/*
**  Licensed to the Apache Software Foundation (ASF) under one or more
** contributor license agreements.  See the NOTICE file distributed with
** this work for additional information regarding copyright ownership.
** The ASF licenses this file to You under the Apache License, Version 2.0
** (the "License"); you may not use this file except in compliance with
** the License.  You may obtain a copy of the License at
**
**      http://www.apache.org/licenses/LICENSE-2.0
**
**  Unless required by applicable law or agreed to in writing, software
**  distributed under the License is distributed on an "AS IS" BASIS,
**  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
**  See the License for the specific language governing permissions and
**  limitations under the License.
*/

#define APR_WANT_STRFUNC
#include "apr_want.h"
#include "apreq_module.h"
#include "apreq_error.h"
#include "apr_strings.h"
#include "apr_lib.h"
#include "apr_env.h"
#include "apreq_util.h"

#include "httpd.h"

#define USER_DATA_KEY "apreq"

/* Parroting APLOG_* ... */

#define	CGILOG_EMERG	0	/* system is unusable */
#define	CGILOG_ALERT	1	/* action must be taken immediately */
#define	CGILOG_CRIT	2	/* critical conditions */
#define	CGILOG_ERR	3	/* error conditions */
#define	CGILOG_WARNING	4	/* warning conditions */
#define	CGILOG_NOTICE	5	/* normal but significant condition */
#define	CGILOG_INFO	6	/* informational */
#define	CGILOG_DEBUG	7	/* debug-level messages */

#define CGILOG_LEVELMASK 7
#define CGILOG_MARK     __FILE__, __LINE__

/** Interactive patch:
 * TODO Don't use 65K buffer
 * TODO Handle empty/non-existent parameters
 * TODO Allow body elements to be files
 * TODO When running body/get/cookies all at once, include previous cached
 * values (and don't start at 0 in count)
 * TODO What happens if user does apreq_param, but needs POST value - we'll
 * never catch it now, as args param will match...
 */

struct cgi_handle {
    struct apreq_handle_t       handle;

    apr_table_t                 *jar, *args, *body;
    apr_status_t                 jar_status,
                                 args_status,
                                 body_status;

    apreq_parser_t              *parser;
    apreq_hook_t                *hook_queue;
    apreq_hook_t                *find_param;

    const char                  *temp_dir;
    apr_size_t                   brigade_limit;
    apr_uint64_t                 read_limit;
    apr_uint64_t                 bytes_read;

    apr_bucket_brigade          *in;
    apr_bucket_brigade          *tmpbb;

    int                         interactive_mode;
    const char                  *promptstr;
    apr_file_t                  *sout, *sin;
};

#define CRLF "\015\012"
static const char *nullstr = 0;
#define DEFAULT_PROMPT "([$t] )$n(\\($l\\))([$d]): "
#define MAX_PROMPT_NESTING_LEVELS 8
#define MAX_BUFFER_SIZE 65536

typedef struct {
    const char *t_name;
    int      t_val;
} TRANS;

static const TRANS priorities[] = {
    {"emerg",   CGILOG_EMERG},
    {"alert",   CGILOG_ALERT},
    {"crit",    CGILOG_CRIT},
    {"error",   CGILOG_ERR},
    {"warn",    CGILOG_WARNING},
    {"notice",  CGILOG_NOTICE},
    {"info",    CGILOG_INFO},
    {"debug",   CGILOG_DEBUG},
    {NULL,      -1},
};

static char* chomp(char* str)
{
    long p = (long)strlen(str);
    while (--p >= 0) {
        switch ((char)(str[p])) {
        case '\015':
        case '\012':str[p]='\000';
                    break;
        default:return str;
        }
    }
    return str;
}

/** TODO: Support wide-characters */
/* prompt takes a apreq_handle and 2 strings - name and type - and prompts a
   user for input via stdin/stdout.  used in interactive mode.
   
   name must be defined.  type can be null.
   
   we take the promptstring defined in the handle and interpolate variables as
   follows:
   
   $n - name of the variable we're asking for (param 2 to prompt())
   $t - type of the variable we're asking for - like cookie, get, post, etc
        (param 3 to prompt())
   parentheses - if a variable is surrounded by parentheses, and interpolates
                 as null, then nothing else in the parentheses will be displayed
                 Useful if you want a string to only show up if a given variable
                 is available
                 
