#!/bin/bash
# DATUM Gateway health check — managed by Ansible (roles/datum_gateway)
#
# The exit code is the answer and systemd keeps it:
#     systemctl is-failed datum-gateway-healthcheck.service
# Reporting anywhere else is optional and generic.
PUSH_URL="${HEALTHCHECK_PUSH_URL:-}"
PUSH_TOKEN="${HEALTHCHECK_PUSH_TOKEN:-}"
STRATUM_PORT={{ datum_gateway_stratum_port }}

check_datum() {
    # Service must be active and stratum port must be listening
    systemctl is-active --quiet datum-gateway && \
    nc -z 127.0.0.1 "${STRATUM_PORT}"
}

report() {
    local status=$1
    local msg=$2
    # No push URL is normal, not an error: the exit code below is still a
    # complete answer for anything reading unit state.
    [ -n "$PUSH_URL" ] || return 0
    # Gatus external endpoint: a POST with a bearer token, NOT Uptime Kuma's
    # GET with ?status=up. The callers still pass up/down, so the mapping is
    # done here rather than at every call site.
    local _ok=false
    [ "${status}" = "up" ] && _ok=true
    curl -s --max-time 15 --retry 2 -o /dev/null -X POST \
        -H "Authorization: Bearer ${PUSH_TOKEN}" \
        "${PUSH_URL}?success=${_ok}&error=${msg// /%20}" || true
}

if check_datum; then
    report "up" "OK"
    exit 0
else
    report "down" "DATUM Gateway not responding"
    exit 1
fi