Merge PR #470 - implement automatic DST toggling

Implements logic to automatically offset daylight saving time settings
when calculating timezone offsets. This should make the DST functions
work automatically with no need for user input in most cases.

Reviewed-by: Matheus Afonso Martins Moreira <[email protected]>
GitHub-Pull-Request: #470

Author: matheusmoreira

movement/movement.c

@@ -44,6 +44,7 @@ of debounce time.
 #include "filesystem.h"
 #include "movement.h"
 #include "shell.h"
+#include "watch_utility.h"
 
 #ifndef MOVEMENT_FIRMWARE
 #include "movement_config.h"
@@ -130,6 +131,11 @@ of debounce time.
 #define MOVEMENT_DEFAULT_BIRTHDATE_DAY 0
 #endif
 
+// Default to having DST get set
+#ifndef MOVEMENT_DEFAULT_DST_ACTIVE
+#define MOVEMENT_DEFAULT_DST_ACTIVE true
+#endif
+
 #if __EMSCRIPTEN__
 #include <emscripten.h>
 #endif
@@ -141,7 +147,8 @@ const int32_t movement_le_inactivity_deadlines[8] = {INT_MAX, 600, 3600, 7200, 2
 const int16_t movement_timeout_inactivity_deadlines[4] = {60, 120, 300, 1800};
 movement_event_t event;
 
-const int16_t movement_timezone_offsets[] = {
+#define NUM_TIME_ZONES 41
+const int16_t movement_timezone_offsets[NUM_TIME_ZONES] = {
     0,      //  0 :   0:00:00 (UTC)
     60,     //  1 :   1:00:00 (Central European Time)
     120,    //  2 :   2:00:00 (South African Standard Time)
@@ -198,94 +205,50 @@ const int16_t movement_timezone_offsets[] = {
  * having to separately change the hour and timezone info
  * in the time set face.
  */
-const uint8_t movement_dst_jump_table[] = {
-    1,  // 0  UTC  + 1 = CET
-    2,  // 1  CET  + 1 = SAST
-    3,  // 2  SAST + 1 = AST
-    5,  // 3  AST  + 1 = GST
-    6,  // 4  IST  + 1 = AT
-    7,  // 5  GST  + 1 = PST
-    8,  // 6  AT   + 1 = IST
-    10, // 7  PST  + 1 = KT
-    11, // 8  IST  + 1 = MT
-    9,  // 9  Nepal has no equivalent DST timezone, but they don't observe DST anyway
-    12, // 10 KT   + 1 = TST
-    11, // 11 Myanmar has no equivalent DST timezone, but they don't observe DST anyway
-    13, // 12 TST  + 1 = CST
-    15, // 13 CST  + 1 = JST
-    14, // 14 ACWST has no equivalent DST timezone, but they don't observe DST anyway
-    17, // 15 JST  + 1 = AEST
-    18, // 16 ACST + 1 = LHST
-    19, // 17 AEST + 1 = SIT
-    18, // 18 LHST has no equivalent DST timezone, but they don't observe DST anyway
-    20, // 19 SIT  + 1 = NZST
-    22, // 20 NZST + 1 = TT
-    23, // 21 CST  + 1 = CDT
-    24, // 22 TT   + 1 = LIT
-    23, // 23 CDT is already a daylight timezone
-    24, // 24 LIT has no equivalent DST timezone, but they don't observe DST anyway
-    26, // 25 BIT  + 1 = NT
-    27, // 26 NT   + 1 = HAST
-    29, // 27 HAST + 1 = AST
-    28, // 28 MIT has no equivalent DST timezone, but they don't observe DST anyway
-    30, // 29 AST  + 1 = PST
-    31, // 30 PST  + 1 = MST
-    32, // 31 MST  + 1 = CST
-    33, // 32 CST  + 1 = EST
-    35, // 33 EST  + 1 = AST
-    36, // 34 VST  + 1 = NST
-    37, // 35 AST  + 1 = BT
-    38, // 36 NST  + 1 = NDT
-    39, // 37 BT   + 1 = 39
-    38, // 38 NDT is already a daylight timezone
-    40, // 39 FNT  + 1 = AST
+const int16_t movement_timezone_dst_offsets[NUM_TIME_ZONES] = {
+    60,  // 0  UTC  + 1 = CET
+    120,  // 1  CET  + 1 = SAST
+    189,  // 2  SAST + 1 = AST
+    240,  // 3  AST  + 1 = GST
+    270,  // 4  IST  + 1 = AT
+    300,  // 5  GST  + 1 = PST
+    330,  // 6  AT   + 1 = IST
+    360, // 7  PST  + 1 = KT
+    390, // 8  IST  + 1 = MT
+    345,  // 9  Nepal has no equivalent DST timezone, but they don't observe DST anyway
+    420, // 10 KT   + 1 = TST
+    390, // 11 Myanmar has no equivalent DST timezone, but they don't observe DST anyway
+    480, // 12 TST  + 1 = CST
+    540, // 13 CST  + 1 = JST
+    525, // 14 ACWST has no equivalent DST timezone, but they don't observe DST anyway
+    600, // 15 JST  + 1 = AEST
+    630, // 16 ACST + 1 = LHST
+    660, // 17 AEST + 1 = SIT
+    630, // 18 LHST has no equivalent DST timezone, but they don't observe DST anyway
+    720, // 19 SIT  + 1 = NZST
+    780, // 20 NZST + 1 = TT
+    825, // 21 CST  + 1 = CDT
+    840, // 22 TT   + 1 = LIT
+    825, // 23 CDT is already a daylight timezone
+    840, // 24 LIT has no equivalent DST timezone, but they don't observe DST anyway
+    -660, // 25 BIT  + 1 = NT
+    -600, // 26 NT   + 1 = HAST
+    -540, // 27 HAST + 1 = AST
+    -570, // 28 MIT has no equivalent DST timezone, but they don't observe DST anyway
+    -480, // 29 AST  + 1 = PST
+    -420, // 30 PST  + 1 = MST
+    -360, // 31 MST  + 1 = CST
+    -300, // 32 CST  + 1 = EST
+    -240, // 33 EST  + 1 = AST
+    -210, // 34 VST  + 1 = NST
+    -180, // 35 AST  + 1 = BT
+    -150, // 36 NST  + 1 = NDT
+    -120, // 37 BT   + 1 = 39
+    -150, // 38 NDT is already a daylight timezone
+    -60, // 39 FNT  + 1 = AST
     0   // 40 AST  + 1 = UTC
 };
 
