/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 "Long.h"
#include <decaf/lang/Character.h>
#include <sstream>

using namespace decaf;
using namespace decaf::lang;

////////////////////////////////////////////////////////////////////////////////
const int Long::SIZE = 64;
const long long Long::MAX_VALUE = (long long) 0x7FFFFFFFFFFFFFFFLL;
const long long Long::MIN_VALUE = (long long) 0x8000000000000000LL;

////////////////////////////////////////////////////////////////////////////////
Long::Long(long long value) : value(value) {
}

////////////////////////////////////////////////////////////////////////////////
Long::Long(const std::string& value) : value(0) {
    this->value = parseLong(value);
}

////////////////////////////////////////////////////////////////////////////////
int Long::compareTo(const Long& l) const {
    return this->value < l.value ? -1 : this->value == l.value ? 0 : 1;
}

////////////////////////////////////////////////////////////////////////////////
int Long::compareTo(const long long& l) const {
    return this->value < l ? -1 : this->value == l ? 0 : 1;
}

////////////////////////////////////////////////////////////////////////////////
int Long::bitCount(long long value) {

    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;

    uvalue = (uvalue & 0x5555555555555555LL) + ((uvalue >> 1) & 0x5555555555555555LL);
    uvalue = (uvalue & 0x3333333333333333LL) + ((uvalue >> 2) & 0x3333333333333333LL);
    // adjust for 64-bit integer
    unsigned int i = (unsigned int) ((uvalue >> 32) + uvalue);
    i = (i & 0x0F0F0F0F) + ((i >> 4) & 0x0F0F0F0F);
    i = (i & 0x00FF00FF) + ((i >> 8) & 0x00FF00FF);
    i = (i & 0x0000FFFF) + ((i >> 16) & 0x0000FFFF);
    return i;
}

////////////////////////////////////////////////////////////////////////////////
Long Long::decode(const std::string& value) {

    int length = (int) value.length(), i = 0;
    if (length == 0) {
        throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::decode - Zero length string given.");
    }

    char firstDigit = value[i];
    bool negative = firstDigit == '-';
    if (negative) {
        if (length == 1) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::decode - Invalid length string given.", value.c_str());
        }
        firstDigit = value[++i];
    }

    int base = 10;
    if (firstDigit == '0') {
        if (++i == length) {
            return valueOf(0LL);
        }
        if ((firstDigit = value[i]) == 'x' || firstDigit == 'X') {
            if (i == length) {
                throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::decode - Invalid length string given.", value.c_str());
            }
            i++;
            base = 16;
        } else {
            base = 8;
        }
    } else if (firstDigit == '#') {
        if (i == length) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::decode - Invalid length string given.", value.c_str());
        }
        i++;
        base = 16;
    }

    long long result = parse(value, i, base, negative);
    return valueOf(result);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::highestOneBit(long long value) {

    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;

    uvalue |= (uvalue >> 1);
    uvalue |= (uvalue >> 2);
    uvalue |= (uvalue >> 4);
    uvalue |= (uvalue >> 8);
    uvalue |= (uvalue >> 16);
    uvalue |= (uvalue >> 32);
    return (uvalue & ~(uvalue >> 1));
}

////////////////////////////////////////////////////////////////////////////////
long long Long::lowestOneBit(long long value) {
    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;
    return (uvalue & (-1 * uvalue));
}

////////////////////////////////////////////////////////////////////////////////
int Long::numberOfLeadingZeros(long long value) {

    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;

    value |= value >> 1;
    value |= value >> 2;
    value |= value >> 4;
    value |= value >> 8;
    value |= value >> 16;
    value |= value >> 32;
    return Long::bitCount(~uvalue);
}

////////////////////////////////////////////////////////////////////////////////
int Long::numberOfTrailingZeros(long long value) {
    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;
    return Long::bitCount((uvalue & (-1 * uvalue)) - 1);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::parseLong(const std::string& value) {

    return Long::parseLong(value, 10);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::parseLong(const std::string& value, int radix) {

    if (radix < Character::MIN_RADIX || radix > Character::MAX_RADIX) {
        throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Given Radix is out of range.");
    }

    int length = (int) value.length();
    int i = 0;

    if (length == 0) {
        throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Zero length string is illegal.");
    }

    bool negative = value[i] == '-';
    if (negative && ++i == length) {
        throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Only a minus given, string is invalid.");
    }

    return Long::parse(value, i, radix, negative);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::parse(const std::string& value, int offset, int radix, bool negative) {

    long long max = Long::MIN_VALUE / radix;
    long long result = 0;
    long long length = value.length();

    while (offset < length) {
        int digit = Character::digit(value[offset++], radix);

        if (digit == -1) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - String contains no digit characters.");
        }

        if (max > result) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Parsed value greater than max for radix.");
        }

        long long next = result * radix - digit;

        if (next > result) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Only a minus given, string is invalid.");
        }

        result = next;
    }

    if (!negative) {
        result = -result;
        if (result < 0) {
            throw exceptions::NumberFormatException(__FILE__, __LINE__, "Long::parseLong - Value less than zero, but no minus sign.");
        }
    }

    return result;
}

////////////////////////////////////////////////////////////////////////////////
long long Long::reverseBytes(long long value) {

