From 89eb99b80f4445798eea39d1a294c070d82e0f6c Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Wed, 17 May 2023 17:55:13 +0100
Subject: [PATCH] Move time update logic from display module to time manager

---
 components/display/display.c   | 27 +++-----------------
 components/time/CMakeLists.txt |  2 +-
 components/time/time_manager.c | 45 ++++++++++++++++++++++++++++++++++
 components/time/time_manager.h |  7 ++++++
 main/main.c                    |  2 +-
 5 files changed, 57 insertions(+), 26 deletions(-)

diff --git a/components/display/display.c b/components/display/display.c
index eafd34a..1016b22 100644
--- a/components/display/display.c
+++ b/components/display/display.c
@@ -16,7 +16,6 @@
 #define TAG "Display"
 
 #define DRIVER_TASK_PERIOD_US 4000UL
-#define TIME_UPDATE_PERIOD_US 1000000UL
 
 #define CLAMP(x, lim) ((x) > (lim) ? (lim) : (x))
 
@@ -52,11 +51,9 @@ static void show_time(unsigned hour, unsigned minute)
 	show_digit(DISPLAY_DIGIT_4, minute % 10);
 }
 
-static void update_time(void *arg)
+static void update_time(const Time *time)
 {
-	(void)arg;
-	const Time time = get_time();
-	show_time(time.hour, time.minute);
+	show_time(time->hour, time->minute);
 }
 
 void display_init()
@@ -83,23 +80,5 @@ void display_init()
 		FATAL();
 	}
 
-	esp_timer_handle_t update_timer;
-	const esp_timer_create_args_t update_timer_config = {
-		.callback = &update_time,
-		.arg = NULL,
-		.name = "display driver task",
-	};
-	error = esp_timer_create(&update_timer_config, &update_timer);
-	if (error != ESP_OK) {
-		ESP_LOGE(TAG, "Error creating timer for driver task: %04x", error);
-		FATAL();
-	}
-
-	error = esp_timer_start_periodic(update_timer, TIME_UPDATE_PERIOD_US);
-	if (error != ESP_OK) {
-		ESP_LOGE(TAG, "Error starting timer for driver task: %04x", error);
-		FATAL();
-	}
-
-	update_time(NULL);
+	add_time_callback(&update_time);
 }
diff --git a/components/time/CMakeLists.txt b/components/time/CMakeLists.txt
index 48e5ec5..9b8272a 100644
--- a/components/time/CMakeLists.txt
+++ b/components/time/CMakeLists.txt
@@ -1,5 +1,5 @@
 idf_component_register(
   SRCS "time_manager.c"
   INCLUDE_DIRS "."
-  REQUIRES console_wrapper lwip nvs_flash settings
+  REQUIRES console_wrapper esp_timer fatal lwip nvs_flash settings
 )
diff --git a/components/time/time_manager.c b/components/time/time_manager.c
index c257942..1024661 100644
--- a/components/time/time_manager.c
+++ b/components/time/time_manager.c
@@ -10,6 +10,8 @@
 
 #include "esp_log.h"
 #include "esp_sntp.h"
+#include "esp_timer.h"
+#include "fatal.h"
 #include "freertos/FreeRTOS.h"
 #include "nvs_flash.h"
 #include <time.h>
@@ -22,6 +24,12 @@
 #define TM_YEAR_OFFSET 1900
 #define TM_MONTH_OFFSET 1
 
+#define UPDATE_PERIOD_US 1000000UL
+#define MAX_CALLBACKS 8
+
+static TimeCallback callbacks[MAX_CALLBACKS];
+static unsigned callback_count;
+
 static void handle_timezone_update(const char *timezone)
 {
 	setenv("TZ", timezone, 1);
@@ -85,6 +93,13 @@ static int store_time(void)
 	return error == ESP_OK ? 0 : 1;
 }
 
+static void run_callbacks(void *arg)
+{
+	const Time time = get_time();
+	for (unsigned i = 0; i < callback_count; ++i)
+		callbacks[i](&time);
+}
+
 static int time_command_func(int argc, char **argv)
 {
 	if (argc == 1) {
@@ -177,6 +192,8 @@ static void time_saver_func(void *arg)
 
 void time_manager_init(void)
 {
+	callback_count = 0;
+
 	char timezone[SETTINGS_MAX_VALUE_SIZE];
 	(void)settings_get_timezone(timezone, SETTINGS_MAX_VALUE_SIZE);
 	handle_timezone_update(timezone);
@@ -225,6 +242,34 @@ void time_manager_init(void)
 	(void)xTaskCreate(
 	    &time_saver_func, "time saver", CONFIG_DEFAULT_TASK_STACK, NULL, 1,
 	    NULL);
+
+	// Create and start timer
+	esp_timer_handle_t update_timer;
+	const esp_timer_create_args_t update_timer_config = {
+		.callback = &run_callbacks,
+		.arg = NULL,
+		.name = "time updates",
+	};
+	error = esp_timer_create(&update_timer_config, &update_timer);
+	if (error != ESP_OK) {
+		ESP_LOGE(TAG, "Error creating update timer: %04x", error);
+		FATAL();
+	}
+	error = esp_timer_start_periodic(update_timer, UPDATE_PERIOD_US);
+	if (error != ESP_OK) {
+		ESP_LOGE(TAG, "Error starting update timer: %04x", error);
+		FATAL();
+	}
+}
+
+void add_time_callback(TimeCallback callback)
+{
+	if (callback_count >= MAX_CALLBACKS) {
+		ESP_LOGE(TAG, "Max number of time callbacks exceeded");
+		return;
+	}
+	callbacks[callback_count] = callback;
+	++callback_count;
 }
 
 Time get_time(void)
diff --git a/components/time/time_manager.h b/components/time/time_manager.h
index 305b544..bbe5865 100644
--- a/components/time/time_manager.h
+++ b/components/time/time_manager.h
@@ -27,11 +27,18 @@ typedef enum {
 	WEEK_DAY_SUNDAY,
 } WeekDay;
 
+typedef void (*TimeCallback)(const Time *time);
+
 /**
  * Initialize the time module.
  */
 void time_manager_init(void);
 
+/**
+ * Add a callback to be regularly invoked with time updates.
+ */
+void add_time_callback(TimeCallback callback);
+
 /**
  * Get the current time.
  */
diff --git a/main/main.c b/main/main.c
index 957bc5d..a3fd129 100644
--- a/main/main.c
+++ b/main/main.c
@@ -15,9 +15,9 @@ void app_main(void)
 {
 	console_init();
 	settings_init();
-	display_init();
 	wifi_init();
 	time_manager_init();
+	display_init();
 	sound_init();
 	buttons_init();
 }