curses_interface.py

#!/usr/bin/env python
import curses
import math
import database_queries
from time import sleep

DEBUG = False # automate input vs. manual db connection info


# ==================================================
# Name: MyApp(object)
#
# Purpose: Serves as the primary starting point of
# the application. creates an curses object, sets
# curses options, establishes connection with db,
# and directs user to db connect screen.
# ==================================================
class MyApp(object):

  def __init__(self, stdscreen):
    
    # Init the main curses program
    self.screen = stdscreen
    #curses.curs_set(0)
    curses.cbreak() 
    curses.echo()
    # Connect to database
    con = connectToDatabase(self.screen)

    # Menu starting point
    printMainMenu(self.screen, con)


# ==================================================
# Name: connectToDatabase(stdscr)
#
# Purpose: Collects db connection information from
# the user including host IP address, db name, db
# user, and password. validates success/failure of
# db connection and informs user. Upon completion,
# redirects to main menu.
# ==================================================
def connectToDatabase(stdscr):


    x,y = stdscr.getmaxyx()
    yTest = 130
    xTest = 70
    while x < xTest and y < yTest:
        stdscr.clear()
        stdscr.addstr(10, 5, "Please make your terminal bigger!")
        stdscr.addstr(11, 5, "Make larger until you see the welcome splash screen")
        x,y = stdscr.getmaxyx()
        stdscr.getstr(1, 1, 0)
        if x < 120 or y < 60:
            stdscr.clear()
            stdscr.addstr(12, 5, "Terminal is almost big enough!")
        stdscr.clear()

  # Collect db data and validate connection
    while(1):
        # Clear the curses screen
        stdscr.clear()

        # Overwrite connection data in debug mode
        if DEBUG:
            username = "root"
            host = "192.168.1.3"
            password = ""
            database = "test"

        else:
            stdscr.clear()
            stdscr.nodelay(0)
            stdscr.keypad(1)
            selection = -2
            option = 0

            while selection < 0:
                graphics = [0]*5
                graphics[option] = curses.A_REVERSE
                #ASCII art creddited to: http://patorjk.com/software/taag/#p=display&f=Graffiti&t=Welcome
                stdscr.addstr(10, 5," __      __        __" )                         
                stdscr.addstr(11, 5,"/  \    /  \ ____ |  |   ____  ____   _____   ____"  )
                stdscr.addstr(12, 5,"\   \/\/   // __ \|  | _/ ___\/  _ \ /     \_/ __ \ ")
                stdscr.addstr(13, 5," \        /\  ___/|  |_\  \__(  <_> )  Y Y  \  ___/ ")
                stdscr.addstr(14, 5,"  \__/\  /  \___  >____/\___  >____/|__|_|  /\___  >")
                stdscr.addstr(15, 5,"       \/       \/          \/            \/     \/")
                stdscr.addstr(15, 5,"Press enter to start the application",graphics[0])

                action = stdscr.getch()
                if action == (ord('\n')):
                    selection = option
                    stdscr.clear()

            # Collect necessary connection info
            stdscr.addstr(10, 5, "Enter the database host address:")
            host = stdscr.getstr(10, 38, 15)
            stdscr.clear()

            stdscr.addstr(10, 5, "Enter the database username:")
            username = stdscr.getstr(10, 38, 15)
            stdscr.clear()

            stdscr.addstr(10, 5, "Enter the database name:")
            database = stdscr.getstr(10, 38, 15)
            stdscr.clear()

            stdscr.addstr(10, 5, "Enter the database password:")
            password = stdscr.getstr(10, 38, 15)
            stdscr.clear()

        # Attempt to connect with db
        con = database_queries.dbConnect(username, password, database, host) 

        # Connection successful
        if con['state'] == 0:
          # Inform user of connection      
          stdscr.addstr(10, 5, "Connection to Database Successful! Press Enter to Continue...")
          stdscr.getstr(1, 1, 0)
          break

