#include "ble/ByteBuffer.h"
#include <string.h>
#include <sstream>
#include <iomanip>
#include <cassert>

using namespace std;

ByteBuffer ByteBuffer::alloc(std::size_t capacity) {
    auto bytes = shared_ptr<uint8_t>(new uint8_t[capacity], [](uint8_t* p) {
        delete[] p;
    });
    return ByteBuffer(bytes, capacity, (size_t) 0, (size_t) 0);
}

ByteBuffer::ByteBuffer(const std::shared_ptr<uint8_t> bytes, size_t capacity) :
    bytes(bytes), capacity(capacity), zero(bytes.get()), end(bytes.get()) {
    ptr = const_cast<uint8_t *>(zero);
}

ByteBuffer::ByteBuffer(const std::shared_ptr<uint8_t> bytes, size_t capacity, size_t size) :
        bytes(bytes), capacity(capacity), zero(bytes.get()), end(&bytes.get()[size]) {
    assert(size <= capacity);
    ptr = const_cast<uint8_t *>(this->zero);
}

ByteBuffer::ByteBuffer(const std::shared_ptr<uint8_t> bytes, size_t capacity, size_t size, size_t zero) :
        bytes(bytes), capacity(capacity), zero(&bytes.get()[zero]), end(&bytes.get()[size]) {
    assert(zero <= size);
    assert(size <= capacity);
    ptr = const_cast<uint8_t *>(this->zero);
}

ByteBuffer::ByteBuffer(const std::shared_ptr<uint8_t> bytes, size_t capacity, const uint8_t *zero, const uint8_t *end) :
        bytes(bytes), capacity(capacity), zero(zero), end(end), ptr((uint8_t *) zero) {
}

ByteBuffer &ByteBuffer::write8(uint8_t value) {
    checkAndUpdateEnd(1);
    (*ptr++) = value;
    return *this;
}

ByteBuffer &ByteBuffer::write16le(uint16_t value) {
    checkAndUpdateEnd(2);
    (*ptr++) = (uint8_t) (value & 0xff);
    (*ptr++) = (uint8_t) ((value >> 8) & 0xff);
    return *this;
}

ByteBuffer &ByteBuffer::write(const ByteBuffer &value) {
    return write(value.zero, value.getSize());
}

ByteBuffer &ByteBuffer::write(const uint8_t *bytes, size_t len) {
    checkAndUpdateEnd(len);

    memcpy(ptr, bytes, len);

    ptr += len;

    return *this;
}

uint8_t ByteBuffer::get8(size_t index) const {
    assertCanAccessRelative(index);
    return ptr[index];
}

uint8_t ByteBuffer::read8() {
    assertCanAccessRelative(0);
    return *ptr++;
}

uint16_t ByteBuffer::read16le() {
    assertCanAccessRelative(0);
    uint16_t value;
    value = *ptr++;
    value |= ((uint16_t) *ptr++) << 8;
    return value;
}

void ByteBuffer::copy(uint8_t *bytes, size_t length) const {
    assertCanAccessRelative(length - 1);

    memcpy(bytes, ptr, length);
}

ByteBuffer ByteBuffer::view() const {
//    DF << "cursor=" << getCursor() << ", size=" << getSize() << ", new size=" << end - ptr << ", ptr=" << (uint64_t) ptr << ", zero=" << (uint64_t) zero;
    return view(ptr, end);
}

ByteBuffer ByteBuffer::view(size_t length) const {
    return ByteBuffer(bytes, length, ptr, ptr + length);
}

ByteBuffer ByteBuffer::view(uint8_t *ptr, const uint8_t *end) const {
    return ByteBuffer(bytes, end - ptr, ptr, end);
}

void ByteBuffer::checkAndUpdateEnd(size_t newBytes) {
    uint8_t *newEnd = ptr + newBytes;
    if (newEnd >= end) {
        if (newEnd >= &zero[capacity]) {
            throw ByteBufferException(string("New size is too large! cursor=") + to_string(getCursor()) + ", size=" + to_string(getSize()) + ", capacity=" + to_string(capacity) + ", new bytes=" + to_string(newBytes));
        }
        end = newEnd;
    }
}

void ByteBuffer::assertCanAccessRelative(size_t diff) const {
    assertCanAccessIndex(ptr + diff);
}

void ByteBuffer::assertCanAccessIndex(uint8_t *p) const {
    if (p >= end || p < zero) {
        throw ByteBufferException(string("Out of bounds! size=") + to_string(getSize()) + ", index=" + to_string(p - zero));
    }
}

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

    for (uint8_t *i = (uint8_t *) zero; i < end; i++) {
        s << hex << setfill('0') << setw(2) << (int) *i << " ";
    }

    return string(s.str());
}