using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text.Json;
using System.Text.Json.Nodes;

static class Program
{
    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
    static extern int MessageBoxW(IntPtr hWnd, string text, string caption, uint type);

    static int Main(string[] args)
    {
        // Preserve a drive root (for example F:\\ on a portable USB drive).
        var root = Path.TrimEndingDirectorySeparator(AppContext.BaseDirectory);
        var rootPrefix = Path.EndsInDirectorySeparator(root) ? root : root + Path.DirectorySeparatorChar;
        var log = Path.Combine(root, "logs", "launcher.log");
        try
        {
            Directory.CreateDirectory(Path.GetDirectoryName(log)!);
            Directory.CreateDirectory(Path.Combine(root, "data"));
            var marker = Path.Combine(root, "data", "runtime-path.txt");
            var engine = File.Exists(marker)
                ? Path.GetFullPath(Path.Combine(root, File.ReadAllText(marker).Trim()))
                : Directory.EnumerateFiles(Path.Combine(root, "runtime"), "FreeCAD.exe", SearchOption.AllDirectories)
                    .First(path => string.Equals(Path.GetFileName(Path.GetDirectoryName(path)), "bin", StringComparison.OrdinalIgnoreCase));
            if (!engine.StartsWith(rootPrefix, StringComparison.OrdinalIgnoreCase) || !File.Exists(engine))
                throw new IOException("Не найдены библиотеки CAD. Выполните scripts\\bootstrap.ps1.");
            var nativeEngine = RuntimePath.ForEngine(root, engine);
            var start = new ProcessStartInfo(nativeEngine) { UseShellExecute = false, WorkingDirectory = root };
            start.Environment["QI_ROOT"] = root;
            start.Environment.Remove("QI_TEST");
            var selfTest = args.Contains("--self-test", StringComparer.Ordinal);
            var profile = Path.Combine(root, "data");
            if (selfTest)
            {
                start.Environment["QI_TEST"] = "1";
                profile = Path.Combine(root, "artifacts", "test-profiles", Guid.NewGuid().ToString("N"));
                Directory.CreateDirectory(profile);
                var report = Path.Combine(root, "artifacts", "validation.json");
                if (File.Exists(report))
                    File.Move(report, Path.Combine(root, "artifacts", $"validation-previous-{DateTime.UtcNow:yyyyMMdd-HHmmss-fffffff}.json"));
            }
            start.ArgumentList.Add("--user-cfg");
            start.ArgumentList.Add(Path.Combine(profile, "user.cfg"));
            start.ArgumentList.Add("--system-cfg");
            start.ArgumentList.Add(Path.Combine(profile, "system.cfg"));
            start.ArgumentList.Add("--write-log");
            start.ArgumentList.Add("--log-file");
            start.ArgumentList.Add(Path.Combine(root, "logs", "cad.log"));
            // Apply first-run native view preferences before restored sketches
            // exist. Setting them afterwards would mark clean projects dirty.
            start.ArgumentList.Add(Path.Combine(root, "scripts", "startup.FCMacro"));
            foreach (var arg in args)
            {
                if (arg != "--self-test") start.ArgumentList.Add(arg);
            }
            File.AppendAllText(log, $"{DateTimeOffset.Now:O} Starting QInventor {engine}\nNative runtime path: {nativeEngine}\n");
            using var process = Process.Start(start) ?? throw new IOException("Не удалось запустить CAD-процесс.");
            process.WaitForExit();
            File.AppendAllText(log, $"{DateTimeOffset.Now:O} Exit {process.ExitCode}\n");
            if (process.ExitCode != 0) throw new IOException($"CAD-процесс завершился с кодом {process.ExitCode}. Подробности: logs\\cad.log.");
            if (selfTest)
            {
                using var report = JsonDocument.Parse(File.ReadAllText(Path.Combine(root, "artifacts", "validation.json")));
                if (report.RootElement.GetProperty("status").GetString() != "passed")
                {
                    File.AppendAllText(log, $"{DateTimeOffset.Now:O} Проверка приложения завершилась с ошибками; artifacts\\validation.json\n");
                    return 2;
                }
            }
            return 0;
        }
        catch (Exception ex)
        {
            try { File.AppendAllText(log, $"{DateTimeOffset.Now:O} {ex}\n"); } catch { }
            if (args.Contains("--self-test", StringComparer.Ordinal))
            {
                // Native failures can interrupt a suite before Python writes its
                // final status. Preserve completed checks and make that failure
                // explicit instead of leaving a misleading running report.
                try
                {
                    var reportPath = Path.Combine(root, "artifacts", "validation.json");
                    Directory.CreateDirectory(Path.GetDirectoryName(reportPath)!);
                    var report = new JsonObject();
                    if (File.Exists(reportPath))
                    {
                        try
                        {
                            report = JsonNode.Parse(File.ReadAllText(reportPath)) as JsonObject ?? new JsonObject();
                        }
                        catch (JsonException)
                        {
                            // A native crash can interrupt Python's live JSON
                            // write. Preserve its remaining bytes, then still
                            // produce a readable failure report.
                            var damaged = Path.Combine(root, "artifacts", $"validation-truncated-{DateTime.UtcNow:yyyyMMdd-HHmmss-fffffff}.json");
                            File.Copy(reportPath, damaged);
                        }
                    }
                    report["status"] = "failed";
                    var previousFailed = report["failed"] is JsonValue count && count.TryGetValue<int>(out var failures) ? failures : 0;
                    report["failed"] = Math.Max(1, previousFailed);
                    report["launcher_error"] = ex.Message;
                    report["finished"] = DateTime.UtcNow.ToString("o");
                    var staged = reportPath + ".launcher-tmp";
                    File.WriteAllText(staged, report.ToJsonString(new JsonSerializerOptions { WriteIndented = true }));
                    File.Move(staged, reportPath, overwrite: true);
                }
                catch { }
                return 1;
            }
            MessageBoxW(IntPtr.Zero, "Не удалось запустить QInventor.\n\nПроверьте, что приложение перенесено вместе с папками runtime, src и scripts. Подробности ошибки сохранены в журнале.\n\nЖурнал: " + log, "QInventor", 0x10);
            return 1;
        }
    }
}