        # Connection Failed
        else:
            selection = -2
            option = 0
            while selection < 0:
                graphics = [0]*2
                graphics[option] = curses.A_REVERSE
                failure_string = "Connection to Database Failed: %s" % (con['msg'])
                stdscr.addstr(10, 5, failure_string)
                stdscr.addstr(13, 13, "Retry",graphics[0])
                stdscr.addstr(13, 35, "Exit Program",graphics[1])
                stdscr.refresh()
            # Collect user's navigation selection
                action = stdscr.getch()
                if action == curses.KEY_RIGHT:
                    option = (option - 1) % 2
                elif action == curses.KEY_LEFT:
                    option = (option + 1) % 2
                elif action == (ord('\n')):
                    selection = option
                stdscr.clear()
            # If user wants to disconnect... Exit
                #if selection == 0:
                    #add in retry statement
            # Return to main menu
                if selection == 1:
                    curses.endwin()
                    exit()
      
    # Return successful connection
    return con


# ==================================================
# Name: printMainMenu(stdscr,con)
#
# Purpose: Serves as the main menu of the application.
# accepts user input and navigates to submenus as
# directed. Submenus redirect to this menu as well.
# makes use of the con[] dictionary provided by
# databases_queries.py.
# ==================================================
def printMainMenu(stdscr, con):
    stdscr.clear()
    stdscr.nodelay(0)
    stdscr.keypad(1)
    selection = -2
    option = 0
    # Print main menu options
    while selection < 0:
        stdscr.border(0)
        # Print main menu header information
        stdscr.addstr(1, 2, "HOST IP:")
        stdscr.addstr(1, 60, con['host'])
        stdscr.addstr(2, 2, "DB USER:")
        stdscr.addstr(2, 60, con['user'])
        stdscr.addstr(3, 2, "DATABASE NAME:")
        stdscr.addstr(3, 60, con['database'])

        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 30, "-- MAIN MENU --")

        graphics = [0]*5
        graphics[option] = curses.A_REVERSE
        stdscr.addstr(9, 6, "View / Edit Table",graphics[0])
        stdscr.addstr(11, 6, "Create Table", graphics[1])
        stdscr.addstr(13, 6, "Delete Table",graphics[2])
        stdscr.addstr(15, 6, "About",graphics[3])
        stdscr.addstr(17, 6, "Log Off / Exit",graphics[4])
        stdscr.refresh()
    # Collect user's navigation selection
        action = stdscr.getch()
        if action == curses.KEY_UP:
            option = (option - 1) % 5
        elif action == curses.KEY_DOWN:
            option = (option + 1) % 5
        elif action == (ord('\n')):
            selection = option
        stdscr.clear()

        # Navigate to submenu
        if selection == 0:
            printViewEditSubmenu(stdscr,con)
        # Navigate to CreateTable
        elif selection == 1:
            printCreateTableSubmenu(stdscr,con)
        # Navigate to DeleteTable
        elif selection == 2:
            printDeleteTableSubmenu(stdscr,con)
        # Navigate to About    
        elif selection == 3:
            printAboutSubmenu(stdscr,con)
        # Navigate to LogOff
        elif selection == 4:
            printLogOffSubMenu(stdscr,con)


    # Navigate to submenu
    # if user_input == ord('1'):
       # printViewEditSubmenu(stdscr,con)
	
    # if user_input == ord('2'):
        # printCreateTableSubmenu(stdscr,con)

    # if user_input == ord('3'):
        # printDeleteTableSubmenu(stdscr,con)

    # if user_input == ord('4'):
        # printAboutSubmenu(stdscr,con)

    # if user_input == ord('5'):
        # printLogOffSubMenu(stdscr,con)


# ==================================================
# Name: printViewEditSubmenu(stdscr,con)
#
# Purpose: This is the submenu that allows a user to 
# view, edit, or search an existing table in the db
# that has been connected to. user can also return
# to the main menu.
# ==================================================
def printViewEditSubmenu(stdscr,con):
    stdscr.clear()
    stdscr.nodelay(0)
    stdscr.keypad(1)
    selection = -2
    option = 0
    # Print View Edit options
    while selection < 0:
        graphics = [0]*5
        graphics[option] = curses.A_REVERSE
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 20, "-- VIEW / EDIT TABLE --")
        stdscr.addstr(9, 6, "View Table",graphics[0])
        stdscr.addstr(11, 6, "Edit Table",graphics[1])
        stdscr.addstr(13, 6, "Back to Main Menu",graphics[2])
        
        stdscr.refresh()
         # Collect user's navigation selection
        action = stdscr.getch()
        if action == curses.KEY_UP:
            option = (option - 1) % 3
        elif action == curses.KEY_DOWN:
            option = (option + 1) % 3
        elif action == (ord('\n')):
            selection = option
        stdscr.clear()

