#
#  Compute the number of lines, words and characters in a text file.
#  The name of the file will be proivded as a command line argument.
#
import sys

# Retrieve the name of the file from the command line.
if len(sys.argv) == 1:
  # Read the input from the keyboard, write the output to the screen
  inf = sys.stdin
  outf = sys.stdout

elif len(sys.argv) == 2:
  # Read the input from a file, write the output to the screen
  fname = sys.argv[1]

  # Open the file for reading.
  inf = open(fname, "r")

  # Output goes to the screen
  outf = sys.stdout

elif len(sys.argv) == 3:
  # Read the input from a file, write the output to a file
  fname = sys.argv[1]
  out_fname = sys.argv[2]

  # Open the file for reading.
  inf = open(fname, "r")

  # Open the file for writing.
  outf = open(out_fname, "w")

else:
  # Too many command line arguments were provided.
  print("The program must be started with 2 or fewer command line arguments.")
  print()
  print("python wc.py [input_file] [output_file]")
  quit()


# Process the file and count the number of lines, words and characters.
lines = 0
words = 0
chars = 0

line = inf.readline()  # Read the first line from the file
while line != "":
  lines = lines + 1
  words = words + len(line.split())
  chars = chars + len(line)

  line = inf.readline()   # Read the next line from the file

# Close the file.
inf.close()

# Display the results.
#print(f"lines: {lines}")
#print(f"words: {words}")
#print(f"characters: {chars}")
outf.write(f"lines: {lines}\n")
outf.write(f"words: {words}\n")
outf.write(f"characters: {chars}\n")

outf.close()