    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;

    long long b7 = (uvalue >> 56);
    long long b6 = (uvalue >> 40) & 0xFF00ULL;
    long long b5 = (uvalue >> 24) & 0xFF0000ULL;
    long long b4 = (uvalue >> 8) & 0xFF000000ULL;
    long long b3 = (uvalue & 0xFF000000ULL) << 8;
    long long b2 = (uvalue & 0xFF0000ULL) << 24;
    long long b1 = (uvalue & 0xFF00ULL) << 40;
    long long b0 = (uvalue << 56);
    return (b0 | b1 | b2 | b3 | b4 | b5 | b6 | b7);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::reverse(long long value) {

    if (value == 0) {
        return 0;
    }

    unsigned long long uvalue = (unsigned long long) value;

    // From Hacker's Delight, 7-1, Figure 7-1
    uvalue = ((uvalue & 0x5555555555555555ULL) << 1) | ((uvalue >> 1) & 0x5555555555555555ULL);
    uvalue = ((uvalue & 0x3333333333333333ULL) << 2) | ((uvalue >> 2) & 0x3333333333333333ULL);
    uvalue = ((uvalue & 0x0F0F0F0F0F0F0F0FULL) << 4) | ((uvalue >> 4) & 0x0F0F0F0F0F0F0F0FULL);

    return reverseBytes(uvalue);
}

////////////////////////////////////////////////////////////////////////////////
long long Long::rotateLeft(long long value, int distance) {
    unsigned long long i = (unsigned long long) value;
    int j = distance & 0x1F;
    return (i << j) | (i >> (-j & 0x1F));
}

////////////////////////////////////////////////////////////////////////////////
long long Long::rotateRight(long long value, int distance) {
    unsigned long long i = (unsigned long long) value;
    int j = distance & 0x1F;
    return (i >> j) | (i << (-j & 0x1F));
}

////////////////////////////////////////////////////////////////////////////////
int Long::signum(long long value) {
    return (value == 0 ? 0 : (value < 0 ? -1 : 1));
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toString() const {
    return Long::toString(this->value, 10);
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toString(long long value) {
    return Long::toString(value, 10);
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toString(long long value, int radix) {

    if (radix < Character::MIN_RADIX || radix > Character::MAX_RADIX) {
        radix = 10;
    }

    if (value == 0) {
        return "0";
    }

    int count = 2;
    long long j = value;
    bool negative = value < 0;

    if (!negative) {
        count = 1;
        j = -value;
    }

    while ((value /= radix) != 0) {
        count++;
    }

    // Save length and allocate a new buffer for the string, add one
    // more for the null character.
    int length = count;
    char* buffer = new char[length + 1];

    do {
        int ch = (int) (0 - (j % radix));
        if (ch > 9) {
            ch = ch - 10 + 'a';
        } else {
            ch += '0';
        }
        buffer[--count] = (char) ch;
    } while ((j /= radix) != 0);

    if (negative) {
        buffer[0] = '-';
    }

    // Ensure there's a null
    buffer[length] = 0;
    std::string result(&buffer[0]);
    delete[] buffer;

    return result;
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toBinaryString(long long value) {

    int count = 1;
    long long j = value;

    if (value < 0) {
        count = 64; // 8 * sizeof(long long);
    } else {
        while ((j >>= 1) != 0) {
            count++;
        }
    }

    // Save length and allocate a new buffer for the string, add one
    // more for the null character.
    int length = count;
    char* buffer = new char[length + 1];

    do {
        buffer[--count] = (char) ((value & 1) + '0');
        value >>= 1;
    } while (count > 0);

    // Ensure there's a null
    buffer[length] = 0;
    std::string result(&buffer[0]);
    delete[] buffer;

    return result;
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toOctalString(long long value) {

    int count = 1;
    long long j = value;
    unsigned long long uvalue = (unsigned long long) value;

    if (value < 0) {
        count = 22; // (8 * sizeof(long long) + 2) / 3;
    } else {
        while ((j >>= 3) != 0) {
            count++;
        }
    }

    // Save length and allocate a new buffer for the string, add one
    // more for the null character.
    int length = count;
    char* buffer = new char[length + 1];

    do {
        buffer[--count] = (char) ((uvalue & 7) + '0');
        uvalue >>= 3;
    } while (count > 0);

    // Ensure there's a null
    buffer[length] = 0;
    std::string result(&buffer[0]);
    delete[] buffer;

    return result;
}

////////////////////////////////////////////////////////////////////////////////
std::string Long::toHexString(long long value) {

    int count = 1;
    long long j = value;

    if (value < 0) {
        count = 16; // 8 * sizeof(long long) / 4
    } else {
        while ((j >>= 4) != 0) {
            count++;
        }
    }

    // Save length and allocate a new buffer for the string, add one
    // more for the null character.
    int length = count;
    char* buffer = new char[length + 1];

    do {
        int t = (int) (value & 15);
        if (t > 9) {
            t = t - 10 + 'a';
        } else {
            t += '0';
        }
        buffer[--count] = (char) t;
        value >>= 4;
    } while (count > 0);

    // Ensure there's a null
    buffer[length] = 0;
    std::string result(&buffer[0]);
    delete[] buffer;

    return result;
}

////////////////////////////////////////////////////////////////////////////////
Long Long::valueOf(const std::string& value) {
    return Long(Long::parseLong(value));
}

////////////////////////////////////////////////////////////////////////////////
Long Long::valueOf(const std::string& value, int radix) {
    return Long(Long::parseLong(value, radix));
}