#include "error.h"

#include <string.h>
#include <stdio.h>

#include <netdb.h>
#include <gnutls/gnutls.h>

/*
 * Helper macros
 */
#define ERROR_NAME(code, name) case code: return name

const char *error_name (err_t code)
{
    switch (code) {
        ERROR_NAME( ERR_CALLOC,                         "calloc"                                        );
        ERROR_NAME( ERR_GETADDRINFO,                    "getaddrinfo"                                   );
        ERROR_NAME( ERR_GETADDRINFO_EMPTY,              "getaddrinfo"                                   );
        ERROR_NAME( ERR_SOCKET,                         "socket"                                        );
        ERROR_NAME( ERR_CONNECT,                        "connect"                                       );
        ERROR_NAME( ERR_READ,                           "read"                                          );
        ERROR_NAME( ERR_WRITE,                          "write"                                         );
        ERROR_NAME( ERR_GNUTLS_CERT_ALLOC_CRED,         "gnutls_certificate_allocate_credentials"       );
        ERROR_NAME( ERR_GNUTLS_GLOBAL_INIT,             "gnutls_global_init"                            );
        ERROR_NAME( ERR_GNUTLS_INIT,                    "gnutls_init"                                   );
        ERROR_NAME( ERR_GNUTLS_SET_DEFAULT_PRIORITY,    "gnutls_set_default_priority"                   );
        ERROR_NAME( ERR_GNUTLS_CRED_SET,                "gnutls_credentials_set"                        );
        ERROR_NAME( ERR_GNUTLS_HANDSHAKE,               "gnutls_handshake"                              );
        default: return "[unknown]";
    }
}

const char *error_msg (struct error_info *err)
{
    static char msg[ERROR_MSG_MAXLEN];

    // intrepret .extra
    switch (err->code & _ERR_EXTRA_MASK) {
        case ERR_EXTRA_NONE:
            // no additional info
            snprintf(msg, ERROR_MSG_MAXLEN, "%s", error_name(err->code));
            break;
        
        case ERR_EXTRA_ERRNO:
            // strerror
            snprintf(msg, ERROR_MSG_MAXLEN, "%s: %s", error_name(err->code), strerror(err->extra));
            break;
        
        case ERR_EXTRA_GAI:
            // gai_strerror
            snprintf(msg, ERROR_MSG_MAXLEN, "%s: %s", error_name(err->code), gai_strerror(err->extra));
            break;
        
        case ERR_EXTRA_GNUTLS:
            // gnutls_strerror
            snprintf(msg, ERROR_MSG_MAXLEN, "%s: %s", error_name(err->code), gnutls_strerror(err->extra));
            break;
        
        default:
            // ???
            snprintf(msg, ERROR_MSG_MAXLEN, "%s(%#.8x): %#.8x", error_name(err->code), err->code, err->extra);
            break;
    }   

    // return static pointer
    return msg;
}