#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <WiFiManager.h>
#include <ESP8266WebServer.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <SSD1306Wire.h>
#include <LittleFS.h>
#include <ArduinoJson.h>

#define SENSOR_PIN A0
#define RESET_PIN 0
#define RESET_TIME 5000

void checkResetButton() {
    if (digitalRead(RESET_PIN) == LOW) {
        if (!buttonPressed) {
            buttonPressStart = millis();
            buttonPressed = true;
        }
        if (millis() - buttonPressStart >= RESET_TIME) {
            Serial.println("Reset-Taster 5 Sekunden gehalten! Setze WiFiManager-Einstellungen zurück...");
            WiFiManager wifiManager;
            wifiManager.resetSettings();
            delay(1000);
            WiFi.disconnect(true);
            delay(1000);
            ESP.restart();
        }
    } else {
        buttonPressed = false;
    }
}

void setup_wifi() {
    WiFiManager wifiManager;
    wifiManager.setTimeout(180);
    if (!wifiManager.autoConnect("WaterMev2")) {
        ESP.restart();
    }
}

void updateSensorData() {
    int sensorValue = analogRead(SENSOR_PIN);
    float moisture = map(sensorValue, 1024, 0, 0, 100);
    client.publish("WaterMev2/feuchtigkeit", String(moisture).c_str());
}

void loop() {
    server.handleClient();
    checkResetButton();
    updateSensorData();
    delay(30000);
}

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <WiFiManager.h>  // WiFiManager Library für AP-Konfiguration
#include <ESP8266WebServer.h>
#include <time.h>        // Für configTime()
#include <SSD1306Wire.h>        // legacy: #include "SSD1306.h"
#include <LittleFS.h>
#include <ArduinoJson.h>
 
#define SENSOR_PIN A0  // Sensor an A0 angeschlossen
#define RESET_PIN 0  // GPIO0 (D3 beim ESP8266)
#define RESET_TIME 5000  // Zeit in Millisekunden (5 Sekunden)

unsigned long buttonPressStart = 0;
bool buttonPressed = false;

unsigned long previousMillis = 0;  // Speichert den Zeitpunkt des letzten MQTT-Sendevorgangs
const long interval = 30000;       // Zeitintervall für das Senden der MQTT-Daten
 
bool resetActive = false; // verhindert, dass andere Funktionen das Display während Reset stören

char mqtt_server[40] = "";
char mqtt_port[6] = "";
char mqtt_user[40] = "";
char mqtt_pass[40] = "";
char mqtt_topic_prefix[40] = "WaterMe"; // Benutzerdefiniertes Präfix
char ntp_server[40] = "pool.ntp.org";  // Standard NTP Server
 
WiFiClient espClient;
PubSubClient client(espClient);
ESP8266WebServer server(80);
SSD1306Wire display(0x3c, SDA, SCL);
 
void saveConfig() {
    Serial.println("Speichere Konfiguration in LittleFS...");
    File configFile = LittleFS.open("/config.json", "w");
    if (!configFile) {
        Serial.println("Fehler beim Speichern der Konfiguration!");
        return;
    }

    DynamicJsonDocument doc(128);
    doc["mqtt_server"] = mqtt_server;
    doc["mqtt_port"] = mqtt_port;
    doc["mqtt_user"] = mqtt_user;
    doc["mqtt_pass"] = mqtt_pass;
    doc["mqtt_topic_prefix"] = mqtt_topic_prefix;
    doc["ntp_server"] = ntp_server;

    serializeJson(doc, configFile);
    configFile.close();
    Serial.println("Konfiguration gespeichert.");
}

void loadConfig() {
    Serial.println("Lade Konfiguration aus LittleFS...");

    File configFile = LittleFS.open("/config.json", "r");
    if (!configFile) {
        Serial.println("Keine gespeicherte Konfiguration gefunden.");
        return;
    }

