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"

UPLOAD_INTERVAL = 5.0  # Upload every 5 seconds

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=5)
        return r.ok
    except:
        return False

# =========================
# 2) MAX30102 CORE
# =========================
MAX30102_ADDR = 0x57
REG_FIFO_DATA = 0x07
REG_MODE_CONFIG = 0x09
REG_SPO2_CONFIG = 0x0A
REG_LED1_PA = 0x0C 
REG_LED2_PA = 0x0D 

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
    bus.write_byte_data(MAX30102_ADDR, REG_LED1_PA, 0x24)    
    bus.write_byte_data(MAX30102_ADDR, REG_LED2_PA, 0x24)    

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

def estimate_bpm_autocorr(ir_signal, fs_hz):
    x = np.array(ir_signal, dtype=np.float64)
    x = x - np.mean(x)
    w = 3 # Smaller smoothing window for smaller buffer
    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) 
    max_lag = int(fs_hz * 60 / 45)  
    if max_lag >= len(ac): return None
    seg = ac[min_lag:max_lag]
    if len(seg) == 0: return None
    return 60.0 * fs_hz / (np.argmax(seg) + min_lag)

# =========================
# 3) MAIN LOGIC
# =========================
def main():
    fs = 50
    N = fs * 2 # <--- CHANGED: Buffer is now 2 seconds (100 samples)
    ir_buf = []
    last_upload_time = time.time()
    bpm_smooth = None

    with SMBus(1) as bus:
        init_max30102(bus)
        print("System Online. Buffer: 2 Seconds. Uploading every 5 seconds.")

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

            if ir_raw > 35000: # 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:
                        # Smoothing factor (slightly faster response)
                        bpm_smooth = bpm if bpm_smooth is None else 0.7*bpm_smooth + 0.3*bpm
                
                print(f"RED: {red_raw} | IR: {ir_raw} | BPM: {int(bpm_smooth) if bpm_smooth else 'Wait 2s...'}")
            else:
                ir_buf = []
                bpm_smooth = None
                print("Searching for Finger...")

            # Upload Check
            current_time = time.time()
            if (current_time - last_upload_time) >= UPLOAD_INTERVAL:
                if ir_raw > 35000 and bpm_smooth is not None:
                    print(">>> Uploading snapshot...")
                    send_to_supabase(bpm_smooth, ir_raw, red_raw)
                last_upload_time = current_time

            time.sleep(1/fs)

if __name__ == "__main__":
    main()