/*********************************************************************************
 *      Copyright:  (C) 2021 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  led.c
 *    Description:  This file is used to control RGB 3-colors LED
 *                  compatible with libgpiod-1.x.x, not compatible with 2.x.x
 *
 *
 * Pin connection:
 *               RGB Led Module           Raspberry Pi Board
 *                   R        <----->      #Pin33(BCM GPIO13)
 *                   G        <----->      #Pin35(BCM GPIO19)
 *                   B        <----->      #Pin37(BCM GPIO26)
 *                  GND       <----->      GND
 *
 * System install:
 *                  sudo apt install -y libgpiod-dev gpiod
 *
 *
 ********************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <signal.h>

#include <gpiod.h>
#include "logger.h"
#include "leds.h"

#define DELAY     500

static led_info_t    leds_info[LED_CNT] =
{
    {"red",   13, 1, NULL },
    {"green", 19, 1, NULL },
    {"blue",  26, 1, NULL },
};

int init_led(led_ctx_t *ctx, int which)
{
    int            i, rv;
    led_info_t    *led;

    if( !ctx )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    ctx->leds = leds_info;
    ctx->count = LED_CNT;

    ctx->chip = gpiod_chip_open_by_name("gpiochip0");
    if( !ctx->chip )
    {
        log_error("open gpiochip failure, maybe you need running as root\n");
        return -2;
    }

	for(i=0; i<ctx->count; i++)
	{
		if( which == i )
		{
			led = &ctx->leds[i];

			led->line = gpiod_chip_get_line(ctx->chip, led->gpio);
			if( !led->line )
			{
				log_error("open gpioline for %s[%d] failed\n", led->name, led->gpio);
				rv = -3;
				goto failed;
			}

			rv  = gpiod_line_request_output(led->line, led->name, !led->active);
			if( rv )
			{
				log_error("request gpio output for %5s[%d] failed: %s\n", led->name, led->gpio, strerror(errno));
				rv = -4;
				goto failed;
			}

			log_debug("request %5s led[%d] for gpio output okay\n", led->name, led->gpio);
		}
	}

    return 0;

failed:
    term_led(ctx, which);
    return rv;
}

int term_led(led_ctx_t *ctx, int which)
{
    int            i;
    led_info_t    *led;

    log_warn("terminate RGB Led gpios\n");

    if( !ctx )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    if( !ctx->chip )
        return 0;

    for(i=0; i<ctx->count; i++)
	{
		if( which == i )
		{
			led = &ctx->leds[i];

			if( led->line )
				gpiod_line_release(led->line);
		}
	}

    gpiod_chip_close(ctx->chip);
    return 0;
}

int turn_led(int which, int cmd)
{
    int            rv = 0;
    led_ctx_t      ctx;
    led_info_t    *led;

    if( which<0 || which>=LED_CNT )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    if( (rv=init_led(&ctx, which)) < 0 )
    {
        log_error("Initial RGB leds failure, rv=%d\n", rv);
        return -2;
    }

    led = &ctx.leds[which];

    if( OFF == cmd )
    {
        gpiod_line_set_value(led->line, !led->active);
    }
    else
    {
        gpiod_line_set_value(led->line, led->active);
    }

    term_led(&ctx, which);
    return 0;
}