/**********************************************************************
 *
 * mod_gsdl.cpp -- front end for apache 1.3 or 2.x module
 * Copyright (C) 2003 DL Consulting Ltd
 *
 * A component of the Greenstone digital library software
 * from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *********************************************************************/

#include <iostream>
using namespace std;

#include "httpd.h"
#include "http_core.h"
#include "http_config.h"
#include "http_protocol.h"
#include "http_main.h"
#include "util_script.h"
#include "ap_config.h"
#include "http_log.h"


#if _APACHE_MOD >= 2

#include "ap_compat.h"

// In addition to the backward compatible features defined in
// ap_compat.h, define 

typedef apr_pool_t ap_pool; // map old type to new apr_* version

// In Apache 2.x, ap_log_error takes extra parameter -- status code
// from the previous command; define macro to automatically add in
// surrogate value of 0 for this
#define ap_log_error(file,line,level,server,fmt) \
	ap_log_error(file,line,level,0,server,fmt)

#endif

#if defined(USE_MYSQL)
#include "mysqlclass.h"
#endif
#if defined(USE_ACCESS)
#include "accessclass.h"
#endif

#include "maincfg.h"
#include "string_pool.h"

#include "receptionist.h"
#include "cgiwrapper.h"
#include "cgiutils.h"
#include "fileutil.h"
#include "nullproto.h"
#include "collectserver.h"
#include "filter.h"
#include "browsefilter.h"

//#ifdef ENABLE_MG
//#include "mgqueryfilter.h"
//#include "mgsearch.h"
//#endif

#include "infodbclass.h"
#include "collectset.h"

#include "gdbmclass.h"

#include "action.h"
#include "ispersistentaction.h"
#include "browserclass.h"

#define GSDL_USE_OSTRINGSTREAM 1
// ostrstream is deprecated => switch to using ostringstream
// Doing this with the above define so it is easy to switch
// back to ostrstream this backwards compatability is needed
// for some reason.

#if defined(GSDL_USE_OSTRINGSTREAM)
#  include <sstream>
#else
#  if defined(GSDL_USE_IOS_H)
#    if defined(__WIN32__)
#      include <strstrea.h> // vc4
#    else
#      include <strstream.h>
#    endif
#  else
#    include <strstream>
#  endif
#endif

receptionist recpt;
nullproto nproto;

extern "C" module MODULE_VAR_EXPORT gsdl_module;

typedef struct {
  char *config_gsdlhome;
  char *config_collecthome;
  char *config_httpprefix;
  char *config_httpweb;
} gsdl_config;

static void *gsdl_create_config(ap_pool *p, server_rec *s) {

#if _APACHE_MOD >= 2
  gsdl_config *cfg = (gsdl_config *)apr_pcalloc(p, sizeof(gsdl_config));
#else
  gsdl_config *cfg = (gsdl_config *)ap_pcalloc(p, sizeof(gsdl_config));
#endif

  return (void *)cfg;
}

static void *gsdl_create_dir_config(ap_pool *p, char *path) {

  return (gsdl_config *) gsdl_create_config(p, NULL);
}

static const char *gsdl_cmd(cmd_parms *cmd, void *mconfig,
			    char *val) {

  server_rec *s = cmd->server;
  gsdl_config *cfg = (gsdl_config *) ap_get_module_config(s->module_config, &gsdl_module);

  if (strcmp(cmd->cmd->name, "gsdlhome") == 0) {
    cfg->config_gsdlhome = val;
  } else if (strcmp(cmd->cmd->name, "collecthome") == 0) {
    cfg->config_collecthome = val;
  } else if (strcmp(cmd->cmd->name, "httpprefix") == 0) {
    cfg->config_httpprefix = val;
  } else if (strcmp(cmd->cmd->name, "httpweb") == 0) {
    cfg->config_httpweb = val;
  }

  return NULL;
}

#if _APACHE_MOD < 2
static void gsdl_exit(void* d) {
#else
static apr_status_t gsdl_exit(void* d) {
#endif

#if defined(USE_ACCESS)
  // shut down com
  CoUninitialize();
#endif  

#if _APACHE_MOD >= 2
  return APR_SUCCESS; 
#endif
}

#if _APACHE_MOD < 2
static void gsdl_init(server_rec *s, ap_pool *p) {
#else
static void gsdl_init(ap_pool *p, server_rec *s) {
#endif

