// SPDX-License-Identifier: GPL-3.0-or-later
// Copyright (C) 2025 - 2026, Patrick Schurig / ETM PowerSync

#include "sgreadyadapter.h"
#include "plugininfo.h"

#include <QDateTime>
#include <QSet>
#include <algorithm>
#include <climits>
#include <integrations/thingmanager.h>
#include <integrations/thing.h>
#include <types/action.h>
#include <types/param.h>

SgReadyAdapter::SgReadyAdapter(ThingManager *thingManager,
                               const QString &id,
                               const QString &label,
                               const QHash<int, QList<QString>> &stateRelays,
                               const QHash<int, double> &estimatedPowerW,
                               int minStateHoldS,
                               int priority,
                               QObject *parent)
    : QObject(parent)
    , m_thingManager(thingManager)
    , m_id(id)
    , m_label(label)
    , m_stateRelays(stateRelays)
    , m_estimatedPowerW(estimatedPowerW)
    , m_minStateHoldS(minStateHoldS)
    , m_priority(priority)
{
    m_states = m_stateRelays.keys();
    std::sort(m_states.begin(), m_states.end());
    Q_ASSERT(!m_states.isEmpty());
    Q_ASSERT(m_stateRelays.contains(2));  // état 2 (normal) = repli sûr obligatoire
}

LoadDescriptor SgReadyAdapter::descriptor() const
{
    LoadDescriptor d;
    d.id       = m_id;
    d.label    = m_label;
    d.adapter  = QStringLiteral("sg-ready");
    d.priority = m_priority;

    d.declared.states          = m_states;
    d.declared.estimatedPowerW = m_estimatedPowerW;
    d.limits.minStateHoldS     = m_minStateHoldS;

    d.supportedKinds = { LoadAction::State };
    return d;
}

LoadTelemetry SgReadyAdapter::telemetry() const
{
    LoadTelemetry t;
    t.available    = true;
    t.lastActionAt = m_lastActionAt;
    // Base du recrédit budget = puissance ALLOUÉE de l'état (déclaré), pas la conso mesurée
    // (états 1/2 → 0 ; états 3/4 → P3/P4). Cf. invariant 8.
    t.currentPowerW = m_estimatedPowerW.value(m_currentState, 0.0);
    return t;
}

LoadContext SgReadyAdapter::toLoadContext(const QDateTime &now) const
{
    LoadContext ctx;
    ctx.id       = m_id;
    ctx.adapter  = QStringLiteral("sg-ready");
    ctx.label    = m_label;
    ctx.priority = m_priority;
    ctx.declared = descriptor().declared;
    ctx.limits   = descriptor().limits;

    ctx.telemetry.currentPowerW = telemetry().currentPowerW;
    ctx.telemetry.state         = m_currentState;
    ctx.telemetry.lastSwitch    = m_lastSwitch;
    // Fenêtre de verrou évaluée au temps de cycle (protection court-cycling PAC).
    lockWindow(now, ctx.telemetry.minState, ctx.telemetry.maxState);
    return ctx;
}

LoadAction SgReadyAdapter::applyAction(const LoadAction &action, const QDateTime &now)
{
    if (action.kind != LoadAction::State)
        return action;

    if (action.reason.isEmpty()) {
        qCWarning(dcNymeaEnergy()) << "[SgReadyAdapter]" << m_label
                                   << "— LoadAction sans reason rejetée.";
        return action;
    }

    // Écrêtage à un état déclaré (borne puis exigence d'appartenance).
    int newState = qBound(m_states.first(), action.state, m_states.last());
    if (!m_stateRelays.contains(newState)) {
        qCWarning(dcNymeaEnergy()) << "[SgReadyAdapter]" << m_label
                                   << "— état non déclaré:" << action.state << "→ ignoré.";
        return action;
    }

    if (newState == m_currentState)
        return action;  // Idempotent

    // Verrou minStateHold évalué au temps de cycle (même fenêtre que le scheduler) —
    // bypassé si force == true (L2 watchdog → état 2).
    if (!action.force && lockActive(newState, now)) {
        qCDebug(dcNymeaEnergy()) << "[SgReadyAdapter]" << m_label
                                 << "— verrou minStateHold actif, état" << newState << "ignoré.";
        return action;
    }

    qCDebug(dcNymeaEnergy()) << "[SgReadyAdapter]" << m_label
                             << "→ état" << newState
                             << "(" << m_estimatedPowerW.value(newState, 0.0) << "W estimés)"
                             << "|" << action.reason;

    applyStateRelays(m_currentState, newState);

    m_currentState = newState;
    m_lastSwitch   = now;
    m_lastActionAt = now;

