// =====================================================================================
//  protocol_client.cpp  -  Implementierung des UART-Protokoll-Clients (P4-Seite)
// =====================================================================================

#include "protocol_client.h"
#include <ArduinoJson.h>   // Bibliothek: "ArduinoJson" (v7) ueber den Library Manager
#if UART_SELFTEST_INTERNAL_LOOPBACK
#include "driver/uart.h"   // fuer uart_set_loop_back()
#endif

// -------------------------------------------------------------------------------------
//  Setup / Hauptschleife
// -------------------------------------------------------------------------------------
void ProtocolClient::begin() {
    // Groesserer RX-Puffer: OTA-Chunks (~1.4 KB) duerfen nicht ueberlaufen (Default 256).
    DISPLAY_UART_PORT.setRxBufferSize(2048);
    DISPLAY_UART_PORT.begin(DISPLAY_UART_BAUDRATE, SERIAL_8N1,
                            DISPLAY_UART_RX_PIN, DISPLAY_UART_TX_PIN);
    // Bewusst NICHT auf PROTO_RX_LINE_MAX (4 KB) reserviert: Der interne RAM ist knapp
    // (statisch ~98 %), und eine Arduino-String kann nicht ins PSRAM alloziert werden.
    // 2 KB deckt die reale State-Zeile (~2,1 KB) fast vollstaendig ab; der Rest waechst
    // in kleinen Schritten nach. Das Limit dient nur als Obergrenze gegen Muell/Overflow.
    _rxBuf.reserve(2048);
    _lastHelloMs = 0;
    _lastHeartbeatMs = 0;
#if UART_SELFTEST_INTERNAL_LOOPBACK
    // DIAGNOSE: TX intern auf RX legen. UART_NUM_1 muss zu DISPLAY_UART_PORT (Serial1) passen.
    uart_set_loop_back(UART_NUM_1, true);
#endif
}

void ProtocolClient::loop() {
    // --- Eingehende Bytes zeilenweise einsammeln ---
    while (DISPLAY_UART_PORT.available() > 0) {
        char c = (char)DISPLAY_UART_PORT.read();
        rxByteCount++;
        if (c == '\r') continue;
        if (c == '\n') {
            if (_rxOverflow) {
                _rxBuf = "";
                _rxOverflow = false;
            } else {
                String line = _rxBuf;
                _rxBuf = "";
                line.trim();
                if (line.length() > 0) { rxLineCount++; handleLine(line); }
            }
            continue;
        }
        if (_rxOverflow) continue;
        if (_rxBuf.length() >= PROTO_RX_LINE_MAX) { _rxOverflow = true; continue; }
        _rxBuf += c;
    }

    maintainLink();
}

// -------------------------------------------------------------------------------------
//  Verbindungspflege: hello-Handshake, Heartbeat, Timeout
// -------------------------------------------------------------------------------------
void ProtocolClient::maintainLink() {
    unsigned long now = millis();

    // Link-Timeout: zu lange nichts empfangen -> Verbindung als tot markieren
    if (_state.linkUp && (now - _state.lastRxMs > PROTO_LINK_TIMEOUT_MS)) {
        _state.linkUp = false;
    }

    if (!_state.linkUp) {
        // Solange keine Verbindung: regelmaessig hello senden
        if (now - _lastHelloMs >= PROTO_HELLO_RETRY_MS) {
            _lastHelloMs = now;
            sendHello();
        }
        return;
    }

    // Verbunden: Heartbeat senden, damit die S3 uns als aktiven Client behaelt
    if (now - _lastHeartbeatMs >= PROTO_HEARTBEAT_MS) {
        _lastHeartbeatMs = now;
        sendPing();
    }
}

// -------------------------------------------------------------------------------------
//  Empfangene Zeile verarbeiten
// -------------------------------------------------------------------------------------
void ProtocolClient::handleLine(const String& line) {
    _state.lastRxMs = millis();
    lastRxLine = line;

    JsonDocument doc;
    DeserializationError err = deserializeJson(doc, line);
    if (err) {
        parseErrorCount++;
#ifdef DBG_SERIAL
        DBG_SERIAL.print(F("[proto] JSON-Fehler: "));
        DBG_SERIAL.println(err.c_str());
#endif
        return;
    }

    const char* type = doc["type"] | "";

    // OTA-Nachrichten (otaBegin/otaData/otaEnd/otaAbort) separat behandeln.
    if (strncmp(type, "ota", 3) == 0) {
        if (_otaCb) _otaCb(line);
        return;
    }

    if (strcmp(type, "state") == 0) {
        applyState(line);
        _state.linkUp = true;             // jeder gueltige state bestaetigt die Verbindung
        if (_stateCb) _stateCb(_state);

