using System.Diagnostics;
using System.Text;

namespace AVSCartonShipmentVerifier.Hosting;

internal static class DesktopBrowserLauncher
{
    internal sealed record LaunchResult(Process? TrackedProcess, bool UsedAppMode);

    public static LaunchResult TryLaunch(string url, bool preferAppMode, string? userDataDir)
    {
        if (preferAppMode && OperatingSystem.IsWindows())
        {
            var profileDir = ResolveProfileDirectory(userDataDir);

            foreach (var (fileName, arguments) in GetAppModeCandidates(url, profileDir))
            {
                if (!File.Exists(fileName))
                {
                    continue;
                }

                try
                {
                    var process = Process.Start(new ProcessStartInfo
                    {
                        FileName = fileName,
                        Arguments = arguments,
                        UseShellExecute = false
                    });

                    if (process is not null)
                    {
                        return new LaunchResult(process, UsedAppMode: true);
                    }
                }
                catch
                {
                    // Try next browser.
                }
            }
        }

        try
        {
            if (OperatingSystem.IsWindows())
            {
                Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
            }
            else if (OperatingSystem.IsMacOS())
            {
                Process.Start("open", url);
            }
            else
            {
                Process.Start(new ProcessStartInfo("xdg-open", url) { UseShellExecute = true });
            }

            return new LaunchResult(null, UsedAppMode: false);
        }
        catch
        {
            return new LaunchResult(null, UsedAppMode: false);
        }
    }

    private static string? ResolveProfileDirectory(string? userDataDir)
    {
        if (string.IsNullOrWhiteSpace(userDataDir))
        {
            return null;
        }

        var profileDir = userDataDir.Trim();
        Directory.CreateDirectory(profileDir);
        return profileDir;
    }

    private static IEnumerable<(string FileName, string Arguments)> GetAppModeCandidates(string url, string? profileDir)
    {
        var builder = new StringBuilder();
        builder.Append("--app=").Append(url);
        builder.Append(" --new-window");

        if (!string.IsNullOrWhiteSpace(profileDir))
        {
            var escapedProfile = profileDir.Replace("\"", "\\\"", StringComparison.Ordinal);
            builder.Append(" --user-data-dir=\"").Append(escapedProfile).Append('"');
        }

        var appArgs = builder.ToString();

        foreach (var edgePath in EdgePaths())
        {
            yield return (edgePath, appArgs);
        }

        foreach (var chromePath in ChromePaths())
        {
            yield return (chromePath, appArgs);
        }
    }

    private static IEnumerable<string> EdgePaths()
    {
        yield return Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86), "Microsoft", "Edge", "Application", "msedge.exe");
        yield return Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles), "Microsoft", "Edge", "Application", "msedge.exe");
    }

    private static IEnumerable<string> ChromePaths()
    {
        yield return Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles), "Google", "Chrome", "Application", "chrome.exe");
        yield return Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86), "Google", "Chrome", "Application", "chrome.exe");
    }
}