#!/bin/bash
# Fulcrum health check — managed by Ansible (roles/fulcrum)
#
# Checks that Fulcrum's Electrum TCP port is accepting connections, and records
# the answer in the exit code, which systemd keeps:
#     systemctl is-failed fulcrum-healthcheck.service
# That is a complete answer with no monitoring system involved. Reporting
# elsewhere is optional and generic — set healthcheck_push_url.

FULCRUM_HOST="{{ fulcrum_tcp_bind }}"
FULCRUM_PORT={{ fulcrum_tcp_port }}
PUSH_URL="${HEALTHCHECK_PUSH_URL:-}"
PUSH_TOKEN="${HEALTHCHECK_PUSH_TOKEN:-}"

check_fulcrum() {
    timeout 5 bash -c "echo > /dev/tcp/${FULCRUM_HOST}/${FULCRUM_PORT}" 2>/dev/null
}

report() {
    local status=$1 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_fulcrum; then
    report "up" "OK"
    exit 0
else
    echo "Fulcrum TCP port ${FULCRUM_PORT} not responding"
    report "down" "Fulcrum TCP port not responding"
    exit 1
fi