-const uint8_t movement_dst_inverse_jump_table[] = {
-    40, // 0
-    0,  // 1
-    1,  // 2
-    2,  // 3
-    4,  // 4
-    3,  // 5
-    4,  // 6
-    5,  // 7
-    6,  // 8
-    9,  // 9
-    7,  // 10
-    8,  // 11
-    10, // 12
-    12, // 13
-    14, // 14
-    13, // 15
-    16, // 16
-    15, // 17
-    16, // 18
-    17, // 19
-    19, // 20
-    21, // 21
-    20, // 22
-    21, // 23
-    24, // 24
-    25, // 25
-    25, // 26
-    26, // 27
-    28, // 28
-    27, // 29
-    29, // 30
-    30, // 31
-    31, // 32
-    32, // 33
-    34, // 34
-    33, // 35
-    34, // 36
-    35, // 37
-    36, // 38
-    37, // 39
-    39  // 40
-};
-
 const char movement_valid_position_0_chars[] = " AaBbCcDdEeFGgHhIiJKLMNnOoPQrSTtUuWXYZ-='+\\/0123456789";
 const char movement_valid_position_1_chars[] = " ABCDEFHlJLNORTtUX-='01378";
 
@@ -323,6 +286,31 @@ static inline void _movement_disable_fast_tick_if_possible(void) {
     }
 }
 
