#!/usr/bin/env python
# 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.
#
"""Run and process output from the Wise2 package tool psw.

Bio.Wise contains modules for running and processing the output of
some of the models in the Wise2 package by Ewan Birney available from:
ftp://ftp.ebi.ac.uk/pub/software/unix/wise2/
http://www.ebi.ac.uk/Wise2/

Bio.Wise.psw is for protein Smith-Waterman alignments
Bio.Wise.dnal is for Smith-Waterman DNA alignments
"""

from __future__ import print_function

import os
import re
import sys

from Bio import Wise


_CMDLINE_PSW = ["psw", "-l", "-F"]
_OPTION_GAP_START = "-g"
_OPTION_GAP_EXTENSION = "-e"
_OPTION_SCORES = "-m"


class AlignmentColumnFullException(Exception):
    pass


class Alignment(list):
    def append(self, column_unit):
        try:
            self[-1].append(column_unit)
        except AlignmentColumnFullException:
            list.append(self, AlignmentColumn(column_unit))
        except IndexError:
            list.append(self, AlignmentColumn(column_unit))


class AlignmentColumn(list):
    def _set_kind(self, column_unit):
        if self.kind == "SEQUENCE":
            self.kind = column_unit.kind

    def __init__(self, column_unit):
        assert column_unit.unit == 0
        self.kind = column_unit.kind
        list.__init__(self, [column_unit.column, None])

    def __repr__(self):
        return "%s(%s, %s)" % (self.kind, self[0], self[1])

    def append(self, column_unit):
        if self[1] is not None:
            raise AlignmentColumnFullException

        assert column_unit.unit == 1

        self._set_kind(column_unit)
        self[1] = column_unit.column


class ColumnUnit(object):
    def __init__(self, unit, column, kind):
        self.unit = unit
        self.column = column
        self.kind = kind

    def __str__(self):
        return "ColumnUnit(unit=%s, column=%s, %s)" % (self.unit, self.column, self.kind)

    __repr__ = __str__


_re_unit = re.compile(r"^Unit +([01])- \[ *(-?\d+)- *(-?\d+)\] \[(\w+)\]$")


def parse_line(line):
    """Parse a line from psw.

    >>> print(parse_line("Column 0:"))
    None
    >>> parse_line("Unit  0- [  -1-   0] [SEQUENCE]")
    ColumnUnit(unit=0, column=0, SEQUENCE)
    >>> parse_line("Unit  1- [  85-  86] [SEQUENCE]")
    ColumnUnit(unit=1, column=86, SEQUENCE)
    """
    match = _re_unit.match(line.rstrip())

    if not match:
        return

    return ColumnUnit(int(match.group(1)), int(match.group(3)), match.group(4))


def parse(iterable):
    """Parse a file.

    format

    Column 0:
    Unit  0- [  -1-   0] [SEQUENCE]
    Unit  1- [  85-  86] [SEQUENCE]

    means that seq1[0] == seq2[86] (0-based)
    """
    alignment = Alignment()
    for line in iterable:
        try:
            if os.environ["WISE_PY_DEBUG"]:
                print(line)
        except KeyError:
            pass

        column_unit = parse_line(line)
        if column_unit:
            alignment.append(column_unit)

    return alignment


def align(pair,
          scores=None,
          gap_start=None,
          gap_extension=None,
          *args, **keywds):

    cmdline = _CMDLINE_PSW[:]
    if scores:
        cmdline.extend((_OPTION_SCORES, scores))
    if gap_start:
        cmdline.extend((_OPTION_GAP_START, str(gap_start)))
    if gap_extension:
        cmdline.extend((_OPTION_GAP_EXTENSION, str(gap_extension)))
    temp_file = Wise.align(cmdline, pair, *args, **keywds)
    return parse(temp_file)


def main():
    print(align(sys.argv[1:3]))


def _test(*args, **keywds):
    import doctest
    doctest.testmod(sys.modules[__name__], *args, **keywds)


if __name__ == "__main__":
    if __debug__:
        _test()
    main()
