# Copyright 2000 by Jeffrey Chang.  All rights reserved.
# This code is part of the Biopython distribution and governed by its
# license.  Please see the LICENSE file that should have been included
# as part of this package.

# Gavin E. Crooks 2001-11-07:
#     Interface and comments modified to reflect changes to the SCOP
#     module, and to SCOP itself.

""" Handle the SCOP DOMain file.

The DOM file has been officially deprecated. For more information see
the SCOP"release notes.":http://scop.berkeley.edu/release-notes-1.55.html 
The DOM files for older releases can be found 
"elsewhere at SCOP.":http://scop.mrc-lmb.cam.ac.uk/scop/parse/
"""


from Residues import Residues

class Record:
    """Holds information for one SCOP domain.

    sid -- The SCOP ID of the entry, e.g. d1anu1

    residues -- The domain definition as a Residues object

    hierarchy -- A string specifying where this domain is in the hierarchy.
    """
    def __init__(self, line=None):
        self.sid = ''
        self.residues = []
        self.hierarchy = ''
        if line:
            self._process(line)

    def _process(self, line):
        """Parses DOM records.
    
        Records consist of 4 tab deliminated fields;
        sid, pdbid, residues, hierarchy
        """
        #For example ::
        #
        #d1sctg_ 1sct    g:      1.001.001.001.001.001
        #d1scth_ 1sct    h:      1.001.001.001.001.001
        #d1flp__ 1flp    -       1.001.001.001.001.002
        #d1moh__ 1moh    -       1.001.001.001.001.002

        line = line.rstrip()  # no trailing whitespace
        columns = line.split("\t")  # separate the tab-delineated cols
        if len(columns) != 4:
            raise ValueError("I don't understand the format of %s" % line)
        self.sid, pdbid, res, self.hierarchy = columns
        self.residues = Residues(res)
        self.residues.pdbid =pdbid


    def __str__(self):
        s = []
        s.append(self.sid)
        s.append(str(self.residues).replace(" ","\t") )
        s.append(self.hierarchy)
        return "\t".join(s) + "\n"


def parse(handle):
    """Iterates over a DOM file, returning a Dom record for each line
    in the file.

    Arguments:
        
        handle -- file-like object.
    """ 
    for line in handle:
        if line.startswith('#'):
            continue
        yield Record(line)