   These are planned for forward-compatibility, but the underlying features
   need some love...  I left these in here just as feature reminders, rather
   than completely removing them from the code - at least they provide sanity
   testing of the default prompt & parentheses - issac
   
   $l - label for the param  - the end-user-developer can provide a textual
        description of the param (name) being requested (currently unused in
        lib)
   $d - default value for the param (currently unused in lib)
   
*/
static char *prompt(apreq_handle_t *handle, const char *name,
                    const char *type) {
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const char *defval = nullstr;
    const char *label = NULL;
    const char *cprompt;
    char buf[MAX_PROMPT_NESTING_LEVELS][MAX_BUFFER_SIZE];
    /* Array of current arg for given p-level */
    char *start, curarg[MAX_PROMPT_NESTING_LEVELS] = ""; 
    /* Parenthesis level (for argument/text grouping) */
    int plevel; 

    cprompt = req->promptstr - 1;
    *buf[0] = plevel = 0;
    start = buf[0];

    while (*(++cprompt) != 0) {
        switch (*cprompt) {
        case '$':  /* interpolate argument; curarg[plevel] => 1 */
            cprompt++;           
            switch (*cprompt) {
            case 't':
                if (type != NULL) {
                    strcpy(start, type);
                    start += strlen(type);
                    curarg[plevel] = 1;
                } else {
                    curarg[plevel] = curarg[plevel] | 0;
                }
                break;
            case 'n':
                /* Name can't be null :-) [If it can, we should 
                 * immediately return NULL] */
                strcpy(start, name);
                start += strlen(name);
                curarg[plevel] = 1;
                break;
            case 'l':
                if (label != NULL) {
                    strcpy(start, label);
                    start += strlen(label);
                    curarg[plevel] = 1;
                } else {
                    curarg[plevel] = curarg[plevel] | 0;
                }
                break;
            case 'd':
                /* TODO: Once null defaults are available, 
                 * remove if and use nullstr if defval == NULL */
                if (defval != NULL) {
                    strcpy(start, defval);
                    start += strlen(defval);
                    curarg[plevel] = 1;
                } else {
                    curarg[plevel] = curarg[plevel] | 0;
                }
                break;
            default:
                /* Handle this? */
                break;
            }
            break;

        case '(':
            if (plevel <= MAX_PROMPT_NESTING_LEVELS) {
                plevel++;
                curarg[plevel] = *buf[plevel] = 0;
                start = buf[plevel];
            }
            /* else? */
            break;

        case ')':
            if (plevel > 0) {
                *start = 0; /* Null terminate current string */
                
                /* Move pointer to end of string */
                plevel--;
                start = buf[plevel] + strlen(buf[plevel]);
                
                /* If old curarg was set, concat buffer with level down */
                if (curarg[plevel + 1]) {
                    strcpy(start, buf[plevel + 1]);
                    start += strlen(buf[plevel + 1]);
                }

                break;
            }
        case '\\': /* Check next character for escape sequence 
                    * (just ignore it for now) */
            (void)*cprompt++;
            /* Fallthrough */

        default:       
            *start++ = *cprompt;
        }
    }

    *start = 0; /* Null terminate the string */
    
    apr_file_printf(req->sout, "%s", buf[0]);
    apr_file_gets(buf[0], MAX_BUFFER_SIZE, req->sin);
    chomp(buf[0]);
    if (strcmp(buf[0], "")) {
/*        if (strcmp(buf[0], nullstr)) */
            return apr_pstrdup(handle->pool, buf[0]);
/*        return NULL; */
    }

    if (defval != nullstr)
        return apr_pstrdup(handle->pool, defval);

    return NULL;
}

static const char *cgi_header_in(apreq_handle_t *handle,
                                 const char *name)
{
    apr_pool_t *p = handle->pool;
    char *key = apr_pstrcat(p, "HTTP_", name, NULL);
    char *k, *value = NULL;

    for (k = key+5; *k; ++k) {
        if (*k == '-')
            *k = '_';
        else
            *k = apr_toupper(*k);
    }