+static bool _check_and_act_on_daylight_savings(void) {
+    if (!movement_state.settings.bit.dst_active) return false;
+    watch_date_time date_time = watch_rtc_get_date_time();
+    // No need for all of the unix time calculations for times not at the beginning or end of the hour
+    if (date_time.unit.minute > 1 && date_time.unit.minute < 59) return false;
+    uint8_t dst_result = get_dst_status(date_time);
+    bool dst_skip_rolling_back = get_dst_skip_rolling_back();
+
+    if (dst_skip_rolling_back && (dst_result == DST_ENDED)) {
+        clear_dst_skip_rolling_back();
+    }
+    else if (dst_result == DST_ENDING && !dst_skip_rolling_back) {
+        date_time.unit.hour = (date_time.unit.hour + 24 - 1) % 24;
+        watch_rtc_set_date_time(date_time);
+        set_dst_skip_rolling_back();
+        return true;
+    }
+    else if (dst_result == DST_STARTING) {
+        date_time.unit.hour = (date_time.unit.hour + 1) % 24;
+        watch_rtc_set_date_time(date_time);
+        return true;
+    }
+    return false;
+}
+
 static void _movement_handle_background_tasks(void) {
     for(uint8_t i = 0; i < MOVEMENT_NUM_FACES; i++) {
         // For each face, if the watch face wants a background task...
@@ -332,6 +320,7 @@ static void _movement_handle_background_tasks(void) {
             watch_faces[i].loop(background_event, &movement_state.settings, watch_face_contexts[i]);
         }
     }
+    _check_and_act_on_daylight_savings();
     movement_state.needs_background_tasks_handled = false;
 }
 
@@ -529,6 +518,12 @@ uint8_t movement_claim_backup_register(void) {
     return movement_state.next_available_backup_register++;
 }
 
+int16_t get_timezone_offset(uint8_t timezone_idx, watch_date_time date_time) {
+    if (movement_state.settings.bit.dst_active && dst_occurring(date_time))
+        return movement_timezone_dst_offsets[timezone_idx];
+    return movement_timezone_offsets[timezone_idx];
+}
+
 void app_init(void) {
 #if defined(NO_FREQCORR)
     watch_rtc_freqcorr_write(0, 0);
@@ -551,6 +546,20 @@ void app_init(void) {
     movement_state.birthdate.bit.year = MOVEMENT_DEFAULT_BIRTHDATE_YEAR;
     movement_state.birthdate.bit.month = MOVEMENT_DEFAULT_BIRTHDATE_MONTH;
     movement_state.birthdate.bit.day = MOVEMENT_DEFAULT_BIRTHDATE_DAY;
+    movement_state.settings.bit.dst_active = MOVEMENT_DEFAULT_DST_ACTIVE;
+
+#ifdef MAKEFILE_TIMEZONE
+    timezone_offsets = dst_occurring(watch_rtc_get_date_time()) ? movement_timezone_dst_offsets : movement_timezone_offsets;
+    for (int i = 0; i < NUM_TIME_ZONES; i++) {
+        if (timezone_offsets[i] == MAKEFILE_TIMEZONE) {
+            movement_state.settings.bit.time_zone = i;
+            break;
+        }
+    }
+#else
+    movement_state.settings.bit.time_zone = 35;  // Atlantic Time as default
+#endif
+
     movement_state.light_ticks = -1;
     movement_state.alarm_ticks = -1;
     movement_state.next_available_backup_register = 4;
@@ -559,11 +568,13 @@ void app_init(void) {
     filesystem_init();
 
 #if __EMSCRIPTEN__
+    const int16_t* timezone_offsets;
     int32_t time_zone_offset = EM_ASM_INT({
         return -new Date().getTimezoneOffset();
     });
-    for (int i = 0, count = sizeof(movement_timezone_offsets) / sizeof(movement_timezone_offsets[0]); i < count; i++) {
-        if (movement_timezone_offsets[i] == time_zone_offset) {
+    timezone_offsets = dst_occurring(watch_rtc_get_date_time()) ? movement_timezone_dst_offsets : movement_timezone_offsets;
+    for (int i = 0; i < NUM_TIME_ZONES; i++) {
+        if (timezone_offsets[i] == time_zone_offset) {
             movement_state.settings.bit.time_zone = i;
             break;
         }

movement/movement.h

@@ -130,8 +130,7 @@ typedef struct {
 } movement_event_t;
 
 extern const int16_t movement_timezone_offsets[];
-extern const uint8_t movement_dst_jump_table[];
-extern const uint8_t movement_dst_inverse_jump_table[];
+extern const int16_t movement_timezone_dst_offsets[];
 extern const char movement_valid_position_0_chars[];
 extern const char movement_valid_position_1_chars[];
 
@@ -321,5 +320,6 @@ void movement_play_alarm(void);
 void movement_play_alarm_beeps(uint8_t rounds, BuzzerNote alarm_note);
 
 uint8_t movement_claim_backup_register(void);
+int16_t get_timezone_offset(uint8_t timezone_idx, watch_date_time date_time);
 
