/*
  Copyright (c) 2021 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#include "audiosynth/WaveModifier_harmonics.h"
#include "utilities/lookup3.h"
#include <math.h>

#define stemobject_implementation WaveModifier_harmonics

stemobject_vtable_begin();
stemobject_vtable_entry(dispose);
stemobject_vtable_entry(copy);
stemobject_vtable_entry(isEqual);
stemobject_vtable_entry(hash);
stemobject_vtable_entry(initState);
stemobject_vtable_entry(disposeState);
stemobject_vtable_entry(setPropertyValue);
stemobject_vtable_entry(getOwnPropertyCount);
stemobject_vtable_entry(getOwnProperties);
stemobject_vtable_entry(sample);
stemobject_vtable_end();

WaveModifier_harmonics * WaveModifier_harmonics_create(float toneCount, float frequencySpacing, float falloff, bool averageAmplitude) {
	stemobject_create_implementation(init, toneCount, frequencySpacing, falloff, averageAmplitude)
}

bool WaveModifier_harmonics_init(WaveModifier_harmonics * self, float toneCount, float frequencySpacing, float falloff, bool averageAmplitude) {
	call_super(init, self);
	self->toneCount = toneCount;
	self->frequencySpacing = frequencySpacing;
	self->falloff = falloff;
	self->averageAmplitude = averageAmplitude;
	return true;
}

void WaveModifier_harmonics_dispose(WaveModifier_harmonics * self) {
	call_super_virtual(dispose, self);
}

WaveModifier_harmonics * WaveModifier_harmonics_copy(WaveModifier_harmonics * self) {
	stemobject_copy_implementation(initCopy)
}

bool WaveModifier_harmonics_isEqual(WaveModifier_harmonics * self, compat_type(WaveModifier_harmonics *) compareUntyped) {
	WaveModifier_harmonics * compare = compareUntyped;
	if (!call_super_virtual(isEqual, self, compare)) {
		return false;
	}
	return self->toneCount == compare->toneCount &&
	       self->frequencySpacing == compare->frequencySpacing &&
	       self->falloff == compare->falloff &&
	       self->averageAmplitude == compare->averageAmplitude;
}

uint32_t WaveModifier_harmonics_hash(WaveModifier_harmonics * self, uint32_t initval) {
	initval = hashlittle(&self->toneCount, sizeof(self->toneCount), initval);
	initval = hashlittle(&self->frequencySpacing, sizeof(self->frequencySpacing), initval);
	initval = hashlittle(&self->falloff, sizeof(self->falloff), initval);
	initval = hashlittle(&self->averageAmplitude, sizeof(self->averageAmplitude), initval);
	return initval;
}

void WaveModifier_harmonics_initCopy(WaveModifier_harmonics * self, WaveModifier_harmonics * original) {
	call_super(initCopy, self, (WaveModifier *) original);
	self->toneCount = original->toneCount;
	self->frequencySpacing = original->frequencySpacing;
	self->falloff = original->falloff;
	self->averageAmplitude = original->averageAmplitude;
}

#define PROPERTY_INDEX_BLEND 0
#define PROPERTY_INDEX_TONE_COUNT 1
#define PROPERTY_INDEX_FREQUENCY_SPACING 2
#define PROPERTY_INDEX_FALLOFF 3
#define PROPERTY_COUNT 4

struct WaveModifier_harmonics_state {
	SamplerObject_state * upstreamStates[WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX + 1];
	float properties[PROPERTY_COUNT];
};

SamplerObject_state * WaveModifier_harmonics_initState(WaveModifier_harmonics * self) {
	struct WaveModifier_harmonics_state * stateStruct = malloc(sizeof(*stateStruct));
	stateStruct->properties[PROPERTY_INDEX_BLEND] = self->blend;
	stateStruct->properties[PROPERTY_INDEX_TONE_COUNT] = self->toneCount;
	stateStruct->properties[PROPERTY_INDEX_FREQUENCY_SPACING] = self->frequencySpacing;
	stateStruct->properties[PROPERTY_INDEX_FALLOFF] = self->falloff;
	for (unsigned int toneIndex = 0; toneIndex <= WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX; toneIndex++) {
		stateStruct->upstreamStates[toneIndex] = call_virtual(initState, self->upstream);
	}
	return stateStruct;
}

