using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using System.Security.Cryptography;
using Microsoft.EntityFrameworkCore;
using Microsoft.IdentityModel.Tokens;
using RadicadeServer.DB;

namespace RadicadeServer.Auth;

internal static class QuestRememberedSession
{
    internal const string Header = "X-Radicade-Quest-Session";

    internal static async Task<long?> ValidateAsync(RecDBContext db, string token, string deviceId, long requestedAccount)
    {
        if (string.IsNullOrWhiteSpace(token) || token.Length > 8192) return null;
        try
        {
            var handler = new JwtSecurityTokenHandler { MapInboundClaims = false };
            var principal = handler.ValidateToken(token, new TokenValidationParameters
            {
                ValidateIssuerSigningKey = true,
                IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(DBConfig.JwtKey)),
                ValidAlgorithms = new[] { SecurityAlgorithms.HmacSha256 },
                ValidateIssuer = true,
                ValidIssuer = DBConfig.TokenIssuer,
                ValidateAudience = false,
                ValidateLifetime = true,
                RequireExpirationTime = true,
                ClockSkew = TimeSpan.Zero
            }, out _);
            string? Claim(string name) => principal.FindFirst(name)?.Value;
            if (Claim("client_id") != "recroom" || Claim("rn.plat") != "7" ||
                Claim("rn.platid") != "radicade-quest:" + deviceId ||
                !long.TryParse(Claim("userId"), out var account) || account <= 0 ||
                (requestedAccount > 0 && requestedAccount != account) ||
                !int.TryParse(Claim("tver"), out var version)) return null;
            var player = await db.Players.AsNoTracking().FirstOrDefaultAsync(x => x.AccountId == account);
            return player != null && player.TokenVersion == version &&
                Claim("q.pwd") == PasswordVersion(player.Hashword) ? account : null;
        }
        catch (Exception ex) when (ex is SecurityTokenException or ArgumentException)
        {
            return null;
        }
    }

    internal static string PasswordVersion(string? hash) =>
        Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(hash ?? "")));
}