#!/usr/bin/env python3
"""Sustained-load test for periodic flow re-checks.

Question: what does repeated interrogation cost thermally over a long
job, and does the loop reach equilibrium or climb without bound? Runs
the driver's real check cadence (M8 held for the duration) with the
cut-profile fans, logging bulk coolant temperature and every verdict.

Usage: flow_sustained.py [minutes]   (default 30)
"""
import math
import os
import shlex
import re
import socket
import subprocess
import sys
import time

HOST = os.environ.get('GF_HOST')
if not HOST:
    raise SystemExit('set GF_HOST to the machine IP address')
# ssh client used to reach the board; override for a wrapper, e.g.
# GF_SSH='wsl -d <distro> -- ssh'.
SSH = shlex.split(os.environ.get('GF_SSH', 'ssh'))
F = 1024.0 * 1.3
RD, BETA = 10000.0, 3380.0
RINF = 10000.0 * math.exp(-3380.0 / 298.15)


def degc(raw):
    r = RD / (F / float(raw) - 1.0)
    return BETA / math.log(r / RINF) - 273.15


def board(cmd):
    r = subprocess.run(SSH + ['-o', 'PreferredAuthentications=none',
                              'root@' + HOST, cmd],
                       capture_output=True, text=True, timeout=30)
    return r.stdout.strip()


def temps():
    o = board('cat /sys/glowforge/pic/water_temp_1 /sys/glowforge/pic/water_temp_2').split()
    return degc(o[0]), degc(o[1])


minutes = float(sys.argv[1]) if len(sys.argv) > 1 else 30

s = socket.create_connection((HOST, 23), timeout=5)
s.settimeout(0.3)
time.sleep(0.5)
try:
    while s.recv(4096):
        pass
except socket.timeout:
    pass

d0, u0 = temps()
print('start: down=%.2f up=%.2f  running M8 for %.0f min' % (d0, u0, minutes))
s.sendall(b'M8\n')

t0 = time.time()
verdicts = []
peak_up = u0
buf = ''
while time.time() - t0 < minutes * 60:
    try:
        buf += s.recv(4096).decode('ascii', 'replace')
    except socket.timeout:
        pass
    for line in buf.split('\n'):
        if 'flow' in line and ('verified' in line or 'FAULT' in line):
            m = re.search(r'rise ([\d.]+) C', line)
            if m and (not verdicts or verdicts[-1][1] != float(m.group(1))):
                el = (time.time() - t0) / 60
                verdicts.append((el, float(m.group(1)), 'FAULT' in line))
                d, u = temps()
                peak_up = max(peak_up, u)
                print('  %5.1f min  rise=%5.2f  %-8s  loop down=%.2f up=%.2f (%+.2f from start)'
                      % (el, float(m.group(1)), 'FAULT' if 'FAULT' in line else 'ok', d, u, u - u0),
                      flush=True)
    buf = buf[-2000:]
    time.sleep(5)

s.sendall(b'M9\n')
time.sleep(1)
s.close()

d, u = temps()
print()
print('checks run: %d over %.0f min' % (len(verdicts), minutes))
if verdicts:
    rises = [v[1] for v in verdicts]
    print('rise values: min=%.2f max=%.2f mean=%.2f  (threshold 13.7)'
          % (min(rises), max(rises), sum(rises) / len(rises)))
    print('false faults: %d' % sum(1 for v in verdicts if v[2]))
print('loop temperature: start %.2f -> end %.2f (%+.2f C), peak %.2f'
      % (u0, u, u - u0, peak_up))
print('cadence: %.1f min between checks' % (minutes / max(1, len(verdicts))))