        # Navigate to submenu
        if selection == 0:
            printViewTableSubmenu(stdscr, con)
        # Navigate to CreateTable
        elif selection == 1:
            printEditTableSubmenu(stdscr, con)
        # Navigate to DeleteTable
        elif selection == 2:
            printMainMenu(stdscr, con)

        # if user_input == ord('1'):
        #     printViewTableSubmenu(stdscr,con)

        # if user_input == ord('2'):
        #     printEditTableSubmenu(stdscr,con)

        # if user_input == ord('3'):
        #     printMainMenu(stdscr,con)


# ==================================================
# Name: printViewTableSubmenu(stdscr,con)
#
# Purpose: Menu for viewing tables in the database.
# returns all tables in a column format. Tables,
# that exceed screen space will be provided in add'l
# spaces.
# ==================================================
def printViewTableSubmenu(stdscr,con):
    stdscr.clear()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 30, "-- VIEW TABLE --")
    stdscr.addstr(22, 45, "[B] Back")

    # Attempt to get tables in database so that they can be printed
    con = database_queries.dbTables(con) 

    # Detect if no tables exist
    if con['tbl_cnt'] == 0:
        stdscr.addstr(9, 6, "No tables in database")
        
        # Collect user's navigation selection
        user_input = stdscr.getch()
        

        # Navigate to submenu
        if user_input == ord('b') or user_input == ord('B'):
            printViewEditSubmenu(stdscr,con)


    # At least 1 table exists so print them
    else:
        y = 8
        x = 6 
        # Print out each table name line by line up to 6 per screen
        for idx, table in enumerate(con['tables']): 
            table_string = "[" + str(idx + 1) + "] " + table[0]
            stdscr.addstr(y, x, table_string)    
            y += 2

            # Detect the last row that can fit on a page (6th)
            if idx != 0 and idx % 5 == 0:
                
                # Detect if there are add'l rows past multiple of 6th
                if (idx + 1) < con['tbl_cnt']:
                    stdscr.addstr(22, 15, "[N] Next")
                
                #Collect user's navigation selection
                user_input = stdscr.getch()


                    # Navigate to submenu
                if user_input == ord('b') or user_input == ord('B'):
                    printViewEditSubmenu(stdscr,con)

                    # Paginate
                elif user_input == ord('n') or user_input == ord('N'):
                    stdscr.clear()
                    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
                    stdscr.addstr(6, 30, "-- VIEW TABLE --")
                    stdscr.addstr(22, 45, "[B] Back")
                    y = 8
                    x = 6

                    # Navigate to view table
                elif user_input >= ord('1') and user_input <= unichr(con['tbl_cnt']):
                    try:
                        printViewTableContentsSubmenu(stdscr, con, int(chr(user_input)) - 1)
                    except ValueError:
                        printViewTableSubmenu(stdscr, con)

                elif user_input == ord('\n'):
                    printViewTableSubmenu(stdscr, con)
                                

        # Collect user's navigation selection
        user_input = stdscr.getch()


        # Navigate to submenu

        if user_input == ord('b') or user_input == ord('B'):
            printViewEditSubmenu(stdscr,con)

        elif user_input >= ord('1') and user_input <= unichr(con['tbl_cnt']):
            try:
                printViewTableContentsSubmenu(stdscr, con, int(chr(user_input)) - 1)
            except ValueError:
                printViewTableSubmenu(stdscr, con)   # Navigate to view table

        if user_input == ord('\n'):
            printViewTableSubmenu(stdscr, con)


# ==================================================
# Name: printViewTableContentsSubmenu(stdscr, con, idx)
#
# Purpose: displays a table's contents upon selection
# from the table select menu. rows will paginate in
# instances that each row exceeds the rows allowed on
# the screen. idx is the table desired in con['tables'].
# ==================================================
def printViewTableContentsSubmenu(stdscr, con, idx):
    stdscr.clear()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 30, "-- VIEW TABLE --")  
    
