Remove sleeping for 10 seconds at the end of the loop since we're much more precise now. Only sleep for 5 minutes after notification dismissal if we're planning another one.

sunset-alarm

@@ -1,24 +1,41 @@
 #!/bin/sh
 
-# sunset-alarm -- Alert before or after sunset
+# sunset-alarm -- Alert before or after sunset.
-# Displays a persistent alert when current time is within
+# Displays an alert when current time is within (sunset - specified minutes).
-# (sunset minus specified minutes) of midnight.
 
 ###############################################################################
 # Defaults
 ###############################################################################
-LATLONG=""
+declare LATLONG="" SUNSET_TIME="" MINUTES="" LAST_DATE="" PERSIST="" NOTIFIED=""
-SUNSET_TIME=""
+typeset -i SUNSET_EPOCH=0 CURRENT_TIME=0
-MINUTES=""
-SUNSET_EPOCH=0
-LAST_DATE=""
-PROMPT="sunset-alarm"
 
 ###############################################################################
 # Usage
 ###############################################################################
 usage() {
-    echo "Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]" >&2
+    cat <<EOF
+Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-p] [-h]
+
+Display a notification when a certain time related to sunset has been reached.
+
+Parameters:
+    -l) Takes a LAT:LONG parameter to check Open Meteo for the sunset time if
+          there is an Internet connection. Otherwise may fail to notify.
+    -t) Takes a hard-coded 24-hour formatted time for guessing when sunset is.
+    -m) Takes the number of minutes that the alert should appear before sunset.
+          Using a negative time is allowed if you prefer having the alert after.
+    -p) Persist the notification, showing back up every 5 minutes to midnight.
+    -h) Display this usage.
+
+Example: Show the alert 90 minutes before sunset in Colorado City AZ.
+    sunset-alarm -l 37:-113 -m 90
+
+Example: Show the alert at exactly 8:30 PM.
+    sunset-alarm -t 20:30 -m 0
+
+Example: Show the alert 30 minutes after sunset in Flagstaff AZ.
+    sunset-alarm -l 35.1987671:-111.651813 -m -30
+EOF
     exit 1
 }
 
@@ -30,20 +47,31 @@ while [ $# -gt 0 ]; do
         -l) LATLONG="$2"; shift 2 ;;
         -t) SUNSET_TIME="$2"; shift 2 ;;
         -m) MINUTES="$2"; shift 2 ;;
+        -p) PERSIST="true"; shift 1 ;;
         -h) usage ;;
         --) shift; break ;;
-        *) echo "Error: unknown argument '$1'" >&2; usage ;;
+        *) echo "ERROR: unknown argument '$1'" >&2; usage ;;
     esac
 done
 
-# Validate inputs
+# Validate inputs.
 if [ -z "$MINUTES" ]; then
-    echo "Error: -m MINUTES is required." >&2
+    echo "ERROR: -m MINUTES is required." >&2
     usage
 fi
 
 if [ -z "$LATLONG" ] && [ -z "$SUNSET_TIME" ]; then
-    echo "Error: must specify either -l LAT:LONG or -t HH:MI." >&2
+    echo "ERROR: must specify either -l LAT:LONG or -t HH:MI." >&2
+    usage
+fi
+
+LATLONG=${LATLONG//\,/:}
+LATLONG=${LATLONG//\ /:}
+LATLONG=${LATLONG//\_/:}
+LATLONG=${LATLONG//\&/:}
+LATLONG=${LATLONG//\?/:}
+if [[ -n "$LATLONG" && "$LATLONG" != *":"* ]]; then
+    echo "ERROR: LAT:LONG is missing the colon." >&2
     usage
 fi
 
@@ -51,12 +79,15 @@ fi
 # Internet connectivity check
 ###############################################################################
 check_internet() {
-    if curl -s --max-time 5 -o /dev/null https://www.google.com/generate_204; then
+    if curl -s --max-time 5 -o /dev/null https://hyperling.com; then
+        echo "Confirmed connectivity with Hyperling."
         return 0
     fi
-    if curl -s --max-time 5 -o /dev/null https://captive.apple.com/hotspot-detect.html; then
+    if curl -s --max-time 5 -o /dev/null https://mullvad.net; then
+        echo "Confirmed connectivity with Mullvad."
         return 0
     fi
+    echo "ERROR: Connectivity checks failed." >&2
     return 1
 }
 
