/*
 * tclStrIdxTree.h --
 *
 *	Declarations of string index tries and other primitives currently
 *  back-ported from tclSE.
 *
 * Copyright (c) 2016 Serg G. Brester (aka sebres)
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#ifndef _TCLSTRIDXTREE_H
#define _TCLSTRIDXTREE_H


/*
 * Main structures declarations of index tree and entry
 */

typedef struct TclStrIdxTree {
    struct TclStrIdx *firstPtr;
    struct TclStrIdx *lastPtr;
} TclStrIdxTree;

typedef struct TclStrIdx {
    struct TclStrIdxTree childTree;
    struct TclStrIdx *nextPtr;
    struct TclStrIdx *prevPtr;
    Tcl_Obj	*key;
    Tcl_Size length;
    void	*value;
} TclStrIdx;


/*
 *----------------------------------------------------------------------
 *
 * TclUtfFindEqual, TclUtfFindEqualNC --
 *
 *  Find largest part of string cs in string cin (case sensitive and not).
 *
 * Results:
 *  Return position of UTF character in cs after last equal character.
 *
 * Side effects:
 *  None.
 *
 *----------------------------------------------------------------------
 */

static inline const char *
TclUtfFindEqual(
    const char *cs,	/* UTF string to find in cin. */
    const char *cse,	/* End of cs */
    const char *cin,	/* UTF string will be browsed. */
    const char *cine)	/* End of cin */
{
    const char *ret = cs;
    Tcl_UniChar ch1, ch2;
    do {
	cs += TclUtfToUniChar(cs, &ch1);
	cin += TclUtfToUniChar(cin, &ch2);
	if (ch1 != ch2) break;
    } while ((ret = cs) < cse && cin < cine);
    return ret;
}

static inline const char *
TclUtfFindEqualNC(
    const char *cs,	/* UTF string to find in cin. */
    const char *cse,	/* End of cs */
    const char *cin,	/* UTF string will be browsed. */
    const char *cine,	/* End of cin */
    const char	     **cinfnd)	/* Return position in cin */
{
    const char *ret = cs;
    Tcl_UniChar ch1, ch2;
    do {
	cs += TclUtfToUniChar(cs, &ch1);
	cin += TclUtfToUniChar(cin, &ch2);
	if (ch1 != ch2) {
	    ch1 = Tcl_UniCharToLower(ch1);
	    ch2 = Tcl_UniCharToLower(ch2);
	    if (ch1 != ch2) break;
	}
	*cinfnd = cin;
    } while ((ret = cs) < cse && cin < cine);
    return ret;
}

static inline const char *
TclUtfFindEqualNCInLwr(
    const char *cs,	/* UTF string (in anycase) to find in cin. */
    const char *cse,	/* End of cs */
    const char *cin,	/* UTF string (in lowercase) will be browsed. */
    const char *cine,	/* End of cin */
    const char	     **cinfnd)	/* Return position in cin */
{
    const char *ret = cs;
    Tcl_UniChar ch1, ch2;
    do {
	cs += TclUtfToUniChar(cs, &ch1);
	cin += TclUtfToUniChar(cin, &ch2);
	if (ch1 != ch2) {
	    ch1 = Tcl_UniCharToLower(ch1);
	    if (ch1 != ch2) break;
	}
	*cinfnd = cin;
    } while ((ret = cs) < cse && cin < cine);
    return ret;
}

/*
 * Primitives to safe set, reset and free references.
 */

#define TclUnsetObjRef(obj) \
    do { \
	if (obj != NULL) { \
	    Tcl_DecrRefCount(obj); \
	    obj = NULL; \
	} \
    } while (0)
#define TclInitObjRef(obj, val) \
    do { \
	obj = val; \
	if (obj) { \
	    Tcl_IncrRefCount(obj); \
	} \
    } while (0)
#define TclSetObjRef(obj, val) \
    do { \
	Tcl_Obj *nval = val; \
	if (obj != nval) { \
	    Tcl_Obj *prev = obj; \
	    TclInitObjRef(obj, nval); \
	    if (prev != NULL) { \
		Tcl_DecrRefCount(prev); \
	    }; \
	} \
    } while (0)

/*
 * Prototypes of module functions.
 */

MODULE_SCOPE const char*
		    TclStrIdxTreeSearch(TclStrIdxTree **foundParent,
			TclStrIdx **foundItem, TclStrIdxTree *tree,
			const char *start, const char *end);

MODULE_SCOPE int    TclStrIdxTreeBuildFromList(TclStrIdxTree *idxTree,
			Tcl_Size lstc, Tcl_Obj **lstv, void **values);

MODULE_SCOPE Tcl_Obj*
		    TclStrIdxTreeNewObj();

MODULE_SCOPE TclStrIdxTree*
		    TclStrIdxTreeGetFromObj(Tcl_Obj *objPtr);

#if 0
/* currently unused, debug resp. test purposes only */
MODULE_SCOPE Tcl_ObjCmdProc TclStrIdxTreeTestObjCmd;
#endif

#endif /* _TCLSTRIDXTREE_H */