    # Create the query string to retrieve the contents of the selected table
    table_string = "SELECT * FROM " + str(con['tables'][idx][0])

    # Conduct SELECT query; results in con['rows']
    con = database_queries.dbQuery(con, table_string)

    y = 12
    x = 14
    c = 10 # New Y Coordinate for columns
    s = 14 # New X Coordinate for columns

    totalRows = "Number of Rows: " + str(con['cnt'])
    stdscr.addstr(8, s, totalRows)

    # TODO: add borders
    # Printing Attribute names. https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-column-names.html
    for idx, col in enumerate(con['cols']):
        if idx != 11:
            #mid = int(math.ceil(s / 2))
            mid = int(math.ceil((s) - 3.5))
            stdscr.addstr(c, mid, "|")
        col_string = str(col)
        if len(col_string) >= 11:   # Trimming column name if it is too long.
            col_string = col_string[:10]
        stdscr.addstr(c, s, col_string)
        s += 15
    stdscr.addstr(y, 5, "--------------------------------------------------------------------------------------------------------------------------------------------------------")    
    y += 2

    # Print out each row line by line up to 6 per screen
    if con['cnt'] == 0:
        stdscr.addstr(y, 14, "No Rows in Table!")
        y += 2
        stdscr.addstr(y, 5, "--------------------------------------------------------------------------------------------------------------------------------------------------------")    

        # Collect user's navigation selection
        user_input = stdscr.getch()
        if user_input == ord('b') or user_input == ord('B'):
            printViewTableSubmenu(stdscr,con)

    else:
        mybool = False
        count = 0
        for idx, row in enumerate(con['rows']):

        #Detect the last row that can fit on a page (6th)
            if idx != 0 and idx % 11 == 0:
                mybool = True
                # Detect if there are add'l rows past multiple of 6th
                if (idx + 1) < con['row_cnt']:
                    y += 2
                    stdscr.addstr(y, 15, "[N] Next")
                    stdscr.addstr(y, 45, "[B] Back")  
                
                #Collect user's navigation selection
                user_input = stdscr.getch()

                # Navigate to submenu
                if user_input == ord('b') or user_input == ord('B'):
                    printViewTableSubmenu(stdscr,con)
                # Paginate
                elif user_input == ord('n') or user_input == ord('N'):
                    stdscr.clear()
                    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
                    stdscr.addstr(6, 30, "-- VIEW TABLE --")
                    y = 12
                    x = 14
            # Collect user's navigation selection
            #user_input = stdscr.getch()
            count += 1
            row_count = "[" + str(count) + "]  "
            x = 5
            stdscr.addstr(y, x, row_count)
            for ndx, col in enumerate(con['cols']): #Created new counter 'ndx' for traversing within the SQL row.

                row_string = str(row[col])
                #DO NOT TOUCH THIS LINE
                if len(row_string) >= 11:   # Trimming column name if it is too long.
                    row_string = row_string[:10]
                if ndx == 0:    # Do this for the first value.
                    x = 14 
                    mid = int(math.ceil((x) - 3.5))
                    stdscr.addstr(y, mid, "|")  
                    stdscr.addstr(y, x, row_string)
                else:
                    x += 15
                    mid = int(math.ceil((x) - 3.5))
                    stdscr.addstr(y, mid, "|")
                    stdscr.addstr(y, x, row_string)   
                #y += 2

            y += 2
            #stdscr.addstr(y, 45, "[B] Back")  

        # y += 2
        if mybool == False:
            stdscr.addstr(y, 45, "[B] Back")
            y += 2  
    
    stdscr.addstr(y, 5, "--------------------------------------------------------------------------------------")    

#     # Detect the last row that can fit on a page (6th)
#     if idx != 0 and idx % 5 == 0:
            
#         # Detect if there are add'l rows past multiple of 6th
#         if (idx + 1) < con['row_cnt']:
#             stdscr.addstr(22, 15, "[N] Next")
            
#         #Collect user's navigation selection
#         user_input = stdscr.getch()

# #---------------------------------------------------------------------
# # TODO: NEED TO REFACTOR WITH HIGHLIGHT
# #---------------------------------------------------------------------

