// SPDX-License-Identifier: GPL-2.0-or-later
#include <exiv2/exiv2.hpp>

#include <iostream>

using Exiv2::BasicIo;
using Exiv2::byte;
using Exiv2::Error;
using Exiv2::FileIo;
using Exiv2::IoCloser;
using Exiv2::MemIo;
using Exiv2::strError;

int WriteReadSeek(BasicIo& io);

// *****************************************************************************
// Main
int main(int argc, char* const argv[]) {
  Exiv2::XmpParser::initialize();
  ::atexit(Exiv2::XmpParser::terminate);

  try {
    if (argc < 4 || argc > 6) {
      std::cout << "Usage: " << argv[0]
                << " filein fileout1 fileout2 [remote [blocksize]]\n"
                   "copy filein to fileout1 and copy filein to fileout2\n"
                   "fileout1 and fileout2 are overwritten and should match filein exactly\n"
                   "\n"
                   "You may optionally provide the URL of a remote file to be copied to filein\n"
                   "If you use `remote`, you may optionally provide a blocksize for the copy buffer (default 10k)\n";
      return 1;
    }
    const char* f0 = argv[1];  // fileIn
    const char* f1 = argv[2];  // fileOut1
    const char* f2 = argv[3];  // fileOut2
    const char* fr = argv[4];  // remote file
    const char* ba = argv[5];  // block argument

    if (argc >= 5) {
      int blocksize = argc == 6 ? atoi(ba) : 10000;
      // ensure blocksize is sane
      if (blocksize > 1024 * 1024)
        blocksize = 10000;

      std::vector<Exiv2::byte> bytes(blocksize);

      // copy fileIn from a remote location.
      auto io = Exiv2::ImageFactory::createIo(fr);
      if (io->open() != 0) {
        Error(Exiv2::ErrorCode::kerFileOpenFailed, io->path(), "rb", strError());
      }
      FileIo output(f0);
      if (!output.open("wb")) {
        Error(Exiv2::ErrorCode::kerFileOpenFailed, output.path(), "w+b", strError());
      }
      size_t l = 0;
      if (!bytes.empty()) {
        size_t r;
        while ((r = io->read(bytes.data(), blocksize)) > 0) {
          l += r;
          output.write(bytes.data(), r);
        }
      } else {
        // read/write byte-wise (#1029)
        while (l++ < io->size()) {
          output.putb(io->getb());
        }
      }
      output.close();
    }

    FileIo fileIn(f0);
    if (fileIn.open() != 0) {
      throw Error(Exiv2::ErrorCode::kerDataSourceOpenFailed, fileIn.path(), strError());
    }

    FileIo fileOut1(f1);
    if (fileOut1.open("w+b") != 0) {
      throw Error(Exiv2::ErrorCode::kerFileOpenFailed, f1, "w+b", strError());
    }

    MemIo memIo1;

    // Copy to output file through memIo
    memIo1.write(fileIn);
    memIo1.seek(0, BasicIo::beg);
    fileOut1.write(memIo1);

    // Make sure they are all the same size
    if (fileIn.size() != memIo1.size() || memIo1.size() != fileOut1.size()) {
      std::cerr << argv[0] << ": Sizes do not match\n";
      return EXIT_FAILURE;
    }

    // Read writereadseek test on MemIo
    MemIo memIo2;
    int rc = WriteReadSeek(memIo2);
    if (rc != 0)
      return rc;

    // Read writereadseek test on FileIo
    // Create or overwrite the file, then close it
    FileIo fileTest("iotest.txt");
    if (fileTest.open("w+b") != 0) {
      throw Error(Exiv2::ErrorCode::kerFileOpenFailed, "iotest.txt", "w+b", strError());
    }

    fileTest.close();
    rc = WriteReadSeek(fileTest);
    if (rc != 0)
      return rc;

