/**
 * Furnace Tracker - multi-system chiptune tracker
 * Copyright (C) 2021-2025 tildearrow and contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _USE_MATH_DEFINES
#include "gui.h"
#include "guiConst.h"
#include "imgui.h"
#include "imgui_internal.h"
#include "misc/cpp/imgui_stdlib.h"

#define FURNACE_TUNER_FFT_SIZE 16384

void FurnaceGUI::drawTuner() {
  if (nextWindow==GUI_WINDOW_TUNER) {
    tunerOpen=true;
    ImGui::SetNextWindowFocus();
    nextWindow=GUI_WINDOW_NOTHING;
  }
  if (!tunerOpen) return;
  if (ImGui::Begin("Tuner",&tunerOpen,globalWinFlags|ImGuiWindowFlags_NoScrollbar,_("Tuner"))) {
    // fft buffer
    if (!tunerFFTInBuf) tunerFFTInBuf=new double[FURNACE_TUNER_FFT_SIZE];
    if (!tunerFFTOutBuf) tunerFFTOutBuf=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*FURNACE_TUNER_FFT_SIZE);

    if (!tunerPlan) {
      tunerPlan=fftw_plan_dft_r2c_1d(FURNACE_TUNER_FFT_SIZE,tunerFFTInBuf,tunerFFTOutBuf,FFTW_ESTIMATE);
    }

    int chans=e->getAudioDescGot().outChans;
    int needle=e->oscReadPos;

    for (int j=0; j<FURNACE_TUNER_FFT_SIZE; j++) {
      int pos=(needle-FURNACE_TUNER_FFT_SIZE+j)&0x7fff;
      double sample=0.0;
      for (int ch=0; ch<chans; ch++) {
        sample+=e->oscBuf[ch][pos];
      }
      sample=sample/chans;

      tunerFFTInBuf[j]=sample*(0.5*(1.0-cos(2.0*M_PI*j/(FURNACE_TUNER_FFT_SIZE-1))));
    }

    fftw_execute(tunerPlan);

    std::vector<double> mag(FURNACE_TUNER_FFT_SIZE/2);
    mag[0]=0;
    mag[1]=0;
    mag[2]=0;
    mag[3]=0; // skip some of the low frequencies
    for (int k=4; k<FURNACE_TUNER_FFT_SIZE/2; k++) {
      mag[k]=sqrt(tunerFFTOutBuf[k][0]*tunerFFTOutBuf[k][0]+tunerFFTOutBuf[k][1]*tunerFFTOutBuf[k][1]);
    }

    // harmonic product spectrum
    int harmonics=1; // disabled for now...
    for (int h=2; h<=harmonics; h++) {
      for (int k=8; k<FURNACE_TUNER_FFT_SIZE/(2*h); k++) {
        mag[k]*=mag[k*h];
      }
    }

    double sampleRate=e->getAudioDescGot().rate;
    // peak with interpolation
    int peakIndex=std::distance(mag.begin(),std::max_element(mag.begin(),mag.end()));

    double freq=0.0;
    if (peakIndex>0 && peakIndex<(int)mag.size()-1) {
      double alpha=mag[peakIndex-1];
      double beta=mag[peakIndex];
      double gamma=mag[peakIndex+1];
      double p=0.5*(alpha-gamma)/(alpha-2.0*beta+gamma);
      freq=(peakIndex+p)*(sampleRate/(double)FURNACE_TUNER_FFT_SIZE);
    } else {
      freq=(double)peakIndex*(sampleRate/(double)FURNACE_TUNER_FFT_SIZE);
    }

    // tuning formulas
    double noteExact=0.0;
    int noteRounded=0;
    double cents=0.0f;
    String noteText="---", subtext="";
    if (freq>0 && freq<5000.0) {
      noteExact=CLAMP(log2(freq/e->song.tuning)*12.0+117.0,0,180);
      noteRounded=round(noteExact);
      cents=(noteExact-noteRounded);
      noteText=fmt::sprintf("%s",noteName(noteRounded));
      subtext=fmt::sprintf("%3.3f Hz %dc",freq,(int)(cents*100.0f));
    }

