/**
 * @file sqlite3odbc.c
 * SQLite3 ODBC Driver main module.
 *
 * $Id: sqlite3odbc.c,v 1.81 2008/09/13 06:22:13 chw Exp chw $
 *
 * Copyright (c) 2004-2008 Christian Werner <chw@ch-werner.de>
 *
 * See the file "license.terms" for information on usage
 * and redistribution of this file and for a
 * DISCLAIMER OF ALL WARRANTIES.
 */

#include "sqlite3odbc.h"

#ifndef WITHOUT_WINTERFACE
#define WINTERFACE
#endif

#ifdef WINTERFACE
#include <sqlucode.h>
#endif

#ifdef _WIN32
#include "resource3.h"
#define ODBC_INI "ODBC.INI"
#else
#define ODBC_INI ".odbc.ini"
#endif

#ifndef DRIVER_VER_INFO
#define DRIVER_VER_INFO "0.0"
#endif

#ifndef COLATTRIBUTE_LAST_ARG_TYPE
#define COLATTRIBUTE_LAST_ARG_TYPE SQLPOINTER
#endif

#undef min
#define min(a, b) ((a) < (b) ? (a) : (b))
#undef max
#define max(a, b) ((a) < (b) ? (b) : (a))

#ifndef PTRDIFF_T
#define PTRDIFF_T int
#endif

#define array_size(x) (sizeof (x) / sizeof (x[0]))

#define stringify1(s) #s
#define stringify(s) stringify1(s)

#define verinfo(maj, min, lev) ((maj) << 16 | (min) << 8 | (lev))

/* Column types for static string column descriptions (SQLTables etc.) */

#if defined(WINTERFACE) && !defined(_WIN32)
#define SCOL_VARCHAR SQL_WVARCHAR
#define SCOL_CHAR SQL_WCHAR
#else
#define SCOL_VARCHAR SQL_VARCHAR
#define SCOL_CHAR SQL_CHAR
#endif

#define ENV_MAGIC  0x53544145
#define DBC_MAGIC  0x53544144
#define DEAD_MAGIC 0xdeadbeef

static const char *xdigits = "0123456789ABCDEFabcdef";

#ifdef MEMORY_DEBUG

static void *
xmalloc_(int n, char *file, int line)
{
    int nn = n + 4 * sizeof (long);
    long *p;

    p = malloc(nn);
    if (!p) {
#if (MEMORY_DEBUG > 1)
	fprintf(stderr, "malloc\t%d\tNULL\t%s:%d\n", n, file, line);
#endif
	return NULL;
    }
    p[0] = 0xdead1234;
    nn = nn / sizeof (long) - 1;
    p[1] = n;
    p[nn] = 0xdead5678;
#if (MEMORY_DEBUG > 1)
    fprintf(stderr, "malloc\t%d\t%p\t%s:%d\n", n, &p[2], file, line);
#endif
    return (void *) &p[2];
}

static void *
xrealloc_(void *old, int n, char *file, int line)
{
    int nn = n + 4 * sizeof (long), nnn;
    long *p, *pp;

    if (n == 0 || !old) {
	return xmalloc_(n, file, line);
    }
    p = &((long *) old)[-2];
    if (p[0] != 0xdead1234) {
	fprintf(stderr, "*** low end corruption @ %p\n", old);
	abort();
    }
    nnn = p[1] + 4 * sizeof (long);
    nnn = nnn / sizeof (long) - 1;
    if (p[nnn] != 0xdead5678) {
	fprintf(stderr, "*** high end corruption @ %p\n", old);
	abort();
    }
    pp = realloc(p, nn);
    if (!pp) {
#if (MEMORY_DEBUG > 1)
	fprintf(stderr, "realloc\t%p,%d\tNULL\t%s:%d\n", old, n, file, line);
#endif
	return NULL;
    }
#if (MEMORY_DEBUG > 1)
    fprintf(stderr, "realloc\t%p,%d\t%p\t%s:%d\n", old, n, &pp[2], file, line);
#endif
    p = pp;
    p[1] = n;
    nn = nn / sizeof (long) - 1;
    p[nn] = 0xdead5678;
    return (void *) &p[2];
}

static void
xfree_(void *x, char *file, int line)
{
    long *p;
    int n;

