/*
* Copyright (C) 2024 Amlogic Corporation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include "BitsMap.h"
#include <string.h>

#define BYTE_IDX(idx) (idx >> 3)
#define BIT_OFFSET(idx) (idx & 0x7)


BitsMap::BitsMap(int bits) {
    mLen = BYTE_IDX(bits) + 1;
    mBits = new char[mLen];
    if (mBits != NULL)
        memset(mBits, 0, mLen);
}

BitsMap::~BitsMap() {
    if (mBits != NULL)
        delete [] mBits;
}

int BitsMap::getZeroBit() {
    int  i = 0;

    if (mBits == NULL)
        return -1;

    for (; i < mLen; i++) {
        if (mBits[i] == 0xFF) {
            continue;
        }

        char byteval = mBits[i];
        int idx = 0;

        if ((byteval & 0xF) == 0xF) {
            byteval >>= 4;
            idx += 4;
        }
        if ((byteval & 0x3) == 0x3) {
            byteval >>= 2;
            idx += 2;
        }
        if ((byteval & 0x1) == 0x1) {
            byteval >>= 1;
            idx += 1;
        }

        idx += i * 8;
        return idx;
    }

    return -1;
}

int BitsMap::setBit(int idx) {
    if (mBits != NULL)
        mBits[BYTE_IDX(idx)] |= 1 << BIT_OFFSET(idx);
    return 0;
}

int BitsMap::clearBit(int idx) {
    if (mBits != NULL)
        mBits[BYTE_IDX(idx)] &= ~(1 << BIT_OFFSET(idx));
    return 0;
}