using System.Text.Json;
using ClawdDotNet.Core.Tools;
using ClawdDotNet.Tools.FileRW;
using Microsoft.Extensions.Logging.Abstractions;
using Shouldly;

namespace ClawdDotNet.Tools.Tests.FileRW;

/// <summary>
/// Sorted, capped listing (#673).
///
/// Occasion from test operation: the operations check reported two hourly files as
/// missing that existed. The directory delivered 105 entries in the order of the
/// file system — finding two names in that is search work, and a cheap model
/// does it wrong.
/// </summary>
public sealed class DirectoryListTests : IDisposable
{
    private readonly string _basis;
    private readonly string _personal;
    private readonly string _shared;
    private readonly FileRWTool _tool = new();

    public DirectoryListTests()
    {
        _basis = Path.Combine(Path.GetTempPath(), "clawd-tests", Guid.NewGuid().ToString("N"));
        _personal = Path.Combine(_basis, "Workspace");
        _shared = Path.Combine(_basis, "SharedWorkspace");
        Directory.CreateDirectory(_personal);
        Directory.CreateDirectory(Path.Combine(_shared, "wetter", "stunden"));
    }

    public void Dispose()
    {
        try { Directory.Delete(_basis, recursive: true); }
        catch { /* Cleaning up is secondary */ }
    }

    private AgentToolContext Context() => new(
        "hausmeister", "inst",
        new Dictionary<string, object?> { ["sharedAccessLevel"] = "ReadWrite" },
        new NullStateStore(),
        NullLogger.Instance,
        CancellationToken.None,
        WorkspacePath: _personal,
        SharedWorkspacePath: _shared);

    private Task<ToolResult> Run(string json)
        => _tool.ExecuteAsync(JsonDocument.Parse(json).RootElement, Context(), CancellationToken.None);

    /// <summary>Hourly files, deliberately written in mixed order.</summary>
    private void HourlyFiles(int count, string tag = "2026-09-21")
    {
        var verzeichnis = Path.Combine(_shared, "wetter", "stunden");
        foreach (var hour in Enumerable.Range(0, count).OrderBy(_ => Guid.NewGuid()))
        {
            var path = Path.Combine(verzeichnis, $"berlin_{tag}_{hour:00}-00.txt");
            File.WriteAllText(path, $"{tag} {hour:00}:00 Temperatur {10 + hour} C");
            File.SetLastWriteTime(path, DateTime.Parse($"{tag}T{hour:00}:05:00"));
        }
    }

    private static List<string> Names(string content) => content
        .Split('\n', StringSplitOptions.RemoveEmptyEntries)
        .Select(z => z.Trim())
        .Where(z => z.StartsWith("20", StringComparison.Ordinal))
        .Select(z => z.Split("  ", StringSplitOptions.RemoveEmptyEntries).Last())
        .ToList();

    // ═══════════════════ Order ═══════════════════

    [Fact]
    public async Task The_newest_file_is_on_top()
    {
        HourlyFiles(6);

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden"}""");

        result.Success.ShouldBeTrue(result.ErrorMessage);
        result.Content.ShouldContain("newest first");
        Names(result.Content).First().ShouldBe("berlin_2026-09-21_05-00.txt");
        Names(result.Content).Last().ShouldBe("berlin_2026-09-21_00-00.txt");
    }

    [Fact]
    public async Task Sorted_by_name_runs_ascending()
    {
        HourlyFiles(4);

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden","sort":"name"}""");

        Names(result.Content).ShouldBe([
            "berlin_2026-09-21_00-00.txt", "berlin_2026-09-21_01-00.txt",
            "berlin_2026-09-21_02-00.txt", "berlin_2026-09-21_03-00.txt"
        ]);
    }

    [Fact]
    public async Task The_direction_can_be_reversed()
    {
        HourlyFiles(4);

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden","sort":"modified","order":"asc"}""");

        result.Content.ShouldContain("oldest first");
        Names(result.Content).First().ShouldBe("berlin_2026-09-21_00-00.txt");
    }