    if (!strcmp(key, "HTTP_CONTENT_TYPE")
        || !strcmp(key, "HTTP_CONTENT_LENGTH")) {

        key += 5; /* strlen("HTTP_") */
    }

    apr_env_get(&value, key, p);

    return value;
}


static void cgi_log_error(const char *file, int line, int level,
                          apr_status_t status, apreq_handle_t *handle,
                          const char *fmt, ...)
{
    apr_pool_t *p = handle->pool;
    char buf[256];
    char *log_level_string, *ra;
    const char *remote_addr;
    unsigned log_level = CGILOG_WARNING;
    char date[APR_CTIME_LEN];
    va_list vp;
#ifndef WIN32
    apr_file_t *err;
#endif

    va_start(vp, fmt);

    if (apr_env_get(&log_level_string, "LOG_LEVEL", p) == APR_SUCCESS)
        log_level = (log_level_string[0] - '0');

    level &= CGILOG_LEVELMASK;

    if (level < (int)log_level) {

        if (apr_env_get(&ra, "REMOTE_ADDR", p) == APR_SUCCESS)
            remote_addr = ra;
        else
            remote_addr = "address unavailable";

        apr_ctime(date, apr_time_now());

#ifndef WIN32

        apr_file_open_stderr(&err, p);
        apr_file_printf(err, "[%s] [%s] [%s] %s(%d): %s: %s\n",
                        date, priorities[level].t_name, remote_addr, file, line,
                        apr_strerror(status,buf,255),apr_pvsprintf(p,fmt,vp));
        apr_file_flush(err);

#else
        fprintf(stderr, "[%s] [%s] [%s] %s(%d): %s: %s\n",
                date, priorities[level].t_name, remote_addr, file, line,
                apr_strerror(status,buf,255),apr_pvsprintf(p,fmt,vp));
#endif
    }

    va_end(vp);

}


APR_INLINE
static const char *cgi_query_string(apreq_handle_t *handle)
{
    char *value = NULL, qs[] = "QUERY_STRING";
    apr_env_get(&value, qs, handle->pool);
    return value;
}


static void init_body(apreq_handle_t *handle)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const char *cl_header = cgi_header_in(handle, "Content-Length");
    apr_bucket_alloc_t *ba = handle->bucket_alloc;
    apr_pool_t *pool = handle->pool;
    apr_file_t *file;
    apr_bucket *eos, *pipe;

    if (cl_header != NULL) {
        apr_off_t content_length;

        if (!ap_parse_strict_length(&content_length, cl_header)) {
            req->body_status = APREQ_ERROR_BADHEADER;
            cgi_log_error(CGILOG_MARK, CGILOG_ERR, req->body_status, handle,
                          "Invalid Content-Length header (%s)", cl_header);
            return;
        }
        if ((apr_uint64_t)content_length > req->read_limit) {
            req->body_status = APREQ_ERROR_OVERLIMIT;
            cgi_log_error(CGILOG_MARK, CGILOG_ERR, req->body_status, handle,
                          "Content-Length header (%s) exceeds configured "
                          "max_body limit (%" APR_UINT64_T_FMT ")",
                          cl_header, req->read_limit);
            return;
        }
    }

    if (req->parser == NULL) {
        const char *ct_header = cgi_header_in(handle, "Content-Type");

        if (ct_header != NULL) {
            apreq_parser_function_t pf = apreq_parser(ct_header);

            if (pf != NULL) {
                req->parser = apreq_parser_make(pool,
                                                ba,
                                                ct_header,
                                                pf,
                                                req->brigade_limit,
                                                req->temp_dir,
                                                req->hook_queue,
                                                NULL);
            }
            else {
                req->body_status = APREQ_ERROR_NOPARSER;
                return;
            }
        }
        else {
            req->body_status = APREQ_ERROR_NOHEADER;
            return;
        }
    }
    else {
        if (req->parser->brigade_limit > req->brigade_limit)
            req->parser->brigade_limit = req->brigade_limit;
        if (req->temp_dir != NULL)
            req->parser->temp_dir = req->temp_dir;
        if (req->hook_queue != NULL)
            apreq_parser_add_hook(req->parser, req->hook_queue);
    }

    req->hook_queue = NULL;
    req->in         = apr_brigade_create(pool, ba);
    req->tmpbb      = apr_brigade_create(pool, ba);

    apr_file_open_stdin(&file, pool); /* error status? */
    pipe = apr_bucket_pipe_create(file, ba);
    eos = apr_bucket_eos_create(ba);
    APR_BRIGADE_INSERT_HEAD(req->in, pipe);
    APR_BRIGADE_INSERT_TAIL(req->in, eos);

    req->body_status = APR_INCOMPLETE;

