using System.Runtime.InteropServices;

namespace Moonlight.Api.Helpers;

public class OsHelper
{
    public static string GetName()
    {
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            return GetWindowsVersion();

        if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
            return GetLinuxVersion();

        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            return "Goofy OS";

        return "Unknown OS";
    }

    private static string GetWindowsVersion()
    {
        var version = Environment.OSVersion.Version;

        // Windows 11 is version 10.0 build 22000+
        if (version.Major == 10 && version.Build >= 22000)
            return $"Windows 11 ({version.Build})";

        if (version.Major == 10)
            return $"Windows 10 ({version.Build})";

        if (version.Major == 6 && version.Minor == 3)
            return "Windows 8.1";

        if (version.Major == 6 && version.Minor == 2)
            return "Windows 8";

        if (version.Major == 6 && version.Minor == 1)
            return "Windows 7";

        return $"Windows {version.Major}.{version.Minor}";
    }

    private static string GetLinuxVersion()
    {
        try
        {
            // Read /etc/os-release, should work everywhere
            if (File.Exists("/etc/os-release"))
            {
                var lines = File.ReadAllLines("/etc/os-release");
                string? name = null;
                string? version = null;

                foreach (var line in lines)
                {
                    if (line.StartsWith("NAME="))
                        name = line.Substring(5).Trim('"');
                    else if (line.StartsWith("VERSION_ID="))
                        version = line.Substring(11).Trim('"');
                }

                if (!string.IsNullOrEmpty(name))
                {
                    return string.IsNullOrEmpty(version) ? name : $"{name} {version}";
                }
            }

            //If for some weird reason it still uses lsb release
            if (File.Exists("/etc/lsb-release"))
            {
                var lines = File.ReadAllLines("/etc/lsb-release");
                string? name = null;
                string? version = null;

                foreach (var line in lines)
                {
                    if (line.StartsWith("DISTRIB_ID="))
                        name = line.Substring(11);
                    else if (line.StartsWith("DISTRIB_RELEASE="))
                        version = line.Substring(16);
                }

                if (!string.IsNullOrEmpty(name))
                {
                    return string.IsNullOrEmpty(version) ? name : $"{name} {version}";
                }
            }
        }
        catch
        {
            // Ignore
        }

        // Fallback
        return $"Linux {Environment.OSVersion.Version}";
    }
}