#include <WiFi.h>
#include <DHT.h>
#include <Wire.h>
#include <Adafruit_SSD1306.h>

// 全局对象声明
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define DHT_PIN       22
#define DHT_TYPE      DHT22
#define TEMP_LED_PIN  17
#define HUM_LED_PIN   16

// 初始化传感器和显示屏对象（确保在全局作用域）
DHT dht(DHT_PIN, DHT_TYPE);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// WiFi配置
const char* WIFI_SSID = "Wokwi-GUEST";
const char* WIFI_PASSWORD = "";  // 无需密码

// 服务器配置
const char* SERVER_URL = "192.168.1.1";
const int SERVER_PORT = 3000;
const char* SERVER_PATH = "/data";

// 阈值设置
const float TEMP_THRESHOLD = 30.0;    // 温度阈值(°C)
const float HUMIDITY_THRESHOLD = 70.0;  // 湿度阈值(%)

// 状态变量
bool wifiConnected = false;
unsigned long lastUpload = 0;
const unsigned long UPLOAD_INTERVAL = 1000;  // 上传间隔(ms)
int humAlertCounter = 0;

void setup() {
  Serial.begin(115200);
  
  // 初始化引脚
  pinMode(TEMP_LED_PIN, OUTPUT);
  pinMode(HUM_LED_PIN, OUTPUT);
  
  // 初始化DHT传感器
  dht.begin();
  
  // 初始化OLED显示屏（确保Wire库正确初始化I2C）
  Wire.begin(18, 19);  // 明确指定I2C引脚（SDA=18, SCL=19，根据Wokwi默认配置）
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306显示屏初始化失败"));
    while(1);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Initializing...");
  display.display();
  
  // 连接WiFi
  connectWiFi();
}

void loop() {
  // 检查WiFi连接
  if (WiFi.status() != WL_CONNECTED) {
    wifiConnected = false;
    connectWiFi();
  } else {
    wifiConnected = true;
  }
  
  // 读取传感器数据
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  
  // 检查读取是否成功
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read sensor data!");
    displaySensorError();
    delay(1000);
    return;
  }
  
  // 更新显示
  updateDisplay(temperature, humidity, wifiConnected);
  
  // 控制温度LED
  digitalWrite(TEMP_LED_PIN, temperature >= TEMP_THRESHOLD);
  
  // 控制湿度LED（修正闪烁逻辑，使用millis()避免阻塞）
  static unsigned long lastHumBlink = 0;
  if (humidity >= HUMIDITY_THRESHOLD) {
    if (millis() - lastHumBlink >= 1000) {  // 每秒切换一次
      lastHumBlink = millis();
      digitalWrite(HUM_LED_PIN, !digitalRead(HUM_LED_PIN));
    }
  } else {
    digitalWrite(HUM_LED_PIN, LOW);
  }
  
  // 定时上传数据
  if (millis() - lastUpload >= UPLOAD_INTERVAL && wifiConnected) {
    uploadData(temperature, humidity);
    lastUpload = millis();
  }
  
  delay(10);  // 短暂延时，避免循环过快
}

void connectWiFi() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("Connecting to WiFi...");
  display.display();
  
  Serial.print("Connecting to ");
  Serial.println(WIFI_SSID);
  
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  
  unsigned long startAttemptTime = millis();
  
  // 等待WiFi连接
  while (WiFi.status() != WL_CONNECTED && millis() - startAttemptTime < 20000) {
    delay(500);
    Serial.print(".");
  }
  
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println();
    Serial.println("WiFi connected!");
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());
    
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("WiFi Connected");
    display.display();
    
    wifiConnected = true;
  } else {
    Serial.println();
    Serial.println("WiFi connection failed");
    
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("WiFi Failed");
    display.display();
    
    wifiConnected = false;
  }
}

void uploadData(float temp, float hum) {
  Serial.print("Uploading data: ");
  Serial.print(temp);
  Serial.print("°C, ");
  Serial.print(hum);
  Serial.println("%");
  
  WiFiClient client;
  
  if (client.connect(SERVER_URL, SERVER_PORT)) {
    // 构建HTTP POST请求
    String postData = "temperature=" + String(temp) + "&humidity=" + String(hum);
    
    client.print("POST ");
    client.print(SERVER_PATH);
    client.print(" HTTP/1.1\r\n");
    client.print("Host: ");
    client.print(SERVER_URL);
    client.print("\r\n");
    client.print("Content-Type: application/x-www-form-urlencoded\r\n");
    client.print("Content-Length: ");
    client.print(postData.length());
    client.print("\r\n");
    client.print("Connection: close\r\n\r\n");
    client.print(postData);
    
    // 等待响应
    unsigned long timeout = millis();
    while (client.available() == 0) {
      if (millis() - timeout > 5000) {
        Serial.println(">>> Server response timed out");
        client.stop();
        return;
      }
    }
    
    // 读取响应
    while(client.available()){
      String line = client.readStringUntil('\r');
      Serial.print(line);
    }
    
    Serial.println();
    Serial.println("Data upload complete");
    client.stop();
  } else {
    Serial.println("Failed to connect to server");
    client.stop();
  }
}

void updateDisplay(float temp, float hum, bool wifiStatus) {
  display.clearDisplay();
  display.setCursor(0, 0);
  
  // 显示温度和湿度
  display.print("Temp: ");
  display.print(temp, 1);  
  display.println(" °C");
  
  display.print("Hum: ");
  display.print(hum, 1);
  display.println(" %");
  
  // 显示WiFi状态
  display.print("WiFi: ");
  display.println(wifiStatus ? "Connected" : "Disconnected");
  
  // 显示阈值状态（关键排版优化）
  display.print("Temp Threshold:");  // 增加空格确保显示完整
  display.println(temp >= TEMP_THRESHOLD ? "Over" : "Normal");
  
  display.print("Hum Threshold:");  // 增加空格确保显示完整
  display.println(hum >= HUMIDITY_THRESHOLD ? "Over" : "Normal");
  
  display.display();
}

void displaySensorError() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("Sensor Read Error!");
  display.display();
}