    if (!x) {
	return;
    }
    p = &((long *) x)[-2];
    if (p[0] != 0xdead1234) {
	fprintf(stderr, "*** low end corruption @ %p\n", x);
	abort();
    }
    n = p[1] + 4 * sizeof (long);
    n = n / sizeof (long) - 1;
    if (p[n] != 0xdead5678) {
	fprintf(stderr, "*** high end corruption @ %p\n", x);
	abort();
    }
#if (MEMORY_DEBUG > 1)
    fprintf(stderr, "free\t%p\t\t%s:%d\n", x, file, line);
#endif
    free(p);
}

static void
xfree__(void *x)
{
    xfree_(x, "unknown location", 0);
}

static char *
xstrdup_(const char *str, char *file, int line)
{
    char *p;

    if (!str) {
#if (MEMORY_DEBUG > 1)
	fprintf(stderr, "strdup\tNULL\tNULL\t%s:%d\n", file, line);
#endif
	return NULL;
    }
    p = xmalloc_(strlen(str) + 1, file, line);
    if (p) {
	strcpy(p, str);
    }
#if (MEMORY_DEBUG > 1)
    fprintf(stderr, "strdup\t%p\t%p\t%s:%d\n", str, p, file, line);
#endif
    return p;
}

#define xmalloc(x)    xmalloc_(x, __FILE__, __LINE__)
#define xrealloc(x,y) xrealloc_(x, y, __FILE__, __LINE__)
#define xfree(x)      xfree_(x, __FILE__, __LINE__)
#define xstrdup(x)    xstrdup_(x, __FILE__, __LINE__)

#else

#define xmalloc(x)    malloc(x)
#define xrealloc(x,y) realloc(x, y)
#define xfree(x)      free(x)
#define xstrdup(x)    strdup_(x)

#endif

#ifdef _WIN32

#define vsnprintf   _vsnprintf
#define snprintf    _snprintf
#define strcasecmp  _stricmp
#define strncasecmp _strnicmp

static HINSTANCE NEAR hModule;	/* Saved module handle for resources */

#endif

#ifdef _WIN32

/*
 * SQLHENV, SQLHDBC, and SQLHSTMT synchronization
 * is done using a critical section in ENV structure.
 */

#define HDBC_LOCK(hdbc)				\
{						\
    DBC *d;					\
						\
    if ((hdbc) == SQL_NULL_HDBC) {		\
	return SQL_INVALID_HANDLE;		\
    }						\
    d = (DBC *) (hdbc);				\
    if (d->magic != DBC_MAGIC || !d->env) {	\
	return SQL_INVALID_HANDLE;		\
    }						\
    if (d->env->magic != ENV_MAGIC) {		\
	return SQL_INVALID_HANDLE;		\
    }						\
    EnterCriticalSection(&d->env->cs);		\
    d->env->owner = GetCurrentThreadId();	\
}

#define HDBC_UNLOCK(hdbc)			\
    if ((hdbc) != SQL_NULL_HDBC) {		\
	DBC *d;					\
						\
	d = (DBC *) (hdbc);			\
	if (d->magic == DBC_MAGIC && d->env &&	\
	    d->env->magic == ENV_MAGIC) {	\
	    d->env->owner = 0;			\
	    LeaveCriticalSection(&d->env->cs);	\
	}					\
    }

#define HSTMT_LOCK(hstmt)			\
{						\
    DBC *d;					\
						\
    if ((hstmt) == SQL_NULL_HSTMT) {		\
	return SQL_INVALID_HANDLE;		\
    }						\
    d = (DBC *) ((STMT *) (hstmt))->dbc;	\
    if (d->magic != DBC_MAGIC || !d->env) {	\
	return SQL_INVALID_HANDLE;		\
    }						\
    if (d->env->magic != ENV_MAGIC) {		\
	return SQL_INVALID_HANDLE;		\
    }						\
    EnterCriticalSection(&d->env->cs);		\
    d->env->owner = GetCurrentThreadId();	\
}

#define HSTMT_UNLOCK(hstmt)			\
    if ((hstmt) != SQL_NULL_HSTMT) {		\
	DBC *d;					\
						\
	d = (DBC *) ((STMT *) (hstmt))->dbc;	\
	if (d->magic == DBC_MAGIC && d->env &&	\
	    d->env->magic == ENV_MAGIC) {	\
	    d->env->owner = 0;			\
	    LeaveCriticalSection(&d->env->cs);	\
	}					\
    }