#             # Navigate to submenu
#         if user_input == ord('b') or user_input == ord('B'):
#             printViewEditSubmenu(stdscr,con)

#         # Paginate
#         elif user_input == ord('n') or user_input == ord('N'):
#             stdscr.clear()
#             stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
#             stdscr.addstr(6, 30, "-- VIEW TABLE --")
#             stdscr.addstr(22, 45, "[B] Back")
#             y = 8
#             x = 6

#     # Collect user's navigation selection
#     user_input = stdscr.getch()

# #---------------------------------------------------------------------
# # TODO: NEED TO REFACTOR WITH HIGHLIGHT
# #---------------------------------------------------------------------

#     # Navigate to submenu
#     if user_input == ord('b') or user_input == ord('B'):
#         printViewEditSubmenu(stdscr,con)

    
# ==================================================
# Name: printEditTableSubmenu(stdscr,con)
#
# Purpose: Provides a list of tables that can be
# edited. User will select a table for editing, or
# can return to the next higher submenu.
# ==================================================
def printEditTableSubmenu(stdscr,con):
    stdscr.clear()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 30, "-- EDIT TABLE --")
    stdscr.addstr(22, 45, "[B] Back")

    # Attempt to get tables in database so that they can be printed
    con = database_queries.dbTables(con) 

    # Detect if no tables exist
    if con['tbl_cnt'] == 0:
        stdscr.addstr(9, 6, "No tables in database")
        
        # Collect user's navigation selection
        user_input = stdscr.getch()

        # Navigate to submenu
        if user_input == ord('b') or user_input == ord('B'):
            printViewEditSubmenu(stdscr,con)

    # At least 1 table exists so print them
    else:
        y = 8
        x = 6 
        # Print out each table name line by line up to 6 per screen
        for idx, table in enumerate(con['tables']): 
            table_string = "[" + str(idx + 1) + "] " + table[0]
            stdscr.addstr(y, x, table_string)    
            y += 2

            # Detect the last row that can fit on a page (6th)
            if idx != 0 and idx % 5 == 0:
                
                # Detect if there are add'l rows past multiple of 6th
                if (idx + 1) < con['tbl_cnt']:
                    stdscr.addstr(22, 15, "[N] Next")
                
                #Collect user's navigation selection
                user_input = stdscr.getch()

                # Navigate to submenu
                if user_input == ord('b') or user_input == ord('B'):
                    printViewEditSubmenu(stdscr,con)

                # Paginate
                elif user_input == ord('n') or user_input == ord('N'):
                    stdscr.clear()
                    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
                    stdscr.addstr(6, 30, "-- EDIT TABLE --")
                    stdscr.addstr(22, 45, "[B] Back")
                    y = 8
                    x = 6

                # Navigate to view table
                elif user_input >= ord('1') and user_input <= unichr(con['tbl_cnt']):
                    try:
                        printViewTableContentsSubmenu(stdscr, con, int(chr(user_input)) - 1)
                    except ValueError:
                        printViewTableSubmenu(stdscr, con)

                elif user_input == ord('\n'):
                    printViewTableSubmenu(stdscr, con)
                
        # Collect user's navigation selection
        user_input = stdscr.getch()
        

        # Navigate to submenu
        if user_input == ord('b') or user_input == ord('B'):
            printViewEditSubmenu(stdscr,con)

        # Navigate to view table
        elif user_input >= ord('1') and user_input <= unichr(con['tbl_cnt']):
            try:
                printViewTableContentsSubmenu(stdscr, con, int(chr(user_input)) - 1)
            except ValueError:
                printViewTableSubmenu(stdscr, con)

        elif user_input == ord('\n'):
            printViewTableSubmenu(stdscr, con)


# ==================================================
# Name: printEditTableContentsSubmenu(stdscr, con, idx)
#
# Purpose: provides an interface for users to enter
# edit queries for the desired table.
#
# NOTE: current functionality will allow any form of 
# SELECT, INSERT, or DELETE query.
#
# ==================================================
def printEditTableContentsSubmenu(stdscr, con, idx):
    stdscr.clear()
    stdscr.refresh()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 28, "-- EDIT TABLE --")

