.Zero);

    /// <summary>The query texts, the event log ones rendered as the scripts show them.</summary>
    private static IEnumerable<(string Name, string Text)> Queries()
    {
        foreach (var field in typeof(CimQueries).GetFields(BindingFlags.Public | BindingFlags.Static)
                     .Where(f => f.IsLiteral && f.Name.EndsWith("Query", StringComparison.Ordinal)))
        {
            yield return ($"CimQueries.{field.Name}", (string)field.GetRawConstantValue()!);
        }

        yield return ("CimQueries.EventXPath", CimQueries.EventXPath(Example));
        yield return ("CimQueries.EventQuery", CimQueries.EventQuery("System", Example));
        yield return ("CimQueries.SingleServiceQuery", CimQueries.SingleServiceQuery("<tjeneste>"));
    }

    [Fact]
    public void Every_windows_query_is_shown_in_a_script_word_for_word()
    {
        var scripts = Scripts().ToDictionary(f => Path.GetFileName(f), f => Flatten(File.ReadAllText(f)));
        var missing = Queries().Where(q => !scripts.Values.Any(s => s.Contains(Flatten(q.Text), StringComparison.Ordinal))).Select(q => q.Name).ToList();
        var without = scripts.Where(s => !Queries().Any(q => s.Value.Contains(Flatten(q.Text), StringComparison.Ordinal))).Select(s => s.Key).ToList();

        Assert.True(missing.Count == 0, "Står ikke ordret i SQL Scripts/SQLI-WIN-*.sql: " + string.Join(", ", missing));
        Assert.True(without.Count == 0, "Viser ingen af agentens forespørgsler: " + string.Join(", ", without));
    }

    /// <summary>The comment text without the "--" prefixes, with all whitespace as single spaces (a query may wrap).</summary>
    private static string Flatten(string text) =>
        Whitespace().Replace(CommentPrefix().Replace(text.Replace("\r\n", "\n", StringComparison.Ordinal), " "), " ");

    private static List<string> Scripts()
    {
        for (var directory = new DirectoryInfo(AppContext.BaseDirectory); directory is not null; directory = directory.Parent)
        {
            var folder = Path.Combine(directory.FullName, "SQL Scripts");
            if (Directory.Exists(folder))
            {
                return Directory.EnumerateFiles(folder, "SQLI-WIN-*.sql").Order(StringComparer.Ordinal).ToList();
            }
        }

        throw new DirectoryNotFoundException("SQL Scripts/ blev ikke fundet over testens mappe.");
    }

    [GeneratedRegex(@"^--", RegexOptions.Multiline)]
    private static partial Regex CommentPrefix();

    [GeneratedRegex(@"\s+")]
    private static partial Regex Whitespace();
}