#!/usr/bin/env python

############################################################################
# Monitor & control fermenter temperature 
# v1.0
#
# $Id: beermon.py,v 1.5 2007/09/28 13:05:11 darius Exp $
#
# Depends on: Python 2.3 (I think)
#
############################################################################
#
# Copyright (C) 2007 Daniel O'Connor. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
############################################################################


import pexpect, re, threading, time, logging, sys, traceback
from logging.handlers import RotatingFileHandler

class ROMReadError(Exception):
    pass

class ThreadDied(Exception):
    pass

class Control():
    targetTemp = 18
    hysteresis = 0.5
    pollInterval = 30
    staleDataTime = 30
    
    def __init__(self, m, _log):
        self.m = m
        global log
        log = _log
        self.cv = threading.Condition()
        self.cv.acquire()
        
    def doit(self):
        log.debug("target temperature - %3.2f" % (self.targetTemp))
        log.debug("fermenterId - %s" % (self.m.fermenterId))
        log.debug("fridgeId - %s" % (self.m.fridgeId))
        log.debug("ambientId - %s" % (self.m.ambientId))
        log.debug("minCoolOnTime - %d, minCoolOffTime - %d" % (self.m.minCoolOnTime, self.m.minCoolOffTime))
        log.debug("minHeatOnTime - %d, minHeatOffTime - %d" % (self.m.minHeatOnTime, self.m.minHeatOffTime))
        log.debug("pollInterval - %d" % (self.pollInterval))
        
        log.debug("=== Starting ===")
        log.debug("Fermenter	Fridge	Ambient	State	New State")
        while True:
            # Check if our monitor thread has died
            if (not self.m.isAlive()):
                raise ThreadDied, "Monitor thread has died"

            # Check for stale data
            if (self.m.lastUpdate[self.m.fermenterId] + self.staleDataTime < time.time()):
                log.debug("Stale data")
                self.cv.wait(self.pollInterval)
                self.m.setState('idle')
                continue

            # Work out what state we should go into
            nextState = "-"
            diff = self.m.temps[self.m.fermenterId] - self.targetTemp
            if (self.m.currState == 'idle'):
                # If we're idle then only heat or cool if the temperate difference is out of the
                # hysteresis band
                if (abs(diff) > self.hysteresis):
                    if (diff < 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
                        nextState = 'heat'
                    elif (diff > 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
                        nextState = 'cool'
            elif (self.m.currState == 'cool'):
                # Go idle as soon as we can, there will be overshoot anyway
                if (diff < 0 and self.m.minCoolOnTime + self.m.lastCoolOn < time.time()):
                    nextState = 'idle'
            elif (self.m.currState == 'heat'):
                # Ditto
                if (diff > 0 and self.m.minHeatOnTime + self.m.lastHeatOn < time.time()):
                    nextState = 'idle'
            else:
                # Not possible..
                raise KeyError

            log.debug("%3.2f   	%3.2f	%3.2f	%s	%s" %
                      (self.m.temps[self.m.fermenterId],
                       self.m.temps[self.m.fridgeId], self.m.temps[self.m.ambientId],
                       self.m.currState, nextState))

            if (nextState != "-"):
                self.m.setState(nextState)

            self.cv.wait(self.pollInterval)
            

class MonitorDev(threading.Thread):
    # Match a ROM ID (eg 00:11:22:33:44:55:66:77)
    romre = re.compile('([0-9a-f]{2}:){7}[0-9a-f]{2}')
    # Match the prompt
    promptre = re.compile('> ')

    coolRelay = 7
    heatRelay = 6
    
    fermenterId = '10:eb:48:21:01:08:00:df'
    fridgeId = '10:a6:2a:c4:00:08:00:11'
    ambientId = '10:97:1b:fe:00:08:00:d1'
    
    # minimum time the cooler must spend on/off
    minCoolOnTime = 10 * 60
    minCoolOffTime = 10 * 60

    # minimum time the heater must spend on/off
    minHeatOnTime = 60
    minHeatOffTime = 60

    # Dictionary of sensor IDs & temperatures
    temps = {}
    # Dictionary of sensor IDs & epoch times
    lastUpdate = {}

    # List of all device IDs
    devs = []
    # List of temperature sensor IDs
    tempdevs = []
    
    # Lock to gate access to the comms
    commsLock = None

    currState = 'idle'

    lastHeatOn = 0
    lastHeatOff = 0
    lastCoolOn = 0
    lastCoolOff = 0

    def __init__(self):
        threading.Thread.__init__(self)
        self.commsLock = threading.Lock()
        self.p = pexpect.spawn('/usr/bin/ssh', ['-xt', '-enone', '-i', '/home/darius/.ssh/id_wrt', 'root@wrt', '(echo logged in; microcom -D/dev/cua/1)'])
        assert(self.p.expect('logged in') == 0)
        self.p.timeout = 3
        self.setspeed()
        self.devs = self.find1wire()
        self.tempdevs = filter(self.istemp, self.devs)

        self.start()
        
    def setspeed(self):
        self.commsLock.acquire()
        self.p.send('~')
        assert(self.p.expect('t - set terminal') == 0)
        self.p.send('t')
        assert(self.p.expect('p - set speed') == 0)
        self.p.send('p')
        assert(self.p.expect('f - 38400') == 0)
        self.p.send('f')
        assert(self.p.expect('done!') == 0)
        self.commsLock.release()
        
    def find1wire(self):
        self.commsLock.acquire()
        self.p.sendline('')
        assert(self.p.expect('> ') == 0)
        self.p.sendline('sr')
        # Echo
        assert(self.p.expect('sr') == 0)