    // Another test of reading and writing
    fileOut1.seek(0, BasicIo::beg);
    memIo2.seek(0, BasicIo::beg);
    FileIo fileOut2(f2);
    if (fileOut2.open("w+b") != 0) {
      throw Error(Exiv2::ErrorCode::kerFileOpenFailed, f2, "w+b", strError());
    }

    size_t readCount = 0;
    byte buf[32];
    while ((readCount = fileOut1.read(buf, sizeof(buf)))) {
      if (memIo2.write(buf, readCount) != readCount) {
        std::cerr << argv[0] << ": MemIo bad write 2\n";
        return 13;
      }
      if (fileOut2.write(buf, readCount) != readCount) {
        std::cerr << argv[0] << ": FileIo bad write 2\n";
        return 14;
      }
    }

    return EXIT_SUCCESS;
  } catch (Exiv2::Error& e) {
    std::cerr << "Caught Exiv2 exception '" << e << "'\n";
    return EXIT_FAILURE;
  }
}

int WriteReadSeek(BasicIo& io) {
  byte buf[4096];
  const char tester1[] = "this is a little test of MemIo";
  const char tester2[] = "Appending this on the end";
  const char expect[] = "this is a little teAppending this on the end";
  const size_t insert = 19;
  const size_t size1 = std::strlen(tester1) + 1;
  const size_t size2 = std::strlen(tester2) + 1;

  if (io.open() != 0) {
    throw Error(Exiv2::ErrorCode::kerDataSourceOpenFailed, io.path(), strError());
  }
  IoCloser closer(io);
  if (io.write(reinterpret_cast<const byte*>(tester1), size1) != size1) {
    std::cerr << ": WRS initial write failed\n";
    return 2;
  }

  if (io.size() != size1) {
    std::cerr << ": WRS size is not " << size1 << "\n";
    return 2;
  }
  auto backup = static_cast<long>(size1);
  io.seek(-backup, BasicIo::cur);

  int c = EOF;
  std::memset(buf, -1, sizeof(buf));
  for (int i = 0; (c = io.getb()) != EOF; ++i) {
    buf[i] = static_cast<byte>(c);
  }

  // Make sure we got the null back
  if (buf[size1 - 1] != 0) {
    std::cerr << ": WRS missing null terminator 1\n";
    return 3;
  }

  if (strcmp(tester1, reinterpret_cast<char*>(buf)) != 0) {
    std::cerr << ": WRS strings don't match 1\n";
    return 4;
  }

  io.seek(-2, BasicIo::end);
  if (io.getb() != 'o') {
    std::cerr << ": WRS bad getb o\n";
    return 5;
  }

  io.seek(-2, BasicIo::cur);
  if (io.getb() != 'I') {
    std::cerr << ": WRS bad getb I\n";
    return 6;
  }

  if (io.putb('O') != 'O') {
    std::cerr << ": WRS bad putb\n";
    return 7;
  }

  io.seek(-1, BasicIo::cur);
  if (io.getb() != 'O') {
    std::cerr << ": WRS bad getb O\n";
    return 8;
  }

  io.seek(insert, BasicIo::beg);
  if (io.write(reinterpret_cast<const byte*>(tester2), size2) != size2) {
    std::cerr << ": WRS bad write 1\n";
    return 9;
  }

  // open should seek to beginning
  if (io.open() != 0) {
    throw Error(Exiv2::ErrorCode::kerDataSourceOpenFailed, io.path(), strError());
  }
  std::memset(buf, -1, sizeof(buf));
  if (io.read(buf, sizeof(buf)) != insert + size2) {
    std::cerr << ": WRS something went wrong\n";
    return 10;
  }

  // Make sure we got the null back
  if (buf[insert + size2 - 1] != 0) {
    std::cerr << ": WRS missing null terminator 2\n";
    return 11;
  }

  if (std::strcmp(expect, reinterpret_cast<char*>(buf)) != 0) {
    std::cerr << ": WRS strings don't match 2\n";
    return 12;
  }

  return 0;
}