    LoadAction applied = action;
    applied.state          = newState;
    applied.estimatedPowerW = m_estimatedPowerW.value(newState, 0.0);
    return applied;
}

// ---- privé ---------------------------------------------------------------

void SgReadyAdapter::lockWindow(const QDateTime &now, int &minState, int &maxState) const
{
    const int lo = m_states.first();
    const int hi = m_states.last();
    const bool valid     = m_lastSwitch.isValid();
    const qint64 elapsed = valid ? m_lastSwitch.secsTo(now) : 0;

    if (valid && elapsed < m_minStateHoldS) {
        // Gel total : la PAC doit tenir son état (protection court-cycling compresseur).
        minState = maxState = m_currentState;
    } else {
        minState = lo;
        maxState = hi;
    }
}

bool SgReadyAdapter::lockActive(int newState, const QDateTime &now) const
{
    // MÊME calcul que la fenêtre exposée au scheduler → décision et exécution coïncident.
    int minState, maxState;
    lockWindow(now, minState, maxState);
    return newState < minState || newState > maxState;
}

int SgReadyAdapter::transientHarm(int state)
{
    // Transitoire le plus doux d'abord : neutre (2) < recommandation (3) < blocage (1) < forcé (4).
    switch (state) {
    case 2:  return 0;  // neutre
    case 3:  return 1;  // recommandation (run doux)
    case 1:  return 2;  // blocage (coupe le chauffage)
    case 4:  return 3;  // forcé (démarrage franc compresseur)
    default: return 2;  // combinaison hors-norme : prudence
    }
}

int SgReadyAdapter::stateForRelays(const QList<QString> &onRelays) const
{
    const QSet<QString> want(onRelays.begin(), onRelays.end());
    for (auto it = m_stateRelays.constBegin(); it != m_stateRelays.constEnd(); ++it) {
        const QSet<QString> s(it.value().begin(), it.value().end());
        if (s == want)
            return it.key();
    }
    return -1;
}

QSet<QString> SgReadyAdapter::allRelays() const
{
    QSet<QString> all;
    for (const auto &list : m_stateRelays)
        for (const QString &id : list)
            all.insert(id);
    return all;
}

void SgReadyAdapter::applyStateRelays(int fromState, int toState)
{
    const QList<QString> targetList = m_stateRelays.value(toState);
    const QSet<QString>  targetOn(targetList.begin(), targetList.end());
    const QList<QString> fromList   = m_stateRelays.value(fromState);
    const QSet<QString>  currentOn(fromList.begin(), fromList.end());

    // Relais dont l'état change lors de la transition.
    QStringList changed;
    for (const QString &relay : allRelays())
        if (targetOn.contains(relay) != currentOn.contains(relay))
            changed << relay;

    auto writeRelay = [&](const QString &thingId, bool on) {
        Thing *relay = m_thingManager->findConfiguredThing(ThingId(thingId));
        if (!relay) {
            qCWarning(dcNymeaEnergy()) << "[SgReadyAdapter]" << m_label << "— relais non trouvé:" << thingId;
            return;
        }
        StateType powerStateType = relay->thingClass().stateTypes().findByName("power");
        if (!powerStateType.id().isNull()) {
            Action powerAction(powerStateType.id(), relay->id(), Action::TriggeredByRule);
            powerAction.setParams(ParamList() << Param(powerStateType.id(), on));
            m_thingManager->executeAction(powerAction);
        } else {
            relay->setStateValue("power", on);  // repli mock
        }
    };

    // Contrat d'atomicité : si 2 relais (ou +) changent, commuter d'abord celui dont le
    // TRANSITOIRE est le plus doux (neutre/reco plutôt que blocage/forcé), puis les autres.
    if (changed.size() >= 2) {
        QString best;
        int bestHarm = INT_MAX;
        for (const QString &r : changed) {
            QSet<QString> transient = currentOn;
            if (targetOn.contains(r)) transient.insert(r); else transient.remove(r);
            const int h = transientHarm(stateForRelays(transient.values()));
            if (h < bestHarm) { bestHarm = h; best = r; }
        }
        writeRelay(best, targetOn.contains(best));
        changed.removeAll(best);
    }
    // Relais restants amenés à leur valeur cible.
    for (const QString &r : changed)
        writeRelay(r, targetOn.contains(r));
}