/*
 * Copyright (C) 2010 Diogo Ferreira <diogo@underdev.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "lights"

#include <cutils/log.h>

#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>

#include <sys/ioctl.h>
#include <sys/types.h>

#include <hardware/lights.h>

static pthread_once_t g_init = PTHREAD_ONCE_INIT;
static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
static struct light_state_t g_notification;
static struct light_state_t g_battery;
static int g_backlight = 255;

char const*const AMBER_LED_FILE = "/sys/class/leds/amber/brightness";
char const*const GREEN_LED_FILE = "/sys/class/leds/green/brightness";

char const*const BUTTON_FILE = "/sys/class/leds/button-backlight/brightness";

char const*const AMBER_BLINK_FILE = "/sys/class/leds/amber/blink";
char const*const GREEN_BLINK_FILE = "/sys/class/leds/green/blink";

char const*const LCD_BACKLIGHT_FILE = "/sys/class/leds/lcd-backlight/brightness";

enum {
	LED_BLANK,
	LED_AMBER,
	LED_GREEN,
	LED_BOTH,
};

/**
 * Aux method, write int to file
 */
static int write_int (const char* path, int value) {
	int fd;
	static int already_warned = 0;

	fd = open(path, O_RDWR);
	if (fd < 0) {
		if (already_warned == 0) {
			LOGE("write_int failed to open %s\n", path);
			already_warned = 1;
		}
		return -errno;
	}

	char buffer[20];
	int bytes = snprintf(buffer, sizeof(buffer), "%d\n",value);
	int written = write (fd, buffer, bytes);
	close (fd);

	return written == -1 ? -errno : 0;
}

void init_globals (void) {
	pthread_mutex_init (&g_lock, NULL);
}

static int is_lit (struct light_state_t const* state) {
	return state->color & 0x00ffffff;
}

static unsigned int rgb_to_led(struct light_state_t *state) {
	unsigned int colorRGB = state->color & 0xFFFFFF;
	unsigned int colorLED = LED_BLANK;

	if (colorRGB & 0xFF)
		colorLED |= LED_GREEN;
	else {
		if ((colorRGB >> 8) & 0xFF)
			colorLED |= LED_GREEN;
		if ((colorRGB >> 16) & 0xFF)
			colorLED |= LED_AMBER;
	}

	return colorLED;
}

static void set_speaker_light_locked (struct light_device_t *dev,
		struct light_state_t *state) {
	unsigned int colorRGB = state->color & 0xFFFFFF;
	unsigned int colorLED = rgb_to_led(state);

	switch (state->flashMode) {
		case LIGHT_FLASH_HARDWARE:
		case LIGHT_FLASH_TIMED:
			switch (colorLED) {
				case LED_BOTH:
					write_int (AMBER_BLINK_FILE, 1);
					write_int (GREEN_BLINK_FILE, 1);
					break;
				case LED_AMBER:
					if (state == &g_battery)
						write_int (AMBER_BLINK_FILE, 4);
					else
						write_int (AMBER_BLINK_FILE, 1);
					write_int (GREEN_LED_FILE, 0);
					break;
				case LED_GREEN:
					write_int (GREEN_BLINK_FILE, 1);
					write_int (AMBER_LED_FILE, 0);
					break;
				case LED_BLANK:
					write_int (AMBER_BLINK_FILE, 0);
					write_int (GREEN_BLINK_FILE, 0);
					break;
				default:
					LOGE("set_led_state: unknown color, colorRGB=0x%08X colorLED=%d\n",
							colorRGB, colorLED);
					break;
			}
			break;
		case LIGHT_FLASH_NONE:
			switch (colorLED) {
				case LED_BOTH:
					write_int (AMBER_LED_FILE, 1);
					write_int (GREEN_LED_FILE, 1);
					break;
				case LED_AMBER:
					write_int (AMBER_LED_FILE, 1);
					write_int (GREEN_LED_FILE, 0);
					break;
				case LED_GREEN:
					write_int (AMBER_LED_FILE, 0);
					write_int (GREEN_LED_FILE, 1);
					break;
				case LED_BLANK:
					write_int (AMBER_LED_FILE, 0);
					write_int (GREEN_LED_FILE, 0);
					break;
				default:
					LOGE("set_led_state: unknown color, colorRGB=0x%08X colorLED=%d\n",
							colorRGB, colorLED);
					break;
			}
			break;
		default:
			LOGE("set_led_state: unknown mode, colorRGB=0x%08X flashMode=%d\n",
					colorRGB, state->flashMode);
	}
}

static void set_speaker_light_locked_dual(struct light_device_t *dev,
		struct light_state_t *bstate,  struct light_state_t *nstate) {
	unsigned int bcolorRGB = bstate->color & 0xFFFFFF;
	unsigned int bcolorLED = rgb_to_led(bstate);