  // Register gsdl_exit has cleanup operation for when pchild (process id
  // of child) exits
#if _APACHE_MOD >= 2
  apr_pool_cleanup_register(p,s, apr_pool_cleanup_null, gsdl_exit);
#else
  ap_register_cleanup(p,s, ap_null_cleanup, gsdl_exit);
#endif

  recpt.loaded = false;

  gsdl_config *cfg = (gsdl_config *) ap_get_module_config(s->module_config, &gsdl_module);

  if (!cfg->config_gsdlhome) {
    ap_log_error("", 0, APLOG_ERR, s, "gsdlhome not set\n");
    return;
  }
  text_t gsdlhome = cfg->config_gsdlhome;

  if (!directory_exists(gsdlhome)) {
    ap_log_error("", 0, APLOG_ERR, s, "gsdlhome directory does not exist\n");
    return;
  }

  if (!cfg->config_collecthome) {
    ap_log_error("", 0, APLOG_ERR, s, "collecthome not set\n");
    return;
  }
  text_t collecthome = cfg->config_collecthome;

  if (!directory_exists(collecthome)) {
    ap_log_error("", 0, APLOG_ERR, s, "collecthome directory does not exist\n");
    return;
  }


  if (!cfg->config_httpprefix) {
    ap_log_error("", 0, APLOG_ERR, s, "httpprefix not set\n");
    return;
  }

  if (!cfg->config_httpweb) {
    ap_log_error("", 0, APLOG_ERR, s, "httpweb not set\n");
    return;
  }
    
  text_t httpprefix = cfg->config_httpprefix;
  text_t httpweb = cfg->config_httpweb;

  text_t collection = "";

  collectset *cservers = new collectset();

  cservers->add_all_collections(gsdlhome,collecthome);

  // set up the null protocol
  nproto.set_collectset(cservers);
  
  // add the protocol to the receptionist
  recpt.add_protocol(&nproto);

  // add database object to receptionist
#if defined(USE_MYSQL)
  mysqlclass *db = new mysqlclass();
#elif defined(USE_ACCESS)
  // start up com
  if(FAILED(CoInitialize(NULL))) {
    cout << "CoInitialize failed\n";
    exit(-1);
  }
  accessclass *db = new accessclass();
#else

  // not using either mysql or access database - we'll use the gdbmclass
  // class as a filler (but most likely won't work) - only useful
  // if creating a binary that doesn't require access to the database
  dbclass *db = new gdbmclass(gsdlhome);

#endif

#if defined(USE_MYSQL) || defined(USE_ACCESS) 
  recpt.add_dbclass(db);
#endif

  userdbclass *udb = new userdbclass(gsdlhome);
  keydbclass *kdb = new keydbclass(gsdlhome);
  // do these two database classes ever get deleted in the module version
  // of Greenstone?

  // librarymain.cpp deletes these when its finished its function
  // does comparable code need to be put into "gsdl_deinit()" routine
  // whatever that might be called in reality?

  add_all_actions(recpt,udb,kdb,isPersistent); // apache is a persistent server with mod_gsdl
  add_all_browsers(recpt);
  

  // configure everything
  recpt.configure("gsdlhome", gsdlhome);
  recpt.configure("collecthome", collecthome);
  recpt.configure("collection", collection);
  recpt.configure("httpweb", httpweb);
  recpt.configure("httpprefix", httpprefix);
  // set httpprefixfull - if httpprefix is a relative path we need to get
  // the server name and port from the web server environment (note that
  // gwcgi and gwcgifull will be configured for each page request (in gsdl_handler)
  // as we need to know that directory info etc.)
  text_t httpprefixfull = httpprefix;
  if ((httpprefixfull.size() < 7) || 
      (substr(httpprefixfull.begin(), httpprefixfull.begin()+7) != "http://")) {
    if (s->server_hostname && s->port) {
      httpprefixfull = "http://" + text_t(s->server_hostname) + ":" + text_t(s->port) + httpprefixfull;
    }
  }
  recpt.configure("httpprefixfull", httpprefixfull);

  // read in main.cfg file
  if (!main_cfg_read(recpt, gsdlhome, collecthome, collection)) {
    ap_log_error("", 0, APLOG_ERR, s, "failed to read main.cfg file\n");
    return;
  }

  text_t error_file = filename_cat (gsdlhome, "etc", "error.txt");
  char *eout = error_file.getcstr();
  ofstream errout (eout, ios::app);
  delete eout;

  // initialise the library software
  if (!recpt.init(errout)) {
    ap_log_error("", 0, APLOG_ERR, s, "Greenstone failed to initialize\n");
    errout.close();
    return;
  }

  errout.close();

  // set flag so gsdl_handler can check that everything initialized
  // successfully
  recpt.loaded = true;
}


