#!/usr/bin/env bash
# _lib.sh — gedeelde helpers; source vanuit andere scripts

: "${AGENT_STATE_DIR:=/var/run/agent}"
: "${AGENT_LOG_DIR:=/var/log/agent}"

log() {
    printf '[%s] [%s] %s\n' \
        "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
        "${0##*/}" \
        "$*" >&2
}

# Schrijf JSON-state atomisch (write tmp + rename).
# Argument: JSON-string. Voegt automatisch $.heartbeatAt = now toe.
write_state() {
    local payload="$1"
    local tmp="${AGENT_STATE_DIR}/state.json.tmp.$$"
    local final="${AGENT_STATE_DIR}/state.json"

    # Merge $payload met heartbeatAt; behoud andere bestaande keys door
    # de bestaande state in te lezen en payload daarover te leggen.
    local existing='{}'
    if [[ -f "$final" ]]; then
        existing=$(cat "$final" 2>/dev/null || echo '{}')
    fi

    jq -n \
        --argjson existing "$existing" \
        --argjson payload "$payload" \
        --arg now "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
        '$existing + $payload + {heartbeatAt: $now}' \
        > "$tmp"

    mv "$tmp" "$final"
}