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

@@ -1,77 +1,252 @@
-#!/usr/bin/env bash
-# sunset-alarm — persistent alert at a calculated offset before sunset
-# Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]
-set -uo pipefail
+#!/bin/sh
 
-SUNSET_EPOCH=""     # epoch of today's sunset
-ALERT_EPOCH=""      # epoch when the window opens (sunset - offset)
-OFFSET_MIN=0        # signed minute offset from sunset
-LAT=""              # latitude   (-l/--location)
-LON=""              # longitude
-HARDCODED_TIME=""  # HH:MM string (-t/--hardcoded)
+# sunset-alarm -- Alert before or after sunset.
+# Displays an alert when current time is within (sunset - specified minutes).
 
+###############################################################################
+# Defaults
+###############################################################################
+declare LATLONG="" SUNSET_TIME="" MINUTES="" LAST_DATE="" PERSIST="" NOTIFIED=""
+typeset -i SUNSET_EPOCH=0 CURRENT_TIME=0
+
+###############################################################################
+# Usage
+###############################################################################
 usage() {
-    cat <<'EOF'
-Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]
+    cat <<EOF
+Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-p] [-h]
 
-Options:
-  -l LAT:LONG        Latitude and longitude, e.g. 32.123:-111.111
-                     (queried from Open-Meteo for today's sunset time)
-  -t HH24:MI         Hardcoded sunset time to use instead.
-                     When combined with -l the offset is applied against
-                     this time and the network call is skipped.
-  -m MINUTES         Minutes before (-), at (= 0), or after (+) sunset
-                     to trigger the alert.  May be negative.
-  -h                 Show this help message and exit.
+Display a notification when a certain time related to sunset has been reached.
 
-Examples:
-  sunset-alarm -l 32.123:-111.111 -m 90   # 90 min before actual sunset
-  sunset-alarm -t 18:00 -m -5             # 5 min after the hardcoded time
+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
 }
 
-die() { echo "Error: $*" >&2; exit 1; }
-
-# ── resolve a fallback command at startup ──────────────────────────
-NOTIFY_CMD=""
-for _cmd in fyi notify-send wall; do
-    if command -v "$_cmd" >/dev/null 2>&1; then
-        NOTIFY_CMD="$_cmd"; break
-    fi
+###############################################################################
+# Parse arguments (handles negative values for -m by using "$@")
+###############################################################################
+while [ $# -gt 0 ]; do
+    case "$1" in
+        -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 ;;
+    esac
 done
 
-fire_alert() {
-    local body="$1"
-    case "$NOTIFY_CMD" in
-        fyi)         fyi "Sunset Alarm: ${body}" ;;
-        notify-send) notify-send -u normal "Sunset Alarm" "${body}" 2>/dev/null || true ;;
-        wall)        echo "Sunset Alarm: ${body}" | wall 2>/dev/null || printf 'Sunset Alarm: %s\n' "$body" ;;
-    esac
+# Validate inputs.
+if [ -z "$MINUTES" ]; then
+    echo "ERROR: -m MINUTES is required." >&2
+    usage
+fi
+
+if [ -z "$LATLONG" ] && [ -z "$SUNSET_TIME" ]; then
+    echo "ERROR: must specify either -l LAT:LONG or -t HH:MI." >&2
+    usage
+fi
+
+LATLONG=${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
+
+###############################################################################
+# Internet connectivity check
+###############################################################################
+check_internet() {
+    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://mullvad.net; then
+        echo "Confirmed connectivity with Mullvad."
+        return 0
+    fi
+    echo "ERROR: Connectivity checks failed." >&2
+    return 1
 }
 
-# ── open-meteo helper ─────────────────────────────────────────────
-fetch_sunset_epoch() {
-    local lat="$1" lon="$2"
-    # curl –silent + HTTP code tail so we can detect failures.
-    local resp; resp=$(curl -sfw "\n%{http_code}" \
-        "https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&current=sunset&timezone=auto" \
-        --connect-timeout 10 --max-time 30) || return 1
+###############################################################################
+# 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'`"
 
-    local code="${resp##*$'\n'}"
-    resp="${resp%$'\n'*}"                          # strip the trailing HTTP code
+    #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."
 
