#pragma once
#include "mbedtls/md.h"
#include <Arduino.h>
#include <ArduinoJson.h>
#include <ESPAsyncWebServer.h>
#include <Preferences.h>
#include <esp_wifi.h>
#include <master.h>


const char *secret = "542ff224606c61fb3024e22f76ef9ac8";

// Preferences für persistente Speicherung
Preferences preferences;

String licence;

// Prototype für Funktionen
String getUniqueDeviceID();
String hmacSHA256(const String &key, const String &message);
bool checkLicense(const String &deviceID, const String &licenseKey);
void setupLicenceAPI(AsyncWebServer &server);
void saveLicenceToPrefs();
void loadLicenceFromPrefs();

String getUniqueDeviceID() {
  uint8_t mac[6];
  esp_wifi_get_mac(WIFI_IF_STA, mac); // Use STA MAC for uniqueness
  char id[13];
  sprintf(id, "%02X%02X%02X%02X%02X%02X", mac[0], mac[1], mac[2], mac[3],
          mac[4], mac[5]);
  return String(id);
}

String hmacSHA256(const String &key, const String &message) {
  byte hmacResult[32];
  mbedtls_md_context_t ctx;
  mbedtls_md_type_t md_type = MBEDTLS_MD_SHA256;

  mbedtls_md_init(&ctx);
  const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(md_type);
  mbedtls_md_setup(&ctx, md_info, 1);
  mbedtls_md_hmac_starts(&ctx, (const unsigned char *)key.c_str(),
                         key.length());
  mbedtls_md_hmac_update(&ctx, (const unsigned char *)message.c_str(),
                         message.length());
  mbedtls_md_hmac_finish(&ctx, hmacResult);
  mbedtls_md_free(&ctx);

  String result = "";
  for (int i = 0; i < 32; i++) {
    char buf[3];
    sprintf(buf, "%02X", hmacResult[i]);
    result += buf;
  }
  return result;
}

int getLicenseTier(const String &deviceID, const String &licenseKey) {
  for (int tier = 1; tier <= 4; ++tier) {
    String data = deviceID + ":" + String(tier);
    String expected = hmacSHA256(secret, data);
    if (licenseKey.equalsIgnoreCase(expected)) {
      return tier; // Found matching tier
    }
  }
  return 0; // No valid tier found
}

void setupLicenceAPI(AsyncWebServer &server) {

  server.on("/api/get-licence", HTTP_GET, [](AsyncWebServerRequest *request) {
    Serial.println("Received request to get licence");
    loadLicenceFromPrefs();
    String deviceID = getUniqueDeviceID();
    int tier = getLicenseTier(deviceID, licence);
    String json = "{\"licence\":\"" + licence +
                  "\","
                  "\"valid\":" +
                  String(tier > 0 ? "true" : "false") +
                  ",\"tier\":" + String(tier) + "}";
    request->send(200, "application/json", json);
  });

  server.on("/api/set-licence", HTTP_POST, [](AsyncWebServerRequest *request) {
    Serial.println("Received request to set licence");
    if (request->hasParam("licence", true)) {
      licence = request->getParam("licence", true)->value();
      Serial.println("Received request to set licence " + licence);
      saveLicenceToPrefs(); // eigene Funktion
      request->send(200, "application/json", "{\"success\":true}");
    } else {
      request->send(400, "application/json", "{\"success\":false}");
    }
  });

  Serial.println("Licence API setup complete");
}

void saveLicenceToPrefs() {
  preferences.begin("key", false);
  preferences.putString("key", licence);
  preferences.end();
}

void loadLicenceFromPrefs() {
  preferences.begin("key", true);
  licence = preferences.getString("key", "");
  preferences.end();
}