/*
** 2016 September 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 contains test code to delete an SQLite database and all
** of its associated files. Associated files include:
**
** * The journal file.
** * The wal file.
** * The SQLITE_ENABLE_8_3_NAMES version of the db, journal or wal files.
** * Files created by the test_multiplex.c module to extend any of the 
** above.
*/

#ifndef SQLITE_OS_WIN
# include <unistd.h>
# include <errno.h>
#endif
#include <string.h>
#include <assert.h>
#include "sqlite3.h"

/* The following #defines are copied from test_multiplex.c */
#ifndef MX_CHUNK_NUMBER 
# define MX_CHUNK_NUMBER 299
#endif
#ifndef SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET
# define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400
#endif
#ifndef SQLITE_MULTIPLEX_WAL_8_3_OFFSET
# define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 700
#endif

/*
** This routine is a copy of (most of) the code from SQLite function
** sqlite3FileSuffix3(). It modifies the filename in buffer z in the
** same way as SQLite does when in 8.3 filenames mode.
*/
static void sqlite3Delete83Name(char *z){
 int i, sz;
 sz = (int)strlen(z);
 for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
 if( z[i]=='.' && (sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);
}

/*
** zFile is a filename. Assuming no error occurs, if this file exists, 
** set *pbExists to true and unlink it. Or, if the file does not exist,
** set *pbExists to false before returning.
**
** If an error occurs, non-zero is returned. Or, if no error occurs, zero.
*/
static int sqlite3DeleteUnlinkIfExists(
 sqlite3_vfs *pVfs,
 const char *zFile, 
 int *pbExists
){
 int rc = SQLITE_ERROR;
#if SQLITE_OS_WIN
 if( pVfs ){
 if( pbExists ) *pbExists = 1;
 rc = pVfs->xDelete(pVfs, zFile, 0);
 if( rc==SQLITE_IOERR_DELETE_NOENT ){
 if( pbExists ) *pbExists = 0;
 rc = SQLITE_OK;
 }
 }
#else
 assert( pVfs==0 );
 rc = access(zFile, F_OK);
 if( rc ){
 if( errno==ENOENT ){ 
 if( pbExists ) *pbExists = 0;
 rc = SQLITE_OK; 
 }
 }else{
 if( pbExists ) *pbExists = 1;
 rc = unlink(zFile);
 }
#endif
 return rc;
}

/*
** Delete the database file identified by the string argument passed to this
** function. The string must contain a filename, not an SQLite URI.
*/
SQLITE_API int sqlite3_delete_database(
 const char *zFile /* File to delete */
){
 char *zBuf; /* Buffer to sprintf() filenames to */
 int nBuf; /* Size of buffer in bytes */
 int rc = 0; /* System error code */
 int i; /* Iterate through azFmt[] and aMFile[] */

 const char *azFmt[] = { "%s", "%s-journal", "%s-wal", "%s-shm" };

 struct MFile {
 const char *zFmt;
 int iOffset;
 int b83;
 } aMFile[] = {
 { "%s%03d", 0, 0 },
 { "%s-journal%03d", 0, 0 },
 { "%s-wal%03d", 0, 0 },
 { "%s%03d", 0, 1 },
 { "%s-journal%03d", SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET, 1 },
 { "%s-wal%03d", SQLITE_MULTIPLEX_WAL_8_3_OFFSET, 1 },
 };

#ifdef SQLITE_OS_WIN
 sqlite3_vfs *pVfs = sqlite3_vfs_find("win32");
#else
 sqlite3_vfs *pVfs = 0;
#endif

 /* Allocate a buffer large enough for any of the files that need to be
 ** deleted. */
 nBuf = (int)strlen(zFile) + 100;
 zBuf = (char*)sqlite3_malloc(nBuf);
 if( zBuf==0 ) return SQLITE_NOMEM;

 /* Delete both the regular and 8.3 filenames versions of the database,
 ** journal, wal and shm files. */
 for(i=0; rc==0 && i<sizeof(azFmt)/sizeof(azFmt[0]); i++){
 sqlite3_snprintf(nBuf, zBuf, azFmt[i], zFile);
 rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, 0);
 if( rc==0 && i!=0 ){
 sqlite3Delete83Name(zBuf);
 rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, 0);
 }
 }

 /* Delete any multiplexor files */
 for(i=0; rc==0 && i<sizeof(aMFile)/sizeof(aMFile[0]); i++){
 struct MFile *p = &aMFile[i];
 int iChunk;
 for(iChunk=1; iChunk<=MX_CHUNK_NUMBER; iChunk++){
 int bExists;
 sqlite3_snprintf(nBuf, zBuf, p->zFmt, zFile, iChunk+p->iOffset);
 if( p->b83 ) sqlite3Delete83Name(zBuf);
 rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, &bExists);
 if( bExists==0 || rc!=0 ) break;
 }
 }

 sqlite3_free(zBuf);
 return (rc ? SQLITE_ERROR : SQLITE_OK);
}