/*
*******************************************************************************
*
*   Copyright (C) 2002, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
*******************************************************************************
*   file name:  uset.c
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2002mar07
*   created by: Markus W. Scherer
*
*   The serialized structure, the array of range limits, is
*   the same as in UnicodeSet, except that the HIGH value is not stored.
*
*   There are functions to efficiently serialize a USet into an array of uint16_t
*   and functions to use such a serialized form efficiently without
*   instantiating a new USet.
*/

#include "unicode/utypes.h"
#include "cmemory.h"
#include "unicode/uset.h"
#include "unicode/uniset.h"

#define USET_STATIC_CAPACITY 12
#define USET_GROW_DELTA 20

U_CAPI USet * U_EXPORT2
uset_open(UChar32 start, UChar32 end) {
    return (USet*) new UnicodeSet(start, end);
}

U_CAPI void U_EXPORT2
uset_close(USet *set) {
    delete (UnicodeSet*) set;
}

U_CAPI void U_EXPORT2
uset_add(USet *set, UChar32 c) {
    ((UnicodeSet*) set)->add(c);
}

U_CAPI void U_EXPORT2
uset_remove(USet *set, UChar32 c) {
    ((UnicodeSet*) set)->remove(c);
}

U_CAPI UBool U_EXPORT2
uset_isEmpty(const USet *set) {
    return ((const UnicodeSet*) set)->isEmpty();
}

U_CAPI UBool U_EXPORT2
uset_contains(const USet *set, UChar32 c) {
    return ((const UnicodeSet*) set)->contains(c);
}

U_CAPI int32_t U_EXPORT2
uset_size(const USet* set) {
    return ((const UnicodeSet*) set)->size();
}

U_CAPI int32_t U_EXPORT2
uset_getRangeCount(const USet *set) {
    return ((const UnicodeSet*) set)->getRangeCount();
}

U_CAPI UBool U_EXPORT2
uset_getRange(const USet *set, int32_t rangeIndex,
              UChar32 *pStart, UChar32 *pEnd) {
    if ((uint32_t) rangeIndex >= (uint32_t) uset_getRangeCount(set)) {
        return FALSE;
    }
    const UnicodeSet* us = (const UnicodeSet*) set;
    *pStart = us->getRangeStart(rangeIndex);
    *pEnd = us->getRangeEnd(rangeIndex);
    return TRUE;
}

/*
 * Serialize a USet into 16-bit units.
 * Store BMP code points as themselves with one 16-bit unit each.
 *
 * Important: the code points in the array are in ascending order,
 * therefore all BMP code points precede all supplementary code points.
 *
 * Store each supplementary code point in 2 16-bit units,
 * simply with higher-then-lower 16-bit halfs.
 *
 * Precede the entire list with the length.
 * If there are supplementary code points, then set bit 15 in the length
 * and add the bmpLength between it and the array.
 *
 * In other words:
 * - all BMP:            (length=bmpLength) BMP, .., BMP
 * - some supplementary: (length|0x8000) (bmpLength<length) BMP, .., BMP, supp-high, supp-low, ..
 */
U_CAPI int32_t U_EXPORT2
uset_serialize(const USet *set, uint16_t *dest, int32_t destCapacity, UErrorCode *ec) {
    if (ec==NULL || U_FAILURE(*ec)) {
        return 0;
    }

    return ((const UnicodeSet*) set)->serialize(dest, destCapacity, *ec);
}

U_CAPI UBool U_EXPORT2
uset_getSerializedSet(USerializedSet *fillSet, const uint16_t *src, int32_t srcLength) {
    int32_t length;

    if(fillSet==NULL) {
        return FALSE;
    }
    if(src==NULL || srcLength<=0) {
        fillSet->length=fillSet->bmpLength=0;
        return FALSE;
    }

    length=*src++;
    if(length&0x8000) {
        /* there are supplementary values */
        length&=0x7fff;
        if(srcLength<(2+length)) {
            fillSet->length=fillSet->bmpLength=0;
            return FALSE;
        }
        fillSet->bmpLength=*src++;
    } else {
        /* only BMP values */
        if(srcLength<(1+length)) {
            fillSet->length=fillSet->bmpLength=0;
            return FALSE;
        }
        fillSet->bmpLength=length;
    }
    fillSet->array=src;
    fillSet->length=length;
    return TRUE;
}

