using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using IdentityShroud.Core.DTO;
using Microsoft.AspNetCore.WebUtilities;

namespace IdentityShroud.Core.Tests;

public class UnitTest1
{
    private const string TestJwt = @"eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJybVZ3TU5rM0o1WHlmMWhyS3NVbEVYN1BNUm42dlZKY0h3U3FYMUVQRnFJIn0.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.Z1mjZkpFLIMsx2EWRNwFXYinwUO4iRmteClGWoj70c9AffhjEN5hmSL2ErLn9RjofODY5JovbDo3RDBrTWMDdGHYavxaZRzn8EJe6Ndp9b2n7kUNHJpBrqIGEMhD5sY_5YRTfMIe7j7k2oRW8QIpcQ5_bYUBKEWfHYQqfi8IfpRjLhgd6zKMC3Faj4e442p5zY2dEdWHEr5j6--_Py4HhNsomtTY6WPFH8nTCJ9pbMM9ThSDmdjbSiMbNLeSAQzJNVXp5GGsSVlkJNRlMI_Mmfd7jWpSDZpNPzxJ-HmkDhY9oiInZW0livnf9-eesKWljO3TAXKEuiqigsblSbLjsQ";
    [Fact]
    public void DecodeTest()
    {
        var decoded = JwtReader.Decode(TestJwt);
        
        Assert.Equal("RS256", decoded.Header.Algorithm);
        Assert.Equal("https://iam.kassacloud.nl/auth/realms/mpluskassa", decoded.Payload.Issuer);
    }

    [Fact]
    public void CreateTest()
    {
        using (RSA rsa = RSA.Create())
        {
            // Option 1: Load from PEM string
            // string privateKeyPem = @"-----BEGIN PRIVATE KEY-----
            // ... your key here ...
            // -----END PRIVATE KEY-----";
            // rsa.ImportFromPem(privateKeyPem);
            
            // Option 2: Load from XML
            // string xmlKey = "<RSAKeyValue>...</RSAKeyValue>";
            // rsa.FromXmlString(xmlKey);
            
            // Option 3: Generate a new key for testing
            rsa.KeySize = 2048;
            
            // Your already encoded header and payload
            string header = "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJybVZ3TU5rM0o1WHlmMWhyS3NVbEVYN1BNUm42dlZKY0h3U3FYMUVQRnFJIn0";
            string payload = "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";
            
            // Generate signature
            string signature = JwtSignatureGenerator.GenerateRS256Signature(header, payload, rsa);
            
            string publicKeyPem = rsa.ExportSubjectPublicKeyInfoPem();
            string token = $"{header}.{payload}.{signature}";
            
            Console.WriteLine($"Signature: {signature}");
            
            // Or generate complete JWT
            // string completeJwt = JwtSignatureGenerator.GenerateCompleteJwt(header, payload, rsa);
            // Console.WriteLine($"Complete JWT: {completeJwt}");
        }
    }        
}

public static class JwtReader
{

    public static JsonWebToken Decode(string jwt)
    {
        // there should only be two, if not one of the base64 decode calls should fail.
        int firstDot = jwt.IndexOf('.');
        int secondDot = jwt.LastIndexOf('.');
        return new JsonWebToken()
        {
            Header = JsonSerializer.Deserialize<JsonWebTokenHeader>(
                Encoding.UTF8.GetString(WebEncoders.Base64UrlDecode(jwt, 0, firstDot))),
            Payload = JsonSerializer.Deserialize<JsonWebTokenPayload>(
                Encoding.UTF8.GetString(WebEncoders.Base64UrlDecode(jwt, firstDot + 1, secondDot - (firstDot + 1)))),
            Signature = WebEncoders.Base64UrlDecode(jwt, secondDot + 1, jwt.Length - (secondDot + 1))
        };
    }
}

public static class RsaKeyLoader
{
    /// <summary>
    /// Load RSA private key from PEM format (.NET 5+)
    /// </summary>
    public static RSA LoadFromPem(string pemKey)
    {
        var rsa = RSA.Create();
        rsa.ImportFromPem(pemKey);
        return rsa;
    }
    
    /// <summary>
    /// Load RSA private key from file
    /// </summary>
    public static RSA LoadFromPemFile(string filePath)
    {
        string pemContent = System.IO.File.ReadAllText(filePath);
        return LoadFromPem(pemContent);
    }
   
}