// src/mqtt/handlers/meter.handler.js
async function handleStateMeter(ctx, mqttTopic, payload, meterKind /* 'evse'|'grid' */) {
    const charger = await ctx.getChargerByMqttTopic(mqttTopic);
    if (!charger) {
        console.warn(`[MQTT] Charger não encontrado para topic: ${mqttTopic}`);
        return;
    }

    const chargerId = charger.id;
    const now = new Date();

    const vrms = ctx.toArr3(payload?.vrms);   // 2 casas
    const irms = ctx.toArr3(payload?.irms);   // 2 casas

    // watt em W -> kW com 2 casas
    const wattKw = ctx.toArr3Kw2(payload?.watt);

    const totalEnergy = ctx.round2(payload?.totalEnergy); // kWh acumulado (2 casas)
    const source = String(payload?.source || meterKind || '').toUpperCase();

    if (Number.isFinite(totalEnergy) && totalEnergy >= 0) {
        ctx.lastTotalEnergyByChargerId.set(chargerId, totalEnergy);
    }

    if (meterKind === 'evse' || source === 'EVSE') {
        const dbUpdate = {
            consumption: totalEnergy,
            charging_current: ctx.round2(irms[0]),

            power_l1: wattKw[0],
            power_l2: wattKw[1],
            power_l3: wattKw[2],

            voltage_l1: vrms[0],
            voltage_l2: vrms[1],
            voltage_l3: vrms[2],

            current_l1: irms[0],
            current_l2: irms[1],
            current_l3: irms[2],

            updated_at: now.toISOString(),
        };

        await ctx.updateChargerDbIfChanged(chargerId, dbUpdate);

        // atualiza sessão ativa com delta (sem fechar)
        const currentlyEnabled = ctx.lastEnabled[chargerId] || false;
        if (currentlyEnabled) {
            const session = await ctx.db('charger_sessions')
                .where({ charger_id: chargerId })
                .whereNull('ended_at')
                .first();

            if (session) {
                const startEnergy = ctx.sessionStartEnergyByChargerId.get(chargerId) ?? 0;
                const delta = Math.max(
                    0,
                    ctx.round2((ctx.lastTotalEnergyByChargerId.get(chargerId) ?? 0) - startEnergy)
                );

                await ctx.db('charger_sessions').where({ id: session.id }).update({ kwh: delta });
            }
        }

        const meta = ctx.lastMetaByChargerId.get(chargerId) || { status: '—', stateCode: undefined };
        ctx.emitter.emit('charging-status', {
            charger_id: chargerId,
            mqtt_topic: mqttTopic,
            status: meta.status,
            stateCode: meta.stateCode,
            consumption: totalEnergy,
            chargingTime: 0,
            power: wattKw,
            voltage: vrms,
            current: irms,
            raw: payload,
        });
    }

    ctx.emitter.emit('meter-live', {
        charger_id: chargerId,
        mqtt_topic: mqttTopic,
        meter: meterKind,
        vrms,
        irms,
        watt: wattKw,
        totalEnergy,
        raw: payload,
        updated_at: now.toISOString(),
    });
}

module.exports = { handleStateMeter };