#!/bin/bash
# Sync calcurse with Google Calendar via calcurse-caldav; start the login prompt when the weekly OAuth login expires.
# --now: called from the UI's pre-load hook (skip the UI check, shorter timeout, no daemon restart).
# --authcode CODE: finish a login (from calcurse-relogin, which checks for the UI itself).
set -uo pipefail

data=${XDG_DATA_HOME:-$HOME/.local/share}/calcurse
state=${XDG_STATE_HOME:-$HOME/.local/state}/calcurse-sync
expired_flag=$state/login-expired
now=false
authcode=()
case ${1:-} in
--now) now=true ;;
--authcode) authcode=(--authcode "$2") ;;
esac

# The UI keeps the data in memory, so syncing under it would lose changes; its post-save hook syncs after it exits.
ui_running() {
    # shellcheck disable=SC2009 # pgrep can't match "has any terminal"
    ps -C calcurse -o tty= | grep -qv '?'
}

if ! $now && ((${#authcode[@]} == 0)) && ui_running; then
    echo "calcurse UI is running, skipping"
    exit 0
fi

mkdir -p "$state"
# BROWSER=true: an expired login must not open browser tabs on its own.
out=$(BROWSER=true timeout "$($now && echo 15 || echo 60)" calcurse-caldav "${authcode[@]}" 2>&1)
rc=$?
printf '%s\n' "$out"

if ((rc != 0)); then
    if grep -q 'Access token is missing or refresh token is expired' <<<"$out"; then
        # Prompt via calcurse-relogin, again daily if the prompt was dismissed.
        if [[ ! -e $expired_flag || -n $(find "$expired_flag" -mmin +1440) ]]; then
            systemctl --user start --no-block calcurse-relogin.service
            touch "$expired_flag"
        fi
    elif grep -q 'Another synchronization instance' <<<"$out"; then
        exit 0
    fi
    exit "$rc"
fi
rm -f "$expired_flag"

# A running daemon never re-reads the data files: restart it so imported appointments get alerts.
if ! $now && ! grep -q '^0 items imported, 0 items removed locally' <<<"$out"; then
    pidfile=$data/.daemon.pid
    if [[ -s $pidfile ]] && pid=$(<"$pidfile") && kill "$pid" 2>/dev/null; then
        timeout 5 tail --pid="$pid" -f /dev/null
        # Own scope, so the daemon outlives this oneshot service.
        systemd-run --user --scope -q calcurse --daemon
        echo "restarted calcurse daemon"
    fi
fi