// -*- mode: c++; c-basic-offset: 2; -*-

#include "common.hh"

#include <cstring>

#include "data.hh"
#include "package.hh"

size_t read_package(Package* pkg, uint8_t const* data, size_t max) {
  if (max < 26) return 0;
  size_t offset = 0;
  pkg->id = read_u32(data + offset);
  offset += 4;
  pkg->timestamp.tv_sec = read_u64(data + offset);
  offset += 8;
  pkg->timestamp.tv_nsec = read_u32(data + offset);
  offset += 4;
  pkg->flags = read_u16(data + offset);
  offset += 2;
  pkg->source_port = read_u16(data + offset);
  offset += 2;
  pkg->target_port = read_u16(data + offset);
  offset += 2;
  auto len = read_u16(data + offset);
  offset += 2;
  if (offset + len + 2 > max) return 0;
  pkg->source_host.assign(reinterpret_cast<char const*>(data) + offset, len);
  offset += len;
  len = read_u16(data + offset);
  offset += 2;
  if (offset + len > max) return 0;
  pkg->target_host.assign(reinterpret_cast<char const*>(data) + offset, len);
  offset += len;
  return offset;
}

size_t write_package(Package const& pkg, uint8_t* data, size_t max) {
  auto len = 26 + pkg.source_host.size() + pkg.target_host.size();
  if (!data || max < len) {
    return len;
  }
  write_u32(data, pkg.id);
  write_u64(data + 4, pkg.timestamp.tv_sec);
  write_u32(data + 12, pkg.timestamp.tv_nsec);
  write_u16(data + 16, pkg.flags);
  write_u16(data + 18, pkg.source_port);
  write_u16(data + 20, pkg.target_port);
  write_u16(data + 22, pkg.source_host.size());
  memcpy(data + 24, pkg.source_host.data(), pkg.source_host.size());
  write_u16(data + 24 + pkg.source_host.size(), pkg.target_host.size());
  memcpy(data + 26 + pkg.source_host.size(),
         pkg.target_host.data(), pkg.target_host.size());
  return len;
}