import time
import numpy as np
from smbus2 import SMBus
import requests

# =========================
# 1) SUPABASE CONFIG
# =========================
SUPABASE_URL = "https://bnrqoovyawxyjbdqmtix.supabase.co"
SUPABASE_ANON_KEY = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6ImJucnFvb3Z5YXd4eWpiZHFtdGl4Iiwicm9sZSI6ImFub24iLCJpYXQiOjE3NjE2NjA3ODEsImV4cCI6MjA3NzIzNjc4MX0.2aXc6ZDLss-nXsj2WQNkvD9AnImr73xVGExKK1LQerM"
TABLE = "heart_reading"

SEND_EVERY_SECONDS = 1.0  # Upload rate

def send_to_supabase(bpm, ir, red, spo2=98):
    url = f"{SUPABASE_URL}/rest/v1/{TABLE}"
    headers = {
        "apikey": SUPABASE_ANON_KEY,
        "Authorization": f"Bearer {SUPABASE_ANON_KEY}",
        "Content-Type": "application/json",
        "Prefer": "return=minimal",
    }
    payload = {
        "bpm": int(round(bpm)) if bpm else None,
        "spo2": int(spo2),
        "ir": int(ir),
        "red": int(red)
    }
    try:
        r = requests.post(url, headers=headers, json=payload, timeout=2)
        return r.ok
    except:
        return False

# =========================
# 2) MAX30102 REGISTERS
# =========================
MAX30102_ADDR = 0x57
REG_FIFO_DATA = 0x07
REG_FIFO_WR_PTR = 0x04
REG_FIFO_RD_PTR = 0x06
REG_MODE_CONFIG = 0x09
REG_SPO2_CONFIG = 0x0A
REG_LED1_PA = 0x0C # RED
REG_LED2_PA = 0x0D # IR

def init_max30102(bus):
    bus.write_byte_data(MAX30102_ADDR, REG_MODE_CONFIG, 0x40) # Reset
    time.sleep(0.1)
    bus.write_byte_data(MAX30102_ADDR, REG_MODE_CONFIG, 0x03) # SpO2 Mode
    bus.write_byte_data(MAX30102_ADDR, REG_SPO2_CONFIG, 0x27) # 100Hz, 411us
    bus.write_byte_data(MAX30102_ADDR, REG_LED1_PA, 0x24)    # Red LED
    bus.write_byte_data(MAX30102_ADDR, REG_LED2_PA, 0x24)    # IR LED
    bus.write_byte_data(MAX30102_ADDR, REG_FIFO_WR_PTR, 0x00)
    bus.write_byte_data(MAX30102_ADDR, REG_FIFO_RD_PTR, 0x00)

def read_fifo(bus):
    d = bus.read_i2c_block_data(MAX30102_ADDR, REG_FIFO_DATA, 6)
    red = ((d[0] << 16) | (d[1] << 8) | d[2]) & 0x3FFFF
    ir = ((d[3] << 16) | (d[4] << 8) | d[5]) & 0x3FFFF
    return red, ir

# =========================
# 3) BPM ALGORITHM
# =========================
def estimate_bpm_autocorr(ir_signal, fs_hz):
    x = np.array(ir_signal, dtype=np.float64)
    x = x - np.mean(x)
    # Bandpass filter simulation (Smoothing)
    w = 5
    x = np.convolve(x, np.ones(w)/w, mode='same')
    ac = np.correlate(x, x, mode='full')
    ac = ac[len(ac)//2:]
    
    min_lag = int(fs_hz * 60 / 180) # 180 BPM
    max_lag = int(fs_hz * 60 / 45)  # 45 BPM
    
    if max_lag >= len(ac): return None
    seg = ac[min_lag:max_lag]
    if len(seg) == 0: return None
    
    peak = np.argmax(seg) + min_lag
    return 60.0 * fs_hz / peak

# =========================
# 4) MAIN LOOP
# =========================
def main():
    fs = 50
    N = fs * 4 # 4-second window for faster response
    ir_buf = []
    last_send = 0
    bpm_smooth = None

    with SMBus(1) as bus:
        init_max30102(bus)
        print("System Ready. Place finger on sensor...")

        while True:
            # Read sample
            try:
                red_raw, ir_raw = read_fifo(bus)
            except:
                continue

            if ir_raw > 30000: # Finger detected
                ir_buf.append(ir_raw)
                if len(ir_buf) > N: ir_buf.pop(0)

                if len(ir_buf) == N:
                    bpm = estimate_bpm_autocorr(ir_buf, fs)
                    if bpm and 40 < bpm < 180:
                        bpm_smooth = bpm if bpm_smooth is None else 0.8*bpm_smooth + 0.2*bpm
                
                print(f"RED: {red_raw} | IR: {ir_raw} | BPM: {int(bpm_smooth) if bpm_smooth else 'Calculating...'}")
            else:
                ir_buf = []
                bpm_smooth = None
                print("No Finger Detected")

            # Supabase Upload
            now = time.time()
            if ir_raw > 30000 and (now - last_send) >= SEND_EVERY_SECONDS:
                success = send_to_supabase(bpm_smooth, ir_raw, red_raw)
                if success: print(">>> Sent to Supabase ✅")
                else: print(">>> Supabase Error ❌")
                last_send = now

            time.sleep(1/fs)

if __name__ == "__main__":
    main()