#else

/*
 * On UN*X assume that we are single-threaded or
 * the driver manager provides serialization for us.
 *
 * In iODBC (3.52.x) serialization can be turned
 * on using the DSN property "ThreadManager=yes".
 *
 * In unixODBC that property is named
 * "Threading=0-3" and takes one of these values:
 *
 *   0 - no protection
 *   1 - statement level protection
 *   2 - connection level protection
 *   3 - environment level protection
 *
 * unixODBC 2.2.11 uses environment level protection
 * by default when it has been built with pthread
 * support.
 */

#define HDBC_LOCK(hdbc)
#define HDBC_UNLOCK(hdbc)
#define HSTMT_LOCK(hdbc)
#define HSTMT_UNLOCK(hdbc)

#endif

#if defined(ENABLE_NVFS) && ENABLE_NVFS
extern void nvfs_init(void);
extern const char *nvfs_makevfs(const char *);
#endif

/*
 * tolower() replacement w/o locale
 */

static const char upper_chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
static const char lower_chars[] = "abcdefghijklmnopqrstuvwxyz";

static int
TOLOWER(int c)
{
    if (c) {
	char *p = strchr(upper_chars, c);

	if (p) {
	    c = lower_chars[p - upper_chars];
	}
    }
    return c;
}

/*
 * isdigit() replacement w/o ctype.h
 */

static const char digit_chars[] = "0123456789";

#define ISDIGIT(c) \
    ((c) && strchr(digit_chars, (c)) != NULL)

/*
 * isspace() replacement w/o ctype.h
 */

static const char space_chars[] = " \f\n\r\t\v";

#define ISSPACE(c) \
    ((c) && strchr(space_chars, (c)) != NULL)


/*
 * Forward declarations of static functions.
 */

static void dbtraceapi(DBC *d, char *fn, const char *sql);
static void freedyncols(STMT *s);
static void freeresult(STMT *s, int clrcols);
static void freerows(char **rowp);
static void unbindcols(STMT *s);

static SQLRETURN drvexecute(SQLHSTMT stmt, int initial);
static SQLRETURN freestmt(HSTMT stmt);
static SQLRETURN mkbindcols(STMT *s, int ncols);
static SQLRETURN setupdyncols(STMT *s, sqlite3_stmt *s3stmt, int *ncolsp);
static SQLRETURN setupparbuf(STMT *s, BINDPARM *p);
static SQLRETURN starttran(STMT *s);
static SQLRETURN setupparam(STMT *s, char *sql, int pnum);

#if defined(_WIN32) && defined(WINTERFACE)
/* MS Access hack part 1 (reserved error -7748) */
static COL statSpec[13];
#endif

#if (MEMORY_DEBUG < 1)
/**
 * Duplicate string using xmalloc().
 * @param str string to be duplicated
 * @result pointer to new string or NULL
 */

static char *
strdup_(const char *str)
{
    char *p = NULL;

    if (str) {
	p = xmalloc(strlen(str) + 1);
	if (p) {
	    strcpy(p, str);
	}
    }
    return p;
}
#endif

#ifdef WINTERFACE

/**
 * Return length of UNICODE string.
 * @param str UNICODE string
 * @result length of string
 */

static int
uc_strlen(SQLWCHAR *str)
{
    int len = 0;

    if (str) {
	while (*str) {
	    ++len;
	    ++str;
	}
    }
    return len;
}

/**
 * Copy UNICODE string like strncpy().
 * @param dest destination area
 * @param src source area
 * @param len length of source area
 * @return pointer to destination area
 */

static SQLWCHAR *
uc_strncpy(SQLWCHAR *dest, SQLWCHAR *src, int len)
{
    int i = 0;

    while (i < len) {
	if (!src[i]) {
	    break;
	}
	dest[i] = src[i];
	++i;
    }
    if (i < len) {
	dest[i] = 0;
    }
    return dest;
}

