# ProcessSalesOrder.py

# Chapter 6 Standard Modules

# os module page 69
# sys module page 71
# subprocess module page 71

# Level 1 Course __main__ statement page 35

'''
Customer Sales Order -> Main Process 16 sec subprocesses + time
Work Order -> shop work order interal process   4 sec
Purchase Order -> vendor order get supplies  12 sec

Process Starts
subprocess 1 starts 
subprocess 2 starts 
wait for the subprocesses complete
Process End
'''
# ProcessSalesOrder.py
import subprocess
import sys
import os
import datetime

# Sales Order Process
def salesOrder():
    print("Sales Order Process Starting...")
    
    # work order process
    workOrder_subprocess = subprocess.Popen(
        [
            sys.executable, # calls an cmd.exe
            '-c',
            'from ProcessSalesOrder import workOrder; workOrder()'
        ]
    ) # Popen()

    # purchase order process
    purchaseOrder_subprocess = subprocess.Popen(
        [
            sys.executable, # calls an cmd.exe
            '-c',
            'from ProcessSalesOrder import purchaseOrder; purchaseOrder()'
        ]
    ) # Popen()

    # At this point there is a main salesOrder process and 2 subprocesses running
    print("Sales Order is waiting for Work Order to Finish...")
    workOrder_subprocess.wait()

    print("Sales Order is waiting for Purchase Order to Finish...")
    purchaseOrder_subprocess.wait()

    # Now all the subprocesses have exited with Exit Code 0 or 1 (pass or fail)
    print("Now the subprocesses have finished, so the main process can continue...")

    # Finally
    print("Now the final cleanup happens...")


# Work Order Process (subprocess)
def workOrder():
    print("Here is where the workOrder processes have run...")
    startTime = datetime.datetime.now()
    print(startTime)
    i = input("Process holding till enter key ...")  # hold the subprocess and check task manager

# Purchase Order Process (subprocess)
def purchaseOrder():
    print("Here is where the purchaseOrder processes have run...")
    startTime = datetime.datetime.now()
    print(startTime)
    i = input("Process holding till enter key ...")  # hold the subprocess and check task manager

# Main Bootstrap Function page 35
def main():
    # Pre Process Operations
    # File I/O page 46 Level 1
    dateStamp = datetime.datetime.now().strftime('%Y%m%d') # string
    # Log File Name to Output data
    # processingLog_20241213.txt
    log_filename = "processingLog_" + dateStamp + ".txt"

    # change sys.stdout() to file
    sys.stdout = open(log_filename, 'w')
    # at this point all print() will go to the log file NOT the terminal


    # sales order process
    salesOrder()

    # Post Process Operations
    # close txt file
    sys.stdout.close() # close() is manual due to no with keyword
    # open() with the with keyword
    ''' page 46 chapter 4
    with open(log_filename, 'w') as file:
       operations here...
    '''

    # change sys.stdout() back to terminal
    sys.stdout = sys.__stdout__

# Program Class
if __name__ == "__main__":   # Page 35
    main()