/*
 * buck_emulator.c
 *
 *  Created on: 12 May 2025
 *      Author: Christian Lind Vie Madsen
 */
#include "buck_emulator.h"

static int isStructOk(BuckEmulator_t *inst){

	if(inst == NULL)return 0;

	return 1;

}

static void buck_emulator_step(BuckEmulator_t *inst, float duty_cycle) {

	float dIL_on = 0.0f, dIL_off = 0.0f;

	// ON-phase
	if (duty_cycle > 0.0f) {
	    float V_L_on = inst->Vin - inst->Vout;
	    dIL_on = (V_L_on / inst->L) * (duty_cycle * inst->dt);
	}

	// OFF-phase
	float V_L_off = 0.0f;
	if ((inst->IL + dIL_on) > 0.0f) {
	    V_L_off = -inst->Vout;  // Diode conducts
	    dIL_off = (V_L_off / inst->L) * ((1.0f - duty_cycle) * inst->dt);
	} else {
	    dIL_off = 0.0f;
	}

	// Total inductor current update
	inst->IL += dIL_on + dIL_off;
	if (inst->IL < 0.0f) inst->IL = 0.0f;

	// Capacitor current
	float capCurrent = inst->IL - inst->Vout / inst->Rload;

	// Diode blocking check
	if (inst->IL == 0.0f && capCurrent < 0.0f) {
	    capCurrent = 0.0f;
	}

	// Vout update
	float dVout = capCurrent / inst->C;
	inst->Vout += dVout * inst->dt;

	// Clamp Vout
	if (inst->Vout < 0.0f) inst->Vout = 0.0f;
	if (inst->Vout > inst->Vin) inst->Vout = inst->Vin;

    return;
}

int buck_emulator_Run(BuckEmulator_t *inst){

	if(!isStructOk(inst))return 1;

	float dutyCycle = 0.0;

	for(float t = 0.0; t < inst->simTime; t+=inst->dt){

		if(inst->regulate_evt != NULL)dutyCycle = inst->regulate_evt(inst->Vout);


		buck_emulator_step(inst, dutyCycle);

		if(inst->getResult_evt != NULL)inst->getResult_evt(dutyCycle,inst->Vout,t);
	}

	return 0;

}

int buck_emulator_RegGetResultEvt(BuckEmulator_t *inst, getResult_evt_t getRes_evt){

	if(!isStructOk(inst))return 1;

	if(getRes_evt != NULL){

		inst->getResult_evt = getRes_evt;
		return 0;
	}

	return 1;
}

int buck_emulator_RegRegulationEvt(BuckEmulator_t *inst, regulate_evt_t reg_evt){

	if(!isStructOk(inst))return 1;

	if(reg_evt != NULL){

		inst->regulate_evt = reg_evt;
		return 0;
	}

	return 1;
}

int buck_emulator_init(BuckEmulator_t *inst, float Vin, float L, float C, float Rload, float dt, float sim_time){

	if(!isStructOk(inst))return 1;

	inst->Vin = Vin;
	inst->L = L;
	inst->C = C;
	inst->Rload = Rload;
	inst->dt = dt;

	inst->Vout = 0.0;
	inst->IL = 0.0;

	inst->simTime = sim_time;

	return 0;

}