/*
** 2009 November 10
**
** 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.
**
*************************************************************************
**
** This file implements a read-only VIRTUAL TABLE that contains the
** content of a C-language array of integer values. See the corresponding
** header file for full details.
**
** This virtual table is used for internal testing of SQLite only. It is
** not recommended for use in production. For a similar virtual table that
** is production-ready, see the "carray" virtual table over in ext/misc.
*/
#include "test_intarray.h"
#include <string.h>
#include <assert.h>


/*
** Definition of the sqlite3_intarray object.
**
** The internal representation of an intarray object is subject
** to change, is not externally visible, and should be used by
** the implementation of intarray only. This object is opaque
** to users.
*/
struct sqlite3_intarray {
 int n; /* Number of elements in the array */
 sqlite3_int64 *a; /* Contents of the array */
 void (*xFree)(void*); /* Function used to free a[] */
};

/* Objects used internally by the virtual table implementation */
typedef struct intarray_vtab intarray_vtab;
typedef struct intarray_cursor intarray_cursor;

/* An intarray table object */
struct intarray_vtab {
 sqlite3_vtab base; /* Base class */
 sqlite3_intarray *pContent; /* Content of the integer array */
};

/* An intarray cursor object */
struct intarray_cursor {
 sqlite3_vtab_cursor base; /* Base class */
 int i; /* Current cursor position */
};

/*
** None of this works unless we have virtual tables.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Free an sqlite3_intarray object.
*/
static void intarrayFree(sqlite3_intarray *p){
 if( p->xFree ){
 p->xFree(p->a);
 }
 sqlite3_free(p);
}

/*
** Table destructor for the intarray module.
*/
static int intarrayDestroy(sqlite3_vtab *p){
 intarray_vtab *pVtab = (intarray_vtab*)p;
 sqlite3_free(pVtab);
 return 0;
}

/*
** Table constructor for the intarray module.
*/
static int intarrayCreate(
 sqlite3 *db, /* Database where module is created */
 void *pAux, /* clientdata for the module */
 int argc, /* Number of arguments */
 const char *const*argv, /* Value for all arguments */
 sqlite3_vtab **ppVtab, /* Write the new virtual table object here */
 char **pzErr /* Put error message text here */
){
 int rc = SQLITE_NOMEM;
 intarray_vtab *pVtab = sqlite3_malloc64(sizeof(intarray_vtab));

 if( pVtab ){
 memset(pVtab, 0, sizeof(intarray_vtab));
 pVtab->pContent = (sqlite3_intarray*)pAux;
 rc = sqlite3_declare_vtab(db, "CREATE TABLE x(value INTEGER PRIMARY KEY)");
 }
 *ppVtab = (sqlite3_vtab *)pVtab;
 return rc;
}

/*
** Open a new cursor on the intarray table.
*/
static int intarrayOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
 int rc = SQLITE_NOMEM;
 intarray_cursor *pCur;
 pCur = sqlite3_malloc64(sizeof(intarray_cursor));
 if( pCur ){
 memset(pCur, 0, sizeof(intarray_cursor));
 *ppCursor = (sqlite3_vtab_cursor *)pCur;
 rc = SQLITE_OK;
 }
 return rc;
}

/*
** Close a intarray table cursor.
*/
static int intarrayClose(sqlite3_vtab_cursor *cur){
 intarray_cursor *pCur = (intarray_cursor *)cur;
 sqlite3_free(pCur);
 return SQLITE_OK;
}

/*
** Retrieve a column of data.
*/
static int intarrayColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
 intarray_cursor *pCur = (intarray_cursor*)cur;
 intarray_vtab *pVtab = (intarray_vtab*)cur->pVtab;
 if( pCur->i>=0 && pCur->i<pVtab->pContent->n ){
 sqlite3_result_int64(ctx, pVtab->pContent->a[pCur->i]);
 }
 return SQLITE_OK;
}

