Draw idle as one timeline, and let the power button answer to its owner

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/scripts/panama-battery

@@ -69,6 +69,53 @@ read_int() {
     printf '%s\n' "$value"
 }
 
+# How much of the pack's design capacity is left, as a whole percent.
+#
+# Energy (µWh) and charge (µAh) are the two spellings of the same pair and a
+# pack has one or the other, never both worth trusting, so each is tried in the
+# order the kernel prefers. Summed across every system pack for the same reason
+# the percentage is: on a two-battery machine, one pack's wear is not the
+# machine's.
+#
+# Fails rather than guessing when the firmware exposes no design capacity,
+# which plenty does not. A health figure computed from a design capacity that
+# was itself invented is a confident number that is wrong, and this page has
+# already decided once (no time-to-empty) that it would rather say nothing.
+battery_health() {
+    local dir full design total_full=0 total_design=0
+    while IFS= read -r dir; do
+        full="$(read_int "$dir/energy_full" || read_int "$dir/charge_full")" || continue
+        design="$(read_int "$dir/energy_full_design" || read_int "$dir/charge_full_design")" || continue
+        (( design > 0 )) || continue
+        total_full=$(( total_full + full ))
+        total_design=$(( total_design + design ))
+    done < <(all_battery_dirs)
+    (( total_design > 0 )) || return 1
+    printf '%s\n' "$(( (total_full * 100 + total_design / 2) / total_design ))"
+}
+
+# Full charge cycles, from the primary pack and then from whichever pack
+# answers.
+#
+# A reported zero is treated as "the firmware does not count", not as a battery
+# that has never been charged: a great many laptops export cycle_count as a
+# permanent 0, and "0 cycles" beside a four-year-old pack reads as a fact
+# rather than the absence of one.
+battery_cycles() {
+    local primary="$1" dir value
+    if [[ -n "$primary" ]] && value="$(read_int "$primary/cycle_count")" && (( value > 0 )); then
+        printf '%s\n' "$value"
+        return 0
+    fi
+    while IFS= read -r dir; do
+        if value="$(read_int "$dir/cycle_count")" && (( value > 0 )); then
+            printf '%s\n' "$value"
+            return 0
+        fi
+    done < <(all_battery_dirs)
+    return 1
+}
+
 cmd_paths() {
     local battery mains threshold=""
     battery="$(battery_dir)" || battery=""
@@ -87,6 +134,7 @@ cmd_paths() {
 
 cmd_status() {
     local battery mains capacity="" state="Unknown" online=1 threshold=0
+    local health="" cycles=""
     battery="$(battery_dir)" || battery=""
     mains="$(mains_dir)" || mains=""
 
@@ -109,16 +157,23 @@ cmd_status() {
             done
             (( total_full > 0 )) && capacity=$(( (total_now * 100 + total_full / 2) / total_full ))
         fi
+
+        health="$(battery_health)" || health=""
+        cycles="$(battery_cycles "$battery")" || cycles=""
     fi
     if [[ -n "$mains" ]]; then
         online="$(read_int "$mains/online")" || online=0
     fi
 
-    printf '{"available":%s,"percent":%s,"status":"%s","acOnline":%s,"chargeLimit":%s}\n' \
+    # health and cycles are JSON null when sysfs does not report them, which is
+    # most desktops and a fair number of laptops. Null rather than 0: a zero
+    # would render as a dead battery that has never been charged.
+    printf '{"available":%s,"percent":%s,"status":"%s","acOnline":%s,"chargeLimit":%s,"healthPercent":%s,"cycleCount":%s}\n' \
         "$([[ -n "$capacity" ]] && echo true || echo false)" \
         "${capacity:-0}" "$state" \
         "$([[ "$online" == "1" ]] && echo true || echo false)" \
-        "$threshold"
+        "$threshold" \
+        "${health:-null}" "${cycles:-null}"
 }
 
 cmd_set_threshold() {
@@ -156,7 +211,9 @@ case "${1:-status}" in
 usage: panama-battery [paths|status|set-threshold <50-100>]
 
   paths           JSON: which sysfs files hold the battery, mains and threshold
-  status          JSON: one reading of charge, state, power source and limit
+  status          JSON: one reading of charge, state, power source, limit,
+                  health against design capacity and charge cycles (the last
+                  two null where the firmware does not report them)
   set-threshold   cap charging at N percent (asks for a password)
 USAGE
         ;;