# 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.
#

from Bio import FSSP
import copy
from Bio.Align import MultipleSeqAlignment
from Bio import Alphabet
from Bio.Seq import Seq
from Bio.SeqRecord import SeqRecord


class FSSPAlign(MultipleSeqAlignment):
    def _add_numbering_table(self, new_record):
        new_record.annotations['abs2pdb'] = {}
        new_record.annotations['pdb2abs'] = {}


class FSSPMultAlign(dict):
    def __init__(self):
        self.abs_res = []
        self.pdb_res = []
        self.data = {}


def mult_align(sum_dict, align_dict):
    """Returns a biopython multiple alignment instance (MultipleSeqAlignment)"""
    mult_align_dict = {}
    for j in align_dict.abs(1).pos_align_dict:
        mult_align_dict[j] = ''

    for i in range(1, len(align_dict)+1):
        # loop on positions
        for j in align_dict.abs(i).pos_align_dict:
            # loop within a position
            mult_align_dict[j] += align_dict.abs(i).pos_align_dict[j].aa
    alpha = Alphabet.Gapped(Alphabet.IUPAC.extended_protein)
    fssp_align = MultipleSeqAlignment([], alphabet=alpha)
    for i in sorted(mult_align_dict):
        fssp_align.append(SeqRecord(Seq(mult_align_dict[i], alpha),
                                    sum_dict[i].pdb2+sum_dict[i].chain2))
    return fssp_align


# Several routines used to extract information from FSSP sections
# filter:
# filters a passed summary section and alignment section according to a numeric
# attribute in the summary section. Returns new summary and alignment sections
# For example, to filter in only  those records which have a zscore greater than
# 4.0 and lesser than 7.5:
# new_sum, new_align = filter(sum, align, 'zscore', 4, 7.5)
#
# Warning: this function really slows down when filtering large FSSP files.
# The reason is the use of copy.deepcopy() to copy align_dict into
# new_align_dict. I have to figure out something better.
# Took me ~160 seconds for the largest FSSP file (1reqA.fssp)
#

def filter(sum_dict, align_dict, filter_attribute, low_bound, high_bound):
    """Filters a passed summary section and alignment section according to a numeric
    attribute in the summary section. Returns new summary and alignment sections"""
    new_sum_dict = FSSP.FSSPSumDict()
    new_align_dict = copy.deepcopy(align_dict)
#    for i in align_dict:
#        new_align_dict[i]  = copy.copy(align_dict[i])
#    new_align_dict = copy.copy(align_dict)
    for prot_num in sum_dict:
        attr_value = getattr(sum_dict[prot_num], filter_attribute)
        if attr_value >= low_bound and attr_value <= high_bound:
            new_sum_dict[prot_num] = sum_dict[prot_num]
    prot_numbers = sorted(new_sum_dict)
    for pos_num in new_align_dict.abs_res_dict:
        new_align_dict.abs(pos_num).pos_align_dict = {}
        for prot_num in prot_numbers:
            new_align_dict.abs(pos_num).pos_align_dict[prot_num] = \
                    align_dict.abs(pos_num).pos_align_dict[prot_num]
    return new_sum_dict, new_align_dict


def name_filter(sum_dict, align_dict, name_list):
    """Accepts a list of names. Returns a new Summary block and Alignment block which
    contain the info only for those names passed."""
    new_sum_dict = FSSP.FSSPSumDict()
    new_align_dict = copy.deepcopy(align_dict)
    for cur_pdb_name in name_list:
        for prot_num in sum_dict:
            if sum_dict[prot_num].pdb2+sum_dict[prot_num].chain2 == cur_pdb_name:
                new_sum_dict[prot_num] = sum_dict[prot_num]
    prot_numbers = sorted(new_sum_dict)
    for pos_num in new_align_dict.abs_res_dict:
        new_align_dict.abs(pos_num).pos_align_dict = {}
        for prot_num in prot_numbers:
            new_align_dict.abs(pos_num).pos_align_dict[prot_num] = \
                    align_dict.abs(pos_num).pos_align_dict[prot_num]
    return new_sum_dict, new_align_dict
