/**
 * db.c
 *
 * Copyright (C) 2003 - 2006 Bojan Smojver, Rexursive
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public Licence as published by the Free
 * Software Foundation; either version 2 of the Licence, 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 Licence for
 * more details.
 *
 * You should have received a copy of the GNU General Public Licence along
 * with this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * 
 * In addition, as two special exceptions, Bojan Smojver, Rexursive, gives
 * permission to:
 *
 * 1. Link, both statically and dynamically, the code of this program with
 * Apache HTTP Server, Apache Portable Runtime and Apache Portable Runtime
 * Utility Library from Apache Software Foundation (or with modified versions
 * of the above, that use the same licence - Apache Software Licence 1.1, 2.0
 * or any later version), and distribute linked combinations including the
 * program and the above software from Apache Software Foundation. You must
 * obey the GNU General Public Licence in all respects for all of the code
 * used other than Apache HTTP Server, Apache Portable Runtime and Apache
 * Portable Runtime Utility Library.
 *
 * 2. Dynamically link any shared library with this program at run-time,
 * through the interface of SpinApplication or LoadModule run-time
 * configuration directives of Apache HTTP Server, as provided by this program
 * or Apache HTTP Server itself, regardless of licensing terms of those shared
 * libraries. You must obey the GNU General Public Licence in all respects for
 * all of the code used other than that of those shared libraries.
 *
 * If you modify this file, you may extend these exceptions to your version of
 * the file, but you are not obligated to do so. If you do not wish to do so,
 * delete one or both of these exception statements from your version.
 *
 */

#include "private.h"

/* various get/set functions */
apr_pool_t *rxv_spin_db_pool(rxv_spin_db_t *db){
  return db?db->pool:NULL;
}

char *rxv_spin_db_cinfo(rxv_spin_db_t *db){
  return db?db->cinfo:NULL;
}

const apr_dbd_driver_t *rxv_spin_db_driver(rxv_spin_db_t *db){
  return db?db->driver:NULL;
}

apr_dbd_t *rxv_spin_db_handle(rxv_spin_db_t *db){
  return db?db->handle:NULL;
}

apr_dbd_transaction_t *rxv_spin_db_txn(rxv_spin_db_txn_t *txn){
  return txn?txn->txn:NULL;
}

/* connection functions */
static apr_status_t db_clean(void *data){
  apr_status_t status;
  rxv_spin_db_t *db=data;

  if((status=apr_dbd_close(db->driver,db->handle))!=APR_SUCCESS)
    return status;

  if(db->cpool){
    apr_hash_set(db->cpool->conns,db->cinfo,APR_HASH_KEY_STRING,NULL);
    APR_RING_REMOVE(db,link);
  }

  return APR_SUCCESS;
}

rxv_spin_db_t *rxv_spin_db_connect(rxv_spin_ctx_t *ctx,const char *conninfo){
  rxv_spin_cpool_t *cpool;
  rxv_spin_db_t *db;
  char *p,*dname;
  apr_pool_t *lpool;

  if(!(ctx && conninfo))
    return NULL;

  cpool=ctx->cpool;

  /* try to reuse connection from the pool */
  if(cpool &&
     (db=apr_hash_get(cpool->conns,conninfo,APR_HASH_KEY_STRING))){
    APR_RING_REMOVE(db,link);
    APR_RING_INSERT_HEAD(&cpool->list,db,rxv_spin_db,link);
    return db;
  }

  /* we have to have driver:conn_string format */
  if(!((p=strchr(conninfo,':')) && *(p+1)))
    return NULL;

  /* connection specific memory pool */
  apr_pool_create(&lpool,cpool?cpool->pool:ctx->pool);

  dname=apr_pstrmemdup(lpool,conninfo,p-conninfo);

  /* connection not found, we'll set one up */
  db=apr_pcalloc(lpool,sizeof(*db));

