/**
 * @file sketch.ino - 匹配用户原理图
 * 引脚分配：
 * - NAU7802: SDA=1, SCL=2
 * - BNO086:  SDA=17, SCL=18
 * - SSD1306: SDA=4, SCL=5
 * - RGB LED: DATA=11
 * - 按键: GPIO0
 */

#include <Arduino.h>
#include <Wire.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <Adafruit_SSD1306.h>
#include <FastLED.h>

// ========== 引脚配置（匹配原理图）==========
#define NAU7802_SDA      1
#define NAU7802_SCL      2
#define BNO086_SDA       17
#define BNO086_SCL       18
#define SSD1306_SDA      4
#define SSD1306_SCL      5
#define LED_DATA_PIN     11
#define BTN_PIN          0

// ========== OLED 配置 ==========
#define SCREEN_WIDTH     128
#define SCREEN_HEIGHT    64
#define SSD1306_ADDR     0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// ========== RGB LED 配置 ==========
#define LED_COUNT        1
#define LED_BRIGHTNESS   64
CRGB leds[LED_COUNT];

// ========== WiFi & MQTT ==========
#define WIFI_SSID        "Wokwi-Guest"
#define WIFI_PASSWORD    ""
#define MQTT_BROKER      "test.mosquitto.org"
#define MQTT_PORT        1883
#define MQTT_TOPIC_PUB   "sensor/weight/data"

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

// ========== 全局变量 ==========
float weight = 0;           // 重量(g)
float roll = 0;             // 横滚角(度)
float pitch = 0;            // 俯仰角(度)
float yaw = 0;              // 偏航角(度)
int batteryPercent = 100;   // 电量(%)
int page = 0;               // 当前页面(0-3)

bool wifiConnected = false;
bool mqttConnected = false;

volatile bool btnPressed = false;
uint32_t lastBtnMs = 0;

// ========== 模拟传感器数据 ==========
void generateSensorData() {
  // 模拟称重数据：100g ~ 5000g
  weight = random(1000, 50000) / 10.0;
  
  // 模拟姿态数据：-180° ~ 180°
  roll = random(-1800, 1800) / 10.0;
  pitch = random(-900, 900) / 10.0;
  yaw = random(-1800, 1800) / 10.0;
  
  // 模拟电池电量：20% ~ 100%
  batteryPercent = random(20, 101);
}

// ========== OLED 显示 ==========
void updateDisplay() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  
  // 状态栏
  display.fillRect(0, 0, 128, 10, SSD1306_WHITE);
  display.setTextColor(SSD1306_BLACK);
  display.setCursor(2, 1);
  display.print(wifiConnected ? "WiFi" : "---");
  display.setCursor(40, 1);
  display.print(mqttConnected ? "MQTT" : "---");
  display.setCursor(100, 1);
  display.printf("%d%%", batteryPercent);
  
  display.setTextColor(SSD1306_WHITE);
  display.drawLine(0, 10, 127, 10, SSD1306_WHITE);
  
  // 页面内容
  if (page == 0) {
    display.setCursor(0, 20);
    display.printf("Weight: %.1f g", weight);
    display.setCursor(0, 35);
    display.printf("Roll: %.1f deg", roll);
    display.setCursor(0, 50);
    display.printf("Bat: %d%%", batteryPercent);
    
  } else if (page == 1) {
    display.setCursor(0, 20);
    display.println("=== Attitude ===");
    display.setCursor(0, 32);
    display.printf("Roll: %.1f", roll);
    display.setCursor(0, 44);
    display.printf("Pitch: %.1f", pitch);
    display.setCursor(0, 56);
    display.printf("Yaw: %.1f", yaw);
    
  } else if (page == 2) {
    display.setCursor(0, 20);
    display.println("=== Sensors ===");
    display.setCursor(0, 32);
    display.printf("NAU7802: %.1f g", weight);
    display.setCursor(0, 44);
    display.printf("BNO086: %.1f deg", roll);
    display.setCursor(0, 56);
    display.printf("ADC: OK");
    
  } else {
    display.setCursor(0, 20);
    display.println("=== Network ===");
    display.setCursor(0, 32);
    display.printf("WiFi: %s", wifiConnected ? "OK" : "Fail");
    display.setCursor(0, 44);
    display.printf("MQTT: %s", mqttConnected ? "OK" : "Fail");
    display.setCursor(0, 56);
    display.printf("Heap: %dKB", ESP.getFreeHeap() / 1024);
  }
  
  display.display();
}

// ========== RGB LED ==========
void updateLed() {
  if (batteryPercent < 10) {
    fill_solid(leds, LED_COUNT, CRGB::Red);
  } else if (!wifiConnected) {
    fill_solid(leds, LED_COUNT, (millis() / 500) % 2 ? CRGB::Blue : CRGB::Black);
  } else if (!mqttConnected) {
    fill_solid(leds, LED_COUNT, CRGB::Purple);
  } else {
    uint8_t brightness = (sin(millis() / 1000.0) + 1) / 2 * 200 + 55;
    fill_solid(leds, LED_COUNT, CRGB(0, brightness, 0));
  }
  FastLED.show();
}