        # Send a new line which will give us a command prompt to stop on
        # later. We could use read() but that would make the code a lot
        # uglier
        self.p.sendline('')

        devlist = []

        # Loop until we get the command prompt (> ) collecting ROM IDs
        while True:
            idx = self.p.expect([self.romre, self.promptre])
            if (idx == 0):
                # Matched a ROM
                #print "Found ROM " + self.p.match.group()
                devlist.append(self.p.match.group(0))
            elif (idx == 1):
                # Matched prompt, exit
                break
            else:
                # Unpossible!
                self.commsLock.release()
                raise SystemError()

        self.commsLock.release()

        return(devlist)

    def istemp(self, id):
        [family, a, b, c, d, e, f, g] = id.split(':')
        if (family == '10'):
            return True
        else:
            return False

    def updateTemps(self):
        for i in self.tempdevs:
            try:
                self.temps[i] = float(self.readTemp(i))
                self.lastUpdate[i] = time.time()
            except ROMReadError:
                # Ignore this - just results in no update reflected by lastUpdate
                pass
            
        return(self.temps)

    def readTemp(self, id):
        self.commsLock.acquire()
        cmd = 'te ' + id
        self.p.sendline(cmd)
        # Echo
        assert(self.p.expect(cmd) == 0)
        # Eat EOL left from expect
        self.p.readline()

        line = self.p.readline().strip()
        self.commsLock.release()
        # 'CRC mismatch' can mean that we picked the wrong ROM..
        if (re.match('CRC mismatch', line) != None):
            raise ROMReadError

        return(line)

    def setState(self, state):
        if (state == 'cool'):
            relay = 1 << self.coolRelay
        elif (state == 'heat'):
            relay = 1 << self.heatRelay
        elif (state == 'idle'):
            relay = 0
        else:
            raise(ValueError)

        if (state == self.currState):
            return

        # Keep track of when we last turned off or on
        if (state == 'cool'):
            if (self.currState == 'heat'):
                self.lastHeatOff = time.time()
            self.lastCoolOn = time.time()
        elif (state == 'heat'):
            if (self.currState == 'cool'):
                self.lastCoolOff = time.time()
            self.lastHeatOn = time.time()
        else:
            if (self.currState == 'cool'):
                self.lastCoolOff = time.time()
            if (self.currState == 'heat'):
                self.lastHeatOff = time.time()

        self.currState = state
        
        self.commsLock.acquire()
        # Need the extra spaces cause the parser in the micro is busted
        cmd = 'out c    %02x' % relay
        self.p.sendline(cmd)
            # Echo
        assert(self.p.expect(cmd) == 0)
        self.commsLock.release()
        
    def polltemps(self, temps):
        while True:
            for d in temps:
                #print d
                t = gettemp(p, d)
                print "%s -> %s" % (d, t)
            print

    def run(self):
        while True:
            self.updateTemps()

def initLog():
    # Init our logging
    log = logging.getLogger("monitor")

    # Default to warts and all logging
    log.setLevel(logging.DEBUG)

    # Log to this file
    logfile = logging.handlers.RotatingFileHandler(filename = "/tmp/beermon.log",
                                                   maxBytes = 1000000, backupCount = 3)

    # And stderr
    logstderr = logging.StreamHandler()

    # Format it nicely
    formatter = logging.Formatter(fmt = "%(asctime)s: %(message)s", datefmt = "%Y/%m/%d %H:%M:%S")

    # Glue it all together
    logfile.setFormatter(formatter)
    logstderr.setFormatter(formatter)
    log.addHandler(logfile)
    log.addHandler(logstderr)
    return(log)

def main():
    import beermon
    
    global log
    log = initLog()

    log.debug("=== Initing ===")
    log.debug("$Id: beermon.py,v 1.5 2007/09/28 13:05:11 darius Exp $")

    m = None
    exitCode = 0
    try:
        m = beermon.MonitorDev()

        c = beermon.Control(m, log)
        # Wait for the first temperature readings to come through, saves
        # getting an 'invalid data' message
        time.sleep(3)
        c.doit()
        log.debug("doit exited")

    except KeyboardInterrupt:
        log.debug("Exiting due to keyboard interrupt")

    except Exception, e:
        log.debug("Something went wrong, details below:")
        log.debug(e)
        log.debug(reduce(lambda x, y: x + y, traceback.format_exception(
            sys.exc_type, sys.exc_value, sys.exc_traceback)))
        exitCode = 1
        
    finally:
        # Make sure we try and turn it off if something goes wrong
        if (m != None):
            m.setState('idle')

    sys.exit(exitCode)
    
if __name__ == "__main__":  
    main()