  /* fetch database specific driver */
  if(apr_dbd_get_driver(ctx->ppool,dname,&db->driver)!=APR_SUCCESS){
    apr_pool_destroy(lpool);
    return NULL;
  }

  /* open up database connection */
  if(apr_dbd_open(db->driver,lpool,p+1,&db->handle)!=APR_SUCCESS){
    apr_pool_destroy(lpool);
    return NULL;
  }

  /* we have to copy into the connection pool now */
  db->cinfo=apr_pstrdup(lpool,conninfo);
  db->pool=lpool;
  db->cleanup=db_clean;
  apr_pool_create(&db->spool,lpool);

  if(cpool){
    db->cpool=cpool;
    APR_RING_INSERT_HEAD(&cpool->list,db,rxv_spin_db,link);
    apr_hash_set(cpool->conns,db->cinfo,APR_HASH_KEY_STRING,db);
    cpool->count++;
  }

  apr_pool_cleanup_register(lpool,db,db_clean,db_clean);

  return db;
}

/*
 * WARNING: BIG TIME CHEATING!
 */

/* the fake apr_dbd_get_name function */
#ifndef HAVE_APR_DBD_GET_NAME
static const char *get_name(const apr_dbd_driver_t *driver,apr_pool_t *pool,
                            apr_dbd_results_t *res,int col){
#if defined (HAVE_LIBPQ) && defined (HAVE_LIBPQ_FE_H)
  struct apr_dbd_pgsql_results_t{
    int random;
    PGconn *handle;
    PGresult *res;
    size_t ntuples;
    size_t sz;
    size_t index;
  } *pgres;
#endif
#if defined (HAVE_LIBMYSQLCLIENT_R) && defined (HAVE_MYSQL_H)
  struct apr_dbd_mysql_results_t{
    int random;
    MYSQL_RES *res;
    MYSQL_STMT *statement;
    MYSQL_BIND *bind;
  } *myres;
#endif
#if defined (HAVE_LIBSQLITE) && defined (HAVE_SQLITE_H)
  struct apr_dbd_sqlite2_results_t{
    int random;
    sqlite *handle;
    char **res;
    size_t ntuples;
    size_t sz;
    size_t index;
  } *s2res;
#endif
#if defined (HAVE_LIBSQLITE3) && defined (HAVE_SQLITE3_H)
  typedef struct{
    char *name;
    char *value;
    int size;
    int type;
  } apr_dbd_sqlite3_column_t;

  typedef struct{
    apr_dbd_results_t *res;
    apr_dbd_sqlite3_column_t **columns;
    apr_dbd_row_t *next_row;
    int columnCount;
    int rownum;
  } apr_dbd_sqlite3_row_t;

  struct apr_dbd_sqlite3_results_t{
    int random;
    sqlite3 *handle;
    sqlite3_stmt *stmt;
    apr_dbd_sqlite3_row_t *next_row;
    size_t sz;
    int tuples;
    char **col_names;
  } *s3res;
#endif
  const char *dname=apr_dbd_name(driver);

  if(!strcmp(dname,"pgsql")){
#if defined (HAVE_LIBPQ) && defined (HAVE_LIBPQ_FE_H)
    pgres=(struct apr_dbd_pgsql_results_t *)res;

    return (pgres->res?PQfname(pgres->res,col):NULL);
#endif
  } else if(!strcmp(dname,"mysql")){
#if defined (HAVE_LIBMYSQLCLIENT_R) && defined (HAVE_MYSQL_H)
    myres=(struct apr_dbd_mysql_results_t *)res;

    if((col<0) || (col>=mysql_num_fields(myres->res)))
      return NULL;

    return mysql_fetch_fields(myres->res)[col].name;
#endif
  } else if(!strcmp(dname,"sqlite2")){
#if defined (HAVE_LIBSQLITE) && defined (HAVE_SQLITE_H)
    s2res=(struct apr_dbd_sqlite2_results_t *)res;

