using System;
using System.Linq;
using Windows.Win32;
using Windows.Win32.Foundation;

namespace AMNet.Server;

internal static class Config
{
    internal const string IOSection = "aimeio";
    private const string ConfigFileName = @".\segatools.ini";

    /// <summary>
    /// Valid physical card identification methods.
    /// IDm - uses the idm of the card to generate a 20-digit identifier (also known as the 0008 number)
    /// Access - prefer the real access code of the card. if not available (i.e. Suica card), fallback to the IDm.
    /// </summary>
    private static readonly string[] ValidPhysicalCardIdentifiers = ["idm", "access"];

    static Config()
    {
        GameId = ReadKey(IOSection, "gameId", 4);
        ServerName = ReadKey(IOSection, "serverName", 26, Environment.MachineName);

        var physicalCardIdentifierPreference = ReadKey(IOSection, "physicalCardIdentifier", 10);
        PhysicalCardIdentifierPreference = ValidPhysicalCardIdentifiers.Contains(physicalCardIdentifierPreference) ? physicalCardIdentifierPreference : ValidPhysicalCardIdentifiers[^1];
        
        EnableAimeTxt = PInvoke.GetPrivateProfileInt(IOSection, "enableKeyboardMode", 1, ConfigFileName) > 0;
        AimeTxtPath = ReadKey("aime", "aimePath", PInvoke.MAX_PATH, @"DEVICE\aime.txt");
    }

    public static string GameId { get; }
    public static string ServerName { get; }
    public static string PhysicalCardIdentifierPreference { get; }

    public static bool EnableAimeTxt { get; }
    public static string AimeTxtPath { get; }

    internal static unsafe string ReadKey(string section, string key, uint maxLength, string @default = null)
    {
        // +1 for null terminator
        var buffer = stackalloc char[(int)maxLength + 1];
        var bufferStr = new PWSTR(buffer);

        PInvoke.GetPrivateProfileString(section, key, @default ?? string.Empty, bufferStr, maxLength + 1, ConfigFileName);
        return bufferStr.ToString();
    }
}