using System.Diagnostics;
using System.Text.Json;

namespace AgentWikiUi.Tests;

/// <summary>Il doppio di test di <c>claude</c> (docs/TESTING.md → FakeClaude, FK-01…FK-05).</summary>
[Trait("Category", "Process")]
public sealed class FakeClaudeTests : IDisposable
{
    readonly string dir = Directory.CreateTempSubdirectory("awui-fake-").FullName;

    public void Dispose() => Directory.Delete(dir, true);

    string LogPath => Path.Combine(dir, "log.jsonl");

    Process Start(IEnumerable<string> args, Dictionary<string, string>? env = null, string? cwd = null)
    {
        var psi = new ProcessStartInfo(FakeClaudePath.Exe)
        {
            UseShellExecute = false, RedirectStandardInput = true, RedirectStandardOutput = true, RedirectStandardError = true,
            WorkingDirectory = cwd ?? dir,
        };
        foreach (var a in args) psi.ArgumentList.Add(a);
        psi.Environment["FAKE_CLAUDE_LOG"] = LogPath;
        foreach (var (k, v) in env ?? []) psi.Environment[k] = v;
        return Process.Start(psi)!;
    }

    [Fact]
    public void Registra_argomenti_cwd_e_stdin()
    {
        var cwd = Directory.CreateDirectory(Path.Combine(dir, "lavoro")).FullName;
        using var p = Start(["-p", "dì \"ciao\" a  tutti", "--model", "m"], cwd: cwd);
        p.StandardInput.Write("dati da stdin");
        p.StandardInput.Close();
        Assert.True(p.WaitForExit(10_000));

        using var line = JsonDocument.Parse(File.ReadAllLines(LogPath).Single());
        var r = line.RootElement;
        Assert.Equal(["-p", "dì \"ciao\" a  tutti", "--model", "m"], r.GetProperty("args").EnumerateArray().Select(a => a.GetString()));
        Assert.Equal(cwd, r.GetProperty("cwd").GetString());
        Assert.Equal("dati da stdin", r.GetProperty("stdin").GetString());
    }

    [Fact]
    public void Output_e_stderr_configurati()
    {
        using var p = Start([], new() { ["FAKE_CLAUDE_OUT"] = "risposta", ["FAKE_CLAUDE_ERR"] = "avviso" });
        p.StandardInput.Close();
        Assert.Equal("risposta", p.StandardOutput.ReadToEnd());
        Assert.Equal("avviso", p.StandardError.ReadToEnd());
        Assert.True(p.WaitForExit(10_000));
    }

    [Theory]
    [InlineData(null, 0)]
    [InlineData("3", 3)]
    [InlineData("127", 127)]
    public void ExitCode_configurato(string? configured, int expected)
    {
        using var p = Start([], configured is null ? null : new() { ["FAKE_CLAUDE_EXIT"] = configured });
        p.StandardInput.Close();
        Assert.True(p.WaitForExit(10_000));
        Assert.Equal(expected, p.ExitCode);
    }

    [Fact]
    public void Ritardo_configurato()
    {
        using var p = Start([], new() { ["FAKE_CLAUDE_DELAY_MS"] = "600" });
        var sw = Stopwatch.StartNew();
        p.StandardInput.Close();
        Assert.True(p.WaitForExit(10_000));
        Assert.True(sw.ElapsedMilliseconds >= 500, $"terminato dopo {sw.ElapsedMilliseconds} ms");
    }

    [Fact]
    public void Attende_la_chiusura_di_stdin()
    {
        using var p = Start([]);
        try
        {
            Assert.False(p.WaitForExit(700), "il processo è terminato con stdin ancora aperto");
            p.StandardInput.Close();
            Assert.True(p.WaitForExit(10_000));
        }
        finally { if (!p.HasExited) p.Kill(); }
    }
}