    DynamicJsonDocument doc(128);
    DeserializationError error = deserializeJson(doc, configFile);
    if (error) {
        Serial.println("Fehler beim Lesen der Konfigurationsdatei!");
        return;
    }

    strlcpy(mqtt_server, doc["mqtt_server"] | "", sizeof(mqtt_server));
    strlcpy(mqtt_port, doc["mqtt_port"] | "", sizeof(mqtt_port));
    strlcpy(mqtt_user, doc["mqtt_user"] | "", sizeof(mqtt_user));
    strlcpy(mqtt_pass, doc["mqtt_pass"] | "", sizeof(mqtt_pass));
    strlcpy(mqtt_topic_prefix, doc["mqtt_topic_prefix"] | "", sizeof(mqtt_topic_prefix));
    strlcpy(ntp_server, doc["ntp_server"] | "", sizeof(ntp_server));

    Serial.println("Konfiguration geladen.");
}
 
void setup_wifi() {
    Serial.println("Starte WiFiManager...");

    uint8_t mac[6];
    WiFi.macAddress(mac);

    char hostname[32];
    snprintf(hostname, sizeof(hostname), "WaterMe_%02X%02X%02X", mac[3], mac[4], mac[5]);

    WiFiManager wifiManager;
    wifiManager.setTimeout(180); // 3 Minuten warten statt unendlich

    //wifiManager.resetSettings();

    WiFiManagerParameter custom_mqtt_server("server", "MQTT Server", mqtt_server, 40);
    WiFiManagerParameter custom_mqtt_port("port", "MQTT Port", mqtt_port, 6);
    WiFiManagerParameter custom_mqtt_topic("topic", "MQTT Topic Prefix", mqtt_topic_prefix, 40);
    WiFiManagerParameter custom_ntp_server("ntp_server", "NTP Server", ntp_server, 40);
 
    wifiManager.addParameter(&custom_mqtt_server);
    wifiManager.addParameter(&custom_mqtt_port);
    wifiManager.addParameter(&custom_mqtt_topic);
    wifiManager.addParameter(&custom_ntp_server);

    if (!wifiManager.autoConnect(hostname)) {
        Serial.println("Fehlgeschlagen! Neustart in 5 Sekunden...");
        delay(5000);
        ESP.restart();
    }

    WiFi.hostname(hostname);

    strncpy(mqtt_server, custom_mqtt_server.getValue(), sizeof(mqtt_server) - 1);
    strncpy(mqtt_port, custom_mqtt_port.getValue(), sizeof(mqtt_port) - 1);
    strncpy(mqtt_topic_prefix, custom_mqtt_topic.getValue(), sizeof(mqtt_topic_prefix) - 1);
    strncpy(ntp_server, custom_ntp_server.getValue(), sizeof(ntp_server) - 1);
    saveConfig();
    Serial.println("WLAN verbunden!");
    Serial.print("IP-Adresse: ");
    Serial.println(WiFi.localIP());
}
 
void handleRoot() {
    Serial.println("Web-Oberfläche aufgerufen");
    String htmlContent = "<!DOCTYPE html><html><head><meta charset='UTF-8'><title>WaterMe Einstellungen</title>"
                         "<style>"
                         "body { font-family: Arial, sans-serif; margin: 40px; background-color: #333; color: #fff; }"
                         "h1 { color: #fff; }"
                         "form { background-color: #222; padding: 20px; border-radius: 8px; box-shadow: 0 0 10px 0 rgba(0,0,0,0.5); }"
                         "label { display: block; margin-top: 20px; margin-bottom: 5px; color: #ccc; }"
                         "input[type='text'], input[type='submit'] { width: 100%; padding: 8px; margin-top: 5px; border: 1px solid #555; border-radius: 4px; }"
                         "input[type='text'] { background-color: #555; color: #ddd; }"
                         "input[type='submit'] { background-color: #008CBA; color: white; cursor: pointer; }"
                         "input[type='submit']:hover { background-color: #005f7a; }"
                         "</style>"
                         "</head><body>"
                         "<h1>WaterMe Einstellungen</h1>"
                         "<form action='/save' method='POST'>"
                         "<label for='server'>MQTT Server:</label> <input type='text' id='server' name='server' value='" + String(mqtt_server) + "'><br>"
                         "<label for='port'>MQTT Port:</label> <input type='text' id='port' name='port' value='" + String(mqtt_port) + "'><br>"
                         "<label for='user'>MQTT Benutzer:</label> <input type='text' id='user' name='user' value='" + String(mqtt_user) + "'><br>"
                         "<label for='pass'>MQTT Passwort:</label> <input type='password' id='pass' name='pass' value='" + String(mqtt_pass) + "'><br>"
                         "<label for='topic'>MQTT Topic Prefix:</label> <input type='text' id='topic' name='topic' value='" + String(mqtt_topic_prefix) + "'><br>"
                         "<label for='ntp_server'>NTP Server:</label> <input type='text' id='ntp_server' name='ntp_server' value='" + String(ntp_server) + "'><br>"
                         "<input type='submit' value='Speichern'>"
                         "</form></body></html>";
    server.send(200, "text/html", htmlContent);
}
 