-    [[ "${code:-599}" == "200" ]] || return 2
+    if [[ -z "$RESPONSE" ]]; then
+        echo "ERROR: Did not receive response. $REQUEST" >&2
+        return 1
+    fi
 
-    local iso; iso=$(printf '%s\n' "$resp" | jq -r '.current.sunset // empty')
-    [[ -n "$iso" ]] || return 3                    # null / missing field
+    # Extract sunset timestamp like "2025-06-15T19:32:00".
+    SUNSET_RAW=$(echo "$RESPONSE" | jq -r '.daily.sunset[0]')
 
-    SUNSET_EPOCH=$(date -d "$iso" +%s)             # local-time epoch
+    if [[ -z "$SUNSET_RAW" ]]; then
+        echo "ERROR: Could not parse time. $RESPONSE" >&2
+        return 1
+    fi
+
+    # Convert to epoch.
+    SUNSET_EPOCH=$(date -d "$(echo "$SUNSET_RAW" | cut -dT -f1) $(echo "$SUNSET_RAW" | cut -dT -f2)" +%s 2>/dev/null)
+
+    if [[ -z "$SUNSET_EPOCH" ]]; then
+        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
 }
 
-# Build today's sunset epoch from a hardcoded HH:MM when -t is used.
-set_sunset_from_time() {
-    local hhmm="$1"
-    local Y M D h m
-    read -r Y M D h m <<< "$(date +%Y-%m-%d) $(echo "$hhmm" | tr ':' ' ')"
-    SUNSET_EPOCH=$(date -d "${Y}-${M}-${D} ${h}:${m}:00" 2>/dev/null +%s \
-                 || die "Invalid time format '${hhmm}')")
+###############################################################################
+# Show alert via fallback chain: fyi -> notify-send -> wall
+###############################################################################
+show_alert() {
+    ALERT=$(date -d @${ALERT_WINDOW_START} +"%H:%M")
+    SUNSET=$(date -d @${SUNSET_EPOCH} +"%H:%M")
+    PLURAL=$(if (( $MINUTES != 1 )); then echo "s"; fi)
+
+    TITLE="Sunset Alarm ($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 $keep_alive "$TITLE" "$MESSAGE"
+    elif command -v notify-send >/dev/null 2>&1; then
+        notify-send $icon $keep_alive "$TITLE" "$MESSAGE"
+    elif command -v wall >/dev/null 2>&1; then
+        echo "${TITLE}: ${MESSAGE}" | wall
+    else
+        echo "ERROR: No notification tool found." >&2
+        echo "Install one of: fyi, notify-send (libnotify-bin), wall (bsd-write)" >&2
+        return 1
+    fi
+}
+
+###############################################################################
+# Sleep until a certain amount of time
+###############################################################################
+rest() {
+    if [[ "$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 "$sleep_seconds"
+    fi
+}
+
+###############################################################################
+# Main loop
+###############################################################################
+while true; do
+    TODAY=$(date +%Y-%m-%d)
+    CURRENT_TIME=$(date +%s)
+
+    # Check if we need to fetch new sunset time for a new day.
+    if [[ "$LAST_DATE" != "$TODAY" || "$SUNSET_EPOCH" == 0 ]]
+    then
+        LAST_DATE="$TODAY"
+
+        if [[ -n "$LATLONG" ]]; then
+            # Need internet to get sunset time.
+            if ! check_internet; then
+                echo "ERROR: No internet connection. Retrying in 5 minutes." >&2
+                sleep 300
+                continue
+            fi
+
+            fetch_sunset_time || {
+                echo "ERROR: Failed fetching sunset time. Retrying in 5 minutes." >&2
+                sleep 300
+                continue
+            }
+
+            if [[ "$SUNSET_EPOCH" == 0 ]]; then
+                echo "ERROR: Sunset time is still null. Retrying in 5 minutes." >&2
+                sleep 300
+                continue
+            fi
+        else
+            # User provided sunset time directly, convert to epoch.
+            SUNSET_EPOCH=$(date -d "${TODAY} ${SUNSET_TIME}" +%s 2>/dev/null)
+
+            if [[ -z "$SUNSET_EPOCH" ]]; then
+                echo "ERROR: Could not parse time '${SUNSET_TIME}'." >&2
+                sleep 60
+                continue
+            fi
+        fi
+    fi
+
+    # Calculate alert window start (sunset minus specified minutes).
+    ALERT_WINDOW_START=$(( 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).
+    if [[ "$SUNSET_EPOCH" -ge 0 \
+        && ( -z "$NOTIFIED" || -n "$PERSIST" ) \
+        && "$CURRENT_TIME" -ge "$ALERT_WINDOW_START" \
+        && "$CURRENT_TIME" -lt "$MIDNIGHT" ]]
+    then
+        echo "Alert time has been reached, show message."
+        show_alert
+        NOTIFIED="true"
+        echo "Alert has been dismissed."
+        if [[ -n "$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
+        echo "Not time to notify yet."
+        rest $ALERT_WINDOW_START
+    fi
+
+    # Reset when we've passed midnight so we fetch the new time for the day.
+    if [[ "$CURRENT_TIME" -ge "$MIDNIGHT" ]]; then
+        LAST_DATE=""
+        NOTIFIED=""
+    fi
+done