 #endif // MOVEMENT_H_

movement/movement_config.h

@@ -111,4 +111,11 @@ const watch_face_t watch_faces[] = {
 #define MOVEMENT_DEFAULT_BIRTHDATE_MONTH 0
 #define MOVEMENT_DEFAULT_BIRTHDATE_DAY 0
 
+/* Set if using DST
+ * Valid values are:
+ * false: Don't allow the watch to use DST
+ * true: Allow the watch to use DST
+ */
+#define MOVEMENT_DEFAULT_DST_ACTIVE true
+
 #endif // MOVEMENT_CONFIG_H_

movement/watch_faces/clock/beats_face.c

@@ -61,7 +61,7 @@ bool beats_face_loop(movement_event_t event, movement_settings_t *settings, void
         case EVENT_ACTIVATE:
         case EVENT_TICK:
             date_time = watch_rtc_get_date_time();
-            centibeats = clock2beats(date_time.unit.hour, date_time.unit.minute, date_time.unit.second, event.subsecond, movement_timezone_offsets[settings->bit.time_zone]);
+            centibeats = clock2beats(date_time.unit.hour, date_time.unit.minute, date_time.unit.second, event.subsecond, get_timezone_offset(settings->bit.time_zone, date_time));
             if (centibeats == state->last_centibeat_displayed) {
                 // we missed this update, try again next subsecond
                 state->next_subsecond_update = (event.subsecond + 1) % BEAT_REFRESH_FREQUENCY;
@@ -76,7 +76,7 @@ bool beats_face_loop(movement_event_t event, movement_settings_t *settings, void
         case EVENT_LOW_ENERGY_UPDATE:
             if (!watch_tick_animation_is_running()) watch_start_tick_animation(432);
             date_time = watch_rtc_get_date_time();
-            centibeats = clock2beats(date_time.unit.hour, date_time.unit.minute, date_time.unit.second, event.subsecond, movement_timezone_offsets[settings->bit.time_zone]);
+            centibeats = clock2beats(date_time.unit.hour, date_time.unit.minute, date_time.unit.second, event.subsecond, get_timezone_offset(settings->bit.time_zone, date_time));
             sprintf(buf, "bt  %4lu  ", centibeats / 100);
 
             watch_display_string(buf, 0);

movement/watch_faces/clock/day_night_percentage_face.c

@@ -62,7 +62,8 @@ void day_night_percentage_face_setup(movement_settings_t *settings, uint8_t watc
     if (*context_ptr == NULL) {
         *context_ptr = malloc(sizeof(day_night_percentage_state_t));
         day_night_percentage_state_t *state = (day_night_percentage_state_t *)*context_ptr;
-        watch_date_time utc_now = watch_utility_date_time_convert_zone(watch_rtc_get_date_time(), movement_timezone_offsets[settings->bit.time_zone] * 60, 0);
+        watch_date_time date_time = watch_rtc_get_date_time();
+        watch_date_time utc_now = watch_utility_date_time_convert_zone(date_time, get_timezone_offset(settings->bit.time_zone, date_time) * 60, 0);
         recalculate(utc_now, state);
     }
 }
@@ -77,7 +78,7 @@ bool day_night_percentage_face_loop(movement_event_t event, movement_settings_t
 
     char buf[12];
     watch_date_time date_time = watch_rtc_get_date_time();
-    watch_date_time utc_now = watch_utility_date_time_convert_zone(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60, 0);
+    watch_date_time utc_now = watch_utility_date_time_convert_zone(date_time, get_timezone_offset(settings->bit.time_zone, date_time) * 60, 0);
 
     switch (event.event_type) {
         case EVENT_ACTIVATE:

movement/watch_faces/clock/mars_time_face.c

@@ -70,7 +70,7 @@ static void _h_to_hms(mars_clock_hms_t *date_time, double h) {
 static void _update(movement_settings_t *settings, mars_time_state_t *state) {
     char buf[11];
     watch_date_time date_time = watch_rtc_get_date_time();
-    uint32_t now = watch_utility_date_time_to_unix_time(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
+    uint32_t now = watch_utility_date_time_to_unix_time(date_time, get_timezone_offset(settings->bit.time_zone, date_time) * 60);
     // TODO: I'm skipping over some steps here.
     // https://www.giss.nasa.gov/tools/mars24/help/algorithm.html
     double jdut = 2440587.5 + ((double)now / 86400.0);

movement/watch_faces/clock/world_clock2_face.c

@@ -154,6 +154,7 @@ void world_clock2_face_activate(movement_settings_t *settings, void *context)
             movement_request_tick_frequency(4);
             break;
     }
+    state->tz = get_timezone_offset(settings->bit.time_zone, watch_rtc_get_date_time());
     refresh_face = true;
 }
 
