#include "Core.hpp"
#include "midi.hpp"
#include "dsp/digital.hpp"

#include <algorithm>


struct QuadMIDIToCVInterface : Module {
	enum ParamIds {
		NUM_PARAMS
	};
	enum InputIds {
		NUM_INPUTS
	};
	enum OutputIds {
		ENUMS(CV_OUTPUT, 4),
		ENUMS(GATE_OUTPUT, 4),
		ENUMS(VELOCITY_OUTPUT, 4),
		ENUMS(AFTERTOUCH_OUTPUT, 4),
		NUM_OUTPUTS
	};
	enum LightIds {
		NUM_LIGHTS
	};

	MidiInputQueue midiInput;

	enum PolyMode {
		ROTATE_MODE,
		// Added REUSE option that reuses a channel when receiving the same note.
		// Good when using sustain pedal so it doesn't "stack" unisons ... not sure this is the best name but it is descriptive...
		REUSE_MODE,
		RESET_MODE,
		REASSIGN_MODE,
		UNISON_MODE,
		NUM_MODES
	};
	PolyMode polyMode = ROTATE_MODE;

	struct NoteData {
		uint8_t velocity = 0;
		uint8_t aftertouch = 0;
	};

	NoteData noteData[128];
	// cachedNotes : UNISON_MODE and REASSIGN_MODE cache all played notes. The other polyModes cache stolen notes (after the 4th one).
	std::vector<uint8_t> cachedNotes;
	uint8_t notes[4];
	bool gates[4];
	// gates set to TRUE by pedal and current gate. FALSE by pedal.
	bool pedalgates[4];
	bool pedal;
	int rotateIndex;
	int stealIndex;

	QuadMIDIToCVInterface() : Module(NUM_PARAMS, NUM_INPUTS, NUM_OUTPUTS, NUM_LIGHTS), cachedNotes(128) {
		onReset();
	}

	json_t *toJson() override {
		json_t *rootJ = json_object();
		json_object_set_new(rootJ, "midi", midiInput.toJson());
		json_object_set_new(rootJ, "polyMode", json_integer(polyMode));
		return rootJ;
	}

	void fromJson(json_t *rootJ) override {
		json_t *midiJ = json_object_get(rootJ, "midi");
		if (midiJ)
			midiInput.fromJson(midiJ);

		json_t *polyModeJ = json_object_get(rootJ, "polyMode");
		if (polyModeJ)
			polyMode = (PolyMode) json_integer_value(polyModeJ);
	}

	void onReset() override {
		for (int i = 0; i < 4; i++) {
			notes[i] = 60;
			gates[i] = false;
			pedalgates[i] = false;
		}
		pedal = false;
		rotateIndex = -1;
		cachedNotes.clear();
	}

	int getPolyIndex(int nowIndex) {
		for (int i = 0; i < 4; i++) {
			nowIndex++;
			if (nowIndex > 3)
				nowIndex = 0;
			if (!(gates[nowIndex] || pedalgates[nowIndex])) {
				stealIndex = nowIndex;
				return nowIndex;
			}
		}
		// All taken = steal (stealIndex always rotates)
		stealIndex++;
		if (stealIndex > 3)
			stealIndex = 0;
		if ((polyMode < REASSIGN_MODE) && (gates[stealIndex]))
			cachedNotes.push_back(notes[stealIndex]);
		return stealIndex;
	}

	void pressNote(uint8_t note) {
		// Set notes and gates
		switch (polyMode) {
			case ROTATE_MODE: {
				rotateIndex = getPolyIndex(rotateIndex);
			} break;

			case REUSE_MODE: {
				bool reuse = false;
				for (int i = 0; i < 4; i++) {
					if (notes[i] == note) {
						rotateIndex = i;
						reuse = true;
						break;
					}
				}
				if (!reuse)
					rotateIndex = getPolyIndex(rotateIndex);
			} break;

			case RESET_MODE: {
				rotateIndex = getPolyIndex(-1);
			} break;

			case REASSIGN_MODE: {
				cachedNotes.push_back(note);
				rotateIndex = getPolyIndex(-1);
			} break;

			case UNISON_MODE: {
				cachedNotes.push_back(note);
				for (int i = 0; i < 4; i++) {
					notes[i] = note;
					gates[i] = true;
					pedalgates[i] = pedal;
					// reTrigger[i].trigger(1e-3);
				}
				return;
			} break;

			default: break;
		}
		// Set notes and gates
		// if (gates[rotateIndex] || pedalgates[rotateIndex])
		// 	reTrigger[rotateIndex].trigger(1e-3);
		notes[rotateIndex] = note;
		gates[rotateIndex] = true;
		pedalgates[rotateIndex] = pedal;
	}