    // ═══════════════════ Cap and total count ═══════════════════

    [Fact]
    public async Task The_header_always_names_the_total()
    {
        HourlyFiles(24);
        HourlyFiles(24, "2026-09-20");
        HourlyFiles(24, "2026-09-19");

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden"}""");

        result.Content.ShouldContain($"{FileRWTool.DefaultEntries} of 72 entries");
        result.Content.ShouldContain("22 more not shown");
        result.Content.ShouldContain("'pattern'", Case.Sensitive, "der Agent soll wissen, wie er gezielt fragt");
        Names(result.Content).Count.ShouldBe(FileRWTool.DefaultEntries);
    }

    [Fact]
    public async Task A_custom_limit_is_respected_and_capped()
    {
        HourlyFiles(10);

        var little = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden","limit":3}""");
        Names(little.Content).Count.ShouldBe(3);
        little.Content.ShouldContain("3 of 10 entries");

        var tooMuch = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden","limit":99999}""");
        Names(tooMuch.Content).Count.ShouldBe(10, "mehr als da ist gibt es nicht");
    }

    // ═══════════════════ Asking specifically ═══════════════════

    [Fact]
    public async Task A_pattern_answers_the_question_for_a_specific_file()
    {
        HourlyFiles(24);
        HourlyFiles(24, "2026-09-20");

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden","pattern":"berlin_2026-09-21_1?-00.txt"}""");

        result.Success.ShouldBeTrue(result.ErrorMessage);
        result.Content.ShouldContain("10 of 10 entries");
        result.Content.ShouldContain("Pattern:");
        Names(result.Content).ShouldAllBe(n => n.StartsWith("berlin_2026-09-21_1"));
    }

    [Fact]
    public async Task An_empty_directory_is_not_an_error_but_a_zero()
    {
        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden"}""");

        result.Success.ShouldBeTrue(result.ErrorMessage);
        result.Content.ShouldContain("0 of 0 entries");
    }

    // ═══════════════════ Form ═══════════════════

    [Fact]
    public async Task Every_entry_is_on_exactly_one_line()
    {
        HourlyFiles(3);
        Directory.CreateDirectory(Path.Combine(_shared, "wetter", "stunden", "alt"));

        var result = await Run("""{"action":"list","workspace":"shared","path":"wetter/stunden"}""");

        result.Content.ShouldNotContain("\"Name\":", Case.Sensitive, "kein eingeruecktes JSON mehr");
        result.Content.ShouldContain("alt/", Case.Sensitive);
        result.Content.ShouldContain("<DIR>", Case.Sensitive);
        Names(result.Content).Count.ShouldBe(4);
    }

    // ═══════════════════ The pattern is not a second path ═══════════════════

    [Theory]
    [InlineData("list")]
    [InlineData("read_many")]
    public async Task A_pattern_must_not_lead_out_of_the_directory(string action)
    {
        // Directory.GetFiles evaluates separators in the pattern: "../*" lists the
        // parent directory without the path check ever being asked.
        HourlyFiles(2);
        File.WriteAllText(Path.Combine(_shared, "wetter", "geheim.txt"), "nicht fuer den Agenten");

        var result = await Run($$"""{"action":"{{action}}","workspace":"shared","path":"wetter/stunden","pattern":"../*"}""");

        result.Success.ShouldBeFalse("ein Muster ist ein Dateiname, kein Pfad");
        result.ErrorMessage.ShouldNotBeNull().ShouldContain("pattern", Case.Insensitive);
        (result.Content ?? "").ShouldNotContain("geheim");
    }

    [Theory]
    [InlineData("unter/*.txt")]
    [InlineData("..\\*")]
    [InlineData("*/../*")]
    public async Task The_other_path_spellings_are_rejected_too(string pattern)
    {
        HourlyFiles(2);

        var input = JsonSerializer.SerializeToElement(
            new { action = "list", workspace = "shared", path = "wetter/stunden", pattern = pattern });
        var result = await _tool.ExecuteAsync(input, Context(), CancellationToken.None);

        result.Success.ShouldBeFalse();
        result.ErrorMessage.ShouldNotBeNull().ShouldContain("not a path");
    }
}