#include "io/gpr/IprbReader.hpp"

#include <cstdint>
#include <fstream>
#include <stdexcept>

namespace geopro::io::gpr {

BScan readIprb(const std::string& path, const IprHeader& h) {
  std::ifstream f(path, std::ios::binary | std::ios::ate);
  if (!f) {
    throw std::runtime_error("readIprb: 无法打开文件: " + path);
  }

  const std::streamsize fileSize = f.tellg();
  const std::int64_t traces = static_cast<std::int64_t>(h.lastTrace) + 1;
  const std::int64_t count = static_cast<std::int64_t>(h.samples) * traces;
  const std::int64_t expected = count * 2;
  if (fileSize != expected) {
    throw std::runtime_error("readIprb: 文件大小与 samples*traces*2 不符: " + path);
  }

  BScan b;
  b.samples = h.samples;
  b.traces = traces;
  b.data.resize(static_cast<std::size_t>(h.samples) * traces);

  f.seekg(0, std::ios::beg);
  f.read(reinterpret_cast<char*>(b.data.data()), static_cast<std::streamsize>(expected));
  if (!f) {
    throw std::runtime_error("readIprb: 读取数据失败: " + path);
  }

  return b;
}

}  // namespace geopro::io::gpr