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

// 定义引脚
#define DHTPIN 2        // DHT传感器数据引脚
#define DHTTYPE DHT11   // DHT11温湿度传感器
#define MQ2PIN A0       // MQ-2传感器模拟输入引脚
#define BUZZERPIN 3     // 蜂鸣器控制引脚
#define LEDPIN 4        // LED控制引脚
#define BUTTON_PIN1 5   // 报警关闭按钮
#define BUTTON_PIN2 6   // 阈值设置按钮
#define BUTTON_PIN3 7   // 阈值增加按钮
#define BUTTON_PIN4 8   // 阈值减少按钮

// OLED显示屏定义
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// 传感器对象
DHT dht(DHTPIN, DHTTYPE);

// 全局变量
float temperature = 0;
float humidity = 0;
int gasValue = 0;
int gasThreshold = 500;  // 烟雾浓度阈值，可调整
int tempThreshold = 40;  // 温度阈值，单位℃，可调整
bool alarmOn = false;
unsigned long previousMillis = 0;
unsigned long previousMillisBlink = 0;
const long interval = 2000;  // 传感器读取间隔（毫秒）
const long blinkInterval = 250;  // LED闪烁间隔（毫秒），加快闪烁频率
bool ledState = LOW;
bool settingMode = false;  // 设置模式标志
int settingIndex = 0;  // 0:温度阈值 1:气体阈值
int buttonState1, buttonState2, buttonState3, buttonState4;
int lastButtonState1 = HIGH, lastButtonState2 = HIGH, lastButtonState3 = HIGH, lastButtonState4 = HIGH;
unsigned long lastDebounceTime1 = 0, lastDebounceTime2 = 0, lastDebounceTime3 = 0, lastDebounceTime4 = 0;
unsigned long debounceDelay = 50;  // 消抖延迟

// 实时时钟模拟
int hour = 12, minute = 0, second = 0;
unsigned long previousMillisTime = 0;
const long intervalTime = 1000;  // 1秒更新一次时间

void setup() {
  Serial.begin(9600);
  
  // 初始化传感器
  dht.begin();
  
  // 初始化OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306显示屏初始化失败"));
    for(;;);
  }
  display.clearDisplay();
  
  // 显示初始化信息
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("System Initializing...");
  display.display();
  
  // 初始化引脚模式
  pinMode(BUZZERPIN, OUTPUT);
  pinMode(LEDPIN, OUTPUT);
  pinMode(BUTTON_PIN1, INPUT_PULLUP);
  pinMode(BUTTON_PIN2, INPUT_PULLUP);
  pinMode(BUTTON_PIN3, INPUT_PULLUP);
  pinMode(BUTTON_PIN4, INPUT_PULLUP);
  
  // 初始状态：蜂鸣器和LED关闭
  digitalWrite(BUZZERPIN, LOW);
  digitalWrite(LEDPIN, HIGH); // 测试LED是否正常工作
  delay(1000);
  digitalWrite(LEDPIN, LOW);
  
  delay(2000);
}

void loop() {
  // 更新实时时钟
  updateTime();
  
  // 读取按钮状态
  readButtons();
  
  // 读取传感器数据
  if (millis() - previousMillis >= interval) {
    previousMillis = millis();
    readSensors();
    checkAlarm();
  }
  
  // 控制LED闪烁 - 修改为持续闪烁，不受settingMode限制
  if (alarmOn) {
    if (millis() - previousMillisBlink >= blinkInterval) {
      previousMillisBlink = millis();
      ledState = !ledState;
      digitalWrite(LEDPIN, ledState);
    }
  } else {
    digitalWrite(LEDPIN, LOW);
    digitalWrite(BUZZERPIN, LOW);
  }
  
  // 显示信息
  displayInfo();
}

// 读取传感器数据
void readSensors() {
  // 读取温湿度
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();
  
  // 读取MQ-2烟雾传感器数据
  gasValue = analogRead(MQ2PIN);
  
  // 检查是否读取失败
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read DHT sensor data!");
  }
}

// 检查是否触发报警
void checkAlarm() {
  if (temperature >= tempThreshold || gasValue >= gasThreshold) {
    alarmOn = true;
    digitalWrite(BUZZERPIN, HIGH);  // 打开蜂鸣器
  } else {
    alarmOn = false;
    digitalWrite(BUZZERPIN, LOW);   // 关闭蜂鸣器
  }
}

// 显示信息到OLED屏幕 - 英语显示
void displayInfo() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  
  // 显示时间
  display.print("Time: ");
  display.print(hour < 10 ? "0" : "");
  display.print(hour);
  display.print(":");
  display.print(minute < 10 ? "0" : "");
  display.print(minute);
  display.print(":");
  display.print(second < 10 ? "0" : "");
  display.println(second);
  
