#!/usr/bin/python -Wall

# ----------------------------------------------------------------
# John Kerl
# kerl.john.r@gmail.com
# 2005-01-11
# (Ported to Python 2006-03-06)
#
# This is a radix-2 fast Fourier transform.  Example:
#
# [xxx fix the example]
#
# This file contains the I/O wrapper.  The library routine is in pyfft_m.py.
# ----------------------------------------------------------------
# This software is released under the terms of the GNU GPL.
# Please see LICENSE.txt in the same directory as this file.
# ================================================================

from __future__ import division # 1/2 = 0.5, not 0.
import sys
import pyfft_m
import pyrcio_m

# ----------------------------------------------------------------
def usage():
	print >> sys.stderr, "Usage:", sys.argv[0], "[options] [file name]"
	print >> sys.stderr, "If the file name is omitted, input is taken from standard input."
	print >> sys.stderr, "Format is in whitespace-delimited decimal rectangular, e.g."
	# xxx fix
	print >> sys.stderr, "  1.0 0.0"
	print >> sys.stderr, "  2.0 0.0"
	print >> sys.stderr, "  3.0 0.0"
	print >> sys.stderr, "  4.0 0.0"
	print >> sys.stderr, "Options:"
	print >> sys.stderr, "  -fi:  input folding"
	print >> sys.stderr, "  -nfi: no input folding"
	print >> sys.stderr, "  -fo:  output folding"
	print >> sys.stderr, "  -nfo: no output folding"
	print >> sys.stderr, "  -fwd: forward FFT (exp(-i 2 pi k/N) kernel)"
	print >> sys.stderr, "  -rev: reverse FFT (exp( i 2 pi k/N) kernel)"
	print >> sys.stderr, "  -s:   scaling"
	print >> sys.stderr, "  -ns:  no scaling"
	print >> sys.stderr, "  -dft: Use DFT.  Allows dimensions not to be a power of 2."
	sys.exit(1)

# ================================================================
# Start of program
fold_in   = 0
fold_out  = 0
forward   = 1
scale     = 1
use_dft   = 0
do_rows   = 1
do_cols   = 1
file_name = "-"

argc = len(sys.argv)
argi = 1
while (argi < argc):
	arg = sys.argv[argi]
	if (arg[0] != '-'):
		break
	if   (arg == "-fi"):
		fold_in  = 1
	elif (arg == "-nfi"):
		fold_in  = 0
	elif (arg == "-fo"):
		fold_out = 1
	elif (arg == "-nfo"):
		fold_out = 0
	elif (arg == "-fwd"):
		forward  = 1
	elif (arg == "-rev"):
		forward  = 0
	elif (arg == "-s"):
		scale    = 1
	elif (arg == "-ns"):
		scale    = 0
	elif (arg == "-dft"):
		use_dft  = 1
	elif (arg == "-ndft"):
		use_dft  = 0
	elif (arg == "-ro"):
		do_rows  = 1
		do_cols  = 0
	elif (arg == "-co"):
		do_rows  = 0
		do_cols  = 1
	else:
		usage()
	argi += 1

if ((argc - argi) == 1):
	file_name = sys.argv[argi]
elif ((argc - argi) == 0):
	file_name = "-"
else:
	usage()

# Input
A = pyrcio_m.read_complex_matrix(file_name)
nr = len(A)
nc = len(A[0])

# Row FFTs
if (do_rows):
	for i in range(0, nr):
		if (use_dft):
			A[i] = pyfft_m.dft(A[i], fold_in, fold_out, forward, scale)
		else:
			A[i] = pyfft_m.fft(A[i], fold_in, fold_out, forward, scale)

# Column FFTs
if (do_cols):
	for j in range(0, nc):

		# Get column
		v = []
		for i in range(0, nr):
			v.append(A[i][j])

		# Transform column
	 	if (use_dft):
	 		v = pyfft_m.dft(v, fold_in, fold_out, forward, scale)
	 	else:
	 		v = pyfft_m.fft(v, fold_in, fold_out, forward, scale)

		# Put column
		for i in range(0, nr):
			A[i][j] = v[i]

# Output
pyrcio_m.print_complex_matrix(A)

# ----------------------------------------------------------------
#
# argc = len(sys.argv)
# if (argc < 2):
# 	print >> sys.stderr, "Usage: %s {file name 1} {file name 2}" % (sys.argv[0])
# 	sys.exit(1)
#
# argi = 2
# while (argi < argc):
# 	B = read_matrix(float, sys.argv[argi])
# 	A = A * B
# 	argi += 1
# print_matrix(A)