/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: PEM.cpp
    Date: 2021-6-12
    Author: Reece
***/
#include <RuntimeInternal.hpp>
#include "../Crypto.hpp"
#include "PEM.hpp"

namespace Aurora::Crypto::PEM
{
    static bool ParsePEM(const AuString &begin, const AuString &end, const AuString &src, AuList<AuUInt8> &buf)
    {
        AuUInt lines = 0;
        AuString str;
        int fail = 0;
        bool finished = 0;

        str.reserve(src.size());

        Parse::SplitNewlines(src,
            [&](const AuString &src)
            {
                if (lines == 0)
                {
                    fail |= (int)(src != begin);
                    lines++;
                    return;
                }

                if (src == end)
                {
                    fail |= (int)!Parse::Base64Decode(str, buf);
                    finished = true;
                    return;
                }

                str += src;
            }
        );

        return fail ? false : finished;
    }

    static AuString SerializePEM(const AuString &begin, const AuString &end, const AuList<AuUInt8> &buf)
    {
        auto delm = Aurora::Build::kCurrentVendor == Aurora::Build::EVendor::eGenericMicrosoft ? "\r\n" : "\n";
        AuString ret;
        ret += begin;
        ret += delm;
        AuString b64;
        if (!Parse::Base64Encode(buf, b64))
        {
            return "";
        }
        else
        {
            b64 = Parse::SplitStringDelm(b64, delm, 16);
        }
        ret += b64;
        ret += delm;
        ret += end;
        return ret;
    }

    AUKN_SYM AuString ToString(const Aurora::Crypto::X509::Certificate &in)
    {
        return SerializePEM("-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----", in);
    }

    AUKN_SYM AuString PrivateToString(const DerBuffer &in)
    {
        return SerializePEM("-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----", in);
    }

    AUKN_SYM AuString PublicToString(const DerBuffer &in)
    {
        return SerializePEM("-----BEGIN PUBLIC KEY-----", "-----END PUBLIC KEY-----", in);
    }

    AUKN_SYM AuString PublicRSAToString(const DerBuffer &in)
    {
        return SerializePEM("-----BEGIN RSA PUBLIC KEY-----", "-----END RSA PUBLIC KEY-----", in);
    }

    AUKN_SYM AuString PrivateRSAToString(const DerBuffer &in)
    {
        return SerializePEM("-----BEGIN RSA PRIVATE KEY-----", "-----END RSA PRIVATE KEY-----", in);
    }

    AUKN_SYM bool FromString(const AuString &in, Aurora::Crypto::X509::Certificate &out)
    {
        return ParsePEM("-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----", in, out);
    }

    AUKN_SYM bool PrivateFromString(const AuString &in, DerBuffer &out)
    {
        return ParsePEM("-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----", in, out);
    }

    AUKN_SYM bool PublicRSAFromString(const AuString &in, DerBuffer &out)
    {
        return ParsePEM("-----BEGIN RSA PUBLIC KEY-----", "-----END RSA PUBLIC KEY-----", in, out);
    }

    AUKN_SYM bool PrivateRSAFromString(const AuString &in, DerBuffer &out)
    {
        return ParsePEM("-----BEGIN RSA PRIVATE KEY-----", "-----END RSA PRIVATE KEY-----", in, out);
    }

    AUKN_SYM bool PublicFromString(const AuString &in, DerBuffer &out)
    {
        return ParsePEM("-----BEGIN PUBLIC KEY-----", "-----END PUBLIC KEY-----", in, out);
    }
}