#include <avr/io.h>
#include <avr/eeprom.h>

#include "lights.h"

#define AMBIENT_VAL_SHIFT 2
static uint16_t ambient_val;
volatile unsigned char ambient_zone;
static unsigned char ambient_min, ambient_max;

/* logging */
#define AMBIENT_LOG_SIZE 128
static unsigned char ambient_log_offset_stored EEMEM;
static unsigned char ambient_log_offset;
static unsigned char ambient_log[AMBIENT_LOG_SIZE] EEMEM;

/* My photodiode reads 0x00C5 .. 0x033B */
typedef struct {
	uint16_t lo, hi;
} ambient_zone_t;

/*
 * Note: these have to be sorted, starting with 0, ending with 0xFFFF
 * and having small overlaps in order to provide a bit of hysteresis.
 */
static ambient_zone_t ambient_zones[] = {
	{ 0x0000                   , 0x0280<<AMBIENT_VAL_SHIFT }, // dark
	{ 0x0270<<AMBIENT_VAL_SHIFT, 0x02f0<<AMBIENT_VAL_SHIFT }, // evening
	{ 0x02e8<<AMBIENT_VAL_SHIFT, 0x030a<<AMBIENT_VAL_SHIFT }, // dawn
	{ 0x0308<<AMBIENT_VAL_SHIFT, 0xffff                    }, // day
};
#define N_AMBIENT_ZONES (sizeof(ambient_zones)/sizeof(ambient_zones[0]))

void init_ambient()
{
	ambient_val = 0;
	ambient_max = 0;
	ambient_min = 0xFF;
	ambient_zone = 1;

	ambient_log_offset = eeprom_read_byte(&ambient_log_offset_stored);

	if (ambient_log_offset == AMBIENT_LOG_SIZE)
		ambient_log_offset = 0; // start over
}

void susp_ambient()
{
	unsigned char stored_offset;

	ambient_log_min_max();

	stored_offset = eeprom_read_byte(&ambient_log_offset_stored);
	if (stored_offset != ambient_log_offset)
		eeprom_write_byte(&ambient_log_offset_stored,
			ambient_log_offset);
}

void ambient_log_min_max()
{
	if (ambient_log_offset >= AMBIENT_LOG_SIZE - 1)
		return;

	eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_min);
	eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_max);

	ambient_min = 0xFF;
	ambient_max = 0;
}

void ambient_zone_changed()
{
#if 1
	log_byte(0xab);
	log_byte(ambient_zone);
	log_word(ambient_val);
	log_flush();
#endif

	// led_set_pattern(N_PWMLEDS, status_led_pattern_select());
	// led_set_pattern(N_PWMLEDS+1, illumination_led_pattern_select());
	// pattern_reload();
}

void ambient_adc(uint16_t adcval)
{
	unsigned char old_zone = ambient_zone;
	unsigned char byte_val;

	ambient_val += adcval - (ambient_val
		>> (AMBIENT_VAL_SHIFT - AMBIENT_ADC_SHIFT));

	while (ambient_zones[ambient_zone].lo > ambient_val)
		ambient_zone--;

	while (ambient_zones[ambient_zone].hi < ambient_val)
		ambient_zone++;

	byte_val = adcval >> 2;

	if (ambient_min > byte_val)
		ambient_min = byte_val;

	if (ambient_max < byte_val)
		ambient_max = byte_val;
#if 0
	if (old_zone != ambient_zone) {
		log_byte(0xab);
		log_byte(ambient_zone);
		log_word(adcval);
		log_flush();
	}
		// ambient_zone_changed();
#endif
}