	void releaseNote(uint8_t note) {
		// Remove the note
		auto it = std::find(cachedNotes.begin(), cachedNotes.end(), note);
		if (it != cachedNotes.end())
			cachedNotes.erase(it);

		switch (polyMode) {
			case REASSIGN_MODE: {
				for (int i = 0; i < 4; i++) {
					if (i < (int) cachedNotes.size()) {
						if (!pedalgates[i])
							notes[i] = cachedNotes[i];
						pedalgates[i] = pedal;
					}
					else {
						gates[i] = false;
					}
				}
			} break;

			case UNISON_MODE: {
				if (!cachedNotes.empty()) {
					uint8_t backnote = cachedNotes.back();
					for (int i = 0; i < 4; i++) {
						notes[i] = backnote;
						gates[i] = true;
					}
				}
				else {
					for (int i = 0; i < 4; i++) {
						gates[i] = false;
					}
				}
			} break;

			// default ROTATE_MODE REUSE_MODE RESET_MODE
			default: {
				for (int i = 0; i < 4; i++) {
					if (notes[i] == note) {
						if (pedalgates[i]) {
							gates[i] = false;
						}
						else if (!cachedNotes.empty()) {
							notes[i] = cachedNotes.back();
							cachedNotes.pop_back();
						}
						else {
							gates[i] = false;
						}
					}
				}
			} break;
		}
	}

	void pressPedal() {
		pedal = true;
		for (int i = 0; i < 4; i++) {
			pedalgates[i] = gates[i];
		}
	}

	void releasePedal() {
		pedal = false;
		// When pedal is off, recover notes for pressed keys (if any) after they were already being "cycled" out by pedal-sustained notes.
		for (int i = 0; i < 4; i++) {
			pedalgates[i] = false;
			if (!cachedNotes.empty()) {
				if (polyMode < REASSIGN_MODE) {
					notes[i] = cachedNotes.back();
					cachedNotes.pop_back();
					gates[i] = true;
				}
			}
		}
		if (polyMode == REASSIGN_MODE) {
			for (int i = 0; i < 4; i++) {
				if (i < (int) cachedNotes.size()) {
					notes[i] = cachedNotes[i];
					gates[i] = true;
				}
				else {
					gates[i] = false;
				}
			}
		}
	}

	void step() override {
		MidiMessage msg;
		while (midiInput.shift(&msg)) {
			processMessage(msg);
		}

		for (int i = 0; i < 4; i++) {
			uint8_t lastNote = notes[i];
			uint8_t lastGate = (gates[i] || pedalgates[i]);
			outputs[CV_OUTPUT + i].value = (lastNote - 60) / 12.f;
			outputs[GATE_OUTPUT + i].value = lastGate ? 10.f : 0.f;
			outputs[VELOCITY_OUTPUT + i].value = rescale(noteData[lastNote].velocity, 0, 127, 0.f, 10.f);
			outputs[AFTERTOUCH_OUTPUT + i].value = rescale(noteData[lastNote].aftertouch, 0, 127, 0.f, 10.f);
		}
	}

	void processMessage(MidiMessage msg) {
		// filter MIDI channel
		if ((midiInput.channel > -1) && (midiInput.channel != msg.channel()))
			return;

		switch (msg.status()) {
			// note off
			case 0x8: {
				releaseNote(msg.note());
			} break;
			// note on
			case 0x9: {
				if (msg.value() > 0) {
					noteData[msg.note()].velocity = msg.value();
					pressNote(msg.note());
				}
				else {
					releaseNote(msg.note());
				}
			} break;
			// channel aftertouch
			case 0xa: {
				noteData[msg.note()].aftertouch = msg.value();
			} break;
			// cc
			case 0xb: {
				processCC(msg);
			} break;
			default: break;
		}
	}

	void processCC(MidiMessage msg) {
		switch (msg.note()) {
			// sustain
			case 0x40: {
				if (msg.value() >= 64)
					pressPedal();
				else
					releasePedal();
			} break;
			default: break;
		}
	}
};


struct QuadMIDIToCVInterfaceWidget : ModuleWidget {
	QuadMIDIToCVInterfaceWidget(QuadMIDIToCVInterface *module) : ModuleWidget(module) {
		setPanel(SVG::load(assetGlobal("res/Core/QuadMIDIToCVInterface.svg")));

