#include "ByteBuffer.h"
#include <stdint-gcc.h>
#include <string.h>
#include <sstream>
#include <iomanip>
#include <cassert>

using namespace std;

ByteBuffer::ByteBuffer(uint8_t *bytes, size_t capacity, size_t size, size_t zero) :
        bytes(bytes), capacity(capacity), size(size), cursor(zero), zero(zero) {
    assert(zero <= size);
    assert(size <= capacity);
}

ByteBuffer &ByteBuffer::add8(uint8_t value) {
    checkAndUpdateSize(1);
    bytes[cursor++] = value;
    return *this;
}

ByteBuffer &ByteBuffer::add16le(uint16_t value) {
    checkAndUpdateSize(2);
    bytes[cursor++] = (uint8_t) (value & 0xff);
    bytes[cursor++] = (uint8_t) ((value >> 8) & 0xff);
    return *this;
}

uint8_t ByteBuffer::get8(size_t index) {
    canAccessIndex(index);
    return bytes[cursor];
}

uint8_t ByteBuffer::get8() {
    canAccessIndex(cursor);
    return bytes[cursor++];
}

uint16_t ByteBuffer::get16le() {
    canAccessIndex(cursor + 1);
    uint16_t value;
    value = bytes[cursor++];
    value |= ((uint16_t) bytes[cursor++]) << 8;
    return value;
}

void ByteBuffer::copy(uint8_t *bytes, size_t length) {
    canAccessIndex(length);

    memcpy(bytes, &this->bytes[cursor], length);
    cursor += length;
}

ByteBuffer ByteBuffer::view(size_t length) {
    canAccessIndex(cursor + length);
    size_t s = cursor + length;
    return ByteBuffer(bytes, s, s, cursor);
}

void ByteBuffer::checkAndUpdateSize(size_t newBytes) {
    size_t newSize = cursor + newBytes;
    if (newSize >= capacity) {
        throw ByteBufferException(string("Out of bounds! zero=") + to_string(zero) + ", cursor=" + to_string(cursor) + ", size=" + to_string(size) + ", capacity=" + to_string(capacity) + ", newSize=" + to_string(newSize));
    }

    size = max(newSize, size);
}

void ByteBuffer::canAccessIndex(size_t index) {
    if (zero + index >= size) {
        throw ByteBufferException(string("Out of bounds! zero=") + to_string(zero) + ", index=" + to_string(index) + ", size=" + to_string(size));
    }
}

std::string ByteBuffer::toString() const {
    stringstream s;

    for(size_t i = zero; i < size; i++) {
        s << hex << setfill('0') << setw(2) << (int) bytes[i] << " ";
    }

    return string(s.str());
}