    } else if (strcmp(type, "hello") == 0) {
        _state.protocolVersion = doc["protocolVersion"] | 0;
        _state.firmwareVersion = String((const char*)(doc["firmwareVersion"] | ""));
        _state.linkUp = true;
#ifdef DBG_SERIAL
        DBG_SERIAL.printf("[proto] hello: FW=%s, proto=%u\n",
                          _state.firmwareVersion.c_str(), _state.protocolVersion);
        if (_state.protocolVersion != PROTO_EXPECTED_VERSION) {
            DBG_SERIAL.printf("[proto] WARNUNG: Protokollversion %u != erwartet %u\n",
                              _state.protocolVersion, (unsigned)PROTO_EXPECTED_VERSION);
        }
#endif

    } else if (strcmp(type, "ack") == 0) {
        // S3 sendet das Erfolgs-Flag als "success"; "ok" als Fallback (aeltere Versionen).
        bool ackOk = doc["success"] | (doc["ok"] | false);
        if (_ackCb) _ackCb(doc["id"] | 0, ackOk,
                           String((const char*)(doc["message"] | "")));

    } else if (strcmp(type, "error") == 0) {
        if (_ackCb) _ackCb(doc["id"] | 0, false,
                           String((const char*)(doc["message"] | "")));

    } else if (strcmp(type, "profiles") == 0) {
        applyProfiles(line);

    } else if (strcmp(type, "profileDetails") == 0) {
        if (_profileDetailsCb) _profileDetailsCb(line);

    } else if (strcmp(type, "usageStats") == 0) {
        if (_usageStatsCb) _usageStatsCb(line);

    } else if (strcmp(type, "wifiNetworks") == 0) {
        if (_wifiNetworksCb) _wifiNetworksCb(line);
    }
}

// -------------------------------------------------------------------------------------
//  state -> MachineState
// -------------------------------------------------------------------------------------
void ProtocolClient::applyState(const String& json) {
    JsonDocument doc;
    if (deserializeJson(doc, json)) return;

    MachineState& s = _state;
    s.protocolVersion = doc["protocolVersion"] | s.protocolVersion;
    s.firmwareVersion = String((const char*)(doc["firmwareVersion"] | s.firmwareVersion.c_str()));

    s.tempW = doc["tempW"] | s.tempW;
    s.setW  = doc["setW"]  | s.setW;
    s.tempD = doc["tempD"] | s.tempD;
    s.setD  = doc["setD"]  | s.setD;

    s.statusText = String((const char*)(doc["statusText"] | ""));
    s.statusKey  = String((const char*)(doc["statusKey"]  | ""));
    s.wasserSensorError    = doc["wasserSensorError"]    | false;
    s.wasserSafetyShutdown = doc["wasserSafetyShutdown"] | false;
    s.dampfSensorError     = doc["dampfSensorError"]     | false;
    s.dampfSafetyShutdown  = doc["dampfSafetyShutdown"]  | false;
    s.shotActive         = doc["shotActive"]         | false;
    s.shotElapsedMs      = doc["shotElapsedMs"]      | 0;
    s.scaleTaring        = doc["scaleTaring"]        | false;
    s.steamCircuitActive = doc["steamCircuitActive"] | false;
    s.steamElapsedMs     = doc["steamElapsedMs"]     | 0;
    s.steamFlushActive   = doc["steamFlushActive"]   | false;
    s.steamFlushElapsedMs= doc["steamFlushElapsedMs"]| 0;
    s.flushActive        = doc["flushActive"]        | false;
    s.flushElapsedMs     = doc["flushElapsedMs"]     | 0;
    s.ecoActive          = doc["ecoActive"]          | false;
    s.ecoCountdownSec    = doc["ecoCountdownSec"]    | (long)-1;
    s.ecoShowInfo        = doc["ecoShowInfo"]        | false;
    s.standbyActive      = doc["standbyActive"]      | false;
    s.standbyShowClock   = doc["standbyShowClock"]   | false;
    s.backlightActive       = doc["backlightActive"]       | s.backlightActive;
    s.backlightStandbyClock = doc["backlightStandbyClock"] | s.backlightStandbyClock;
    s.maintenanceActive  = doc["maintenanceActive"]  | false;
    s.steamHeatDisabled  = doc["steamHeatDisabled"]  | false;
    s.steamDelayActive   = doc["steamDelayActive"]   | false;
    s.steamDelayRemainSec= doc["steamDelayRemainSec"]| (long)0;
    s.heatUpMinutes      = doc["heatUpMinutes"]      | 0;
    s.heatUpRemainSec    = doc["heatUpRemainSec"]    | (long)-1;
    s.lightOn            = doc["lightOn"]            | false;
    s.piezoEnabled       = doc["piezoEnabled"]       | false;
    s.activeProfile      = String((const char*)(doc["profile"] | ""));   // fehlt bei aelterer S3-FW -> leer
    s.profileDirty       = doc["profDirty"]          | false;