		addChild(Widget::create<ScrewSilver>(Vec(RACK_GRID_WIDTH, 0)));
		addChild(Widget::create<ScrewSilver>(Vec(box.size.x - 2 * RACK_GRID_WIDTH, 0)));
		addChild(Widget::create<ScrewSilver>(Vec(RACK_GRID_WIDTH, RACK_GRID_HEIGHT - RACK_GRID_WIDTH)));
		addChild(Widget::create<ScrewSilver>(Vec(box.size.x - 2 * RACK_GRID_WIDTH, RACK_GRID_HEIGHT - RACK_GRID_WIDTH)));

		addOutput(Port::create<PJ301MPort>(mm2px(Vec(3.894335, 60.144478)), Port::OUTPUT, module, QuadMIDIToCVInterface::CV_OUTPUT + 0));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(15.494659, 60.144478)), Port::OUTPUT, module, QuadMIDIToCVInterface::GATE_OUTPUT + 0));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(27.094986, 60.144478)), Port::OUTPUT, module, QuadMIDIToCVInterface::VELOCITY_OUTPUT + 0));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(38.693935, 60.144478)), Port::OUTPUT, module, QuadMIDIToCVInterface::AFTERTOUCH_OUTPUT + 0));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(3.894335, 76.144882)), Port::OUTPUT, module, QuadMIDIToCVInterface::CV_OUTPUT + 1));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(15.494659, 76.144882)), Port::OUTPUT, module, QuadMIDIToCVInterface::GATE_OUTPUT + 1));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(27.094986, 76.144882)), Port::OUTPUT, module, QuadMIDIToCVInterface::VELOCITY_OUTPUT + 1));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(38.693935, 76.144882)), Port::OUTPUT, module, QuadMIDIToCVInterface::AFTERTOUCH_OUTPUT + 1));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(3.894335, 92.143906)), Port::OUTPUT, module, QuadMIDIToCVInterface::CV_OUTPUT + 2));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(15.494659, 92.143906)), Port::OUTPUT, module, QuadMIDIToCVInterface::GATE_OUTPUT + 2));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(27.094986, 92.143906)), Port::OUTPUT, module, QuadMIDIToCVInterface::VELOCITY_OUTPUT + 2));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(38.693935, 92.143906)), Port::OUTPUT, module, QuadMIDIToCVInterface::AFTERTOUCH_OUTPUT + 2));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(3.894335, 108.1443)), Port::OUTPUT, module, QuadMIDIToCVInterface::CV_OUTPUT + 3));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(15.494659, 108.1443)), Port::OUTPUT, module, QuadMIDIToCVInterface::GATE_OUTPUT + 3));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(27.094986, 108.1443)), Port::OUTPUT, module, QuadMIDIToCVInterface::VELOCITY_OUTPUT + 3));
		addOutput(Port::create<PJ301MPort>(mm2px(Vec(38.693935, 108.1443)), Port::OUTPUT, module, QuadMIDIToCVInterface::AFTERTOUCH_OUTPUT + 3));

		MidiWidget *midiWidget = Widget::create<MidiWidget>(mm2px(Vec(3.4009969, 14.837336)));
		midiWidget->box.size = mm2px(Vec(44, 28));
		midiWidget->midiIO = &module->midiInput;
		addChild(midiWidget);
	}

	void appendContextMenu(Menu *menu) override {
		QuadMIDIToCVInterface *module = dynamic_cast<QuadMIDIToCVInterface*>(this->module);

		struct PolyphonyItem : MenuItem {
			QuadMIDIToCVInterface *module;
			QuadMIDIToCVInterface::PolyMode polyMode;
			void onAction(EventAction &e) override {
				module->polyMode = polyMode;
				module->onReset();
			}
		};

		menu->addChild(MenuEntry::create());
		menu->addChild(MenuLabel::create("Polyphony mode"));
		std::vector<std::string> polyModeNames = {
			"Rotate",
			"Reuse",
			"Reset",
			"Reassign",
			"Unison"
		};
		for (int i = 0; i < QuadMIDIToCVInterface::NUM_MODES; i++) {
			PolyphonyItem *item = MenuItem::create<PolyphonyItem>(polyModeNames[i], CHECKMARK(module->polyMode == i));
			item->module = module;
			item->polyMode = (QuadMIDIToCVInterface::PolyMode) i;
			menu->addChild(item);
		}
	}
};


Model *modelQuadMIDIToCVInterface = Model::create<QuadMIDIToCVInterface, QuadMIDIToCVInterfaceWidget>("Core", "QuadMIDIToCVInterface", "MIDI-4", MIDI_TAG, EXTERNAL_TAG, QUAD_TAG);