Add an xmobar indicator and daily reminder for overdue backups

backup.sh shows the days since the last simple_backup (orange from 7,
red from 14); backup-reminder.timer notifies daily once it is overdue.

.config/systemd/user/backup-reminder.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Notify when the last simple_backup is 14 days old or more
+StartLimitIntervalSec=2h
+StartLimitBurst=4
+
+[Service]
+Type=oneshot
+ExecStart=%h/.config/xmobar/backup.sh remind
+# no notification daemon yet (e.g. caught up right after login)? retry a few times
+Restart=on-failure
+RestartSec=5min

.config/systemd/user/backup-reminder.timer

@@ -0,0 +1,9 @@
+[Unit]
+Description=Check daily whether a backup is overdue
+
+[Timer]
+OnCalendar=*-*-* 10:00:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target

.config/xmobar/backup.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+# Days since the last simple_backup for xmobar, e.g. " 9d | ": hidden under 7 days, orange from 7, red from 14
+# Reads simple_backup's state file and the journal (versions before the state file only log there), whichever is newer.
+# With "list": show the date in a notification (for a click on the bar)
+# With "remind": notify only when a backup is overdue (run daily by backup-reminder.timer)
+
+warn=7 overdue=14
+state="${XDG_STATE_HOME:-$HOME/.local/state}/simple_backup/last_backup"
+
+last=0 dir=""
+if [[ -r $state ]]; then
+    { read -r time; read -r dir; } < "$state"
+    last=$(date -d "$time" +%s 2>/dev/null) || last=0
+fi
+
+# The journal drops old entries, so after a long gap there may be nothing left to find
+line=$(journalctl -q -t /usr/bin/simple_backup -r -o short-unix 2>/dev/null | grep -m1 'Backup completed')
+jlast=${line%%.*}
+if [[ $jlast =~ ^[0-9]+$ ]] && (( jlast > last )); then
+    last=$jlast dir=""
+fi
+
+days=$(( ($(date +%s) - last) / 86400 ))
+
+age() {
+    case $days in
+        0) echo "today" ;;
+        1) echo "1 day ago" ;;
+        *) echo "$days days ago" ;;
+    esac
+}
+
+case ${1:-} in
+    list)
+        if (( last )); then
+            body="$(date -d "@$last" '+%Y-%m-%d %H:%M') ($(age))"
+            [[ -n $dir ]] && body+=$'\n'"$dir"
+        else
+            body="No backup found"
+        fi
+        notify-send "Last backup" "$body"
+        exit ;;
+    remind)
+        (( last && days < overdue )) && exit 0
+        if (( last )); then
+            body="Last backup $(age) ($(date -d "@$last" '+%Y-%m-%d'))"
+        else
+            body="No backup found"
+        fi
+        # A failure (e.g. no notification daemon yet) makes the service retry
+        exec notify-send "Backup overdue" "$body. Plug in the backup disk." ;;
+esac
+
+(( last && days < warn )) && exit 0
+icon=$'\xef\x82\xa0'    # nf-fa-hdd_o, as UTF-8 bytes so the locale doesn't matter
+if (( ! last )); then
+    text="<fc=#f7768e>$icon ?</fc>"
+elif (( days >= overdue )); then
+    text="<fc=#f7768e>$icon ${days}d</fc>"
+else
+    text="<fc=#ffb86c>$icon ${days}d</fc>"
+fi
+echo "$text | "

.config/xmobar/xmobarrc_hdmi

@@ -52,9 +52,10 @@ Config { overrideRedirect   = True
                               , Run Com "/home/fuxino/.config/xmobar/pactl_volume.sh" [] "pactl_volume" 10
                               , Run Com "/home/fuxino/.config/xmobar/ens_brief.sh" [] "ens_brief" 18000
                               , Run Com "/home/fuxino/.config/xmobar/updates.sh" [] "updates" 600
+                              , Run Com "/home/fuxino/.config/xmobar/backup.sh" [] "backup" 3600
                               , Run UnsafeXMonadLog
                               ]
         , sepChar           = "%"
         , alignSep          = "}{"
-        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% "
+        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/backup.sh list`>%backup%</action><action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% "
         }

.config/xmobar/xmobarrc_laptop

@@ -53,9 +53,10 @@ Config { overrideRedirect   = True
                               , Run Com "/home/fuxino/.config/xmobar/pactl_volume.sh" [] "pactl_volume" 10
                               , Run Com "/home/fuxino/.config/xmobar/ens_brief.sh" [] "ens_brief" 18000
                               , Run Com "/home/fuxino/.config/xmobar/updates.sh" [] "updates" 600
+                              , Run Com "/home/fuxino/.config/xmobar/backup.sh" [] "backup" 3600
                               , Run UnsafeXMonadLog
                               ]
         , sepChar           = "%"
         , alignSep          = "}{"
-        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% %_XMONAD_TRAYPAD% "
+        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/backup.sh list`>%backup%</action><action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% %_XMONAD_TRAYPAD% "
         }