#!/bin/bash
# Sample breaktimer's state into a cache file, for widgets/breaktimer.lua.
#
# Conky's Lua cannot run a process, so it cannot call `kill -0` to learn whether
# the daemon is alive, and shelling out every two seconds to ask breaktimer.sh
# `status` would parse prose rather than read the four small files the daemon
# already writes under $XDG_RUNTIME_DIR. Those files are the whole interface;
# this script is the one place that interprets them.

set -u

CACHE_DIR="${XDG_CACHE_HOME:-$HOME/.cache}/udt"
CACHE="$CACHE_DIR/breaktimer.txt"

umask 077
mkdir -p "$CACHE_DIR"

TMP="$CACHE.tmp.$$"
trap 'rm -f "$TMP"' EXIT

RUNTIME="${XDG_RUNTIME_DIR:-/tmp}"
PID_FILE="$RUNTIME/breaktimer.pid"
STATE_FILE="$RUNTIME/breaktimer.state"
PHASE_FILE="$RUNTIME/breaktimer.phase"
REMAIN_FILE="$RUNTIME/breaktimer.remain"

# The daemon's own tick. Used only to decide how stale the remain file may be
# before the clock counts as frozen.
TICK=5

running=no
if [ -f "$PID_FILE" ] && kill -0 "$(cat "$PID_FILE" 2>/dev/null)" 2>/dev/null; then
    running=yes
fi

state=stopped
phase=stopped
remain=0
if [ "$running" = yes ]; then
    state=$(cat "$STATE_FILE" 2>/dev/null)
    phase=$(cat "$PHASE_FILE" 2>/dev/null)
    remain=$(cat "$REMAIN_FILE" 2>/dev/null)
fi
[ -z "$state" ] && state=stopped
[ -z "$phase" ] && phase=stopped
case "$remain" in ''|*[!0-9]*) remain=0 ;; esac

# Outside the work-hours window the daemon leaves the phase at 'working' without
# decrementing, so the remain file stops being rewritten; its age is the honest
# signal that the clock is frozen. Three ticks of slack, so a sample landing a
# moment before the next tick never reads as frozen. A paused daemon freezes the
# file too but reports 'paused' and is handled on its own, and a hung daemon
# freezes it as well, which is a state worth showing rather than hiding.
frozen=no
if [ "$running" = yes ] && [ "$state" = running ] && [ "$phase" = working ] \
   && [ -f "$REMAIN_FILE" ]; then
    mt=$(stat -c %Y "$REMAIN_FILE" 2>/dev/null || echo 0)
    [ $(( $(date +%s) - mt )) -gt $((TICK * 3)) ] && frozen=yes
fi

{
    echo "generated $(date +%s)"
    echo "running $running"
    echo "state $state"
    echo "phase $phase"
    echo "remain $remain"
    echo "frozen $frozen"
} > "$TMP"

mv -f "$TMP" "$CACHE"