#include <cstdio>
#include <fstream>
#include <iostream>
#include <map>
#include <sstream>
#include <string>
#include <vector>

struct Sample {
  std::string name;
  float freq, dur, amp, attack, harmonic_decay;
  int harmonics;
};

struct Event {
  float beat;
  std::string sample_name;
  float volume, pan;
};

struct Pattern {
  std::string name;
  std::vector<Event> events;
};

struct Trigger {
  float time;
  std::string pattern_name;
};

int main(int argc, char** argv) {
  if (argc < 3) {
    fprintf(stderr, "Usage: %s <input.track> <output.cc>\n", argv[0]);
    return 1;
  }

  std::ifstream in(argv[1]);
  if (!in.is_open()) {
    fprintf(stderr, "Could not open input file: %s\n", argv[1]);
    return 1;
  }

  float bpm = 120.0f;
  std::vector<Sample> samples;
  std::map<std::string, int> sample_map;
  std::vector<Pattern> patterns;
  std::map<std::string, int> pattern_map;
  std::vector<Trigger> score;

  std::string line;
  std::string current_section = "";

  while (std::getline(in, line)) {
    if (line.empty() || line[0] == '#')
      continue;

    std::stringstream ss(line);
    std::string cmd;
    ss >> cmd;

    if (cmd == "BPM") {
      ss >> bpm;
    } else if (cmd == "SAMPLE") {
      Sample s;
      std::string name;
      ss >> name;
      if (name.back() == ',')
        name.pop_back();
      s.name = name;

      // Very simple parsing: freq, dur, amp, attack, harmonics, harmonic_decay
      char comma;
      ss >> s.freq >> comma >> s.dur >> comma >> s.amp >> comma >> s.attack >>
          comma >> s.harmonics >> comma >> s.harmonic_decay;

      sample_map[s.name] = samples.size();
      samples.push_back(s);
    } else if (cmd == "PATTERN") {
      Pattern p;
      ss >> p.name;
      current_section = "PATTERN:" + p.name;
      patterns.push_back(p);
      pattern_map[p.name] = patterns.size() - 1;
    } else if (cmd == "SCORE") {
      current_section = "SCORE";
    } else {
      if (current_section.rfind("PATTERN:", 0) == 0) {
        // Parse event: beat, sample, vol, pan
        Event e;
        float beat;
        std::stringstream ss2(line);
        ss2 >> beat;
        char comma;
        ss2 >> comma;
        std::string sname;
        ss2 >> sname;
        if (sname.back() == ',')
          sname.pop_back();
        e.beat = beat;
        e.sample_name = sname;
        ss2 >> e.volume >> comma >> e.pan;
        patterns.back().events.push_back(e);
      } else if (current_section == "SCORE") {
        Trigger t;
        float time;
        std::stringstream ss2(line);
        ss2 >> time;
        char comma;
        ss2 >> comma;
        std::string pname;
        ss2 >> pname;
        t.time = time;
        t.pattern_name = pname;
        score.push_back(t);
      }
    }
  }

  FILE* out_file = fopen(argv[2], "w");
  if (!out_file) {
    fprintf(stderr, "Could not open output file: %s\n", argv[2]);
    return 1;
  }
  fprintf(out_file, "// Generated by tracker_compiler. Do not edit.\n\n");
  fprintf(out_file, "#include \"audio/tracker.h\"\n\n");

  fprintf(out_file, "const NoteParams g_tracker_samples[] = {\n");
  for (const auto& s : samples) {
    fprintf(out_file,
            "    { %.1ff, %.2ff, %.1ff, %.2ff, 0.0f, 0.0f, 0.0f, %d, %.1ff, "
            "0.0f, 0.0f }, // %s\n",
            s.freq, s.dur, s.amp, s.attack, s.harmonics, s.harmonic_decay,
            s.name.c_str());
  }
  fprintf(out_file, "};\n");
  fprintf(out_file, "const uint32_t g_tracker_samples_count = %zu;\n\n",
          samples.size());

  for (const auto& p : patterns) {
    fprintf(out_file, "static const TrackerEvent PATTERN_EVENTS_%s[] = {\n",
            p.name.c_str());
    for (const auto& e : p.events) {
      fprintf(out_file, "    { %.1ff, %d, %.1ff, %.1ff },\n", e.beat,
              sample_map[e.sample_name], e.volume, e.pan);
    }
    fprintf(out_file, "};\n");
  }
  fprintf(out_file, "\n");

  fprintf(out_file, "const TrackerPattern g_tracker_patterns[] = {\n");
  for (const auto& p : patterns) {
    fprintf(out_file, "    { PATTERN_EVENTS_%s, %zu, 4.0f }, // %s\n",
            p.name.c_str(), p.events.size(), p.name.c_str());
  }
  fprintf(out_file, "};\n");
  fprintf(out_file, "const uint32_t g_tracker_patterns_count = %zu;\n\n",
          patterns.size());

  fprintf(out_file,
          "static const TrackerPatternTrigger SCORE_TRIGGERS[] = {\n");
  for (const auto& t : score) {
    fprintf(out_file, "    { %.1ff, %d },\n", t.time,
            pattern_map[t.pattern_name]);
  }
  fprintf(out_file, "};\n\n");

  fprintf(out_file, "const TrackerScore g_tracker_score = {\n");
  fprintf(out_file, "    SCORE_TRIGGERS, %zu, %.1ff\n", score.size(), bpm);
  fprintf(out_file, "};\n");

  fclose(out_file);

  return 0;
}