void WaveModifier_harmonics_disposeState(WaveModifier_harmonics * self, SamplerObject_state * state) {
	struct WaveModifier_harmonics_state * stateStruct = state;
	for (unsigned int toneIndex = 0; toneIndex <= WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX; toneIndex++) {
		call_virtual(disposeState, self->upstream, stateStruct->upstreamStates[toneIndex]);
	}
	free(state);
}

void WaveModifier_harmonics_setPropertyValue(WaveModifier_harmonics * self, SamplerObject_state * state, SynthPropertyIdentifier propertyIdentifier, float value) {
	struct WaveModifier_harmonics_state * stateStruct = state;
	if (propertyIdentifier.propertyIndex < 4) {
		stateStruct->properties[propertyIdentifier.propertyIndex] = value;
	} else {
		propertyIdentifier.propertyIndex -= 4;
		for (unsigned int toneIndex = 0; toneIndex <= WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX; toneIndex++) {
			call_virtual(setPropertyValue, self->upstream, stateStruct->upstreamStates[toneIndex], propertyIdentifier, value);
		}
	}
}

unsigned int WaveModifier_harmonics_getOwnPropertyCount(WaveModifier_harmonics * self) {
	return PROPERTY_COUNT;
}

SynthProperty * WaveModifier_harmonics_getOwnProperties(WaveModifier_harmonics * self) {
	static SynthProperty properties[PROPERTY_COUNT] = {
		{.propertyIndex = 0, .description = "Blend (harmonics)", .offset = offsetof(WaveModifier_harmonics, blend),            .minValue = 0.0f, .maxValue = 1.0f, .defaultValue = 1.0f, .stepIncrement = 0.05f},
		{.propertyIndex = 1, .description = "Tone count",        .offset = offsetof(WaveModifier_harmonics, toneCount),        .minValue = 0.0f, .maxValue = WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX, .defaultValue = 4.0f, .stepIncrement = 1.0f},
		{.propertyIndex = 2, .description = "Tone spacing",      .offset = offsetof(WaveModifier_harmonics, frequencySpacing), .minValue = 0.0f, .maxValue = 2.0f, .defaultValue = 1.0f, .stepIncrement = 1.0f / 12.0f},
		{.propertyIndex = 3, .description = "Falloff",           .offset = offsetof(WaveModifier_harmonics, falloff),          .minValue = 0.0f, .maxValue = 1.0f, .defaultValue = 0.5f, .stepIncrement = 0.05f}
	};
	return properties;
}

float WaveModifier_harmonics_sample(WaveModifier_harmonics * self, SamplerObject_state * state, float phase, float phaseDelta, float time, float timeDelta) {
	struct WaveModifier_harmonics_state * stateStruct = state;
	float blend = stateStruct->properties[PROPERTY_INDEX_BLEND];
	float toneCount = fminf(stateStruct->properties[PROPERTY_INDEX_TONE_COUNT], WAVE_MODIFIER_HARMONICS_TONE_COUNT_MAX);
	float frequencySpacing = stateStruct->properties[PROPERTY_INDEX_FREQUENCY_SPACING];
	float falloff = stateStruct->properties[PROPERTY_INDEX_FALLOFF];
	float sample = call_virtual(sample, self->upstream, stateStruct->upstreamStates[0], phase, phaseDelta, time, timeDelta);
	float amplitudeTotal = 1.0f;
	float modifiedSample = sample;
	unsigned int toneCountInteger = ceilf(toneCount);
	for (unsigned int toneIndex = 0; toneIndex < toneCountInteger; toneIndex++) {
		float amplitude = powf(falloff, toneIndex + 1) * fminf(1.0f, toneCount - toneIndex);
		float multiplier = 1.0f + frequencySpacing * (toneIndex + 1);
		modifiedSample += call_virtual(sample, self->upstream, stateStruct->upstreamStates[toneIndex + 1], phase * multiplier, phaseDelta * multiplier, time, timeDelta) * amplitude;
		amplitudeTotal += amplitude;
	}
	if (self->averageAmplitude) {
		modifiedSample /= amplitudeTotal;
	}
	return modifiedSample * blend + sample * (1.0f - blend);
}