from serial import Serial
from threading import Thread
import time

class printcore():
    def __init__(self,port=None,baud=None):
        self.baud=None
        self.port=None
        self.printer=None
        self.clear=0
        self.mainqueue=[]
        self.priqueue=[]
        if port is not None and baud is not None:
            print port, baud
            self.connect(port, baud)
            print "connected\n"
        self.readthread=None
        self.queueindex=0
        self.lineno=0
        self.resendfrom=-1
        self.online=False
        self.printing=False
        self.sentlines={}
        
    def disconnect(self):
        if(self.printer):
            self.printer.close()
        self.printer=None
        self.online=False
        self.printing=False
        
    def connect(self,port=None,baud=None):
        if(self.printer):
            self.disconnect()
        if port is not None:
            self.port=port
        if baud is not None:
            self.baud=baud
        if self.port is not None and self.baud is not None:
            self.printer=Serial(self.port,self.baud,timeout=5)
            Thread(target=self._listen).start()
            
    def _listen(self):
        """This function acts on messages from the firmware
        """
        time.sleep(1)
        print "listening:"
        while(True):
            if(not self.printer or not self.printer.isOpen):
                print "port not open"
                break
            line=self.printer.readline()
            print "RECV:",line
            if(line.startswith('start')):
                self.clear=True
                self.online=True
            elif(line.startswith('ok')):
                self.clear=True
                self.resendfrom=-1
                #put temp handling here
            elif(line.startswith('Error')):
                pass
            if "Resend" in line or "rs" in line:
                toresend=int(line.split(':')[1])
                self.resendfrom=toresend
                self.clear=True
        print "done listening"
            
    def checksum(self,command):
        return reduce(lambda x,y:x^y, map(ord,command))
        
    def startprint(self,data):
        if(self.printing):
            return False
        self.printing=True
        self.mainqueue=[]+data
        self._send("M110",-1, True)
        Thread(target=self._print).start()
        return True
        
    def pause(self):
        self.printing=False
        
    def resume(self):
        self.printing=True
        threading.Thread(target=self._print).start()
        
    def send_now(self,command):
        if(self.printing):
            self.priqueue+=[command]
        else:
            self._send(command)
        
    def _print(self):
        while(self.printing and self.printer):
            self.sendnext()
        
    def sendnext(self):
        if(not self.printer):
            return
        if(self.resendfrom>-1):
            while(self.resendfrom<self.lineno):
                while not self.clear:
                    time.sleep(0.001)
                self.clear=False
                self._send(self.sentlines[self.resendfrom],self.resendfrom,False)
                self.resendfrom+=1
            self.resendfrom=-1
        for i in self.priqueue[:]:
            while not self.clear:
                time.sleep(0.001)
            self.clear=False
            self._send(i)
            del(self.preque[0])
        if(self.printing and self.queueindex<len(self.mainqueue)):
            tline=self.mainqueue[self.queueindex]
            if(not tline.startswith(';') and len(tline)>0):
                while not self.clear:
                    time.sleep(0.001)
                self.clear=False
                self._send(tline,self.lineno,True)
            self.lineno+=1
            self.queueindex+=1
        else:
            self.printing=False
            self.queueindex=0
            self.lineno=0
            self._send("M110",-1, True)
            
    def _send(self, command, lineno=0, calcchecksum=False):
        if(calcchecksum):
            prefix="N"+str(lineno)+" "+command
            command=prefix+"*"+str(self.checksum(prefix))
            self.sentlines[lineno]=command
        if(self.printer):
            print "sending: "+command+"\n"
            self.printer.write(command+"\n")

if __name__ == '__main__':
    p=printcore('/dev/ttyUSB0',115200)
    time.sleep(5)
    testdata="""G28
G1 X0 Y0
G1 X10 Y10
G1 X0 Y0
;
"""
    p.startprint(testdata.split('\n'))
    time.sleep(10)
    p.disconnect()