U_CAPI void U_EXPORT2
uset_setSerializedToOne(USerializedSet *fillSet, UChar32 c) {
    if(fillSet==NULL || (uint32_t)c>0x10ffff) {
        return;
    }

    fillSet->array=fillSet->staticArray;
    if(c<0xffff) {
        fillSet->bmpLength=fillSet->length=2;
        fillSet->staticArray[0]=(uint16_t)c;
        fillSet->staticArray[1]=(uint16_t)c+1;
    } else if(c==0xffff) {
        fillSet->bmpLength=1;
        fillSet->length=3;
        fillSet->staticArray[0]=0xffff;
        fillSet->staticArray[1]=1;
        fillSet->staticArray[2]=0;
    } else if(c<0x10ffff) {
        fillSet->bmpLength=0;
        fillSet->length=4;
        fillSet->staticArray[0]=(uint16_t)(c>>16);
        fillSet->staticArray[1]=(uint16_t)c;
        ++c;
        fillSet->staticArray[2]=(uint16_t)(c>>16);
        fillSet->staticArray[3]=(uint16_t)c;
    } else /* c==0x10ffff */ {
        fillSet->bmpLength=0;
        fillSet->length=2;
        fillSet->staticArray[0]=0x10;
        fillSet->staticArray[1]=0xffff;
    }
}

U_CAPI UBool U_EXPORT2
uset_serializedContains(const USerializedSet *set, UChar32 c) {
    const uint16_t *array;

    if(set==NULL || (uint32_t)c>0x10ffff) {
        return FALSE;
    }

    array=set->array;
    if(c<=0xffff) {
        /* find c in the BMP part */
        int32_t i, bmpLength=set->bmpLength;
        for(i=0; i<bmpLength && (uint16_t)c>=array[i]; ++i) {}
        return (UBool)(i&1);
    } else {
        /* find c in the supplementary part */
        int32_t i, length=set->length;
        uint16_t high=(uint16_t)(c>>16), low=(uint16_t)c;
        for(i=set->bmpLength;
            i<length && (high>array[i] || (high==array[i] && low>=array[i+1]));
            i+=2) {}

        /* count pairs of 16-bit units even per BMP and check if the number of pairs is odd */
        return (UBool)(((i+set->bmpLength)&2)!=0);
    }
}

U_CAPI int32_t U_EXPORT2
uset_countSerializedRanges(const USerializedSet *set) {
    if(set==NULL) {
        return 0;
    }

    return (set->bmpLength+(set->length-set->bmpLength)/2+1)/2;
}

U_CAPI UBool U_EXPORT2
uset_getSerializedRange(const USerializedSet *set, int32_t rangeIndex,
                        UChar32 *pStart, UChar32 *pEnd) {
    const uint16_t *array;
    int32_t bmpLength, length;

    if(set==NULL || rangeIndex<0 || pStart==NULL || pEnd==NULL) {
        return FALSE;
    }

    array=set->array;
    length=set->length;
    bmpLength=set->bmpLength;

    rangeIndex*=2; /* address start/limit pairs */
    if(rangeIndex<bmpLength) {
        *pStart=array[rangeIndex++];
        if(rangeIndex<bmpLength) {
            *pEnd=array[rangeIndex];
        } else if(rangeIndex<length) {
            *pEnd=(((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1];
        } else {
            *pEnd=0x110000;
        }
        --*pEnd;
        return TRUE;
    } else {
        rangeIndex-=bmpLength;
        rangeIndex*=2; /* address pairs of pairs of units */
        length-=bmpLength;
        if(rangeIndex<length) {
            array+=bmpLength;
            *pStart=(((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1];
            rangeIndex+=2;
            if(rangeIndex<length) {
                *pEnd=(((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1];
            } else {
                *pEnd=0x110000;
            }
            --*pEnd;
            return TRUE;
        } else {
            return FALSE;
        }
    }
}

