feat(config file): add a config file

.gitmodules

@@ -1,3 +1,12 @@
 [submodule "lib/log.c"]
 	path = lib/log.c
 	url = https://github.com/rxi/log.c
+[submodule "lib/tomlc99"]
+	path = lib/tomlc99
+	url = https://github.com/cktan/tomlc99
+[submodule "lib/tinyexpr"]
+	path = lib/tinyexpr
+	url = https://github.com/codeplea/tinyexpr
+[submodule "lib/cargs"]
+	path = lib/cargs
+	url = https://github.com/likle/cargs

config.h

@@ -1,11 +0,0 @@
-#include <math.h>
-
-static const char *notification_name = "Event Handler"; /* name to use in notifications */
-static const char *battery_dir = "/sys/class/power_supply/BAT1"; /* path to the batteries directory */
-static const char *linefile = "/sys/class/power_supply/ACAD/online"; /* path to the file which tells us if we are online (plugged in) */
-static const char *ledfile = "/sys/class/leds/input0::capslock/brightness"; /* path to the file which lights up the led */
-static const char *acpid_sock = "/run/acpid.socket"; /* acpid socket file */
-static const int blink_start = 15;  /* percentage to start blinking at */
-const double blink_formula(int x) { /* formula used to set the blinking rate, this function takes in one argument: the battery percentage */
-  return 1.7 + 18.5 * exp(-0.29 * x);
-}

example_config.toml

@@ -0,0 +1,16 @@
+[battery]
+status_path = "/sys/class/power_supply/BAT1"
+power_source = "/sys/class/power_supply/ACAD/online"
+
+[led]
+brightness_path = "/sys/class/leds/input0::capslock/brightness"
+
+[led.blink]
+trigger_level = 15
+timing_formula = "1.7 + 18.5 * exp(-0.29 * p)"
+
+[acpi_daemon]
+socket_path = "/run/acpid.socket"
+
+[log]
+level = "INFO"

include/config.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#define LED_BLINK_TRIGGER_DISABLED 101
+
+/**
+ * @brief parse the config file
+ *
+ * @param path the path to the config file
+ */
+void parse_config_file(char *path);
+
+/**
+ * @brief setup the led formula
+ */
+void setup_led_formula(void);
+
+extern char *battery_status_path;
+extern char *battery_power_source;
+
+extern char *led_brightness_path;
+
+extern unsigned int led_blink_trigger_level;
+extern char *led_blink_timing_formula;
+
+double led_blink_timing_func(int percent);
+
+extern char *acpi_daemon_socket_path;

meson.build

@@ -9,7 +9,9 @@ srcfiles = files(
   'src/led.c',
   'src/wayland.c',
   'src/acpi.c',
-  'src/utils.c'
+  'src/utils.c',
+  'src/battery.c',
+  'src/config.c'
 )
 
 # wayland stuff
@@ -55,10 +57,22 @@ executable('eh', srcfiles,
   ],
   include_directories: [
     'lib/log.c/src',
+    'lib/tinyexpr',
+    'lib/tomlc99',
+    'lib/cargs/include',
     'include'
   ],
   link_with: [
     static_library('log.c', 'lib/log.c/src/log.c',
-      include_directories: 'lib/log.c/src')
+      include_directories: 'lib/log.c/src'),
+
+    static_library('tinyexpr', 'lib/tinyexpr/tinyexpr.c',
+      include_directories: 'lib/tinyexpr'),
+
+    static_library('tomlc99', 'lib/tomlc99/toml.c',
+      include_directories: 'lib/tomlc99'),
+
+    static_library('cargs', 'lib/cargs/src/cargs.c',
+      include_directories: 'lib/cargs/include')
   ]
 )

src/battery.c

@@ -15,7 +15,7 @@ char
   FILE *f;
 
   /* open up the battery capacity for reading */
-  d = concat(battery_dir, "/capacity");
+  d = concat(battery_status_path, "/capacity");
   f = fopen(d, "r");
   free(d);
 