#if _APACHE_MOD < 2

typedef const char *(*CMD_HAND_TYPE) ();
static command_rec gsdl_cmds[] = {
  {"gsdlhome", (CMD_HAND_TYPE)gsdl_cmd,
   (void *)XtOffsetOf(gsdl_config, config_gsdlhome),
   OR_ALL, TAKE1, "GSDLHOME directory."},
  {"collecthome", (CMD_HAND_TYPE)gsdl_cmd,
   (void *)XtOffsetOf(gsdl_config, config_collecthome),
   OR_ALL, TAKE1, "COLLECTHOME directory."},
  {"httpprefix", (CMD_HAND_TYPE)gsdl_cmd,
   (void *)XtOffsetOf(gsdl_config, config_httpprefix),
   OR_ALL, TAKE1, "GSDLHOME http path."},
  {"httpweb", (CMD_HAND_TYPE)gsdl_cmd,
   (void *)XtOffsetOf(gsdl_config, config_httpweb),
   OR_ALL, TAKE1, "GSDLHOME http web path."},
  {NULL, NULL, NULL, 0, cmd_how(0), NULL}
};
#else

/* 
static const char 
*set_max_cache_size(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    apr_size_t val;

    return NULL;
}

  AP_INIT_TAKE1("MCacheSize", set_max_cache_size, NULL, RSRC_CONF,
		"The maximum amount of memory used by the cache in KBytes"),

*/

// const char *(*cmd_func)();

static const command_rec gsdl_cmds[] = {
  AP_INIT_TAKE1("gsdlhome", (cmd_func)gsdl_cmd, NULL, OR_ALL,"GSDLHOME directory."),
  AP_INIT_TAKE1("collecthome", (cmd_func)gsdl_cmd, NULL, OR_ALL,"COLLECTHOME directory."),
  AP_INIT_TAKE1("httpprefix", (cmd_func)gsdl_cmd, NULL, OR_ALL,"GSDLHOME http path."),
  AP_INIT_TAKE1("httpweb", (cmd_func)gsdl_cmd, NULL, OR_ALL,"GSDLHOME http web path."),
  {NULL}
};


#endif

static int gsdl_handler(request_rec *r) {

  if (strcmp(r->handler, "gsdl")) {
    return DECLINED;
  }

  // check that everything has been initialized
  if (!recpt.loaded) {
    ap_log_error("", 0, APLOG_ERR, r->server,  "gsdl_handler: attempt to use uninitialized receptionist - aborting\n");
    return 500;
  }

  gsdl_config *cfg = (gsdl_config *) ap_get_module_config(r->server->module_config, &gsdl_module);

  if (!cfg->config_gsdlhome) {
    ap_log_error("", 0, APLOG_ERR, r->server,  "gsdl_handler: gsdlhome not set\n");
    return 500;
  }

  if (!cfg->config_collecthome) {
    ap_log_error("", 0, APLOG_ERR, r->server,  "gsdl_handler: collecthome not set\n");
    return 500;
  }

  // configure gwcgi and gwcgifull
  recpt.configure("gwcgi", r->uri);
  recpt.configure("gwcgifull", "http://" + text_t(r->server->server_hostname) + 
		  ":" + text_t(r->server->port) + r->uri);
  
  string_pool str_pool;

  text_t gsdlhome = cfg->config_gsdlhome;

  text_t error_file = filename_cat (gsdlhome, "etc", "error.txt");
  char *eout = str_pool.get_cstr_from_pool(error_file);
  ofstream errout (eout, ios::app);

  text_t argstr;
  fileupload_tmap fileuploads;

  char *request_method_str = getenv("REQUEST_METHOD");
  char *content_length_str = getenv("CONTENT_LENGTH");
  if (request_method_str != NULL && strcmp(request_method_str, "POST") == 0 &&
      content_length_str != NULL)  {
    // POST form data
    long content_length = (content_length_str ? atoi(content_length_str) : 0);
    if (content_length > 0) {
#ifdef __WIN32__
      // On Windows it is important that standard input be read in binary
      // mode, otherwise end of line "<CR><LF>" is turned into <LF> only
      // which breaks the MIME standard (and our parsing code!)
      
      int result = _setmode( _fileno( stdin ), _O_BINARY );
      if( result == -1 ) {
	cerr << "Warning: Failed to set standard input to binary mode." << endl;
	cerr << "         Parsing of multi-part MIME will most likely fail" << endl;
      }
#endif
      
      long length = content_length;
      unsigned char * buffer = new unsigned char[content_length];
      
      int chars_read = fread(buffer,1,content_length,stdin);
      
      if (chars_read != content_length) {
	cerr << "Warning: mismatch between CONTENT_LENGTH and data read from standard in" << endl;
      }
      
      argstr.setcarr((char *)buffer, content_length);     
      
      text_t content_type;
      char *content_type_str = getenv("CONTENT_TYPE");
      if (content_type_str) content_type = content_type_str;
      argstr = parse_post_data(content_type, argstr, fileuploads, gsdlhome);
    }
  } else {
    
    if (r->args) argstr = r->args;
  }

  // parse the cgi arguments and produce the resulting page if there
  // have been no errors so far
  cgiargsclass args;
  text_tmap fastcgienv; // Not being used in this case
  if (!recpt.parse_cgi_args (argstr, fileuploads, args, errout, fastcgienv)) {
    errout.close();
    ap_log_error("", 0, APLOG_ERR, r->server,  "parse_cgi_args failed\n");
    return 500;
  } 

