"""
====================================================
            VIRTUAL DOCTOR APPLICATION 
====================================================

Platform: ESP32 
Language: MicroPython  

PROJECT OVERVIEW:
This project is a **Virtual Doctor Application** built using an ESP32, 
temperature sensor (DHT22), heart rate signal simulation, LCD display, 
buzzer, LED, and ThingSpeak IoT cloud.  

The system continuously monitors:
- **Heart Rate (HR)** → simulated using a sine wave to mimic a pulse sensor.
- **Body Temperature (°C)** → measured with a DHT22 sensor.  

It then:
- Displays the readings on a **16x2 LCD**.
- Provides **health feedback (Normal / Fever / Hypothermia / Bradycardia / Tachycardia)** like a doctor.
- Activates **alerts** (buzzer + LED) if abnormal conditions are detected.
- Sends the data to **ThingSpeak IoT cloud** every 20 seconds.

====================================================
                WORKING PRINCIPLE:
====================================================

1. **WiFi Connection**  
   - The ESP32 connects to WiFi.  
   - Enables sending data to ThingSpeak for remote monitoring.  

2. **Heartbeat Monitoring (Simulated)**  
   - Since no real pulse sensor exists in Wokwi, a **sine wave signal** is generated.  
   - Each wave peak is treated as a heartbeat → time between peaks is used to calculate **BPM**.  
   - Heart rate ranges are classified:  
        - <40 BPM → Bradycardia (Doctor Alert)  
        - 40-100 BPM → Normal  
        - 100-120 BPM → Slightly High  
        - 120-150 BPM → Abnormal HR (Doctor Alert)  
        - >150 BPM → Tachycardia Emergency  

3. **Temperature Monitoring**  
   - DHT22 sensor measures body temperature.  
   - Temperature ranges are classified:  
        - <35°C → Hypothermia (Doctor Alert)  
        - 35-37.5°C → Normal  
        - 38-39.5°C → Fever (Doctor Alert)  
        - >39.5°C → High Fever Emergency  

4. **LCD Display**  
   - Shows real-time HR and Temperature values.  
   - In case of abnormal readings, it displays **Doctor advice messages** like:  
     "Visit Doctor", "Emergency", "Stay Healthy".  

5. **Alerts**  
   - If abnormal HR or Temp is detected → Buzzer beeps + LED blinks 3 times.  
   - Gives both **visual + audio alerts** for the patient.  

6. **ThingSpeak IoT Upload**  
   - Every 20 seconds, HR, Temp, and Alert Code are sent to ThingSpeak.  
   - Alert Codes mapping:  
        0 → Normal  
        1 → Low Temp  
        2 → Fever  
        3 → High Fever Emergency  
        4 → Very Low HR  
        5 → Abnormal HR  
        6 → Very High HR  

====================================================
"""

import network
import urequests
import machine
import time
import dht
import math
from machine import Pin, ADC, I2C
from lcd_api import LcdApi
from i2c_lcd import I2cLcd

# ===== WiFi Config =====
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

# ===== ThingSpeak Config =====
TS_WRITE_KEY = "FNGRXJ6BJWEACFRC"
TS_URL = "http://api.thingspeak.com/update"

# ===== Pin Setup =====
adc = ADC(Pin(34))          # Potentiometer or pulse sensor
adc.atten(ADC.ATTN_11DB)    # Full range (0-3.3V)

d = dht.DHT22(Pin(4))       # DHT22 temperature sensor

buzzer = Pin(25, Pin.OUT)   # Active buzzer
led = Pin(2, Pin.OUT)       # Status LED

i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=400000)
lcd = I2cLcd(i2c, 0x27, 2, 16)

# ===== Connect WiFi =====
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(WIFI_SSID, WIFI_PASS)
print("Connecting to WiFi", end="")
while not wlan.isconnected():
    print(".", end="")
    time.sleep(0.5)
print("\nConnected:", wlan.ifconfig())

# ===== Beat detection variables =====
threshold = 2000      # Adjust for sensor/simulation
hysteresis = 150
in_peak = False
last_beat = 0
bpm = 0
bpm_values = []        # for smoothing
refractory_period = 300  # ms, to avoid double detection

# ===== Track ThingSpeak updates =====
last_update = time.ticks_ms()

# ===== Alert codes =====
alert_codes = {
    "Normal": 0,
    "Low Temp": 1,
    "Fever": 2,
    "High Fever Emergency": 3,
    "Very Low HR": 4,
    "Abnormal HR": 5,
    "Very High HR": 6
}

