/* Compare two data files.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <iostream>
#include <unistd.h>

#include <jansson.h>

#include <villas/exceptions.hpp>
#include <villas/format.hpp>
#include <villas/log.hpp>
#include <villas/node/config.hpp>
#include <villas/pool.hpp>
#include <villas/sample.hpp>
#include <villas/tool.hpp>
#include <villas/utils.hpp>

using namespace villas;

namespace villas {
namespace node {
namespace tools {

class CompareSide {

public:
  std::string path;
  std::string dtypes;
  std::string format;

  struct Sample *sample;

  Format *formatter;

  FILE *stream;

  CompareSide(const CompareSide &) = delete;
  CompareSide &operator=(const CompareSide &) = delete;

  CompareSide(const std::string &pth, const std::string &fmt,
              const std::string &dt, struct Pool *p)
      : path(pth), dtypes(dt), format(fmt) {
    json_t *json_format;
    json_error_t err;

    // Try parsing format config as JSON
    json_format = json_loads(format.c_str(), 0, &err);
    formatter = json_format ? FormatFactory::make(json_format)
                            : FormatFactory::make(format);
    if (!formatter)
      throw RuntimeError("Failed to initialize formatter");

    formatter->start(dtypes);

    stream = fopen(path.c_str(), "r");
    if (!stream)
      throw SystemError("Failed to open file: {}", path);

    sample = sample_alloc(p);
    if (!sample)
      throw RuntimeError("Failed to allocate samples");
  }

  ~CompareSide() noexcept(false) {
    int ret __attribute((unused));

    ret = fclose(stream);

    delete formatter;

    sample_decref(sample);
  }
};

class Compare : public Tool {

public:
  Compare(int argc, char *argv[])
      : Tool(argc, argv, "test-cmp"), pool(), epsilon(1e-6),
        format("villas.human"), dtypes("64f"),
        flags((int)SampleFlags::HAS_SEQUENCE | (int)SampleFlags::HAS_DATA |
              (int)SampleFlags::HAS_TS_ORIGIN) {
    int ret;

    ret = memory::init(DEFAULT_NR_HUGEPAGES);
    if (ret)
      throw RuntimeError("Failed to initialize memory");
  }

protected:
  struct Pool pool;

  double epsilon;
  std::string format;
  std::string dtypes;
  int flags;

  std::vector<std::string> filenames;

  void usage() {
    std::cout << "Usage: villas-compare [OPTIONS] FILE1 FILE2 ... FILEn"
              << std::endl
              << "  FILE     a list of files to compare" << std::endl
              << "  OPTIONS is one or more of the following options:"
              << std::endl
              << "    -d LVL  adjust the debug level" << std::endl
              << "    -e EPS  set epsilon for floating point comparisons to EPS"
              << std::endl
              << "    -v      ignore data values" << std::endl
              << "    -T      ignore timestamp" << std::endl
              << "    -s      ignore sequence no" << std::endl
              << "    -f FMT  file format for all files" << std::endl
              << "    -t DT   the data-type format string" << std::endl
              << "    -h      show this usage information" << std::endl
              << "    -V      show the version of the tool" << std::endl
              << std::endl
              << "Return codes:" << std::endl
              << "  0   files are equal" << std::endl
              << "  1   file length not equal" << std::endl
              << "  2   sequence no not equal" << std::endl
              << "  3   timestamp not equal" << std::endl
              << "  4   number of values is not equal" << std::endl
              << "  5   data is not equal" << std::endl
              << std::endl;

    printCopyright();
  }

  void parse() {
    // Parse Arguments
    int c;
    char *endptr;
    while ((c = getopt(argc, argv, "he:vTsf:t:Vd:")) != -1) {
      switch (c) {
      case 'e':
        epsilon = strtod(optarg, &endptr);
        goto check;

      case 'v':
        flags &= ~(int)SampleFlags::HAS_DATA;
        break;

      case 'T':
        flags &= ~(int)SampleFlags::HAS_TS_ORIGIN;
        break;

      case 's':
        flags &= ~(int)SampleFlags::HAS_SEQUENCE;
        break;

      case 'f':
        format = optarg;
        break;

      case 't':
        dtypes = optarg;
        break;

      case 'V':
        printVersion();
        exit(EXIT_SUCCESS);

      case 'd':
        Log::getInstance().setLevel(optarg);
        break;

      case 'h':
      case '?':
        usage();
        exit(c == '?' ? EXIT_FAILURE : EXIT_SUCCESS);
      }

      continue;

    check:
      if (optarg == endptr)
        throw RuntimeError("Failed to parse parse option argument '-{} {}'", c,
                           optarg);
    }

    if (argc - optind < 2) {
      usage();
      exit(EXIT_FAILURE);
    }

    // Open files
    for (int i = 0; i < argc - optind; i++)
      filenames.push_back(argv[optind + i]);
  }

  int main() {
    int ret, rc = 0, failed;
    unsigned eofs;

    ret = pool_init(&pool, filenames.size(),
                    SAMPLE_LENGTH(DEFAULT_SAMPLE_LENGTH), &memory::heap);
    if (ret)
      throw RuntimeError("Failed to initialize pool");

    // Open files
    std::vector<CompareSide *> sides;
    for (auto filename : filenames) {
      auto *s = new CompareSide(filename, format, dtypes, &pool);
      if (!s)
        throw MemoryAllocationError();

      sides.push_back(s);
    }

    while (true) {
      // Read next sample from all files
    retry:
      eofs = 0;
      for (auto side : sides) {
        ret = feof(side->stream);
        if (ret)
          eofs++;
      }

      if (eofs) {
        if (eofs == sides.size())
          ret = 0;
        else {
          std::cout << "length unequal" << std::endl;
          rc = 1;
        }

        goto out;
      }

      failed = 0;
      for (auto side : sides) {
        ret = side->formatter->scan(side->stream, side->sample);
        if (ret <= 0)
          failed++;
      }
      if (failed)
        goto retry;

      // We compare all files against the first one
      for (auto side : sides) {
        ret = sample_cmp(sides[0]->sample, side->sample, epsilon, flags);
        if (ret) {
          rc = ret;
          goto out;
        }
      }
    }

  out:
    for (auto side : sides)
      delete side;

    ret = pool_destroy(&pool);
    if (ret)
      throw RuntimeError("Failed to destroy pool");

    return rc;
  }
};

} // namespace tools
} // namespace node
} // namespace villas

int main(int argc, char *argv[]) {
  villas::node::tools::Compare t(argc, argv);

  return t.run();
}