/*
** Retrieve the current rowid.
*/
static int intarrayRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
 intarray_cursor *pCur = (intarray_cursor *)cur;
 *pRowid = pCur->i;
 return SQLITE_OK;
}

static int intarrayEof(sqlite3_vtab_cursor *cur){
 intarray_cursor *pCur = (intarray_cursor *)cur;
 intarray_vtab *pVtab = (intarray_vtab *)cur->pVtab;
 return pCur->i>=pVtab->pContent->n;
}

/*
** Advance the cursor to the next row.
*/
static int intarrayNext(sqlite3_vtab_cursor *cur){
 intarray_cursor *pCur = (intarray_cursor *)cur;
 pCur->i++;
 return SQLITE_OK;
}

/*
** Reset a intarray table cursor.
*/
static int intarrayFilter(
 sqlite3_vtab_cursor *pVtabCursor, 
 int idxNum, const char *idxStr,
 int argc, sqlite3_value **argv
){
 intarray_cursor *pCur = (intarray_cursor *)pVtabCursor;
 pCur->i = 0;
 return SQLITE_OK;
}

/*
** Analyse the WHERE condition.
*/
static int intarrayBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
 return SQLITE_OK;
}

/*
** A virtual table module that merely echos method calls into TCL
** variables.
*/
static sqlite3_module intarrayModule = {
 0, /* iVersion */
 intarrayCreate, /* xCreate - create a new virtual table */
 intarrayCreate, /* xConnect - connect to an existing vtab */
 intarrayBestIndex, /* xBestIndex - find the best query index */
 intarrayDestroy, /* xDisconnect - disconnect a vtab */
 intarrayDestroy, /* xDestroy - destroy a vtab */
 intarrayOpen, /* xOpen - open a cursor */
 intarrayClose, /* xClose - close a cursor */
 intarrayFilter, /* xFilter - configure scan constraints */
 intarrayNext, /* xNext - advance a cursor */
 intarrayEof, /* xEof */
 intarrayColumn, /* xColumn - read data */
 intarrayRowid, /* xRowid - read data */
 0, /* xUpdate */
 0, /* xBegin */
 0, /* xSync */
 0, /* xCommit */
 0, /* xRollback */
 0, /* xFindMethod */
 0, /* xRename */
 0, /* xSavepoint */
 0, /* xRelease */
 0, /* xRollbackTo */
 0, /* xShadowName */
 0 /* xIntegrity */
};

#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */

/*
** Invoke this routine to create a specific instance of an intarray object.
** The new intarray object is returned by the 3rd parameter.
**
** Each intarray object corresponds to a virtual table in the TEMP table
** with a name of zName.
**
** Destroy the intarray object by dropping the virtual table. If not done
** explicitly by the application, the virtual table will be dropped implicitly
** by the system when the database connection is closed.
*/
SQLITE_API int sqlite3_intarray_create(
 sqlite3 *db,
 const char *zName,
 sqlite3_intarray **ppReturn
){
 int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_VIRTUALTABLE
 sqlite3_intarray *p;

 *ppReturn = p = sqlite3_malloc64( sizeof(*p) );
 if( p==0 ){
 return SQLITE_NOMEM;
 }
 memset(p, 0, sizeof(*p));
 rc = sqlite3_create_module_v2(db, zName, &intarrayModule, p,
 (void(*)(void*))intarrayFree);
 if( rc==SQLITE_OK ){
 char *zSql;
 zSql = sqlite3_mprintf("CREATE VIRTUAL TABLE temp.%Q USING %Q",
 zName, zName);
 rc = sqlite3_exec(db, zSql, 0, 0, 0);
 sqlite3_free(zSql);
 }
#endif
 return rc;
}

/*
** Bind a new array array of integers to a specific intarray object.
**
** The array of integers bound must be unchanged for the duration of
** any query against the corresponding virtual table. If the integer
** array does change or is deallocated undefined behavior will result.
*/
SQLITE_API int sqlite3_intarray_bind(
 sqlite3_intarray *pIntArray, /* The intarray object to bind to */
 int nElements, /* Number of elements in the intarray */
 sqlite3_int64 *aElements, /* Content of the intarray */
 void (*xFree)(void*) /* How to dispose of the intarray when done */
){
 if( pIntArray->xFree ){
 pIntArray->xFree(pIntArray->a);
 }
 pIntArray->n = nElements;
 pIntArray->a = aElements;
 pIntArray->xFree = xFree;
 return SQLITE_OK;
}