    # Draw input table
    stdscr.addstr(8, 6, "Enter a sql statement:")
    stdscr.addstr(10, 5, "+")
    stdscr.addstr(10, 6, "--------------------------------------------------------------------")
    stdscr.addstr(10, 74, "+")
    stdscr.addstr(11, 5, "|")
    stdscr.addstr(12, 5, "|")
    stdscr.addstr(13, 5, "|")
    stdscr.addstr(11, 74, "|")
    stdscr.addstr(12, 74, "|")
    stdscr.addstr(13, 74, "|")
    stdscr.addstr(14, 5, "+")
    stdscr.addstr(14, 6, "--------------------------------------------------------------------")
    stdscr.addstr(14, 74, "+")

    # Collect user input
    user_input = stdscr.getstr(12, 7, 66)
    
#---------------------------------------------------------------------
# TODO: NEED TO REFACTOR WITH HIGHLIGHT
#---------------------------------------------------------------------

    # Attempt to submit query
    con = database_queries.dbQuery(con, user_input)

    # Edit query success; return to main menu
    if queryCheck(con) == 1:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- EDIT TABLE --")
        stdscr.addstr(10, 5, "Query Success! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printMainMenu(stdscr,con)

    # Edit query failure; return to main menu
    else:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- EDIT TABLE --")
        stdscr.addstr(10, 5, "Query Failure! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printEditTableSubmenu(stdscr,con)


# ==================================================
# Name: printCreateTableSubmenu(stdscr,con)
#
# Purpose: Redirects from main menu to the create
# table menu. In current instantiation, user is
# provided with the ability to enter a "create"
# query which will be submitted to db. 
#
# NOTE: user can technically enter a select, insert,
# or delete query and, upon successful submission,
# it will work. 
# ==================================================
def printCreateTableSubmenu(stdscr,con):
    stdscr.clear()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 28, "-- CREATE TABLE --")

    # Draw input table
    stdscr.addstr(8, 6, "Enter a sql statement:")
    stdscr.addstr(10, 5, "+")
    stdscr.addstr(10, 6, "--------------------------------------------------------------------")
    stdscr.addstr(10, 74, "+")
    stdscr.addstr(11, 5, "|")
    stdscr.addstr(12, 5, "|")
    stdscr.addstr(13, 5, "|")
    stdscr.addstr(11, 74, "|")
    stdscr.addstr(12, 74, "|")
    stdscr.addstr(13, 74, "|")
    stdscr.addstr(14, 5, "+")
    stdscr.addstr(14, 6, "--------------------------------------------------------------------")
    stdscr.addstr(14, 74, "+")

    # Collect user input
    user_input = stdscr.getstr(12, 7, 66)

#---------------------------------------------------------------------
# TODO: NEED TO REFACTOR WITH HIGHLIGHT
#---------------------------------------------------------------------

    # Attempt to submit query
    con = database_queries.dbQuery(con, user_input)

    # create query success; return to main menu
    if queryCheck(con) == 0:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- CREATE TABLE --")
        stdscr.addstr(10, 5, "Query Success! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printMainMenu(stdscr,con)

    # create query failure; return to main menu
    else:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- CREATE TABLE --")
        stdscr.addstr(10, 5, "Query Failure! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printMainMenu(stdscr,con)


# ==================================================
# Name: queryCheck(con)
#
# Purpose: Verifies connection message and validates
# if query is success (return 1) or failure (return 0).
# ==================================================
def queryCheck(con):
    # Parse query message response
    response = con['msg'].split() 

    # Successful query
    if response[0] == 'Successful':
        return 1
    
    # Failed query
    else:
        return 0 


# ==================================================
# Name: printDeleteTableSubmenu(stdscr,con)
#
# Purpose: Redirects from main menu to the create
# table menu. In current instantiation, user is
# provided with the ability to enter a "Delete"
# query which will be submitted to db. 
#
# NOTE: user can technically enter a select, insert,
# or delete query and, upon successful submission,
# it will work. 
# ==================================================
def printDeleteTableSubmenu(stdscr,con):
    stdscr.clear()
    stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
    stdscr.addstr(6, 28, "-- DELETE TABLE --")

