# Author:  James Tam
# Version: June 3, 2020
# A program that reads the information for starting positions for a chess
# board into a 2D list that is dynamically created using append().
# Limitation: no functionality implemented aside from reading the starting positions from file.

NEWLINE = "\n"
"""
@display
 *Arguments: list reference,integer,integer (the last two reflect the size of the list)
 *Return: nothing

 Displays the contents of the 2D list with each row appearing on its
 own line. It's followed by a separator a line of stars and two blank
 lines.
"""
def display(aBoard,numRows,numColumns):
    currentRow = 0
    currentColumn = 0
    print("DISPLAY BOARD")
    while (currentRow < numRows):
        currentColumn = 0
        while (currentColumn < numColumns):
            print("%s" %(aBoard[currentRow][currentColumn]),end="")
            currentColumn = currentColumn + 1
        currentRow = currentRow + 1
        print()
    for currentColumn in range (0,numColumns,1):
        print("*", end="")
    print(NEWLINE)

"""
@displayWithGrid
 *Arguments: list reference,integer,integer (the last two reflect the size of the list)
 *Return: nothing

 Displays the contents of the 2D list with each row appearing on its
 own line. Each element in the list is bound: above, below, left and right
 with a line to visually separate it from other elements.
"""
def displayWithGrid(aBoard,numRows,numColumns):
    currentRow = 0
    currentColumn = 0
    print("DISPLAY BOARD WITH GRID")
    while (currentRow < numRows):

        for currentColumn in range(0,numColumns,1):
            print(" -", end="")
        print()
        currentColumn = 0
        while (currentColumn < numColumns):
            print("|%s" %(aBoard[currentRow][currentColumn]),end="")
            currentColumn = currentColumn + 1
        currentRow = currentRow + 1
        print("|")
    for currentColumn in range(0,numColumns,1):
        print(" -", end="")

"""
@readBoardFromFile
 *Arguments: None
 *Return: list reference,integer,integer (the last two reflect the size of the list)

 Reads the starting positions from a text file. Each piece or an empty space is 
 represented by a character. A line in the file will be a row in the chess board.
"""
def readBoardFromFile():
    inputFileOK = False
    aBoard = []
    while (inputFileOK == False):
        try:
            inputFileName = input("Enter name of input file: ")
            inputFile = open(inputFileName,"r")
            print("Opening file "+ inputFileName + \
                  " for reading.")
            currentRow = 0
            for line in inputFile:
                 aBoard.append([])
                 #currentColumn = 0
                 for ch in line:
                     if (ch != NEWLINE):
                         aBoard[currentRow].append(ch)
                 currentRow = currentRow + 1  
            inputFileOK = True
            print("Completed reading of file " + inputFileName)
        except IOError:
            print("Error: File", inputFileName, "couldn't" + \
                  "be opened.")
    numRows = len(aBoard)
    numColumns = len(aBoard[0])
    return(aBoard,numRows,numColumns)

#########################
# Execution begins here #
#########################
def start():
    aBoard,numRows,numColumns = readBoardFromFile()
    display(aBoard,numRows,numColumns)
    displayWithGrid(aBoard,numRows,numColumns)

start()