/*
** 2008 March 19
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** implements new SQL functions used by the test scripts.
**
** $Id: test_func.c,v 1.2 2008/03/19 16:35:24 drh Exp $
*/
#include "sqlite3.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>


/*
** Allocate nByte bytes of space using sqlite3_malloc(). If the
** allocation fails, call sqlite3_result_error_nomem() to notify
** the database handle that malloc() has failed.
*/
static void *testContextMalloc(sqlite3_context *context, int nByte){
  char *z = sqlite3_malloc(nByte);
  if( !z && nByte>0 ){
    sqlite3_result_error_nomem(context);
  }
  return z;
}

/*
** This function generates a string of random characters.  Used for
** generating test data.
*/
static void randStr(sqlite3_context *context, int argc, sqlite3_value **argv){
  static const unsigned char zSrc[] = 
     "abcdefghijklmnopqrstuvwxyz"
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "0123456789"
     ".-!,:*^+=_|?/<> ";
  int iMin, iMax, n, r, i;
  unsigned char zBuf[1000];

  /* It used to be possible to call randstr() with any number of arguments,
  ** but now it is registered with SQLite as requiring exactly 2.
  */
  assert(argc==2);

  iMin = sqlite3_value_int(argv[0]);
  if( iMin<0 ) iMin = 0;
  if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
  iMax = sqlite3_value_int(argv[1]);
  if( iMax<iMin ) iMax = iMin;
  if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
  n = iMin;
  if( iMax>iMin ){
    sqlite3_randomness(sizeof(r), &r);
    r &= 0x7fffffff;
    n += r%(iMax + 1 - iMin);
  }
  assert( n<sizeof(zBuf) );
  sqlite3_randomness(n, zBuf);
  for(i=0; i<n; i++){
    zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
  }
  zBuf[n] = 0;
  sqlite3_result_text(context, (char*)zBuf, n, SQLITE_TRANSIENT);
}

/*
** The following two SQL functions are used to test returning a text
** result with a destructor. Function 'test_destructor' takes one argument
** and returns the same argument interpreted as TEXT. A destructor is
** passed with the sqlite3_result_text() call.
**
** SQL function 'test_destructor_count' returns the number of outstanding 
** allocations made by 'test_destructor';
**
** WARNING: Not threadsafe.
*/
static int test_destructor_count_var = 0;
static void destructor(void *p){
  char *zVal = (char *)p;
  assert(zVal);
  zVal--;
  sqlite3_free(zVal);
  test_destructor_count_var--;
}
static void test_destructor(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  char *zVal;
  int len;
  
  test_destructor_count_var++;
  assert( nArg==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  len = sqlite3_value_bytes(argv[0]); 
  zVal = testContextMalloc(pCtx, len+3);
  if( !zVal ){
    return;
  }
  zVal[len+1] = 0;
  zVal[len+2] = 0;
  zVal++;
  memcpy(zVal, sqlite3_value_text(argv[0]), len);
  sqlite3_result_text(pCtx, zVal, -1, destructor);
}
static void test_destructor16(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  char *zVal;
  int len;
  
  test_destructor_count_var++;
  assert( nArg==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  len = sqlite3_value_bytes16(argv[0]); 
  zVal = testContextMalloc(pCtx, len+3);
  if( !zVal ){
    return;
  }
  zVal[len+1] = 0;
  zVal[len+2] = 0;
  zVal++;
  memcpy(zVal, sqlite3_value_text16(argv[0]), len);
  sqlite3_result_text16(pCtx, zVal, -1, destructor);
}
static void test_destructor_count(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  sqlite3_result_int(pCtx, test_destructor_count_var);
}

/*
** Routines for testing the sqlite3_get_auxdata() and sqlite3_set_auxdata()
** interface.
**
** The test_auxdata() SQL function attempts to register each of its arguments
** as auxiliary data.  If there are no prior registrations of aux data for
** that argument (meaning the argument is not a constant or this is its first
** call) then the result for that argument is 0.  If there is a prior
** registration, the result for that argument is 1.  The overall result
** is the individual argument results separated by spaces.
*/
static void free_test_auxdata(void *p) {sqlite3_free(p);}
static void test_auxdata(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  int i;
  char *zRet = testContextMalloc(pCtx, nArg*2);
  if( !zRet ) return;
  memset(zRet, 0, nArg*2);
  for(i=0; i<nArg; i++){
    char const *z = (char*)sqlite3_value_text(argv[i]);
    if( z ){
      int n;
      char *zAux = sqlite3_get_auxdata(pCtx, i);
      if( zAux ){
        zRet[i*2] = '1';
        assert( strcmp(zAux,z)==0 );
      }else {
        zRet[i*2] = '0';
      }
      n = strlen(z) + 1;
      zAux = testContextMalloc(pCtx, n);
      if( zAux ){
        memcpy(zAux, z, n);
        sqlite3_set_auxdata(pCtx, i, zAux, free_test_auxdata);
      }
      zRet[i*2+1] = ' ';
    }
  }
  sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
}

/*
** A function to test error reporting from user functions. This function
** returns a copy of its first argument as an error.
*/
static void test_error(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  sqlite3_result_error(pCtx, (char*)sqlite3_value_text(argv[0]), 0);
}

static int registerTestFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     unsigned char eTextRep; /* 1: UTF-16.  0: UTF-8 */
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
  } aFuncs[] = {
    { "randstr",               2, SQLITE_UTF8, randStr    },
    { "test_destructor",       1, SQLITE_UTF8, test_destructor},
    { "test_destructor16",     1, SQLITE_UTF8, test_destructor16},
    { "test_destructor_count", 0, SQLITE_UTF8, test_destructor_count},
    { "test_auxdata",         -1, SQLITE_UTF8, test_auxdata},
    { "test_error",            1, SQLITE_UTF8, test_error},
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }
  return SQLITE_OK;
}

/*
** TCLCMD:  autoinstall_test_functions
**
** Invoke this TCL command to use sqlite3_auto_extension() to cause
** the standard set of test functions to be loaded into each new
** database connection.
*/
static int autoinstall_test_funcs(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_auto_extension((void*)registerTestFunctions);
  return TCL_OK;
}



/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest_func_Init(Tcl_Interp *interp){
  static struct {
     char *zName;
     Tcl_ObjCmdProc *xProc;
  } aObjCmd[] = {
     { "autoinstall_test_functions",    autoinstall_test_funcs },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
  }
  sqlite3_auto_extension((void*)registerTestFunctions);
  return TCL_OK;
}