  // 显示温湿度
  display.print("Temp: ");
  display.print(temperature);
  display.print(" C (Threshold: ");
  display.print(tempThreshold);
  display.println(")");
  
  display.print("Humidity: ");
  display.print(humidity);
  display.println(" %");
  
  // 显示气体浓度
  display.print("Gas: ");
  display.print(gasValue);
  display.print(" (Threshold: ");
  display.print(gasThreshold);
  display.println(")");
  
  // 显示报警状态
  display.print("Alarm: ");
  display.println(alarmOn ? "ON" : "OFF");
  
  // 显示设置模式状态
  if (settingMode) {
    display.print("Setting: ");
    display.println(settingIndex == 0 ? "Temperature Threshold" : "Gas Threshold");
  }
  
  display.display();
}

// 更新实时时钟
void updateTime() {
  if (millis() - previousMillisTime >= intervalTime) {
    previousMillisTime = millis();
    second++;
    if (second >= 60) {
      second = 0;
      minute++;
      if (minute >= 60) {
        minute = 0;
        hour++;
        if (hour >= 24) {
          hour = 0;
        }
      }
    }
  }
}

// 读取按钮状态并处理
void readButtons() {
  // 读取按钮1（报警关闭）
  int reading1 = digitalRead(BUTTON_PIN1);
  if (reading1 != lastButtonState1) {
    lastDebounceTime1 = millis();
  }
  if ((millis() - lastDebounceTime1) > debounceDelay) {
    if (reading1 != buttonState1) {
      buttonState1 = reading1;
      if (buttonState1 == LOW) {  // 按钮被按下
        if (alarmOn) {
          alarmOn = false;
          digitalWrite(BUZZERPIN, LOW);
          digitalWrite(LEDPIN, LOW);
        }
      }
    }
  }
  lastButtonState1 = reading1;
  
  // 读取按钮2（设置模式切换）
  int reading2 = digitalRead(BUTTON_PIN2);
  if (reading2 != lastButtonState2) {
    lastDebounceTime2 = millis();
  }
  if ((millis() - lastDebounceTime2) > debounceDelay) {
    if (reading2 != buttonState2) {
      buttonState2 = reading2;
      if (buttonState2 == LOW) {  // 按钮被按下
        settingMode = !settingMode;
        if (!settingMode) {  // 退出设置模式时检查报警
          checkAlarm();
        } else {
          alarmOn = false;  // 设置模式下关闭报警
          digitalWrite(BUZZERPIN, LOW);
          digitalWrite(LEDPIN, LOW);
        }
      }
    }
  }
  lastButtonState2 = reading2;
  
  // 读取按钮3（阈值增加）
  if (settingMode) {
    int reading3 = digitalRead(BUTTON_PIN3);
    if (reading3 != lastButtonState3) {
      lastDebounceTime3 = millis();
    }
    if ((millis() - lastDebounceTime3) > debounceDelay) {
      if (reading3 != buttonState3) {
        buttonState3 = reading3;
        if (buttonState3 == LOW) {  // 按钮被按下
          if (settingIndex == 0) {  // 调整温度阈值
            tempThreshold++;
          } else {  // 调整气体阈值
            gasThreshold++;
          }
        }
      }
    }
    lastButtonState3 = reading3;
    
    // 读取按钮4（阈值减少）
    int reading4 = digitalRead(BUTTON_PIN4);
    if (reading4 != lastButtonState4) {
      lastDebounceTime4 = millis();
    }
    if ((millis() - lastDebounceTime4) > debounceDelay) {
      if (reading4 != buttonState4) {
        buttonState4 = reading4;
        if (buttonState4 == LOW) {  // 按钮被按下
          if (settingIndex == 0 && tempThreshold > 0) {  // 调整温度阈值
            tempThreshold--;
          } else if (settingIndex == 1 && gasThreshold > 0) {  // 调整气体阈值
            gasThreshold--;
          }
        }
      }
    }
    lastButtonState4 = reading4;
    
    // 长按按钮2切换设置项
    static unsigned long pressStartTime2 = 0;
    static bool isLongPress2 = false;
    
    if (digitalRead(BUTTON_PIN2) == LOW) {
      if (!isLongPress2) {
        pressStartTime2 = millis();
        isLongPress2 = true;
      } else if (millis() - pressStartTime2 > 1000) {  // 长按1秒
        settingIndex = (settingIndex + 1) % 2;
        isLongPress2 = false;
        delay(200);  // 防止连续切换
      }
    } else {
      isLongPress2 = false;
    }
  }
}