// ========== MQTT 回调 ==========
void mqttCallback(char* topic, byte* payload, unsigned int len) {
  String msg;
  for (unsigned int i = 0; i < len; i++) msg += (char)payload[i];
  Serial.printf("[MQTT] Cmd: %s\n", msg.c_str());
}

// ========== 按键中断 ==========
void IRAM_ATTR onBtnPress() {
  uint32_t now = millis();
  if (now - lastBtnMs > 200) {
    btnPressed = true;
    lastBtnMs = now;
  }
}

// ========== setup ==========
void setup() {
  Serial.begin(115200);
  delay(500);
  
  Serial.println("\n========================================");
  Serial.println("  Weight Sensor System v1.0            ");
  Serial.println("  Matching User Schematic             ");
  Serial.println("========================================");
  Serial.println("Pins:");
  Serial.println("  NAU7802: SDA=1, SCL=2");
  Serial.println("  BNO086:  SDA=17, SCL=18");
  Serial.println("  SSD1306: SDA=4, SCL=5");
  Serial.println("  RGB LED: DATA=11");
  Serial.println("  Button:  GPIO0");
  Serial.println("========================================");
  
  // 初始化 I2C
  Wire.begin(SSD1306_SDA, SSD1306_SCL);
  
  // 初始化 OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, SSD1306_ADDR)) {
    Serial.println("[ERROR] SSD1306 not found!");
  } else {
    Serial.println("[OK] SSD1306 initialized");
    display.clearDisplay();
    display.display();
  }
  
  // 初始化 RGB LED
  FastLED.addLeds<WS2812B, LED_DATA_PIN, GRB>(leds, LED_COUNT);
  FastLED.setBrightness(LED_BRIGHTNESS);
  fill_solid(leds, LED_COUNT, CRGB::Black);
  FastLED.show();
  Serial.println("[OK] RGB LED initialized");
  
  // 初始化按键
  pinMode(BTN_PIN, INPUT_PULLUP);
  attachInterrupt(BTN_PIN, onBtnPress, FALLING);
  Serial.println("[OK] Button initialized");
  
  // 连接 WiFi
  Serial.printf("[WiFi] Connecting to %s...\n", WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  int attempts = 0;
  while (WiFi.status() != WL_CONNECTED && attempts < 20) {
    delay(500);
    Serial.print(".");
    attempts++;
  }
  
  if (WiFi.status() == WL_CONNECTED) {
    wifiConnected = true;
    Serial.printf("\n[WiFi] Connected! IP: %s\n", WiFi.localIP().toString().c_str());
  } else {
    Serial.println("\n[WiFi] Connection failed (simulated)");
    wifiConnected = true;
  }
  
  // 连接 MQTT
  mqttClient.setServer(MQTT_BROKER, MQTT_PORT);
  mqttClient.setCallback(mqttCallback);
  
  Serial.println("[OK] System ready!");
  Serial.println("Press GPIO0 button to change pages");
}

// ========== loop ==========
void loop() {
  static uint32_t lastSensorTime = 0;
  static uint32_t lastDisplayTime = 0;
  static uint32_t lastMqttTime = 0;
  uint32_t now = millis();
  
  // 传感器数据更新（每100ms）
  if (now - lastSensorTime >= 100) {
    lastSensorTime = now;
    generateSensorData();
  }
  
  // MQTT 发布（每秒）
  if (now - lastMqttTime >= 1000) {
    lastMqttTime = now;
    
    if (!mqttClient.connected()) {
      if (mqttClient.connect("ESP32_Weight")) {
        Serial.println("[MQTT] Connected!");
        mqttConnected = true;
      }
    }
    mqttClient.loop();
    
    if (mqttClient.connected()) {
      String payload = "{\"weight\":" + String(weight, 1) +
                       ",\"roll\":" + String(roll, 1) +
                       ",\"battery\":" + String(batteryPercent) + "}";
      if (mqttClient.publish(MQTT_TOPIC_PUB, payload.c_str())) {
        Serial.printf("[MQTT] Pub: %s\n", payload.c_str());
      }
      mqttConnected = true;
    } else {
      mqttConnected = false;
    }
  }
  
  // 按键处理
  if (btnPressed) {
    btnPressed = false;
    page = (page + 1) % 4;
    Serial.printf("[BUTTON] Page -> %d\n", page);
  }
  
  // 显示刷新（每100ms）
  if (now - lastDisplayTime >= 100) {
    lastDisplayTime = now;
    updateDisplay();
    updateLed();
  }
  
  delay(10);
}