    {
      ImDrawList* dl=ImGui::GetWindowDrawList();
      ImVec2 origin=ImGui::GetWindowPos();
      ImVec2 size=ImGui::GetWindowSize();
      float titleBar=ImGui::GetCurrentWindow()->TitleBarHeight;
      origin.y+=titleBar;
      size.y-=titleBar;
      // debug stuff
      // ImVec2* plot=new ImVec2[FURNACE_TUNER_FFT_SIZE];
      // for (size_t i=0; i<FURNACE_TUNER_FFT_SIZE; i++) {
      //   plot[i].x=origin.x+size.x*(float)i/FURNACE_TUNER_FFT_SIZE;
      //   plot[i].y=origin.y+size.y-size.y*(tunerFFTInBuf[i]+1.0f)/2.0f;
      // }
      // dl->AddPolyline(plot, FURNACE_TUNER_FFT_SIZE, 0xff00ff00, 0, 1.0f);
      // for (size_t i=0; i<mag.size(); i++) {
      //   plot[i].x=origin.x+size.x*scaleFuncLog((float)i/mag.size());
      //   plot[i].y=origin.y+size.y-size.y*(mag[i]/FURNACE_TUNER_FFT_SIZE);
      // }
      // dl->AddPolyline(plot, mag.size(), 0xffffffff, 0, 1.0f);
      // dl->AddLine(origin+ImVec2(size.x*scaleFuncLog((double)peakIndex/(mag.size()-1)),0),origin+ImVec2(size.x*scaleFuncLog((double)peakIndex/(mag.size()-1)),size.y), 0xff000fff);
      // delete[] plot;
      const float boxHeight=20.0f*dpiScale;
      const float needleHeight=18.0f*dpiScale;
      ImU32 lowColor=ImGui::GetColorU32(uiColors[GUI_COLOR_TUNER_SCALE_LOW]);
      ImU32 highColor=ImGui::GetColorU32(uiColors[GUI_COLOR_TUNER_SCALE_HIGH]);

      // needle bg
      ImGui::Dummy(ImVec2(size.x,boxHeight));
      dl->AddRectFilledMultiColor(origin,origin+ImVec2(size.x/2.0f,boxHeight),highColor,lowColor,lowColor,highColor);
      dl->AddRectFilledMultiColor(origin+ImVec2(size.x/2.0f,0),origin+ImVec2(size.x,boxHeight),lowColor,highColor,highColor,lowColor);
      dl->AddLine(origin+ImVec2(size.x/2.0f,0),origin+ImVec2(size.x/2.0f,boxHeight),ImGui::GetColorU32(uiColors[GUI_COLOR_TUNER_NEEDLE]),2.0f*dpiScale);
      // needle
      float needleX=size.x*(0.5f+cents);
      dl->AddLine(origin+ImVec2(needleX,boxHeight-needleHeight),origin+ImVec2(needleX,needleHeight),ImGui::GetColorU32(uiColors[GUI_COLOR_TUNER_NEEDLE]),4.0f*dpiScale);
      // text
      ImGui::PushFont(bigFont);
      ImVec2 textSize=ImGui::CalcTextSize(noteText.c_str());
      ImGui::SetCursorPosX((size.x-textSize.x)/2.0f);
      ImGui::TextUnformatted(noteText.c_str());
      ImGui::PopFont();
      textSize=ImGui::CalcTextSize(subtext.c_str());
      ImGui::SetCursorPosX((size.x-textSize.x)/2.0f);
      ImGui::TextUnformatted(subtext.c_str());
      // piano
      int noteMod=noteRounded%12;
      ImVec2 pianoPos=ImGui::GetCursorScreenPos();
      pianoPos.x=ImGui::GetWindowPos().x;
      ImVec2 pianoSize=ImVec2(ImGui::GetWindowSize().x,ImGui::GetContentRegionAvail().y);
      if (pianoSize.y>1.0f) {
        float keySize=pianoSize.x/7.0f;
        for (int i=0; i<7; i++) {
          dl->AddRectFilled(
            pianoPos+ImVec2(keySize*i,0),
            pianoPos+ImVec2(keySize*(i+1),pianoSize.y),
            ImGui::GetColorU32(uiColors[(noteRounded && bottomKeyNotes[i]==noteMod)?GUI_COLOR_PIANO_KEY_BOTTOM_HIT:GUI_COLOR_PIANO_KEY_BOTTOM]));
          dl->AddLine(
            pianoPos+ImVec2(keySize*i,0),
            pianoPos+ImVec2(keySize*i,pianoSize.y),
            ImGui::GetColorU32(uiColors[GUI_COLOR_PIANO_BACKGROUND]),
          dpiScale);
        }
        for (int i=0; i<5; i++) {
          dl->AddRectFilled(
            pianoPos+ImVec2(pianoSize.x*topKeyStarts[i]-keySize/3.0f,0),
            pianoPos+ImVec2(pianoSize.x*topKeyStarts[i]+keySize/3.0f,2.0f*pianoSize.y/3.0f),
            ImGui::GetColorU32(uiColors[(noteRounded && topKeyNotes[i]==noteMod)?GUI_COLOR_PIANO_KEY_TOP_HIT:GUI_COLOR_PIANO_KEY_TOP]));
        }
        ImGui::Dummy(pianoSize);
      }
    }
  }

  if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows))
    curWindow=GUI_WINDOW_TUNER;

  ImGui::End();
}