#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

// ===== WIFI & API =====
const char* WIFI_SSID = "Wokwi-GUEST";   // ganti ke WiFi real kalau bisa
const char* WIFI_PASS = "";              // (Wokwi bisa membatasi koneksi ke googleapis)
const char* GEMINI_API_KEY = "AIzaSyAnfUJ_vq5IX3G2Hyk5gkjeifxoa606hIc"; // JANGAN commit secara publik

const char* HOST = "generativelanguage.googleapis.com";
const uint16_t PORT = 443;
const char* PATH_PREFIX = "/v1beta/models/gemini-2.0-flash:generateContent?key=";

// ===== DUMMY SENSOR =====
const int PIN_SENSOR = 34;

WiFiClientSecure ssl;
HTTPClient http;

const char* httpErrorStr(int code) {
  switch (code) {
    case -1: return "CONNECTION_REFUSED/FAILED";
    case -2: return "SEND_HEADER_FAILED";
    case -3: return "SEND_PAYLOAD_FAILED";
    case -4: return "NOT_CONNECTED";
    case -5: return "CONNECTION_LOST";
    case -6: return "NO_STREAM";
    case -7: return "NO_HTTP_SERVER";
    case -8: return "TOO_LESS_RAM";
    case -9: return "ENCODING";
    case -10: return "STREAM_WRITE";
    case -11: return "READ_TIMEOUT";
    default: return "UNKNOWN";
  }
}

String buildPrompt(float tempC) {
  String p = "Sensor dummy membaca suhu ~";
  p += String(tempC, 1);
  p += " C. Jelaskan status singkat (nyaman/tidak) dan 1 rekomendasi ringkas (<=20 kata).";
  return p;
}

String buildRequestBody(const String& prompt) {
  StaticJsonDocument<512> doc;
  JsonArray contents = doc.createNestedArray("contents");
  JsonObject item = contents.createNestedObject();
  JsonArray parts = item.createNestedArray("parts");
  parts.createNestedObject()["text"] = prompt;

  JsonObject cfg = doc.createNestedObject("generationConfig");
  cfg["maxOutputTokens"] = 96;
  cfg["temperature"] = 0.3;

  String out; serializeJson(doc, out);
  return out;
}

bool beginGemini() {
  // DEV ONLY: tanpa verifikasi sertifikat biar cepat running di dev.
  // PRODUKSI: gunakan root CA / certificate pinning!
  ssl.setInsecure();
  ssl.setTimeout(15000);

  // Susun path final
  String path = String(PATH_PREFIX) + GEMINI_API_KEY;

  // Bentuk begin(host, port, path, https=true)
  bool ok = http.begin(ssl, HOST, PORT, path, true);
  if (!ok) return false;

  http.setTimeout(15000);
  http.setReuse(true);
  http.addHeader("Content-Type", "application/json");
  http.addHeader("Accept", "application/json");
  // http.addHeader("User-Agent", "ESP32-Gemini/1.0");
  return true;
}

String postToGemini(const String& body) {
  if (!beginGemini()) return "ERR: http.begin gagal";

  int code = http.POST(body);
  if (code <= 0) {
    String msg = String("ERR HTTP ") + code + " (" + httpErrorStr(code) + ")";
    http.end();
    return msg;
  }

  String resp = http.getString();
  http.end();
  return resp;
}

String extractTextFromResponse(const String& json) {
  // Jangan parse kalau respons bukan JSON
  if (!json.startsWith("{") && !json.startsWith("[")) {
    return "ERR: bukan JSON. Body: " + json;
  }

  DynamicJsonDocument doc(8192);
  DeserializationError err = deserializeJson(doc, json);
  if (err) return String("ERR parse: ") + err.c_str();

  JsonVariant j = doc["candidates"][0]["content"]["parts"][0]["text"];
  if (j.isNull()) {
    // tampilkan sebagian body untuk debug
    String snippet = json.substring(0, 200);
    return "ERR: tak ada teks balasan. Snip: " + snippet;
  }
  return j.as<String>();
}

void setup() {
  Serial.begin(115200);
  delay(200);

  WiFi.mode(WIFI_STA);
  WiFi.setSleep(false);
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  Serial.print("WiFi");
  unsigned long t0 = millis();
  while (WiFi.status() != WL_CONNECTED) {
    delay(300); Serial.print(".");
    if (millis() - t0 > 20000) {
      Serial.println("\nWiFi timeout. Cek SSID/password atau jaringan.");
      break;
    }
  }
  Serial.println("\nIP: " + WiFi.localIP().toString());

  // Tes sekali saat boot
  int raw = analogRead(PIN_SENSOR);
  float tempC = (raw / 4095.0) * 60.0;
  String prompt = buildPrompt(tempC);
  String req = buildRequestBody(prompt);

  Serial.println("\n=== PROMPT ===");
  Serial.println(prompt);

  String resp = postToGemini(req);
  Serial.println("\n=== RAW RESPONSE ===");
  Serial.println(resp);

  String text = extractTextFromResponse(resp);
  Serial.println("\n=== GEMINI TEXT ===");
  Serial.println(text);
}

unsigned long last = 0;
void loop() {
  if (millis() - last > 20000) {
    last = millis();

    int raw = analogRead(PIN_SENSOR);
    float tempC = (raw / 4095.0) * 60.0;

    String prompt = buildPrompt(tempC);
    String req = buildRequestBody(prompt);
    String resp = postToGemini(req);
    String text = extractTextFromResponse(resp);

    Serial.print("\n[");
    Serial.print(millis()/1000);
    Serial.print("s] ");
    Serial.println(text);
  }
}