# ===== Main Loop =====
while True:
    now = time.ticks_ms()

    # --- Simulated Pulse Signal (comment if using real sensor) ---
    t = time.ticks_ms() / 1000  # seconds
    val = int(2000 + 1000 * math.sin(2 * math.pi * 1.2 * t))  # ~72 bpm
    # val = adc.read()  # uncomment if using real pulse sensor

    # --- Beat Detection ---
    if not in_peak and val > threshold:
        if time.ticks_diff(now, last_beat) > refractory_period:
            in_peak = True
            if last_beat != 0:
                ibi = time.ticks_diff(now, last_beat)  # ms
                if 300 < ibi < 2000:  # valid HR range
                    bpm = int(60000 / ibi)
                    bpm_values.append(bpm)
                    if len(bpm_values) > 5:   # rolling average of last 5
                        bpm_values.pop(0)
                    bpm = sum(bpm_values) // len(bpm_values)
                    led.on()
                    buzzer.on()
                    time.sleep(0.05)
                    buzzer.off()
                    led.off()
            last_beat = now
    if in_peak and val < threshold - hysteresis:
        in_peak = False

    # --- Temperature ---
    try:
        d.measure()
        temp = d.temperature()
    except:
        temp = None

    # --- Debug Print for Clear Vision ---
    print("ADC: {:4d} | BPM: {:3d} | Temp: {}".format(
        val,
        bpm if bpm > 0 else 0,
        "{:.1f}C".format(temp) if temp is not None else "--"
    ))

    # --- LCD Display ---
    lcd.clear()
    lcd.putstr("HR:{} bpm".format(bpm if bpm > 0 else "--"))
    if temp is not None:
        lcd.move_to(0, 1)
        lcd.putstr("T:{:.1f}C".format(temp))

    # --- Alerts & Doctor Features ---
    alert = False
    alert_msg = "Normal"

    if temp is not None:
        if temp < 35:
            lcd.clear()
            lcd.putstr("Hypothermia!")
            lcd.move_to(0, 1)
            lcd.putstr("See Doctor")
            alert = True
            alert_msg = "Low Temp"
        elif 35 <= temp <= 37.5:
            lcd.clear()
            lcd.putstr("Normal Temp")
            lcd.move_to(0, 1)
            lcd.putstr("Stay Healthy")
        elif temp > 39.5:
            lcd.clear()
            lcd.putstr("High Fever!")
            lcd.move_to(0, 1)
            lcd.putstr("Emergency")
            alert = True
            alert_msg = "High Fever Emergency"
        elif temp > 38:
            lcd.clear()
            lcd.putstr("Fever! Visit")
            lcd.move_to(0, 1)
            lcd.putstr("Doctor")
            alert = True
            alert_msg = "Fever"

    if bpm != 0:
        if bpm < 40:
            lcd.clear()
            lcd.putstr("Bradycardia!")
            lcd.move_to(0, 1)
            lcd.putstr("See Doctor")
            alert = True
            alert_msg = "Very Low HR"
        elif 40 <= bpm <= 100:
            lcd.clear()
            lcd.putstr("HR Normal")
            lcd.move_to(0, 1)
            lcd.putstr("Stay Healthy")
        elif bpm > 150:
            lcd.clear()
            lcd.putstr("Tachycardia!")
            lcd.move_to(0, 1)
            lcd.putstr("Emergency")
            alert = True
            alert_msg = "Very High HR"
        elif bpm > 120:
            lcd.clear()
            lcd.putstr("HR Abnormal!")
            lcd.move_to(0, 1)
            lcd.putstr("Visit Doctor")
            alert = True
            alert_msg = "Abnormal HR"

    if alert:
        for _ in range(3):   # Beep + Blink 3 times
            buzzer.on()
            led.on()
            time.sleep(0.2)
            buzzer.off()
            led.off()
            time.sleep(0.2)

    # --- Send to ThingSpeak (every 20s) ---
    if time.ticks_diff(now, last_update) > 20000:
        try:
            alert_code = alert_codes.get(alert_msg, 0)
            url = "{}?api_key={}&field1={}&field2={}&field3={}".format(
                TS_URL, TS_WRITE_KEY,
                bpm if bpm > 0 else 0,
                temp if temp is not None else 0,
                alert_code
            )
            r = urequests.get(url)
            print("ThingSpeak:", r.text)
            r.close()
        except Exception as e:
            print("HTTP error:", e)
        last_update = now   # reset timer

    time.sleep(0.05)