}

static apr_status_t cgi_read(apreq_handle_t *handle,
                             apr_off_t bytes)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    apr_bucket *e;
    apr_status_t s;

    if (req->body_status == APR_EINIT)
        init_body(handle);

    if (req->body_status != APR_INCOMPLETE)
        return req->body_status;


    switch (s = apr_brigade_partition(req->in, bytes, &e)) {
        apr_off_t len;

    case APR_SUCCESS:

        apreq_brigade_move(req->tmpbb, req->in, e);
        req->bytes_read += bytes;

        if (req->bytes_read > req->read_limit) {
            req->body_status = APREQ_ERROR_OVERLIMIT;
            cgi_log_error(CGILOG_MARK, CGILOG_ERR, req->body_status,
                          handle, "Bytes read (%" APR_UINT64_T_FMT
                          ") exceeds configured limit (%" APR_UINT64_T_FMT ")",
                          req->bytes_read, req->read_limit);
            break;
        }

        req->body_status =
            apreq_parser_run(req->parser, req->body, req->tmpbb);
        apr_brigade_cleanup(req->tmpbb);
        break;


    case APR_INCOMPLETE:

        apreq_brigade_move(req->tmpbb, req->in, e);
        s = apr_brigade_length(req->tmpbb, 1, &len);

        if (s != APR_SUCCESS) {
            req->body_status = s;
            break;
        }
        req->bytes_read += len;

        if (req->bytes_read > req->read_limit) {
            req->body_status = APREQ_ERROR_OVERLIMIT;
            cgi_log_error(CGILOG_MARK, CGILOG_ERR, req->body_status, handle,
                          "Bytes read (%" APR_UINT64_T_FMT
                          ") exceeds configured limit (%" APR_UINT64_T_FMT ")",
                          req->bytes_read, req->read_limit);

            break;
        }

        req->body_status =
            apreq_parser_run(req->parser, req->body, req->tmpbb);
        apr_brigade_cleanup(req->tmpbb);
        break;

    default:
        req->body_status = s;
    }

    return req->body_status;
}



static apr_status_t cgi_jar(apreq_handle_t *handle,
                            const apr_table_t **t)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->interactive_mode && req->jar_status != APR_SUCCESS) {
        char buf[65536];
        const char *name, *val;
        apreq_cookie_t *p;
        int i = 1;
        apr_file_printf(req->sout, "[CGI] Requested all cookies\n");
        while (1) {
            apr_file_printf(req->sout, "[CGI] Please enter a name for cookie %d (or just hit ENTER to end): ",
                     i++);
            apr_file_gets(buf, 65536, req->sin);
            chomp(buf);
            if (!strcmp(buf, "")) {
                break;
            }
            name = apr_pstrdup(handle->pool, buf);
            val = prompt(handle, name, "cookie");
            if (val == NULL)
                val = "";
            p = apreq_cookie_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return APR_ENOMEM;
            apreq_cookie_tainted_on(p);
            apreq_value_table_add(&p->v, req->jar);
        }
        req->jar_status = APR_SUCCESS;
    } /** Fallthrough */

    if (req->jar_status == APR_EINIT) {
        const char *cookies = cgi_header_in(handle, "Cookie");
        if (cookies != NULL) {
            req->jar_status =
                apreq_parse_cookie_header(handle->pool, req->jar, cookies);
        }
        else
            req->jar_status = APREQ_ERROR_NODATA;
    }