    s.weight        = doc["weight"]        | s.weight;
    s.targetWeight  = doc["targetWeight"]  | s.targetWeight;
    s.lastShotWeight   = doc["lastShotWeight"]   | s.lastShotWeight;
    s.lastShotByWeight = doc["lastShotByWeight"] | false;
    s.flowRate      = doc["flowRate"]      | 0.0f;
    s.scaleEnabled  = doc["scaleEnabled"]  | false;
    s.scaleType     = doc["scaleType"]     | 0;
    s.scaleConnected= doc["scaleConnected"]| false;

    s.piEnabled  = doc["piEnabled"]  | false;
    s.bbtEnabled = doc["bbtEnabled"] | false;
    s.bbwEnabled = doc["bbwEnabled"] | false;
    s.sbtEnabled = doc["sbtEnabled"] | false;
    s.bbtSecs    = doc["bbtSecs"]    | s.bbtSecs;
    s.sbtSecs    = doc["sbtSecs"]    | s.sbtSecs;
    s.piDurSecs  = doc["piDurSecs"]  | s.piDurSecs;
    s.piPauseSecs= doc["piPauseSecs"]| s.piPauseSecs;
    s.piState    = doc["piState"]    | (uint8_t)0;   // fehlt bei aelterer S3-FW -> 0 (UI leitet dann zeitbasiert ab)
    s.bbwTarget  = doc["bbwTarget"]  | s.bbwTarget;
    s.bbwOffset  = doc["bbwOffset"]  | s.bbwOffset;

    // Cold Extraction (fehlt bei S3-FW < 5.3.0 -> cxEnabled bleibt false, UI blendet alles aus)
    s.cxEnabled  = doc["cxEnabled"]  | false;
    s.cxActive   = doc["cxActive"]   | false;
    s.cxShot     = doc["cxShot"]     | false;
    s.cxAllowed  = doc["cxAllowed"]  | false;
    s.cxResting  = doc["cxResting"]  | false;
    s.cxMaxTemp  = doc["cxMaxTemp"]  | s.cxMaxTemp;
    s.cxTarget   = doc["cxTarget"]   | s.cxTarget;
    s.cxPreInfSec= doc["cxPreInf"]   | s.cxPreInfSec;
    s.cxMaxSecs  = doc["cxMaxSecs"]  | s.cxMaxSecs;
    s.cxBlock    = doc["cxBlock"]    | (uint8_t)0;
    s.cxNotice   = doc["cxNotice"]   | (uint8_t)0;

    s.caseSensorEnabled = doc["caseSensorEnabled"] | false;
    s.caseTempDashboard = doc["caseTempDashboard"] | false;
    s.caseSensorType    = doc["caseSensorType"]    | 0;
    if (doc["caseTemp"].isNull()) {
        s.hasCaseTemp = false;
    } else {
        s.hasCaseTemp = true;
        s.caseTemp = doc["caseTemp"] | 0.0f;
    }

    s.maintenanceInterval        = doc["maintenanceInterval"]        | 0;
    s.maintenanceIntervalCounter = doc["maintenanceIntervalCounter"] | 0;
    s.flushDurationSeconds       = doc["flushDurationSeconds"]       | 0;
    s.steamFlushDurationSeconds  = doc["steamFlushDurationSeconds"]  | 0;
    s.cleaningActive         = doc["cleaningActive"]         | false;
    s.cleaningWaiting        = doc["cleaningWaiting"]        | false;
    s.cleaningBrewPhase      = doc["cleaningBrewPhase"]      | false;
    s.cleaningCycle          = doc["cleaningCycle"]          | 0;
    s.cleaningCycles         = doc["cleaningCycles"]         | 0;
    s.cleaningBrewSeconds    = doc["cleaningBrewSeconds"]    | 0;
    s.cleaningPauseSeconds   = doc["cleaningPauseSeconds"]   | 0;
    s.cleaningPhaseRemainSec = doc["cleaningPhaseRemainSec"] | (long)0;