src/config.c

@@ -0,0 +1,109 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <log.h>
+#include <toml.h>
+#include <tinyexpr.h>
+
+#include "config.h"
+
+#define table(tt, v, vn) do {				\
+		v = toml_table_in(tt, vn);			\
+		if (!v) {												\
+			log_warn("missing [%s]", vn);	\
+		}																\
+	} while (0);
+
+#define set_str_conf(op, tt, v) do {	\
+		toml_datum_t val;									\
+		val = toml_string_in(tt, v);			\
+		if (val.ok) {											\
+			op = val.u.s;										\
+		}																	\
+	} while (0);
+
+#define set_int_conf(op, tt, v) do {	\
+		toml_datum_t val;									\
+		val = toml_int_in(tt, v);					\
+		if (val.ok) {											\
+			op = val.u.i;										\
+		}																	\
+	} while (0);
+
+static te_expr *expr;
+static double percentage;
+
+char *battery_status_path = "/sys/class/power_supply/BAT1";
+char *battery_power_source = "/sys/class/power_supply/ACAD/online";
+
+char *led_brightness_path = "/sys/class/leds/input0::capslock/brightness";
+
+unsigned int led_blink_trigger_level = 15;
+char *led_blink_timing_formula = "1.7 + 18.5 * exp(-0.29 * p)";
+
+char *acpi_daemon_socket_path = "/run/acpid.socket";
+
+double
+led_blink_timing_func(int percent)
+{
+	percentage = percent;
+	return te_eval(expr);
+
+  // return 1.7 + 18.5 * exp(-0.29 * percent);
+}
+
+static void
+free_eval(int sig)
+{
+	te_free(expr);
+	exit(sig);
+}
+
+void
+setup_led_formula(void)
+{
+	int err;
+
+	te_variable vars[] = { { "p", &percentage } };
+	expr = te_compile(led_blink_timing_formula, vars, 1, &err);
+	signal(SIGINT, free_eval);
+	if (!expr) {
+		log_fatal("%s", led_blink_timing_formula);
+		log_fatal("%*s^ Error near here", err - 1, "");
+
+		exit(1);
+	}
+}
+
+void
+parse_config_file(char *path)
+{
+	FILE *f;
+	toml_table_t *config, *battery, *led, *led_blink, *acpi_daemon;
+	char errbuf[200];
+
+	f = fopen(path, "r");
+	if (!f) {
+		log_fatal("Failed to open config file: %s", path);
+	}
+
+	config = toml_parse_file(f, errbuf, sizeof(errbuf));
+	fclose(f);
+
+	if (!config) {
+		log_fatal("error: %s", errbuf);
+	}
+
+	table(config, battery, "battery");
+	table(config, led, "led");
+	table(led, led_blink, "blink");
+	table(config, acpi_daemon, "acpi_daemon");
+
+	set_str_conf(battery_status_path, battery, "status_path");
+	set_str_conf(battery_power_source, battery, "power_source");
+	set_str_conf(led_brightness_path, led, "brightness_path");
+	set_int_conf(led_blink_trigger_level, led_blink, "power_source");
+	set_str_conf(led_blink_timing_formula, led_blink, "timing_formula");
+	set_str_conf(acpi_daemon_socket_path, acpi_daemon, "socket_path");
+}

src/main.c

@@ -11,7 +11,9 @@
 #include <unistd.h>
 #include <stdbool.h>
 
-#include "log.h"
+#include <cargs.h>
+#include <log.h>
+
 #include "led.h"
 #include "wayland.h"
 #include "acpi.h"
@@ -22,6 +24,22 @@
 
 #define MAX_BUFLEN 1024
 
+static struct cag_option options[] = {
+	{
+		.identifier = 'c',
+		.access_letters = "c",
+		.access_name = "config",
+		.value_name = "PATH",
+		.description = "Config file"
+	},
+	{
+		.identifier = 'h',
+		.access_letters = "h",
+		.access_name = "help",
+		.description = "Shows the command help"
+	}
+};
+
 void
 on_battery_event(char *percent, bool plugged)
 {
@@ -33,8 +51,8 @@ on_battery_event(char *percent, bool plugged)
     /* convert battery percentage to an int */
     res = strtol(percent, &ep, 10);
 
-    if (res <= blink_start) {
-      rate = blink_formula(res);
+    if (res <= led_blink_trigger_level) {
+      rate = led_blink_timing_func(res);
       if (rate >= 1) {
         led_set_rate(rate);
       }
@@ -54,18 +72,40 @@ on_battery_event(char *percent, bool plugged)
 int
 main(int argc, char *argv[])
 {
-  bool plugged = plugged_in((char *)linefile);
-  char buffer[MAX_BUFLEN], *out[4];
+  cag_option_context context;
+  bool plugged = plugged_in(battery_power_source);
+  char buffer[MAX_BUFLEN], *out[4], *config_path;
   int sock_fd;
 
+  cag_option_init(&context, options, CAG_ARRAY_SIZE(options), argc, argv);
+  while (cag_option_fetch(&context)) {
+		switch (cag_option_get_identifier(&context)) {
+			case 'c':
+				config_path = (char *)cag_option_get_value(&context);
+				parse_config_file(config_path);
+				break;
+			case 'h':
+				printf("Usage: eh [OPTION]...\n");
+				printf("Demonstrates the cargs library.\n\n");
+				cag_option_print(options, CAG_ARRAY_SIZE(options), stdout);
+				return EXIT_SUCCESS;
+			case '?':
+				cag_option_print_error(&context, stdout);
+				break;
+		}
+  }
+
+	/* configure the led blinking formula */
+	setup_led_formula();
+
   /* set the logging level */
   log_set_level(LOG_DEBUG);
 
   /* open up socket address */
-  sock_fd = acpi_create_socket((char *)acpid_sock);
+  sock_fd = acpi_create_socket(acpi_daemon_socket_path);
 
   /* create the led thread */
-  led_create_thread((char *)ledfile);
+  led_create_thread(led_brightness_path);
 
 	/* create the wayland thread */
   wayland_create_thread();
@@ -96,7 +136,7 @@ main(int argc, char *argv[])
       char *s = get_substring(out[1], 0, 2);
 
       if (strcmp(s, "AC") == 0) {
-        plugged = plugged_in((char *)linefile);
+        plugged = plugged_in(battery_power_source);
       }
 
       free(s);