// TODO Investigate incorporating this code into UnicodeSet to improve
// efficiency.
// ---
// static U_INLINE int32_t
// findChar(const UChar32 *array, int32_t length, UChar32 c) {
//     int32_t i;
// 
//     /* check the last range limit first for more efficient appending */
//     if(length>0) {
//         if(c>=array[length-1]) {
//             return length;
//         }
// 
//         /* do not check the last range limit again in the loop below */
//         --length;
//     }
// 
//     for(i=0; i<length && c>=array[i]; ++i) {}
//     return i;
// }
// 
// static UBool
// addRemove(USet *set, UChar32 c, int32_t doRemove) {
//     int32_t i, length, more;
// 
//     if(set==NULL || (uint32_t)c>0x10ffff) {
//         return FALSE;
//     }
// 
//     length=set->length;
//     i=findChar(set->array, length, c);
//     if((i&1)^doRemove) {
//         /* c is already in the set */
//         return TRUE;
//     }
// 
//     /* how many more array items do we need? */
//     if(i<length && (c+1)==set->array[i]) {
//         /* c is just before the following range, extend that in-place by one */
//         set->array[i]=c;
//         if(i>0) {
//             --i;
//             if(c==set->array[i]) {
//                 /* the previous range collapsed, remove it */
//                 set->length=length-=2;
//                 if(i<length) {
//                     uprv_memmove(set->array+i, set->array+i+2, (length-i)*4);
//                 }
//             }
//         }
//         return TRUE;
//     } else if(i>0 && c==set->array[i-1]) {
//         /* c is just after the previous range, extend that in-place by one */
//         if(++c<=0x10ffff) {
//             set->array[i-1]=c;
//             if(i<length && c==set->array[i]) {
//                 /* the following range collapsed, remove it */
//                 --i;
//                 set->length=length-=2;
//                 if(i<length) {
//                     uprv_memmove(set->array+i, set->array+i+2, (length-i)*4);
//                 }
//             }
//         } else {
//             /* extend the previous range (had limit 0x10ffff) to the end of Unicode */
//             set->length=i-1;
//         }
//         return TRUE;
//     } else if(i==length && c==0x10ffff) {
//         /* insert one range limit c */
//         more=1;
//     } else {
//         /* insert two range limits c, c+1 */
//         more=2;
//     }
// 
//     /* insert <more> range limits */
//     if(length+more>set->capacity) {
//         /* reallocate */
//         int32_t newCapacity=set->capacity+set->capacity/2+USET_GROW_DELTA;
//         UChar32 *newArray=(UChar32 *)uprv_malloc(newCapacity*4);
//         if(newArray==NULL) {
//             return FALSE;
//         }
//         set->capacity=newCapacity;
//         uprv_memcpy(newArray, set->array, length*4);
// 
//         if(set->array!=set->staticBuffer) {
//             uprv_free(set->array);
//         }
//         set->array=newArray;
//     }
// 
//     if(i<length) {
//         uprv_memmove(set->array+i+more, set->array+i, (length-i)*4);
//     }
//     set->array[i]=c;
//     if(more==2) {
//         set->array[i+1]=c+1;
//     }
//     set->length+=more;
// 
//     return TRUE;
// }
// 
// U_CAPI UBool U_EXPORT2
// uset_add(USet *set, UChar32 c) {
//     return addRemove(set, c, 0);
// }
// 
// U_CAPI void U_EXPORT2
// uset_remove(USet *set, UChar32 c) {
//     addRemove(set, c, 1);
// }