#! /usr/bin/env python

"""
TTB compare tools.
"""


# ***


def MyLogger( name ) :
    # external:
    import logging
    import sys
    # setup logger:
    logger = logging.getLogger( name )
    # no handlers yet ? then print to standard output:
    if len(logger.handlers) == 0 : logger.addHandler(logging.StreamHandler(sys.stdout))
    # no level set yet ? then set for info and higher:
    if logger.level == 0 : logger.setLevel(logging.INFO)
    # ok:
    return logger
#enddef


# ***


def df_files( fname1, fname2, sample=None, verbose=3 ) :

    """
    Compare 2 hdf/netcdf files.
    Print diagnostics to logger system.
    Verbose defines a verbosity level:
       1: never,    i.e. nothing is printed (i.e. error returned/raised if differences are found)
       2: on error, i.e. print info about differences only
       3: always,   i.e. print general info even if identical files (DEFAULT)
    """
    
    # external:
    import os
    import numpy

    # tools:
    import mdf

    # get logger:
    logger = MyLogger('ttb')
    
    # variables:
    vnames1 = mdf.get_varnames( fname1 )
    vnames2 = mdf.get_varnames( fname2 )
    # merge:
    vnames = []
    for vname1 in vnames1 :
        if vname1 not in vnames : vnames.append(vname1)
    for vname2 in vnames2 :
        if vname2 not in vnames : vnames.append(vname2)
    #endfor
    
    # info ...
    if verbose == 3: logger.info( 'compare files: ' )
    for f in [fname1,fname2] :
        if verbose == 3:
            if sample != None :
                logger.info( '  %s (sample %i)' % (f,sample) )
            else :
                logger.info( '  %s' % f )

        if not os.path.exists(f) :
            logger.error( '     file not found ...' )
            raise Exception

    # loop over variables:
    ok = True
    for vname in vnames :

        ## info ...
        if verbose == 3:logger.info( '  check %s ...' % vname )

        # check ...
        if vname not in vnames1 :
            if verbose > 1 : logger.info( '  variable "%s" not in file 1 ...' % vname )
            continue

        if vname not in vnames2 :
            if verbose > 1 : logger.info( '  variable "%s" not in file 2 ...' % vname )
            continue

        # read fields:
        field1 = mdf.get_var( fname1, vname, sample=sample )
        field2 = mdf.get_var( fname2, vname, sample=sample )

        
        # deal with degenerated cases (empty list or array)
        if (type(field1) == list):
            if not field1:
                if not field2:
                    differ = False
                else:
                    if verbose > 1 : logger.info( '  variable "%s" empty in file 1 ...' % vname )
                    differ = True
                continue
            if not field2:
                if verbose > 1 : logger.info( '  variable "%s" empty in file 2 ...' % vname )
                differ = True
                continue
        else:
            if field1.size == 0:
                if field2.size == 0:
                    differ = False
                else:
                    if verbose > 1 : logger.info( '  variable "%s" empty in file 1 ...' % vname )
                    differ = True
                continue
            if field2.size == 0:
                if verbose > 1 : logger.info( '  variable "%s" empty in file 2 ...' % vname )
                differ = True
                continue


        # scalar, list or array ?
        if numpy.isscalar(field1):
            if field1 != field2:
                differ = True
                if verbose > 1 :
                    logger.info( '      difference found in %s' % vname )
                    logger.info( '      where field #1 = %s' % repr(field1) )
                    logger.info( '      where field #2 = %s' % repr(field2) )
            else:
                differ = False

        elif (type(field1) == list) or (type(field1[0]) == numpy.string_) :
            # loop over elements:
            for i in range(min(len(field1),len(field2))) :
                differ = field1[i] != field2[i]
                if differ :
                    print field1
                    print field2
                    break
            
            # different ?
            if differ :
                # info ..
                if verbose > 1 : logger.info( '  found differences in %s ; first diff. in element %s' % (vname,str(i+1)) )
                
        elif numpy.any( numpy.isnan(field1) ) :
            # info ...
            if verbose > 1 : logger.info( '  found NaN in first field ...' )
            # set flag:
            differ = True
        elif numpy.any( numpy.isnan(field2) ) :
            # info ...
            if verbose > 1 : logger.info( '  found NaN in second field ...' )
            # set flag:
            differ = True
        else :
            # difference field:
            dd = abs(field2-field1)
            # test:
            differ = dd.max() > 0.0            
            # different ?
            if differ :

                # tupple with location of maximum difference:
                iimax0 = numpy.unravel_index( dd.argmax(), dd.shape )

                # convert to Fortran default indexing (ie start at 1)
                iimax = []
                for i in iimax0 : iimax.append(i+1)
                iimax.reverse()
                
                # relative difference:
                sfrac=''
                if field1[iimax0] != 0.0 :
                    rdif = dd[iimax0]*100. / field1[iimax0]
                    sfrac = '(rel.diff. %f %%)' % rdif

                # info ...
                if verbose > 1 :
                    try:
                        nbad = (numpy.nonzero( dd > 0.0 ))[0].size
                    except MemoryError:
                        logger.info('      Not enough memory to determine number of different datapoint')
                    else:
                        logger.info( '      %s (out of %s) differences found in %s' % (nbad, dd.size,vname) )
                    logger.info( '      max diff. in : %s %s' % (str(iimax),sfrac) )
                    logger.info( '      where field #1 = %s' % repr(field1[iimax0]) )
                    logger.info( '      where field #2 = %s' % repr(field2[iimax0]) )


        # reset flag:
        if differ : ok = False

    # info ...
    if ok :
        if verbose==3: logger.info( '  ok' )
    else :
        if __name__ == "__main__" : return 1
        raise ValueError
    
    return
    
#////////////////////////////////////////////////////////

if __name__ == "__main__":

    from optparse import OptionParser
    import sys
   
    parser = OptionParser(usage='%prog [--sample=sample] [--verbose=1|2|3] file_1 file_2')
    
    parser.add_option("-s", "--sample", type="int", dest="sample",
                      help="define record number to use, if there is several with the same name in HDF")

    parser.add_option("-v", "--verbose", type="int", dest="verbose", default=3,
                      help="define level of verbosity, 1: never (check return code \$?), 2: only if differences are found, 3: always (default)")

    options, args = parser.parse_args()    
    
    if len(args) != 2 :
        print "Must pass TWO file names to compare!"
        sys.exit(1)        
        
    sys.exit( df_files( args[0], args[1], sample=options.sample, verbose=options.verbose) )