/*****************************************************************************
** Everything below is interface for testing this module.
*/
#ifdef SQLITE_TEST
#if defined(INCLUDE_SQLITE_TCL_H)
# include "sqlite_tcl.h"
#else
# include "tcl.h"
# ifndef SQLITE_TCLAPI
# define SQLITE_TCLAPI
# endif
#endif

/*
** Routines to encode and decode pointers
*/
extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
extern void *sqlite3TestTextToPtr(const char*);
extern int sqlite3TestMakePointerStr(Tcl_Interp*, char *zPtr, void*);
extern const char *sqlite3ErrName(int);

/*
** sqlite3_intarray_create DB NAME
**
** Invoke the sqlite3_intarray_create interface. A string that becomes
** the first parameter to sqlite3_intarray_bind.
*/
static int SQLITE_TCLAPI test_intarray_create(
 ClientData clientData, /* Not used */
 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */
 int objc, /* Number of arguments */
 Tcl_Obj *CONST objv[] /* Command arguments */
){
 sqlite3 *db;
 const char *zName;
 sqlite3_intarray *pArray;
 int rc = SQLITE_OK;
 char zPtr[100];

 if( objc!=3 ){
 Tcl_WrongNumArgs(interp, 1, objv, "DB");
 return TCL_ERROR;
 }
 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
 zName = Tcl_GetString(objv[2]);
#ifndef SQLITE_OMIT_VIRTUALTABLE
 rc = sqlite3_intarray_create(db, zName, &pArray);
#endif
 if( rc!=SQLITE_OK ){
 Tcl_AppendResult(interp, sqlite3ErrName(rc), (char*)0);
 return TCL_ERROR;
 }
 sqlite3TestMakePointerStr(interp, zPtr, pArray);
 Tcl_AppendResult(interp, zPtr, (char*)0);
 return TCL_OK;
}

/*
** sqlite3_intarray_bind INTARRAY ?VALUE ...?
**
** Invoke the sqlite3_intarray_bind interface on the given array of integers.
*/
static int SQLITE_TCLAPI test_intarray_bind(
 ClientData clientData, /* Not used */
 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */
 int objc, /* Number of arguments */
 Tcl_Obj *CONST objv[] /* Command arguments */
){
 sqlite3_intarray *pArray;
 int rc = SQLITE_OK;
 int i, n;
 sqlite3_int64 *a;

 if( objc<2 ){
 Tcl_WrongNumArgs(interp, 1, objv, "INTARRAY");
 return TCL_ERROR;
 }
 pArray = (sqlite3_intarray*)sqlite3TestTextToPtr(Tcl_GetString(objv[1]));
 n = objc - 2;
#ifndef SQLITE_OMIT_VIRTUALTABLE
 a = sqlite3_malloc64( sizeof(a[0])*n );
 if( a==0 ){
 Tcl_AppendResult(interp, "SQLITE_NOMEM", (char*)0);
 return TCL_ERROR;
 }
 for(i=0; i<n; i++){
 Tcl_WideInt x = 0;
 Tcl_GetWideIntFromObj(0, objv[i+2], &x);
 a[i] = x;
 }
 rc = sqlite3_intarray_bind(pArray, n, a, sqlite3_free);
 if( rc!=SQLITE_OK ){
 Tcl_AppendResult(interp, sqlite3ErrName(rc), (char*)0);
 return TCL_ERROR;
 }
#endif
 return TCL_OK;
}

/*
** Register commands with the TCL interpreter.
*/
int Sqlitetestintarray_Init(Tcl_Interp *interp){
 static struct {
 char *zName;
 Tcl_ObjCmdProc *xProc;
 void *clientData;
 } aObjCmd[] = {
 { "sqlite3_intarray_create", test_intarray_create, 0 },
 { "sqlite3_intarray_bind", test_intarray_bind, 0 },
 };
 int i;
 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
 aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
 }
 return TCL_OK;
}

#endif /* SQLITE_TEST */