@@ -183,8 +184,8 @@ static bool mode_display(movement_event_t event, movement_settings_t *settings,
 
             /* Determine current time at time zone and store date/time */
 	    date_time = watch_rtc_get_date_time();
-	    timestamp = watch_utility_date_time_to_unix_time(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
-	    date_time = watch_utility_date_time_from_unix_time(timestamp, movement_timezone_offsets[state->current_zone] * 60);
+	    timestamp = watch_utility_date_time_to_unix_time(date_time, state->tz * 60);
+	    date_time = watch_utility_date_time_from_unix_time(timestamp, state->tz * 60);
 	    previous_date_time = state->previous_date_time;
 	    state->previous_date_time = date_time.reg;
 
@@ -289,7 +290,7 @@ static bool mode_settings(movement_event_t event, movement_settings_t *settings,
                 watch_clear_indicator(WATCH_INDICATOR_PM);
                 refresh_face = false;
             }
-	    result = div(movement_timezone_offsets[state->current_zone], 60);
+	    result = div(state->tz, 60);
 	    hours = result.quot;
 	    minutes = result.rem;
 

movement/watch_faces/clock/world_clock2_face.h

@@ -104,6 +104,7 @@ typedef struct {
     world_clock2_mode_t current_mode;
     uint8_t current_zone;
     uint32_t previous_date_time;
+    int16_t tz;
 } world_clock2_state_t;
 
 void world_clock2_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void **context_ptr);

movement/watch_faces/clock/world_clock_face.c

@@ -60,15 +60,16 @@ static bool world_clock_face_do_display_mode(movement_event_t event, movement_se
     watch_date_time date_time;
     switch (event.event_type) {
         case EVENT_ACTIVATE:
-            if (settings->bit.clock_mode_24h && !settings->bit.clock_24h_leading_zero) watch_set_indicator(WATCH_INDICATOR_24H);
+            state->tz = get_timezone_offset(settings->bit.time_zone, watch_rtc_get_date_time());
+            if (settings->bit.clock_mode_24h) watch_set_indicator(WATCH_INDICATOR_24H);
             watch_set_colon();
             state->previous_date_time = 0xFFFFFFFF;
             // fall through
         case EVENT_TICK:
         case EVENT_LOW_ENERGY_UPDATE:
             date_time = watch_rtc_get_date_time();
-            timestamp = watch_utility_date_time_to_unix_time(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
-            date_time = watch_utility_date_time_from_unix_time(timestamp, movement_timezone_offsets[state->settings.bit.timezone_index] * 60);
+            timestamp = watch_utility_date_time_to_unix_time(date_time, state->tz * 60);
+            date_time = watch_utility_date_time_from_unix_time(timestamp, state->tz * 60);
             previous_date_time = state->previous_date_time;
             state->previous_date_time = date_time.reg;
 
@@ -176,8 +177,8 @@ static bool _world_clock_face_do_settings_mode(movement_event_t event, movement_
     sprintf(buf, "%c%c %3d%02d  ",
         movement_valid_position_0_chars[state->settings.bit.char_0],
         movement_valid_position_1_chars[state->settings.bit.char_1],
-        (int8_t) (movement_timezone_offsets[state->settings.bit.timezone_index] / 60),
-        (int8_t) (movement_timezone_offsets[state->settings.bit.timezone_index] % 60) * (movement_timezone_offsets[state->settings.bit.timezone_index] < 0 ? -1 : 1));
+        (int8_t) (state->tz / 60),
+        (int8_t) (state->tz % 60) * (state->tz < 0 ? -1 : 1));
     watch_set_colon();
     watch_clear_indicator(WATCH_INDICATOR_PM);