	switch (bcolorLED) {
		case LED_BOTH:
		case LED_AMBER:
			write_int (AMBER_BLINK_FILE, 4);
			write_int (GREEN_LED_FILE, 1);
			break;
		case LED_GREEN:
			write_int (AMBER_BLINK_FILE, 1);
			write_int (GREEN_LED_FILE, 1);
			break;
		case LED_BLANK:
		default:
			LOGE("set_led_state_dual: unexpected color, bcolorRGB=0x%08X bcolorLED=%d\n",
					bcolorRGB, bcolorLED);
			break;
	}
}

static void handle_speaker_battery_locked (struct light_device_t *dev) {
	if (is_lit (&g_battery) && is_lit (&g_notification)) {
		set_speaker_light_locked_dual(dev, &g_battery, &g_notification);
	} else if (is_lit (&g_battery)) {
		set_speaker_light_locked (dev, &g_battery);
	} else {
		set_speaker_light_locked (dev, &g_notification);
	}
}

static int set_light_buttons (struct light_device_t* dev,
		struct light_state_t const* state) {
	int err = 0;
	int on = is_lit (state);
	pthread_mutex_lock (&g_lock);
	err = write_int (BUTTON_FILE, on?255:0);
	pthread_mutex_unlock (&g_lock);

	return 0;
}

static int rgb_to_brightness(struct light_state_t const* state)
{
    int color = state->color & 0x00ffffff;
    return ((77*((color>>16)&0x00ff))
            + (150*((color>>8)&0x00ff)) + (29*(color&0x00ff))) >> 8;
}

static int set_light_backlight(struct light_device_t* dev,
		struct light_state_t const* state) {
	int err = 0;
	int brightness = rgb_to_brightness(state);
	LOGV("%s brightness=%d color=0x%08x",
		__func__,brightness, state->color);
	pthread_mutex_lock(&g_lock);
	g_backlight = brightness;
	err = write_int(LCD_BACKLIGHT_FILE, brightness);
	pthread_mutex_unlock(&g_lock);
	return err;
}

static int set_light_battery (struct light_device_t* dev,
		struct light_state_t const* state) {
	pthread_mutex_lock (&g_lock);
	g_battery = *state;
	handle_speaker_battery_locked(dev);
	pthread_mutex_unlock (&g_lock);

	return 0;
}

static int set_light_attention (struct light_device_t* dev,
		struct light_state_t const* state) {
	/* tattoo has no attention */

	return 0;
}

static int set_light_notifications (struct light_device_t* dev,
		struct light_state_t const* state) {
	pthread_mutex_lock (&g_lock);
	g_notification = *state;
	handle_speaker_battery_locked (dev);
	pthread_mutex_unlock (&g_lock);
	return 0;
}

static int close_lights (struct light_device_t *dev) {
	if (dev)
		free (dev);

	return 0;
}

static int open_lights (const struct hw_module_t* module, char const* name,
		struct hw_device_t** device) {
	int (*set_light)(struct light_device_t* dev,
			struct light_state_t const* state);

	if (0 == strcmp(LIGHT_ID_BACKLIGHT, name)) {
		set_light = set_light_backlight;
	}
	else if (0 == strcmp(LIGHT_ID_BUTTONS, name)) {
		set_light = set_light_buttons;
	}
	else if (0 == strcmp(LIGHT_ID_BATTERY, name)) {
		set_light = set_light_battery;
	}
	else if (0 == strcmp(LIGHT_ID_ATTENTION, name)) {
		set_light = set_light_attention;
	}
	else if (0 == strcmp(LIGHT_ID_NOTIFICATIONS, name))  {
		set_light = set_light_notifications;
	}
	else {
		return -EINVAL;
	}

	pthread_once (&g_init, init_globals);
	struct light_device_t *dev = malloc (sizeof (struct light_device_t));
	memset (dev,0,sizeof(*dev));

	dev->common.tag = HARDWARE_DEVICE_TAG;
	dev->common.version = 0;
	dev->common.module = (struct hw_module_t*)module;
	dev->common.close = (int (*)(struct hw_device_t*))close_lights;
	dev->set_light = set_light;

	*device = (struct hw_device_t*) dev;
	return 0;
}

static struct hw_module_methods_t lights_module_methods = {
	.open = open_lights,
};

const struct hw_module_t HAL_MODULE_INFO_SYM = {
	.tag = HARDWARE_MODULE_TAG,
	.version_major = 2,
	.version_minor = 0,
	.id = LIGHTS_HARDWARE_MODULE_ID,
	.name = "Tattoo lights module",
	.author = "Diogo Ferreira <diogo@underdev.org>",
	.methods = &lights_module_methods,
};