#pragma once
#include <openssl/ec.h>
#include <openssl/crypto.h>
#include <openssl/evp.h>
#include <openssl/conf.h>
#include <openssl/err.h>
#include <openssl/ecdsa.h>
#include <openssl/ecdh.h>
#include <openssl/sha.h>
#include <openssl/obj_mac.h>

/** 
 * @file openssl.hpp
 * Provides common utility calls for wrapping openssl c api.
 */
namespace fc 
{

    template <typename ssl_type>
    struct ssl_wrapper
    {
        ssl_wrapper(ssl_type* obj):obj(obj) {}

        operator ssl_type*()
        {
            return obj;
        }
        ssl_type* operator->() { return obj; }

        ssl_type* obj;
    };

    #define SSL_TYPE(name, ssl_type, free_func) \
        struct name  : public ssl_wrapper<ssl_type> \
        { \
            name(ssl_type* obj=nullptr) \
              : ssl_wrapper(obj) {} \
            ~name() \
            { \
                if( obj != nullptr ) \
                free_func(obj); \
            } \
        };

    SSL_TYPE(ec_group,       EC_GROUP,       EC_GROUP_free)
    SSL_TYPE(ec_point,       EC_POINT,       EC_POINT_free)
    SSL_TYPE(ecdsa_sig,      ECDSA_SIG,      ECDSA_SIG_free)
    SSL_TYPE(bn_ctx,         BN_CTX,         BN_CTX_free)
    SSL_TYPE(evp_cipher_ctx, EVP_CIPHER_CTX, EVP_CIPHER_CTX_free )

    /** allocates a bignum by default.. */
    struct ssl_bignum : public ssl_wrapper<BIGNUM>
    {
        ssl_bignum() : ssl_wrapper(BN_new()) {}
        ~ssl_bignum() { BN_free(obj); }
    };

    int init_openssl();

} // namespace fc