#include <stdio.h>
#include <string.h>

#include "battery.h"

#include "esp_log.h"
#include "esp_adc/adc_oneshot.h"
#include "esp_adc/adc_cali.h"
#include "esp_adc/adc_cali_scheme.h"

#define TAG "battery"

battery_conf_t* get_battery_configuration(nvs_handle_t nvs){
	battery_conf_t* conf = malloc(sizeof(battery_conf_t));

  conf->read_retry_nb = 5;
  
	ESP_ERROR_CHECK(nvs_get_u16(nvs, "poll_delay", &conf->poll_delay));
	
	uint16_t min_mv, max_mv;
	nvs_get_u16(nvs, "min_mv", &min_mv);
	nvs_get_u16(nvs, "max_mv", &max_mv);
	
	battery_data_t data = {
		.battery_percent = 0,
		.min_mv = min_mv,
		.scale = (max_mv - min_mv) / 100,
	};

	ESP_LOGI("CONF", "min %d, max %d, scale %d", data.min_mv, max_mv,  data.scale);
	
	battery_data_t* data_h = malloc(sizeof(battery_data_t));
	memcpy(data_h, &data, sizeof(battery_data_t));
	conf->data = data_h;
	conf->adc_channel = CONFIG_BATTMS_CHANNEL;
	return conf;
}

void update_battery_level(battery_conf_t* batt_conf){
	int val_raw = 0;
  for(int tries=0; tries < batt_conf->read_retry_nb; tries++){
		esp_err_t res = ESP_OK;
		res = adc_oneshot_read(batt_conf->adc_handle, batt_conf->adc_channel, &val_raw);
		if(res == ESP_ERR_TIMEOUT)// valeur invalide
      continue;
    
		ESP_ERROR_CHECK(res);
		battery_data_t* data = batt_conf->data;
		int val_mv=0;
		ESP_ERROR_CHECK(adc_cali_raw_to_voltage(batt_conf->cali_handle, val_raw, &val_mv));
		val_mv *= 2; // external voltage divider
		data->battery_mv = val_mv;
		if(val_mv < data->min_mv) data->battery_percent = 0;
		else data->battery_percent = (val_mv - data->min_mv) / data->scale;
		ESP_LOGI("BATTMS", "raw : %d, mv : %d, percent : %d, min %d, scale %d", val_raw, val_mv, data->battery_percent, data->min_mv, data->scale);
    break;
	}
}

void init_battery_level_adc(battery_conf_t* batt_conf){
	adc_oneshot_unit_init_cfg_t init_config1 = {
    .unit_id = ADC_UNIT_1,
    .ulp_mode = ADC_ULP_MODE_DISABLE,
	};
	ESP_LOGI(TAG, "pointer inir config  %d", (int)&init_config1);
	ESP_ERROR_CHECK(adc_oneshot_new_unit(&init_config1, &batt_conf->adc_handle));

	adc_bitwidth_t bitwidth = ADC_BITWIDTH_DEFAULT;
	switch(CONFIG_BATTMS_ADC_BITWIDTH){
		case 9:
			bitwidth = ADC_BITWIDTH_9;
		break;
		case 10:
			bitwidth = ADC_BITWIDTH_10;
		break;
		case 11:
			bitwidth = ADC_BITWIDTH_11;
		break;
		case 12:
			bitwidth = ADC_BITWIDTH_12;
		break;
		case 13:
			bitwidth = ADC_BITWIDTH_13;
		break;
		default:
			bitwidth = ADC_BITWIDTH_DEFAULT;
		break;
	}
	
	adc_oneshot_chan_cfg_t config = {
    .bitwidth = bitwidth,
    .atten = ADC_ATTEN_DB_11,
	};
	ESP_ERROR_CHECK(adc_oneshot_config_channel(batt_conf->adc_handle, batt_conf->adc_channel, &config));

	adc_cali_curve_fitting_config_t cali_config = {
    .unit_id = ADC_UNIT_1,
    .atten = ADC_ATTEN_DB_11,
    .bitwidth = bitwidth,
	};
	ESP_ERROR_CHECK(adc_cali_create_scheme_curve_fitting(&cali_config, &batt_conf->cali_handle));
}