import serial
import time
from Tkinter import *
import tkMessageBox


COMPORT = "COM7"
BAUD = 115200


class Stepper_gui:
    def __init__(self):
        self.window = Tk()
        self.window.title("Stepper Control")

        self.zero_button = Button(self.window, text="Setup Zero Position", command=self.setup_zero)
        self.zero_button.pack()

        self.move_zero_button = Button(self.window, text="Move to set Zero", command=self.move_to_zero)
        self.move_zero_button.pack()

        dl_lab = Label(self.window, text="Drive Length (mm)")
        dl_lab.pack()
        self.drive_length = StringVar()
        self.drive_length.set("1")
        self.drive_length_entry = Entry(self.window, textvariable=self.drive_length)
        self.drive_length_entry.pack()
        
        dd_lab = Label(self.window, text="Drive Duration (s)")
        dd_lab.pack()

        self.drive_duration = StringVar()
        self.drive_duration.set("10")
        self.drive_duration_entry = Entry(self.window, textvariable=self.drive_duration)
        self.drive_duration_entry.pack()

        dir_lab = Label(self.window, text="Drive Direction")
        dir_lab.pack()

        self.dir_str = StringVar()
        self.dir_str.set("1")
        self.frwd_btn = Radiobutton(self.window, text="Forward", variable=self.dir_str, value="1")
        self.frwd_btn.pack()
        self.back_btn = Radiobutton(self.window, text="Backward", variable=self.dir_str, value="-1")
        self.back_btn.pack()

        self.go_button = Button(self.window, text="Drive Syringe", command=self.drive)
        self.go_button.pack()

        self.stop_button = Button(self.window, text="STOP", command=self.stop_drive)
        self.stop_button.pack()
        
        self.ser = Simple_serial(COMPORT, BAUD)
        
    def setup_zero(self):
        self.ser.write("7777,7777,7777")
        self.zero_button.config(text="Set Zero")
        self.zero_button.config(command=self.set_zero)

    def set_zero(self):
        self.ser.write("6666,6666,6666")
        self.zero_button.config(text="Setup Zero Position")
        self.zero_button.config(command=self.setup_zero)

    def move_to_zero(self):
        self.ser.write("8888,8888,8888")

    def drive(self):
        self.ser.write( str(int(round(float( self.drive_length.get() ) * 1000)))  + "," + str( int(round(float(self.drive_duration.get())) * 1000000 )) + "," + self.dir_str.get())
        self.check_code( self.ser.readline() )

    def stop_drive(self):
        self.ser.write("9999,9999,9999")

    def check_code(self, code):
        if code != "1":
            if code == "-1":
                tkMessageBox.showwarning("Warning", "Move velocity is too high")
            elif code == "-2":
                tkMessageBox.showwarning("Warning", "Move distance too far")
            elif code == "-3":
                tkMessageBox.showwarning("Warning", "Move distance beyond zero point")
            else:
                tkMessageBox.showwarning("Warning", "Unknown Error")


class Simple_serial:
    def __init__(self, com, baud):
        self.serial = None
        self.com = com
        self.baud = baud
        self.__connect__()

    def __connect__(self):
        try:
            self.serial = serial.Serial(self.com, self.baud, timeout = 1)
        except ValueError:
            print "Value Error Exception!!!"
            #Raise some warning in future
        except SerialException:
            print "Serial Exception!!!"
        else: #Serial connection threw no exceptions
            if not self.serial.isOpen():
                self.serial.open()
            '''
            Wait for connection to form. When serial connection is established
            the arduino restarts. The code below waits until the arduino reports
            back. On the arduino, in the setup() block, there should be:
                Serial.begin(28800);
                Serial.write("X");
            Thus, as soon as the connection is established, arduio sends "X" and
            when we recieve "X", we know the connection is good. 
            '''
            read = ""
            start = time.time()
            connection_timeout = 3 #seconds
            while time.time()-start < connection_timeout:
                read = self.serial.read()
                if read == "X":
                    break
            if read == "":
                raise SerialException("Incorrectly configured device")

    def write(self, output):
        self.serial.write(output)

    def readline(self):
        ms = time.time()*1000.0
        line = ""
        while True:
            line += self.serial.read(1)
            if "\n" in line:
                return line[0:-2]
            if time.time()*1000.0 - ms > 5000:
                return ""
        


if __name__ == '__main__':
    App = Stepper_gui()
    App.window.mainloop()