#ifdef GSDL_USE_OSTRINGSTREAM
  ostringstream pageout;
#else
  ostrstream pageout;
#endif

  // get http headers
  text_tmap headers;
  recpt.get_cgihead_info(args, headers, errout, fastcgienv);

  if (headers.find("Location") != headers.end()) {
    // redirect
    char *val = str_pool.get_cstr_from_pool(headers.find("Location")->second);
#if _APACHE_MOD >= 2
    apr_table_set(r->headers_out, "location", val);
#else
    ap_table_set(r->headers_out, "location", val);
#endif
    return HTTP_MOVED_TEMPORARILY;
  }

  text_tmap::iterator here = headers.begin();
  text_tmap::iterator end = headers.end();
  while (here != end) {
    text_t namet = (*here).first;
    lc(namet);
    char *name = str_pool.get_cstr_from_pool(namet);
    char *val = str_pool.get_cstr_from_pool((*here).second);

    if ((*here).first == "content-type") {
#if _APACHE_MOD < 2
      r->content_type = val;
#else

      char* val_copy = strdup(val); // if note freed by r->content_type => Memory leak!
      ap_set_content_type(r, val_copy);
#endif
    }
    else if ((*here).first == "content-encoding") {
      r->content_encoding = strdup(val);
    }
    else {
#if _APACHE_MOD >= 2
      apr_table_set(r->headers_out, name, val);
#else
      ap_table_set(r->headers_out, name, val);
#endif
    }

    here++;
  }
  ap_send_http_header(r);

  if (!r->header_only) {
    if (!recpt.produce_content(args, pageout, errout)) {
      ap_log_error("", 0, APLOG_ERR, r->server,  "produce_content failed\n");
      return 500;
    } 
#ifdef GSDL_USE_OSTRINGSTREAM
    string out = pageout.str();
    ap_rwrite(out.c_str(), out.size(), r);
#else
    char *out = pageout.str();
    ap_rwrite(out, pageout.pcount(), r);
    pageout.rdbuf()->freeze(0);
#endif
  }

  errout.close();  

  return OK;
}

#if _APACHE_MOD < 2

static const handler_rec gsdl_handlers[] = { 
  { "gsdl", gsdl_handler }, 
  { NULL, NULL }
};


extern "C" {
  module MODULE_VAR_EXPORT gsdl_module = {
    STANDARD_MODULE_STUFF, 
    NULL,                       /* module \initializer                  */
    gsdl_create_dir_config,     /* create per-dir    config structures */
    NULL,                       /* merge  per-dir    config structures */
    gsdl_create_config,         /* create per-server config structures */
    NULL,                       /* merge  per-server config structures */
    gsdl_cmds,                  /* table of config file commands       */
    gsdl_handlers,              /* [#8] MIME-typed-dispatched handlers */
    NULL,                       /* [#1] URI to filename translation    */
    NULL,                       /* [#4] validate user id from request  */
    NULL,                       /* [#5] check if the user is ok _here_ */
    NULL,                       /* [#3] check access by host address   */
    NULL,                       /* [#6] determine MIME type            */
    NULL,                       /* [#7] pre-run fixups                 */
    NULL,                       /* [#9] log a transaction              */
    NULL,                       /* [#2] header parser                  */
    gsdl_init,                  /* child_init                          */
    NULL,                       /* child_exit                          */
    NULL                        /* [#0] post read-request              */
#ifdef EAPI
    ,NULL,                      /* EAPI: add_module                    */
    NULL,                       /* EAPI: remove_module                 */
    NULL,                       /* EAPI: rewrite_command               */
    NULL,                       /* EAPI: new_connection                */
    NULL                        /* EAPI: close_connection              */
#endif
  };
};

#else

static void gsdl_register_hooks(ap_pool *p)
{
  ap_hook_child_init(gsdl_init,NULL,NULL,APR_HOOK_MIDDLE);
  ap_hook_handler(gsdl_handler, NULL, NULL, APR_HOOK_MIDDLE);

}

extern "C" {
  module AP_MODULE_DECLARE_DATA gsdl_module = {
    STANDARD20_MODULE_STUFF, 
    gsdl_create_dir_config,     /* create per-dir    config structures   */
    NULL,                       /* merge  per-dir    config structures   */
    gsdl_create_config,         /* create per-server config structures   */
    NULL,                       /* merge  per-server config structures   */
    gsdl_cmds,                  /* command handlers                      */
    gsdl_register_hooks,        /* set up other request processing hooks */
  };
};
#endif