#!/bin/bash

# UPS heartbeat check - managed by Ansible (infra/nodito/34_nut_ups_setup_playbook.yml)
#
# The exit code is the answer and systemd keeps it:
#     systemctl is-failed {{ ups_systemd_service_name }}.service
# Reporting anywhere else is optional and generic.

LOG_FILE="{{ ups_log_file }}"
UPS_NAME="{{ ups_name }}"
PUSH_URL="${HEALTHCHECK_PUSH_URL:-}"

log_message() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" >> "$LOG_FILE"
}

report() {
    local status="$1"
    local message="$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

    local encoded_message
    encoded_message=$(printf '%s\n' "$message" | sed 's/%/%25/g; s/ /%20/g; s/(/%28/g; s/)/%29/g; s/:/%3A/g; s/\//%2F/g')

    local response http_code
    response=$(curl -s --max-time 10 --retry 2 -w "\n%{http_code}" "${PUSH_URL}?status=${status}&msg=${encoded_message}&ping=" 2>&1)
    http_code=$(echo "$response" | tail -n1)

    if [ "$http_code" = "200" ] || [ "$http_code" = "201" ]; then
        log_message "Reported ${status}: $message (HTTP $http_code)"
        return 0
    else
        log_message "ERROR: Failed to report ${status} (HTTP $http_code)"
        return 1
    fi
}

main() {
    local status charge runtime load

    status=$(upsc ${UPS_NAME}@localhost ups.status 2>/dev/null)

    if [ -z "$status" ]; then
        log_message "ERROR: Cannot communicate with UPS"
        report "down" "cannot communicate with UPS ${UPS_NAME}"
        exit 1
    fi

    charge=$(upsc ${UPS_NAME}@localhost battery.charge 2>/dev/null)
    runtime=$(upsc ${UPS_NAME}@localhost battery.runtime 2>/dev/null)
    load=$(upsc ${UPS_NAME}@localhost ups.load 2>/dev/null)

    if [[ "$status" == *"OL"* ]]; then
        local message="UPS on mains (charge=${charge}% runtime=${runtime}s load=${load}%)"
        log_message "$message"
        report "up" "$message"
        exit 0
    else
        log_message "UPS not on mains power (status=$status)"
        report "down" "UPS not on mains (status=${status} charge=${charge}%)"
        exit 1
    fi
}

main