    if((col<0) || (col>=s2res->sz))
      return NULL;

    return s2res->res[col];
#endif
  } else if(!strcmp(dname,"sqlite3")){
#if defined (HAVE_LIBSQLITE3) && defined (HAVE_SQLITE3_H)
    s3res=(struct apr_dbd_sqlite3_results_t *)res;

    if((col<0) || (col>=s3res->sz))
      return NULL;

    return s3res->next_row->columns[col]->name;
#endif
  }

  return apr_psprintf(pool,"column%d",col);
}
#endif

/* result conversion functions */
rxv_spin_data_t *rxv_spin_db_data(apr_pool_t *pool,rxv_spin_db_t *db,
                                  apr_dbd_results_t *dbdres){
  rxv_spin_data_t *result;
  apr_dbd_row_t *row=NULL;
  int i,j,cols,rows;
  rxv_spin_data_t **arrays,*array;
  const char *entry;

  if(!(pool && dbdres))
    return NULL;

  cols=apr_dbd_num_cols(db->driver,dbdres);
  rows=apr_dbd_num_tuples(db->driver,dbdres);

  result=apr_pcalloc(pool,sizeof(*result));

  /* return empty result if number of rows/columns isn't above zero */
  if(cols<=0 || rows<=0)
    return result;

  arrays=apr_palloc(pool,sizeof(*arrays)*cols);

  result->type=RXV_SPIN_DATA_RWS;
  result->size=rows;
  result->cols=apr_hash_make(pool);

  for(j=0;j<cols;j++){
#ifndef HAVE_APR_DBD_GET_NAME
    const char *cname=get_name(db->driver,pool,dbdres,j);
#else
    const char *cname=apr_dbd_get_name(db->driver,dbdres,j);
#endif

    if(!cname)
      return NULL;

    array=apr_pcalloc(pool,sizeof(*array)*rows);
    apr_hash_set(result->cols,cname,APR_HASH_KEY_STRING,*(arrays+j)=array);
  }

  for(i=0;i<rows;i++){
    if(!apr_dbd_get_row(db->driver,pool,dbdres,&row,-1)){
      for(j=0;j<cols;j++){
        rxv_spin_data_t *single=(*(arrays+j))+i;

        entry=apr_dbd_get_entry(db->driver,row,j);

        single->type=RXV_SPIN_DATA_SGL;
        if(entry){
          single->data=apr_pstrdup(pool,entry);
          single->size=strlen(entry);
        }
      }
    } else{
      return NULL;
    }
  }
  
  return result;
}

/* query related functions */
rxv_spin_data_t *rxv_spin_db_select(apr_pool_t *pool,rxv_spin_db_t *db,
                                    const char *query){
  apr_dbd_results_t *dbdres=NULL;
  rxv_spin_data_t *res;

  if(!(pool && db && query))
    return NULL;

  apr_pool_clear(db->spool);

  if(apr_dbd_select(db->driver,db->spool,db->handle,&dbdres,query,1))
    return NULL;

  res=rxv_spin_db_data(pool,db,dbdres);

  return res;
}

int rxv_spin_db_query(apr_pool_t *pool,rxv_spin_db_t *db,const char *query){
  int nrows=-1;

  if(!(pool && db && query))
    return -1;

  if(apr_dbd_query(db->driver,db->handle,&nrows,query))
    return -1;

  return nrows;
}

/* point here if there is prepared statement support, but prepare failed */
static const apr_dbd_prepared_t *badstmt=(apr_dbd_prepared_t *)"";

/* prepared statement related functions */
static apr_dbd_prepared_t *db_prepare(apr_pool_t *pool,rxv_spin_db_t *db,
                                      const char *query){
  apr_dbd_prepared_t *stmt=NULL;
  apr_pool_t *lpool=NULL;
  char *q,*ascdig;

  if(!(pool && db && query))
    return NULL;