/**
 * Make UNICODE string from UTF8 string into buffer.
 * @param str UTF8 string to be converted
 * @param uc destination area to receive UNICODE string
 * @param ucLen byte length of destination area
 */

static void
uc_from_utf_buf(unsigned char *str, SQLWCHAR *uc, int ucLen)
{
    ucLen = ucLen / sizeof (SQLWCHAR);
    if (!uc || ucLen < 0) {
	return;
    }
    uc[0] = 0;
    if (str) {
	int i = 0;

	while (*str && i < ucLen) {
	    unsigned char c = str[0];

	    if (c < 0xc0) {
		uc[i++] = c;
		++str;
	    } else if (c < 0xe0) {
		if ((str[1] & 0xc0) == 0x80) {
		    unsigned long t = ((c & 0x1f) << 6) | (str[1] & 0x3f);

		    uc[i++] = t;
		    str += 2;
		} else {
		    uc[i++] = c;
		    ++str;
		}
	    } else if (c < 0xf0) {
		if ((str[1] & 0xc0) == 0x80 && (str[2] & 0xc0) == 0x80) {
		    unsigned long t = ((c & 0x0f) << 12) |
			((str[1] & 0x3f) << 6) | (str[2] & 0x3f);

		    uc[i++] = t;
		    str += 3;
		} else {
		    uc[i++] = c;
		    ++str;
		}
	    } else if (c < 0xf8) {
		if ((str[1] & 0xc0) == 0x80 && (str[2] & 0xc0) == 0x80 &&
		    (str[3] & 0xc0) == 0x80) {
		    unsigned long t = ((c & 0x03) << 18) |
			((str[1] & 0x3f) << 12) | ((str[2] & 0x3f) << 6) |
			(str[4] & 0x3f);

		    if (sizeof (SQLWCHAR) == 2 * sizeof (char) &&
			t >= 0x10000) {
			t -= 0x10000;
			uc[i++] = 0xd800 | (t & 0x3ff);
			if (i >= ucLen) {
			    break;
			}
			t = 0xdc00 | ((t >> 10) & 0x3ff);
		    }
		    uc[i++] = t;
		    str += 4;
		} else {
		    uc[i++] = c;
		    ++str;
		}
	    } else if (c < 0xfc) {
		if ((str[1] & 0xc0) == 0x80 && (str[2] & 0xc0) == 0x80 &&
		    (str[3] & 0xc0) == 0x80 && (str[4] & 0xc0) == 0x80) {
		    unsigned long t = ((c & 0x01) << 24) |
			((str[1] & 0x3f) << 18) | ((str[2] & 0x3f) << 12) |
			((str[4] & 0x3f) << 6) | (str[5] & 0x3f);

		    if (sizeof (SQLWCHAR) == 2 * sizeof (char) &&
			t >= 0x10000) {
			t -= 0x10000;
			uc[i++] = 0xd800 | (t & 0x3ff);
			if (i >= ucLen) {
			    break;
			}
			t = 0xdc00 | ((t >> 10) & 0x3ff);
		    }
		    uc[i++] = t;
		    str += 5;
		} else {
		    uc[i++] = c;
		    ++str;
		}
	    } else {
		/* ignore */
		++str;
	    }
	}
	if (i < ucLen) {
	    uc[i] = 0;
	}
    }
}

/**
 * Make UNICODE string from UTF8 string.
 * @param str UTF8 string to be converted
 * @param len length of UTF8 string
 * @return alloc'ed UNICODE string to be free'd by uc_free()
 */

static SQLWCHAR *
uc_from_utf(unsigned char *str, int len)
{
    SQLWCHAR *uc = NULL;

    if (str) {
	if (len == SQL_NTS) {
	    len = strlen((char *) str);
	}
	len = sizeof (SQLWCHAR) * (len + 1);
	uc = xmalloc(len);
	if (uc) {
	    uc_from_utf_buf(str, uc, len);
	}
    }
    return uc;
}

/**
 * Make UTF8 string from UNICODE string.
 * @param str UNICODE string to be converted
 * @param len length of UNICODE string in bytes
 * @return alloc'ed UTF8 string to be free'd by uc_free()
 */

static char *
uc_to_utf(SQLWCHAR *str, int len)
{
    int i;
    char *cp, *ret = NULL;

    if (!str) {
	return ret;
    }
    if (len == SQL_NTS) {
	len = uc_strlen(str);
    } else {
	len = len / sizeof (SQLWCHAR);
    }
    cp = xmalloc(len * 6 + 1);
    if (!cp) {
	return ret;
    }