#!/command/with-contenv bash
# shellcheck shell=bash
# Start the CERTSYNC service

set -o errexit -o nounset -o pipefail

# Logs should be sent to stdout so that s6 can collect them

# Not `nginx -s reload`: that has root parse /tmp/nginx/conf, which the
# unprivileged nginx user can rewrite, and nginx chowns path directives on load.
function reload_nginx() {
    local pid

    if ! pid=$(cat /tmp/nginx/nginx.pid 2>/dev/null); then
        echo "[ERROR] No nginx pid file found, not reloading"
        return 0
    fi

    if [[ ! "$pid" =~ ^[0-9]+$ ]] || [[ "$(cat "/proc/${pid}/comm" 2>/dev/null)" != "nginx" ]]; then
        echo "[ERROR] nginx pid file does not name a running nginx process, not reloading"
        return 0
    fi

    kill -HUP "$pid"
}

echo "[INFO] Starting certsync..."

# Resolved once, and the condition must stay identical to the nginx run
# script's. Testing only fullchain.pem here would pick the mounted cert on a
# half-populated mount that nginx rejected, and the two fingerprints would then
# never agree, reloading nginx every cycle forever.
if [ -f /etc/letsencrypt/live/frigate/privkey.pem ] && [ -f /etc/letsencrypt/live/frigate/fullchain.pem ]; then
    lefile="/etc/letsencrypt/live/frigate/fullchain.pem"
else
    lefile="/config/tls/fullchain.pem"
fi

tls_enabled=`python3 /usr/local/nginx/get_nginx_settings.py | jq -r .tls.enabled`
listen_external_port=`python3 /usr/local/nginx/get_nginx_settings.py | jq -r .listen.external_port`

while true
do
    if [[ "$tls_enabled" == 'false' ]]; then
        sleep 9999
        continue
    fi

    if [ ! -e $lefile ]
    then
        echo "[ERROR] TLS certificate does not exist: $lefile"
    fi

    leprint=`openssl x509 -in $lefile -fingerprint -noout 2>&1 || echo 'failed'`

    case "$leprint" in
        *Fingerprint*)
            ;;
        *)
            echo "[ERROR] Missing fingerprint from $lefile"
            ;;
    esac

    liveprint=`echo | openssl s_client -showcerts -connect 127.0.0.1:$listen_external_port 2>&1 | openssl x509 -fingerprint 2>&1 | grep -i fingerprint  || echo 'failed'`

    case "$liveprint" in
        *Fingerprint*)
            ;;
        *)
            echo "[ERROR] Missing fingerprint from current nginx TLS cert"
            ;;
    esac

    if [[ "$leprint" != "failed" && "$liveprint" != "failed" && "$leprint" != "$liveprint" ]]
    then
        echo "[INFO] Reloading nginx to refresh TLS certificate"
        echo "$lefile: $leprint"
        reload_nginx
    fi

    sleep 60

done

exit 0