    // v2
    s.dutyW = doc["dutyW"] | 0.0f;
    s.dutyD = doc["dutyD"] | 0.0f;
    s.kpW = doc["kpW"] | 0.0f; s.kiW = doc["kiW"] | 0.0f; s.kdW = doc["kdW"] | 0.0f;
    s.kpD = doc["kpD"] | 0.0f; s.kiD = doc["kiD"] | 0.0f; s.kdD = doc["kdD"] | 0.0f;
    s.autoTuneW = doc["autoTuneW"] | false;
    s.autoTuneD = doc["autoTuneD"] | false;
    s.autoTuneWStatus = doc["autoTuneWStatus"] | s.autoTuneWStatus;
    s.autoTuneDStatus = doc["autoTuneDStatus"] | s.autoTuneDStatus;

    s.wifiConnected = doc["wifiConnected"] | false;
    s.apMode        = doc["apMode"]        | false;
    s.ip            = String((const char*)(doc["ip"]   | ""));
    s.ssid          = String((const char*)(doc["ssid"] | ""));
    s.rssi          = doc["rssi"] | 0;
    s.timeStr       = String((const char*)(doc["time"] | ""));
}

// -------------------------------------------------------------------------------------
//  profiles -> Callback (Array von Namen)
// -------------------------------------------------------------------------------------
void ProtocolClient::applyProfiles(const String& json) {
    if (!_profilesCb) return;
    JsonDocument doc;
    if (deserializeJson(doc, json)) return;

    JsonArray arr = doc["profiles"].as<JsonArray>();
    static const int MAX_PROFILES = 32;
    String names[MAX_PROFILES];
    int count = 0;
    for (JsonVariant v : arr) {
        if (count >= MAX_PROFILES) break;
        names[count++] = String((const char*)(v | ""));
    }
    _profilesCb(names, count);
}

// -------------------------------------------------------------------------------------
//  Senden
// -------------------------------------------------------------------------------------
uint32_t ProtocolClient::sendCommand(const String& op, const String& extraFields) {
    uint32_t id = _nextId++;
    String msg = "{\"op\":\"" + op + "\",\"id\":" + String(id);
    if (extraFields.length() > 0) {
        msg += ",";
        msg += extraFields;
    }
    msg += "}";
    DISPLAY_UART_PORT.println(msg);
    txCmdCount++;
    return id;
}

uint32_t ProtocolClient::sendHello()        { helloCount++; return sendCommand("hello", "\"firmwareVersion\":\"" DISPLAY_FW_VERSION "\""); }
uint32_t ProtocolClient::sendPing()         { return sendCommand("ping", "\"firmwareVersion\":\"" DISPLAY_FW_VERSION "\""); }
uint32_t ProtocolClient::sendGetState()     { return sendCommand("getState"); }
uint32_t ProtocolClient::sendListProfiles() { return sendCommand("listProfiles"); }
uint32_t ProtocolClient::sendGetUsageStats(){ return sendCommand("getUsageStats"); }

uint32_t ProtocolClient::sendLoadProfile(const String& profile) {
    return sendCommand("loadProfile", "\"profile\":\"" + profile + "\"");
}
uint32_t ProtocolClient::sendGetProfileDetails(const String& profile) {
    return sendCommand("getProfileDetails", "\"profile\":\"" + profile + "\"");
}
uint32_t ProtocolClient::sendAction(const String& action, const String& value) {
    String fields = "\"action\":\"" + action + "\"";
    if (value.length() > 0) fields += ",\"value\":\"" + value + "\"";
    return sendCommand("action", fields);
}
uint32_t ProtocolClient::sendSetPid(const String& fieldsJson) {
    return sendCommand("setPid", fieldsJson);
}
uint32_t ProtocolClient::sendStartAutotune(const String& target) {
    return sendCommand("startAutotune", "\"target\":\"" + target + "\"");
}
uint32_t ProtocolClient::sendStopAutotune() {
    return sendCommand("stopAutotune");
}

// Minimal-Escaping fuer JSON-Strings (Backslash + Anfuehrungszeichen).
static String jsonEsc(const String& s) {
    String o; o.reserve(s.length() + 4);
    for (size_t i = 0; i < s.length(); i++) {
        char c = s[i];
        if (c == '\\' || c == '"') { o += '\\'; o += c; }
        else if (c == '\n' || c == '\r') { /* weglassen */ }
        else o += c;
    }
    return o;
}

uint32_t ProtocolClient::sendScanWifi() {
    return sendCommand("scanWifi");
}
uint32_t ProtocolClient::sendSetWifi(const String& ssid, const String& password) {
    String f = "\"ssid\":\"" + jsonEsc(ssid) + "\",\"password\":\"" + jsonEsc(password) + "\"";
    return sendCommand("setWifi", f);
}