#########################################################################
#
#   aviris.py - This file is part of the Spectral Python (SPy) package.
#
#   Copyright (C) 2001-2010 Thomas Boggs
#
#   Spectral Python is free software; you can redistribute it and/
#   or modify it under the terms of the GNU General Public License
#   as published by the Free Software Foundation; either version 2
#   of the License, or (at your option) any later version.
#
#   Spectral Python is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#     
#   You should have received a copy of the GNU General Public License
#   along with this software; if not, write to
#
#               Free Software Foundation, Inc.
#               59 Temple Place, Suite 330
#               Boston, MA 02111-1307
#               USA
#
#########################################################################
#
# Send comments to:
# Thomas Boggs, tboggs@users.sourceforge.net
#

'''
Functions for handling AVIRIS image files.
'''

from exceptions import DeprecationWarning
from warnings import warn

def open(file, band_file = None):
    '''
    Returns a SpyFile object for an AVIRIS image file.
    
    Arguments:
    
        `file` (str):
	
	    Name of the AVIRIS data file.
	
	`band_file` (str):
	
	    Optional name of the AVIRIS spectral calibration file.
	
    Returns:
    
	A SpyFile object for the image file.
	
    Raises:
    
	IOError
    '''

    from spectral.io.bipfile import BipFile
    import os, glob
    from exceptions import IOError
    from spyfile import find_file_path

    class Params: pass
    p = Params()

    p.filename = find_file_path(file)
    p.nbands = 224
    p.ncols = 614
    fileSize = os.stat(p.filename)[6]
    if fileSize % 275072 != 0:
        raise IOError, 'File size not consitent with Aviris format.'
    p.nrows = int(fileSize / 275072)
    p.format = 'h'
    p.typecode = 'h'
    p.offset = 0
    p.byte_order = 1
    metadata = {'default bands' : ['29', '18', '8']}

    img = BipFile(p, metadata)
    img.scale_factor = 10000.0
    
    if band_file:
	img.bands = read_aviris_bands(find_file_path(band_file))
    else:
	# Let user know if band cal files are available
	fileDir = os.path.split(p.filename)[0]
	calFiles = glob.glob(fileDir + '/*.spc')
	if len(calFiles) > 0:
	    print '\nThe following band calibration files are located in the same ' \
	          'directory as the opened AVIRIS file:\n'
	    for f in calFiles:
		print "    " + os.path.split(f)[1]
	    print '\nTo associate a band calibration file with an AVIRIS data file, ' \
	          're-open the AVIRIS file with the following syntax:\n'
	    print '    >>> img = aviris.open(fileName, calFileName)\n'
    return img

def read_aviris_bands(cal_filename):
    '''
    Returns a BandInfo object for an AVIRIS spectral calibration file.
    
    Arguments:
    
        `cal_filename` (str):
	
	    Name of the AVIRIS spectral calibration file.

    Returns:
    
	A :class:`spectral.BandInfo` object
    '''
    import __builtin__
    from spectral import BandInfo
    from spyfile import find_file_path
    bands = BandInfo()
    bands.band_quantity = 'Wavelength'
    bands.band_unit = 'nm'
    
    fin = __builtin__.open(find_file_path(cal_filename))
    rows = [line.split() for line in fin]
    rows = [[float(x) for x in row] for row in rows if len(row) == 5]
    columns = zip(*rows)
    bands.centers = columns[0]
    bands.bandwidths = columns[1]
    bands.center_stdevs = columns[2]
    bands.bandwidth_stdevs = columns[3]
    bands.band_unit = 'nm'
    return bands

def readAvirisBands(calFilename):
    warn('readAvirisBands has been deprecated.  Use read_aviris_bands.',
	 DeprecationWarning)
    return read_aviris_bands(cal_filename)