    *t = req->jar;
    return req->jar_status;
}

static apr_status_t cgi_args(apreq_handle_t *handle,
                             const apr_table_t **t)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->interactive_mode && req->args_status != APR_SUCCESS) {
        char buf[65536];
        const char *name, *val;
        apreq_param_t *p;
        int i = 1;
        apr_file_printf(req->sout, "[CGI] Requested all argument parameters\n");
        while (1) {
            apr_file_printf(req->sout, "[CGI] Please enter a name for parameter %d (or just hit ENTER to end): ",
                     i++);
            apr_file_gets(buf, 65536, req->sin);
            chomp(buf);
            if (!strcmp(buf, "")) {
                break;
            }
            name = apr_pstrdup(handle->pool, buf);
            val = prompt(handle, name, "parameter");
            if (val == NULL)
                val = "";
            p = apreq_param_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return APR_ENOMEM;
            apreq_param_tainted_on(p);
            apreq_value_table_add(&p->v, req->args);
            val = p->v.data;
        }
        req->args_status = APR_SUCCESS;
    } /** Fallthrough */

    if (req->args_status == APR_EINIT) {
        const char *qs = cgi_query_string(handle);
        if (qs != NULL) {
            req->args_status =
                apreq_parse_query_string(handle->pool, req->args, qs);
        }
        else
            req->args_status = APREQ_ERROR_NODATA;
    }

    *t = req->args;
    return req->args_status;
}




static apreq_cookie_t *cgi_jar_get(apreq_handle_t *handle,
                                   const char *name)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const apr_table_t *t;
    const char *val = NULL;

    if (req->jar_status == APR_EINIT && !req->interactive_mode)
        cgi_jar(handle, &t);
    else
        t = req->jar;

    val = apr_table_get(t, name);
    if (val == NULL) {
        if (!req->interactive_mode) {
            return NULL;
        } else {
            apreq_cookie_t *p;
            val = prompt(handle, name, "cookie");
            if (val == NULL)
                return NULL;
            p = apreq_cookie_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return NULL;
            apreq_cookie_tainted_on(p);
            apreq_value_table_add(&p->v, req->jar);
            val = p->v.data;
        }
    }


    return apreq_value_to_cookie(val);
}

static apreq_param_t *cgi_args_get(apreq_handle_t *handle,
                                   const char *name)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const apr_table_t *t;
    const char *val = NULL;

    if (req->args_status == APR_EINIT && !req->interactive_mode)
        cgi_args(handle, &t);
    else
        t = req->args;

    val = apr_table_get(t, name);
    if (val == NULL) {
        if (!req->interactive_mode) {
            return NULL;
        } else {
            apreq_param_t *p;
            val = prompt(handle, name, "parameter");
            if (val == NULL)
                return NULL;
            p = apreq_param_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return NULL;
            apreq_param_tainted_on(p);
            apreq_value_table_add(&p->v, req->args);
            val = p->v.data;
        }
    }


    return apreq_value_to_param(val);
}



static apr_status_t cgi_body(apreq_handle_t *handle,
                             const apr_table_t **t)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->interactive_mode && req->body_status != APR_SUCCESS) {
        const char *name, *val;
        apreq_param_t *p;
        int i = 1;
        apr_file_printf(req->sout, "[CGI] Requested all body parameters\n");
        while (1) {
            char buf[65536];
            apr_file_printf(req->sout, "[CGI] Please enter a name for parameter %d (or just hit ENTER to end): ",
                     i++);
            apr_file_gets(buf, 65536, req->sin);
            chomp(buf);
            if (!strcmp(buf, "")) {
                break;
            }
            name = apr_pstrdup(handle->pool, buf);
            val = prompt(handle, name, "parameter");
            if (val == NULL)
                val = "";
            p = apreq_param_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return APR_ENOMEM;
            apreq_param_tainted_on(p);
            apreq_value_table_add(&p->v, req->body);
            val = p->v.data;
        }
        req->body_status = APR_SUCCESS;
    } /** Fallthrough */
    
    switch (req->body_status) {

    case APR_EINIT:
        init_body(handle);
        if (req->body_status != APR_INCOMPLETE)
            break;

    case APR_INCOMPLETE:
        while (cgi_read(handle, APREQ_DEFAULT_READ_BLOCK_SIZE)
               == APR_INCOMPLETE)
            ;   /*loop*/
    }

