#include "common.hpp"

using dtl::Diff;
using dtl::elemInfo;
using dtl::uniHunk;

static void showStats(std::string fp1, std::string fp2);
static void unifiedDiff(std::string fp1, std::string fp2);

static void showStats(std::string fp1, std::string fp2) {
  const int MAX_LENGTH = 255;
  char time_format[] = "%Y-%m-%d %H:%M:%S %z";
  time_t rawtime[2];
  struct tm *timeinfo[2];
  struct stat st[2];

  if (stat(fp1.c_str(), &st[0]) == -1) {
    std::cerr << "argv1 is invalid." << std::endl;
    exit(-1);
  }
  if (stat(fp2.c_str(), &st[1]) == -1) {
    std::cerr << "argv2 is invalid" << std::endl;
    exit(-1);
  }

  char buf[2][MAX_LENGTH + 1];
  rawtime[0] = st[0].st_mtime;
  timeinfo[0] = localtime(&rawtime[0]);
  strftime(buf[0], MAX_LENGTH, time_format, timeinfo[0]);
  std::cout << "--- " << fp1 << '\t' << buf[0] << std::endl;
  rawtime[1] = st[1].st_mtime;
  timeinfo[1] = localtime(&rawtime[1]);
  strftime(buf[1], MAX_LENGTH, time_format, timeinfo[1]);
  std::cout << "+++ " << fp2 << '\t' << buf[1] << std::endl;
}

static void unifiedDiff(std::string fp1, std::string fp2) {
  typedef std::string elem;
  typedef std::vector<elem> sequence;
  typedef std::pair<elem, elemInfo> sesElem;

  std::ifstream Aifs(fp1.c_str());
  std::ifstream Bifs(fp2.c_str());
  elem buf;
  sequence ALines, BLines;

  while (getline(Aifs, buf)) {
    ALines.push_back(buf);
  }
  while (getline(Bifs, buf)) {
    BLines.push_back(buf);
  }

  Diff<elem> diff(ALines, BLines);
  diff.onHuge();
  // diff.onUnserious();
  diff.compose();

  // type unihunk definition test
  uniHunk<sesElem> hunk;

  if (diff.getEditDistance() > 0) {
    showStats(fp1, fp2); // show file info
  }

  diff.composeUnifiedHunks();
  diff.printUnifiedFormat();
}

int main(int argc, char *argv[]) {
  if (isFewArgs(argc)) {
    std::cerr << "Too few arguments." << std::endl;
    return -1;
  }

  std::string s1(argv[1]);
  std::string s2(argv[2]);
  bool fileExist = true;

  if (!isFileExist(s1)) {
    std::cerr << s1 << " is invalid." << std::endl;
    fileExist = false;
  }

  if (!isFileExist(s2)) {
    std::cerr << s2 << " is invalid." << std::endl;
    fileExist = false;
  }

  if (!fileExist) {
    return -1;
  }

  unifiedDiff(s1, s2);
  return 0;
}