void handleSave() {
    Serial.println("Speichere neue Einstellungen...");
    if (server.hasArg("server")) strncpy(mqtt_server, server.arg("server").c_str(), sizeof(mqtt_server) - 1);
    if (server.hasArg("port")) strncpy(mqtt_port, server.arg("port").c_str(), sizeof(mqtt_port) - 1);
    if (server.hasArg("user")) strlcpy(mqtt_user, server.arg("user").c_str(), sizeof(mqtt_user));
    if (server.hasArg("pass")) strlcpy(mqtt_pass, server.arg("pass").c_str(), sizeof(mqtt_pass));
    if (server.hasArg("topic")) strncpy(mqtt_topic_prefix, server.arg("topic").c_str(), sizeof(mqtt_topic_prefix) - 1);
    if (server.hasArg("ntp_server")) strncpy(ntp_server, server.arg("ntp_server").c_str(), sizeof(ntp_server) - 1);
    saveConfig();
    server.send(200, "text/html", "<html><body><h1>Gespeichert! Neustart...</h1></body></html>");
    delay(3000);
    ESP.restart();
}
 
void checkResetButton() {
    static int lastSecondsLeft = -1;

    if (digitalRead(RESET_PIN) == LOW) {
        if (!buttonPressed) {
            buttonPressStart = millis();
            buttonPressed = true;
            resetActive = true;
            lastSecondsLeft = -1;
        }

        unsigned long heldTime = millis() - buttonPressStart;
        int secondsLeft = (RESET_TIME - heldTime) / 1000;

        if (secondsLeft != lastSecondsLeft && heldTime < RESET_TIME) {
            lastSecondsLeft = secondsLeft;

            display.clear();
            display.setFont(ArialMT_Plain_16);
            display.setTextAlignment(TEXT_ALIGN_CENTER_BOTH);
            display.drawString(display.getWidth() / 2, 20, "Reset in");
            display.setFont(ArialMT_Plain_24);
            display.drawString(display.getWidth() / 2, 44, String(secondsLeft));
            display.display();
        }

        if (heldTime >= RESET_TIME) {
            display.clear();
            display.setFont(ArialMT_Plain_16);
            display.setTextAlignment(TEXT_ALIGN_CENTER_BOTH);
            display.drawString(display.getWidth() / 2, 28, "RESET!");
            display.display();
            delay(1000);

            Serial.println("Reset-Taster 5 Sekunden gehalten! Setze WiFiManager-Einstellungen zurück...");
            WiFiManager wifiManager;
            wifiManager.resetSettings();
            delay(500);
            WiFi.disconnect(true);
            delay(500);
            ESP.restart();
        }

    } else {
        if (buttonPressed) {
            buttonPressed = false;
            resetActive = false;

            // <<< Hier neu ergänzen:
            previousMillis = millis() - interval;  
            // <<< Dadurch wird beim nächsten loop() direkt aktualisiert!
        }
    }
}

void setup() {
    pinMode(RESET_PIN, INPUT_PULLUP);
    Serial.begin(115200);
    Serial.println("WaterMe startet...");

    if (!LittleFS.begin()) {
        Serial.println("LittleFS-Fehler");
    } else {
        loadConfig();
    }