    # Draw input table
    stdscr.addstr(8, 6, "Enter a sql statement:")
    stdscr.addstr(10, 5, "+")
    stdscr.addstr(10, 6, "--------------------------------------------------------------------")
    stdscr.addstr(10, 74, "+")
    stdscr.addstr(11, 5, "|")
    stdscr.addstr(12, 5, "|")
    stdscr.addstr(13, 5, "|")
    stdscr.addstr(11, 74, "|")
    stdscr.addstr(12, 74, "|")
    stdscr.addstr(13, 74, "|")
    stdscr.addstr(14, 5, "+")
    stdscr.addstr(14, 6, "--------------------------------------------------------------------")
    stdscr.addstr(14, 74, "+")

    # Collect user input
    user_input = stdscr.getstr(12, 7, 66)

#---------------------------------------------------------------------
# TODO: NEED TO REFACTOR WITH HIGHLIGHT
#---------------------------------------------------------------------

    # Attempt to submit query
    con = database_queries.dbQuery(con, user_input)

    # Delete query success; return to main menu
    if queryCheck(con) == 1:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- DELETE TABLE --")
        stdscr.addstr(10, 5, "Query Success! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printMainMenu(stdscr,con)

    # Delete query failure; return to main menu
    else:
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 28, "-- DELETE TABLE --")
        stdscr.addstr(10, 5, "Query Failure! Press Enter to Continue...")
        stdscr.getstr(1, 1, 0)
        printMainMenu(stdscr,con)


# ==================================================
# Name: printAboutSubmenu(stdscr,con)
#
# Purpose: accessed from the main menu, prints info
# about the program including version.
# ==================================================
def printAboutSubmenu(stdscr,con):

    stdscr.clear()
    selection = -2
    option = 0    
    while selection < 0:
        graphics = [0]*1
        graphics[option] = curses.A_REVERSE


        stdscr.refresh()
         # Collect user's navigation selection
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 30, "-- ABOUT --")
    
        string_line0 = "curses_database_interface v1.0"
        string_line1 = "This program has been written by authors Nick Mastrokalos, Bryan Bauer,"
        string_line2 = "and Darnel Clayton for Fall 2015 CS419's final software project."
        stdscr.addstr(8, 4, "Version:")
        stdscr.addstr(9, 4, string_line0)
        stdscr.addstr(11, 4, "Notes:")
        stdscr.addstr(12, 4, string_line1)
        stdscr.addstr(13, 4, string_line2)


        stdscr.addstr(22, 32, "Back",graphics[0])
        action = stdscr.getch()
        if action == (ord('\n')):
            selection = option
        stdscr.clear()

        # Navigate to submenu
        if selection == 0:
            printMainMenu(stdscr,con) 


# ==================================================
# Name: printLogOffSubMenu(stdscr,con)
#
# Purpose: accessed from the main menu, starts the
# process of logging off. After confirmation,
# disconnects from db and exits program. Otherwise,
# returns to the main menu.
# ==================================================
def printLogOffSubMenu(stdscr,con):
    selection = -2
    option = 0
    while selection < 0:
        graphics = [0]*2
        graphics[option] = curses.A_REVERSE

        stdscr.refresh()
        stdscr.clear()
        stdscr.addstr(4, 2, "----------------------------------------------------------------------------")
        stdscr.addstr(6, 30, "-- LOG OFF --")
        stdscr.addstr(10, 13, "Are you sure you'd like to log off?")
        stdscr.addstr(13, 13, "Log Off",graphics[0])
        stdscr.addstr(13, 35, "Return to Program",graphics[1])

    # Collect user's navigation selection
        action = stdscr.getch()
        if action == curses.KEY_RIGHT:
            option = (option - 1) % 2
        elif action == curses.KEY_LEFT:
            option = (option + 1) % 2
        elif action == (ord('\n')):
            selection = option
        stdscr.clear()
    # If user wants to disconnect... Exit
        if selection == 0:
            # Close connection with db and exit
            con = database_queries.dbClose(con)
            curses.endwin()
            exit()

    # Return to main menu
        if selection == 1:
            printMainMenu(stdscr,con)