@@ -64,29 +95,40 @@ check_internet() {
 # Get sunset from Open Meteo API
 ###############################################################################
 fetch_sunset_time() {
+    echo "Checking for sunset time of lat:long ${LATLONG}."
     LAT=$(echo "$LATLONG" | cut -d: -f1)
     LON=$(echo "$LATLONG" | cut -d: -f2)
+    TODAY="`date +'%Y-%m-%d'`"
 
-    RESPONSE=$(curl -s "https://api.open-meteo.com/v1/forecast?latitude=${LAT}&longitude=${LON}&timezone=auto&daily=sunset&date=today")
+    #REQUEST="https://api.open-meteo.com/v1/forecast?latitude=${LAT}&longitude=${LON}&timezone=auto&daily=sunset&date=today"
+    #REQUEST="https://api.open-meteo.com/v1/forecast?latitude=${LAT}&longitude=${LON}&timezone=auto&daily=sunset&forecast_days=1"
+    REQUEST="https://api.open-meteo.com/v1/forecast?latitude=${LAT}&longitude=${LON}&timezone=auto&daily=sunset&start_date=${TODAY}&end_date=${TODAY}"
+    RESPONSE=$(curl -s "$REQUEST")
+    status="$?"
+    echo "Curl command completed with a status of $status."
 
-    if [ -z "$RESPONSE" ]; then
+    if [[ -z "$RESPONSE" ]]; then
+        echo "ERROR: Did not receive response. $REQUEST" >&2
         return 1
     fi
 
-    # Extract sunset timestamp like "2025-06-15T19:32:00"
+    # Extract sunset timestamp like "2025-06-15T19:32:00".
-    SUNSET_RAW=$(echo "$RESPONSE" | grep -o '"sunset":"[^"]*"' | head -1 | sed 's/.*://"//;s/"$//')
+    SUNSET_RAW=$(echo "$RESPONSE" | jq -r '.daily.sunset[0]')
 
-    if [ -z "$SUNSET_RAW" ]; then
+    if [[ -z "$SUNSET_RAW" ]]; then
+        echo "ERROR: Could not parse time. $RESPONSE" >&2
         return 1
     fi
 
-    # Convert to epoch
+    # Convert to epoch.
     SUNSET_EPOCH=$(date -d "$(echo "$SUNSET_RAW" | cut -dT -f1) $(echo "$SUNSET_RAW" | cut -dT -f2)" +%s 2>/dev/null)
 
-    if [ -z "$SUNSET_EPOCH" ]; then
+    if [[ -z "$SUNSET_EPOCH" ]]; then
+        echo "ERROR: Could not calculate epoch. $SUNSET_RAW" >&2
         return 1
     fi
 
+    echo "Got ${SUNSET_RAW} and converted it to epoch ${SUNSET_EPOCH}."
     return 0
 }
 
@@ -94,16 +136,20 @@ fetch_sunset_time() {
 # Show alert via fallback chain: fyi -> notify-send -> wall
 ###############################################################################
 show_alert() {
-    TITLE="Sunset Alarm"
+    ALERT=$(date -d @${ALERT_WINDOW_START} +"%H:%M")
-    MESSAGE="Sunset is in ${MINUTES} minute(s)."
+    SUNSET=$(date -d @${SUNSET_EPOCH} +"%H:%M")
+    PLURAL=$(if (( $MINUTES != 1 )); then echo "s"; fi)
 
-    persistent="-t 0 --wait"
+    TITLE="Sunset Alarm ($ALERT)"
+    MESSAGE="It's ${MINUTES} minute${PLURAL} to $SUNSET."
+
+    keep_alive="-t 0 --wait"
     icon="-i weather-clear -u critical"
 
     if command -v fyi >/dev/null 2>&1; then
-        fyi $icon $persistent "$TITLE" "$MESSAGE"
+        fyi $icon $keep_alive "$TITLE" "$MESSAGE"
     elif command -v notify-send >/dev/null 2>&1; then
-        notify-send $icon $persistent "$TITLE" "$MESSAGE"
+        notify-send $icon $keep_alive "$TITLE" "$MESSAGE"
     elif command -v wall >/dev/null 2>&1; then
         echo "${TITLE}: ${MESSAGE}" | wall
     else
@@ -113,6 +159,18 @@ show_alert() {
     fi
 }
 