    *t = req->body;
    return req->body_status;
}

static apreq_param_t *cgi_body_get(apreq_handle_t *handle,
                                   const char *name)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const char *val = NULL;
    apreq_hook_t *h;
    apreq_hook_find_param_ctx_t *hook_ctx;

    if (req->interactive_mode) {
        val = apr_table_get(req->body, name);
        if (val == NULL) {
            return NULL;
        } else {
            apreq_param_t *p;
            val = prompt(handle, name, "parameter");
            if (val == NULL)
                return NULL;
            p = apreq_param_make(handle->pool, name, strlen(name), val, strlen(val));
            if (p == NULL)
                return NULL;
            apreq_param_tainted_on(p);
            apreq_value_table_add(&p->v, req->body);
            val = p->v.data;
            return apreq_value_to_param(val);
        }
    }


    switch (req->body_status) {

    case APR_SUCCESS:

        val = apr_table_get(req->body, name);
        if (val != NULL)
            return apreq_value_to_param(val);
        return NULL;


    case APR_EINIT:

        init_body(handle);
        if (req->body_status != APR_INCOMPLETE)
            return NULL;
        cgi_read(handle, APREQ_DEFAULT_READ_BLOCK_SIZE);


    case APR_INCOMPLETE:

        val = apr_table_get(req->body, name);
        if (val != NULL)
            return apreq_value_to_param(val);

        /* Not seen yet, so we need to scan for
           param while prefetching the body */

        hook_ctx = apr_palloc(handle->pool, sizeof *hook_ctx);

        if (req->find_param == NULL)
            req->find_param = apreq_hook_make(handle->pool,
                                              apreq_hook_find_param,
                                              NULL, NULL);
        h = req->find_param;
        h->next = req->parser->hook;
        req->parser->hook = h;
        h->ctx = hook_ctx;
        hook_ctx->name = name;
        hook_ctx->param = NULL;
        hook_ctx->prev = req->parser->hook;

        do {
            cgi_read(handle, APREQ_DEFAULT_READ_BLOCK_SIZE);
            if (hook_ctx->param != NULL)
                return hook_ctx->param;
        } while (req->body_status == APR_INCOMPLETE);

        req->parser->hook = h->next;
        return NULL;


    default:

        if (req->body == NULL)
            return NULL;

        val = apr_table_get(req->body, name);
        if (val != NULL)
            return apreq_value_to_param(val);
        return NULL;
    }

    /* not reached */
    return NULL;
}

static apr_status_t cgi_parser_get(apreq_handle_t *handle,
                                   const apreq_parser_t **parser)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    *parser = req->parser;
    return APR_SUCCESS;
}

static apr_status_t cgi_parser_set(apreq_handle_t *handle,
                                   apreq_parser_t *parser)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->parser == NULL) {

        if (req->hook_queue != NULL) {
            apr_status_t s = apreq_parser_add_hook(parser, req->hook_queue);
            if (s != APR_SUCCESS)
                return s;
        }
        if (req->temp_dir != NULL) {
            parser->temp_dir = req->temp_dir;
        }
        if (req->brigade_limit < parser->brigade_limit) {
            parser->brigade_limit = req->brigade_limit;
        }

        req->hook_queue = NULL;
        req->parser = parser;
        return APR_SUCCESS;
    }
    else
        return APREQ_ERROR_MISMATCH;
}


static apr_status_t cgi_hook_add(apreq_handle_t *handle,
                                     apreq_hook_t *hook)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->parser != NULL) {
        return apreq_parser_add_hook(req->parser, hook);
    }
    else if (req->hook_queue != NULL) {
        apreq_hook_t *h = req->hook_queue;
        while (h->next != NULL)
            h = h->next;
        h->next = hook;
    }
    else {
        req->hook_queue = hook;
    }
    return APR_SUCCESS;