    // *** Display direkt am Anfang initialisieren und "AP" anzeigen ***
    display.init();
    display.flipScreenVertically();
    display.clear();
    display.setFont(ArialMT_Plain_24);
    display.setTextAlignment(TEXT_ALIGN_CENTER_BOTH);
    display.drawString(display.getWidth() / 2, 28, "AP");
    display.display();
    delay(500);  // Kurze Verzögerung (optional), damit man es sicher sieht

    setup_wifi();
 
    if (strlen(mqtt_server) > 0 && strlen(mqtt_port) > 0) {
        client.setServer(mqtt_server, atoi(mqtt_port));
        Serial.println("MQTT-Konfiguration geladen.");
    } else {
        Serial.println("MQTT-Daten fehlen! Webinterface zur Konfiguration nutzen.");
    }
 
    server.on("/", handleRoot);
    server.on("/save", HTTP_POST, handleSave);
    server.begin();
    Serial.println("Webserver gestartet!");
    Serial.print("Rufe auf: http://");
    Serial.println(WiFi.localIP());

    // Sofortiges erstes Update erzwingen
    previousMillis = millis() - interval;
    handleMQTTAndDisplayUpdate(millis());

    // Sommerzeitregel für Mitteleuropa: letzte So im März + Okt
    configTime("CET-1CEST,M3.5.0/2,M10.5.0/3", ntp_server);

    Serial.print("Warte auf Zeit...");
    time_t now = time(nullptr);
    while (now < 100000) {
        delay(100);
        Serial.print(".");
        now = time(nullptr);
    }
    Serial.println(" Zeit empfangen.");
}
 
void reconnect() {
    static unsigned long lastReconnectAttempt = 0;
    uint8_t mac[6];
    WiFi.macAddress(mac);
    char clientId[32];
    snprintf(clientId, sizeof(clientId), "WaterMe_%02X%02X%02X", mac[3], mac[4], mac[5]);

    if (!client.connected() && millis() - lastReconnectAttempt > 5000) {
        lastReconnectAttempt = millis();
        Serial.print("Verbindungsversuch mit MQTT-Broker als ");
        Serial.println(clientId);

        if (client.connect(clientId, mqtt_user, mqtt_pass)) {
            Serial.println("MQTT-Verbindung hergestellt!");
        } else {
            Serial.print("MQTT-Verbindung fehlgeschlagen, Fehlercode: ");
            Serial.print(client.state());
            Serial.println(" - Neuer Versuch in 5 Sekunden...");
        }
    }
}

void loop() {
    checkResetButton();

    if (resetActive) {
        return;
    }

    server.handleClient();

    if (!client.connected()) {
        reconnect();
    }
    client.loop();

    handleMQTTAndDisplayUpdate(millis());
}

void handleMQTTAndDisplayUpdate(unsigned long currentMillis) {
    if (resetActive) return;

    if (currentMillis - previousMillis >= interval) {
        previousMillis = currentMillis;
        if (!client.connected()) {
            reconnect();
        }
        updateSensorData();
    }
}

void updateSensorData() {
    if (resetActive) return;
    int sensorValue = analogRead(SENSOR_PIN);
    float moisture = map(sensorValue, 1024, 0, 0, 100);

    time_t now = time(nullptr);
    struct tm *timeinfo = localtime(&now);
    char buffer[20];
    strftime(buffer, sizeof(buffer), "%H:%M:%S", timeinfo);
    String timestamp = String(buffer);

    updateDisplay(moisture, timestamp);
    sendMQTTData(moisture, timestamp);
}

void updateDisplay(float moisture, String timestamp) {
    Serial.println("Aktualisiere Display...");
    Serial.print("Feuchtigkeit: "); Serial.println(moisture);
    Serial.print("Timestamp: "); Serial.println(timestamp);

    String text = String(moisture, 0) + "%";
    display.clear();
    display.setFont(ArialMT_Plain_24);
    display.setTextAlignment(TEXT_ALIGN_CENTER_BOTH);
    display.drawString(display.getWidth() / 2, 28, text);
    display.drawLine(0, 42, 128, 42);
    display.setFont(ArialMT_Plain_16);
    display.drawString(display.getWidth() / 2, 54, timestamp);
    display.display();
}

void sendMQTTData(float moisture, const String& timestamp) {
    char topic[50], message[50];

    snprintf(topic, sizeof(topic), "%s/feuchtigkeit", mqtt_topic_prefix);
    snprintf(message, sizeof(message), "%.2f", moisture);
    client.publish(topic, message);

    snprintf(topic, sizeof(topic), "%s/timestamp", mqtt_topic_prefix);
    client.publish(topic, timestamp.c_str());
}