/**

 * @file agCgi.c

 *

 *  This is a CGI wrapper for AutoGen.  It will take POST-method

 *  name-value pairs and emit AutoGen definitions to a spawned

 *  AutoGen process.

 *

 *  This file is part of AutoGen.

 *  AutoGen Copyright (C) 1992-2016 by Bruce Korb - all rights reserved

 *

 * AutoGen is free software: you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * AutoGen is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 * See the GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

typedef struct {

    char const * name;

    char *       cgi_val;

} name_map_t;

#define ENV_TABLE \

    _ET_(REQUEST_METHOD) \

    _ET_(QUERY_STRING) \

    _ET_(CONTENT_LENGTH) \

\

    _ET_(AUTH_TYPE) \

    _ET_(CONTENT_TYPE) \

    _ET_(GATEWAY_INTERFACE) \

    _ET_(HTTP_ACCEPT) \

    _ET_(HTTP_REFERER) \

    _ET_(HTTP_USER_AGENT) \

    _ET_(PATH_INFO) \

    _ET_(PATH_TRANSLATED) \

    _ET_(REMOTE_ADDR) \

    _ET_(REMOTE_HOST) \

    _ET_(REMOTE_IDENT) \

    _ET_(REMOTE_USER) \

    _ET_(SCRIPT_NAME) \

    _ET_(SERVER_NAME) \

    _ET_(SERVER_PORT) \

    _ET_(SERVER_PROTOCOL) \

    _ET_(SERVER_SOFTWARE)

static name_map_t name_val_map[] = {

#define _ET_(n) { #n, NULL },

    ENV_TABLE

#undef _ET_

    { NULL, NULL }

};

typedef enum {

#define _ET_(n) n ## _IDX,

    ENV_TABLE

#undef _ET_

    NAME_CT

} name_idx_t;

#define cgi_method name_val_map[ REQUEST_METHOD_IDX ].cgi_val

#define cgi_query  name_val_map[ QUERY_STRING_IDX   ].cgi_val

#define cgi_len    name_val_map[ CONTENT_LENGTH_IDX ].cgi_val

 static inline char *

parse_input(char * src, int len)

{

    size_t rsz = (len * 4) + PARSE_INPUT_AG_DEF_STR_LEN;

    char * res = AGALOC(rsz, "CGI Defs");

    memcpy(res, PARSE_INPUT_AG_DEF_STR, PARSE_INPUT_AG_DEF_STR_LEN);

    (void)cgi_run_fsm(src, len, res + PARSE_INPUT_AG_DEF_STR_LEN, len * 2);

    assert(rsz > strlen(res));

    return AGREALOC(res, strlen(res)+1, "CGI input");

}

LOCAL void

load_cgi(void)

{

    /*

     *  Redirect stderr to a file.  If it gets used, we must trap it

     *  and emit the content-type: preamble before actually emitting it.

     *  First, tho, do a simple stderr->stdout redirection just in case

     *  we stumble before we're done with this.

     */

    dup2(STDOUT_FILENO, STDERR_FILENO);

    {

        FILE * fp = fdopen(STDERR_FILENO, "w" FOPEN_BINARY_FLAG);

        (void)fp;

    }

    {

        int tmpfd;

        oops_pfx = CGI_ERR_MSG_FMT;

        AGDUPSTR(cgi_stderr, CGI_TEMP_ERR_FILE_STR, "stderr file");

        tmpfd = mkstemp(cgi_stderr);

        if (tmpfd < 0)

            AG_ABEND(aprf(MKSTEMP_FAIL_FMT, cgi_stderr));

        dup2(tmpfd, STDERR_FILENO);

        close(tmpfd);

    }

    /*

     *  Pull the CGI-relevant environment variables.  Anything we don't find

     *  gets an empty string default.

     */

    {

        name_map_t * nm_map = name_val_map;

        name_idx_t   ix     = (name_idx_t)0;

        do  {

            nm_map->cgi_val = getenv(nm_map->name);

            if (nm_map->cgi_val == NULL)

                nm_map->cgi_val = (char *)zNil;

        } while (nm_map++, ++ix < NAME_CT);

    }

    base_ctx = (scan_ctx_t *)AGALOC(sizeof(scan_ctx_t), "CGI ctx");

    memset(VOIDP(base_ctx), 0, sizeof(scan_ctx_t));

    {

        size_t len = strtoul(cgi_len, NULL, 0);

        char * text;

        if (strcasecmp(cgi_method, "POST") == 0) {

            if (len == 0)

                AG_ABEND(LOAD_CGI_NO_DATA_MSG);

            text  = AGALOC(len + 1, "CGI POST");

            if (fread(text, (size_t)1, len, stdin) != len)

                AG_CANT(LOAD_CGI_READ_NAME, LOAD_CGI_READ_WHAT);

            text[ len ] = NUL;

            base_ctx->scx_data = parse_input(text, (int)len);

            AGFREE(text);

        } else if (strcasecmp(cgi_method, LOAD_CGI_GET_NAME) == 0) {

            if (len == 0)

                len = strlen(cgi_query);

            base_ctx->scx_data = parse_input(cgi_query, (int)len);

        } else {

            AG_ABEND(aprf(LOAD_CGI_INVAL_REQ_FMT, cgi_method));

            /* NOTREACHED */

#ifdef  WARNING_WATCH

            text = NULL;

#endif

        }

    }

    base_ctx->scx_line  = 1;

    base_ctx->scx_fname = LOAD_CGI_DEFS_MARKER;

    base_ctx->scx_scan  = base_ctx->scx_data;

}

/*

 * Local Variables:

 * mode: C

 * c-file-style: "stroustrup"

 * indent-tabs-mode: nil

 * End:

 * end of agen5/agCgi.c */