  /* try to reuse statement from the connection */
  if(db->stmts){
    if((stmt=apr_hash_get(db->stmts,query,APR_HASH_KEY_STRING)))
      return stmt==badstmt?NULL:stmt;
  } else{
    db->stmts=apr_hash_make(db->pool);
  }

  if(!(ascdig=rxv_spin_hash(pool,query)))
    return NULL;

  q=apr_pstrdup(db->pool,query);

  /* set up a new prepared statment */
  apr_pool_create(&lpool,db->pool);

  if(apr_dbd_prepare(db->driver,lpool,
                     db->handle,query,ascdig,&stmt)==APR_SUCCESS){
    apr_hash_set(db->stmts,q,APR_HASH_KEY_STRING,stmt);
  } else{
    apr_hash_set(db->stmts,q,APR_HASH_KEY_STRING,badstmt);
    apr_pool_destroy(lpool);
  }

  return stmt;
}

rxv_spin_data_t *rxv_spin_db_pselect(apr_pool_t *pool,rxv_spin_db_t *db,
                                     const char *query,...){
  apr_dbd_prepared_t *stmt=NULL;
  apr_dbd_results_t *dbdres=NULL;
  rxv_spin_data_t *res;
  int nargs=0;
  const char **args,**p;
  va_list ap;

  /* find the number of arguments */
  va_start(ap,query);
  for(;va_arg(ap,char*);nargs++)
    ;
  va_end(ap);

  /* copy arguments to an array */
  args=apr_pcalloc(pool,sizeof(*args)*(nargs+1));

  va_start(ap,query);
  for(p=args;(*p=va_arg(ap,char*));p++)
    ;
  va_end(ap);

  if(!(stmt=db_prepare(pool,db,query)))
    return NULL;

  apr_pool_clear(db->spool);

  if(apr_dbd_pselect(db->driver,db->spool,db->handle,&dbdres,stmt,1,nargs,args))
    return NULL;

  res=rxv_spin_db_data(pool,db,dbdres);

  return res;
}

int rxv_spin_db_pquery(apr_pool_t *pool,rxv_spin_db_t *db,
                       const char *query,...){
  apr_dbd_prepared_t *stmt=NULL;
  int nrows=-1,nargs=0;
  const char **args,**p;
  va_list ap;

  /* find the number of arguments */
  va_start(ap,query);
  for(;va_arg(ap,char*);nargs++)
    ;
  va_end(ap);

  /* copy arguments to an array */
  args=apr_pcalloc(pool,sizeof(*args)*(nargs+1));

  va_start(ap,query);
  for(p=args;(*p=va_arg(ap,char*));p++)
    ;
  va_end(ap);

  if(!(stmt=db_prepare(pool,db,query)))
    return -1;
  
  if(apr_dbd_pquery(db->driver,pool,db->handle,&nrows,stmt,nargs,args))
    return -1;

  return nrows;
}

rxv_spin_db_txn_t *rxv_spin_db_start(apr_pool_t *pool,rxv_spin_db_t *db){
  rxv_spin_db_txn_t *txn;

  if(!(pool && db))
    return NULL;

  txn=apr_pcalloc(pool,sizeof(*txn));

  if(!apr_dbd_transaction_start(db->driver,pool,db->handle,&txn->txn)){
    txn->pool=pool;
    txn->db=db;
    return txn;
  }
  
  return NULL;
}

apr_status_t rxv_spin_db_end(rxv_spin_db_txn_t *txn){
  if(!txn)
    return APR_EGENERAL;

  if(!apr_dbd_transaction_end(txn->db->driver,txn->pool,txn->txn))
    return APR_SUCCESS;
  
  return APR_EGENERAL;
}

apr_status_t rxv_spin_db_status(apr_pool_t *pool,rxv_spin_db_t *db){
  if(!(pool && db))
    return APR_EGENERAL;

  return apr_dbd_check_conn(db->driver,pool,db->handle);
}