// Copyright 2013 Emilie Gillet.
//
// Author: Emilie Gillet (emilie.o.gillet@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// 
// See http://creativecommons.org/licenses/MIT/ for more information.
//
// -----------------------------------------------------------------------------
//
// Multistage envelope.

#ifndef PEAKS_MODULATIONS_MULTISTAGE_ENVELOPE_H_
#define PEAKS_MODULATIONS_MULTISTAGE_ENVELOPE_H_

#include "stmlib/stmlib.h"
#include "stmlib/utils/ring_buffer.h"

#include "peaks/gate_processor.h"

namespace peaks {

enum EnvelopeShape {
  ENV_SHAPE_LINEAR,
  ENV_SHAPE_EXPONENTIAL,
  ENV_SHAPE_QUARTIC
};

const uint16_t kMaxNumSegments = 8;

class MultistageEnvelope {
 public:
  MultistageEnvelope() { }
  ~MultistageEnvelope() { }
  
  void Init();
  void Process(const GateFlags* gate_flags, int16_t* out, size_t size);
  
  void Configure(uint16_t* parameter, ControlMode control_mode) {
    if (control_mode == CONTROL_MODE_HALF) {
      set_ad(parameter[0], parameter[1]);
    } else {
      set_adsr(parameter[0], parameter[1], parameter[2] >> 1, parameter[3]);
    }
    if (segment_ > num_segments_) {
      segment_ = 0;
      phase_ = 0;
      value_ = 0;
    }
  }
  
  inline void set_time(uint16_t segment, uint16_t time) {
    time_[segment] = time;
  }
  
  inline void set_level(uint16_t segment, int16_t level) {
    level_[segment] = level;
  }
  
  inline void set_num_segments(uint16_t num_segments) {
    num_segments_ = num_segments;
  }
  
  inline void set_sustain_point(uint16_t sustain_point) {
    sustain_point_ = sustain_point;
  }
  
  inline void set_adsr(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 3;
    sustain_point_ = 2;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = release;
    
    shape_[0] = ENV_SHAPE_QUARTIC;
    shape_[1] = ENV_SHAPE_EXPONENTIAL;
    shape_[2] = ENV_SHAPE_EXPONENTIAL;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_ad(uint16_t attack, uint16_t decay) {
    num_segments_ = 2;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = 0;

    time_[0] = attack;
    time_[1] = decay;
    
    shape_[0] = ENV_SHAPE_EXPONENTIAL;
    shape_[1] = ENV_SHAPE_EXPONENTIAL;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_adr(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 3;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = release;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    shape_[2] = ENV_SHAPE_LINEAR;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_ar(uint16_t attack, uint16_t decay) {
    num_segments_ = 2;
    sustain_point_ = 1;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = 0;

    time_[0] = attack;
    time_[1] = decay;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_adsar(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 4;
    sustain_point_ = 2;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 32767;
    level_[4] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = attack;
    time_[3] = release;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    shape_[2] = ENV_SHAPE_LINEAR;
    shape_[3] = ENV_SHAPE_LINEAR;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_adar(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 4;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 32767;
    level_[4] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = attack;
    time_[3] = release;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    shape_[2] = ENV_SHAPE_LINEAR;
    shape_[3] = ENV_SHAPE_LINEAR;
    
    loop_start_ = loop_end_ = 0;
  }
  
  inline void set_ad_loop(uint16_t attack, uint16_t decay) {
    num_segments_ = 2;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = 0;

    time_[0] = attack;
    time_[1] = decay;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    
    loop_start_ = 0;
    loop_end_ = 2;
  }
  
  inline void set_adr_loop(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 3;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = release;
    
    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    shape_[2] = ENV_SHAPE_LINEAR;
    
    loop_start_ = 0;
    loop_end_ = 3;
  }
  
  inline void set_adar_loop(
      uint16_t attack,
      uint16_t decay,
      uint16_t sustain,
      uint16_t release) {
    num_segments_ = 4;
    sustain_point_ = 0;

    level_[0] = 0;
    level_[1] = 32767;
    level_[2] = sustain;
    level_[3] = 32767;
    level_[4] = 0;

    time_[0] = attack;
    time_[1] = decay;
    time_[2] = attack;
    time_[3] = release;

    shape_[0] = ENV_SHAPE_LINEAR;
    shape_[1] = ENV_SHAPE_LINEAR;
    shape_[2] = ENV_SHAPE_LINEAR;
    shape_[3] = ENV_SHAPE_LINEAR;

    loop_start_ = 0;
    loop_end_ = 4;
  }
  
  inline void set_hard_reset(bool hard_reset) {
    hard_reset_ = hard_reset;
  }
  
 private:
  int16_t level_[kMaxNumSegments] = {};
  uint16_t time_[kMaxNumSegments] = {};
  EnvelopeShape shape_[kMaxNumSegments] = {};
  
  int16_t segment_;
  int16_t start_value_;
  int16_t value_;

  uint32_t phase_;
  uint32_t phase_increment_;
  
  uint16_t num_segments_;
  uint16_t sustain_point_;
  uint16_t loop_start_;
  uint16_t loop_end_;
  
  bool hard_reset_;
  
  DISALLOW_COPY_AND_ASSIGN(MultistageEnvelope);
};

}  // namespace peaks

#endif  // PEAKS_MODULATIONS_MULTISTAGE_ENVELOPE_H_