}

static apr_status_t cgi_brigade_limit_set(apreq_handle_t *handle,
                                          apr_size_t bytes)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    apr_size_t *limit = (req->parser == NULL)
                      ? &req->brigade_limit
                      : &req->parser->brigade_limit;

    if (*limit > bytes) {
        *limit = bytes;
        return APR_SUCCESS;
    }

    return APREQ_ERROR_MISMATCH;
}

static apr_status_t cgi_brigade_limit_get(apreq_handle_t *handle,
                                          apr_size_t *bytes)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    *bytes = (req->parser == NULL)
           ?  req->brigade_limit
           :  req->parser->brigade_limit;

    return APR_SUCCESS;
}

static apr_status_t cgi_read_limit_set(apreq_handle_t *handle,
                                       apr_uint64_t bytes)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;

    if (req->read_limit > bytes && req->bytes_read < bytes) {
        req->read_limit = bytes;
        return APR_SUCCESS;
    }

    return APREQ_ERROR_MISMATCH;
}


static apr_status_t cgi_read_limit_get(apreq_handle_t *handle,
                                       apr_uint64_t *bytes)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    *bytes = req->read_limit;
    return APR_SUCCESS;
}


static apr_status_t cgi_temp_dir_set(apreq_handle_t *handle,
                                     const char *path)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    const char **temp_dir = (req->parser == NULL)
                          ? &req->temp_dir
                          : &req->parser->temp_dir;


    if (*temp_dir == NULL && req->bytes_read == 0) {
        if (path != NULL)
            *temp_dir = apr_pstrdup(handle->pool, path);
        return APR_SUCCESS;
    }

    return APREQ_ERROR_MISMATCH;
}


static apr_status_t cgi_temp_dir_get(apreq_handle_t *handle,
                                     const char **path)
{
    struct cgi_handle *req = (struct cgi_handle *)handle;
    *path = (req->parser == NULL)
           ? req->temp_dir
           : req->parser->temp_dir;
    return APR_SUCCESS;
}



#ifdef APR_POOL_DEBUG
static apr_status_t ba_cleanup(void *data)
{
    apr_bucket_alloc_t *ba = data;
    apr_bucket_alloc_destroy(ba);
    return APR_SUCCESS;
}
#endif

/** Determine if we're interactive mode or not.  Order is
  QUERY_STRING ? NO : Interactive

 I think we should just rely on GATEWAY_INTERFACE to set
 non-interactive mode, and be interactive if it's not there

 Behaviour change should really be:
 Always check query_string before prompting user,
  but rewrite body/cookies to get if interactive

 Definitely more work needed here...
*/
static int is_interactive_mode(apr_pool_t *pool)
{
    char *value = NULL, qs[] = "GATEWAY_INTERFACE";
    apr_status_t rv;

    rv = apr_env_get(&value, qs, pool);
    if (rv != APR_SUCCESS)
        if (rv == APR_ENOENT)
            return 1;
        
        /** handle else? (!SUCCESS && !ENOENT) */
    return 0;
}

static APREQ_MODULE(cgi, 20090110);

APREQ_DECLARE(apreq_handle_t *)apreq_handle_cgi(apr_pool_t *pool)
{
    apr_bucket_alloc_t *ba;
    struct cgi_handle *req;
    void *data;

    apr_pool_userdata_get(&data, USER_DATA_KEY, pool);

    if (data != NULL)
        return data;

    req = apr_pcalloc(pool, sizeof *req);
    ba = apr_bucket_alloc_create(pool);

    /* check pool's userdata first. */

    req->handle.module        = &cgi_module;
    req->handle.pool          = pool;
    req->handle.bucket_alloc  = ba;
    req->read_limit           = (apr_uint64_t) -1;
    req->brigade_limit        = APREQ_DEFAULT_BRIGADE_LIMIT;

    req->args = apr_table_make(pool, APREQ_DEFAULT_NELTS);
    req->body = apr_table_make(pool, APREQ_DEFAULT_NELTS);
    req->jar  = apr_table_make(pool, APREQ_DEFAULT_NELTS);

    req->args_status =
        req->jar_status =
            req->body_status = APR_EINIT;

    if (is_interactive_mode(pool)) {
        req->interactive_mode = 1;
        apr_file_open_stdout(&(req->sout), pool);
        apr_file_open_stdin(&(req->sin), pool);
        req->promptstr=apr_pstrdup(pool, DEFAULT_PROMPT);
    }

    apr_pool_userdata_setn(&req->handle, USER_DATA_KEY, NULL, pool);

#ifdef APR_POOL_DEBUG
    apr_pool_cleanup_register(pool, ba, ba_cleanup, ba_cleanup);
#endif

    return &req->handle;
}