+###############################################################################
+# Sleep until a certain amount of time
+###############################################################################
+rest() {
+    if [[ "$CURRENT_TIME" -ge 0 ]]; then
+        TARGET="$1"
+        sleep_seconds=$(( TARGET - CURRENT_TIME ))
+        echo "Sleeping ${sleep_seconds}s until $(date -d @$TARGET +%H:%M:%S)."
+        sleep "$sleep_seconds"
+    fi
+}
+
 ###############################################################################
 # Main loop
 ###############################################################################
@@ -120,52 +178,75 @@ while true; do
     TODAY=$(date +%Y-%m-%d)
     CURRENT_TIME=$(date +%s)
 
-    # Check if we need to fetch new sunset time for a new day
+    # Check if we need to fetch new sunset time for a new day.
-    if [ "$LAST_DATE" != "$TODAY" ]; then
+    if [[ "$LAST_DATE" != "$TODAY" || "$SUNSET_EPOCH" == 0 ]]
+    then
         LAST_DATE="$TODAY"
 
-        if [ -n "$LATLONG" ]; then
+        if [[ -n "$LATLONG" ]]; then
-            # Need internet to get sunset time
+            # Need internet to get sunset time.
             if ! check_internet; then
-                echo "No internet connection. Retrying in 5 minutes..." >&2
+                echo "ERROR: No internet connection. Retrying in 5 minutes." >&2
                 sleep 300
                 continue
             fi
 
             fetch_sunset_time || {
-                echo "Error fetching sunset time. Retrying in 5 minutes..." >&2
+                echo "ERROR: Failed fetching sunset time. Retrying in 5 minutes." >&2
                 sleep 300
                 continue
             }
+
+            if [[ "$SUNSET_EPOCH" == 0 ]]; then
+                echo "ERROR: Sunset time is still null. Retrying in 5 minutes." >&2
+                sleep 300
+                continue
+            fi
         else
-            # User provided sunset time directly, convert to epoch
+            # User provided sunset time directly, convert to epoch.
             SUNSET_EPOCH=$(date -d "${TODAY} ${SUNSET_TIME}" +%s 2>/dev/null)
 
-            if [ -z "$SUNSET_EPOCH" ]; then
+            if [[ -z "$SUNSET_EPOCH" ]]; then
-                echo "Error: could not parse time '${SUNSET_TIME}'." >&2
+                echo "ERROR: Could not parse time '${SUNSET_TIME}'." >&2
                 sleep 60
                 continue
             fi
         fi
     fi
 
-    # Calculate alert window start (sunset minus specified minutes)
+    # Calculate alert window start (sunset minus specified minutes).
     ALERT_WINDOW_START=$(( SUNSET_EPOCH - (MINUTES * 60) ))
 
     # Calculate midnight of the current day
     MIDNIGHT=$(date -d "${TODAY} +1 day" +%s)
 
-    # Alert while current time is within the window (from window start until midnight)
+    # Alert while current time is within the window (from window start until midnight).
-    if [ "$CURRENT_TIME" -ge "$ALERT_WINDOW_START" ] && \
+    if [[ "$SUNSET_EPOCH" -ge 0 \
-       [ "$CURRENT_TIME" -lt "$MIDNIGHT" ]; then
+        && ( -z "$NOTIFIED" || -n "$PERSIST" ) \
+        && "$CURRENT_TIME" -ge "$ALERT_WINDOW_START" \
+        && "$CURRENT_TIME" -lt "$MIDNIGHT" ]]
+    then
+        echo "Alert time has been reached, show message."
         show_alert
-        sleep 5  # Re-alert every 5 minutes while in alert window
+        NOTIFIED="true"
+        echo "Alert has been dismissed."
+        if [[ -n "$PERSIST" ]]; then
+            echo "Sleeping for 5 minutes before next notification."
+            sleep 300
+        fi
+    elif [[ "$SUNSET_EPOCH" == 0 ]]; then
+        echo "ERROR: Sunset time has not been calculated yet, cannot alert." >&2
+    elif [[ -n "$NOTIFIED" && -z "$PERSIST" ]]; then
+        echo "Already notified for today ($TODAY)."
+        rest $MIDNIGHT
     else
-        sleep 60
+        echo "Not time to notify yet."
+        rest $ALERT_WINDOW_START
     fi
 
-    # Reset when we've passed midnight so we fetch new time tomorrow
+    # Reset when we've passed midnight so we fetch the new time for the day.
-    if [ "$CURRENT_TIME" -ge "$MIDNIGHT" ]; then
+    if [[ "$CURRENT_TIME" -ge "$MIDNIGHT" ]]; then
         LAST_DATE=""
+        NOTIFIED=""
     fi
 done