# pyXLWriter: A library for generating Excel Spreadsheets
# Copyright (c) 2004 Evgeny Filatov <fufff@users.sourceforge.net>
# Copyright (c) 2002-2004 John McNamara (Perl Spreadsheet::WriteExcel)
#
# This library is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# This library 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 Lesser
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#----------------------------------------------------------------------------
# This module was written/ported from PERL Spreadsheet::WriteExcel module
# The author of the PERL Spreadsheet::WriteExcel module is John McNamara
# <jmcnamara@cpan.org>
#----------------------------------------------------------------------------
# See the README.txt distributed with pyXLWriter for more details.

"""pyXLWriter.utilites

Utilities for work with reference to cells

"""
__revision__ = """$Id: utilites.py,v 1.23 2004/08/20 05:16:17 fufff Exp $"""

#
# TODO: Optimazation - I must use re.compale everywhere.
#

import re

__all__ = ["cell_to_rowcol", "cell_to_rowcol2", "rowcol_to_cell", 
           "cellrange_to_rowcol_pair"]


_re_cell_ex = re.compile(r"(\$?)([A-I]?[A-Z])(\$?)(\d+)")
_re_row_range = re.compile(r"\$?(\d+):\$?(\d+)")
_re_col_range = re.compile(r"\$?([A-I]?[A-Z]):\$?([A-I]?[A-Z])")
_re_cell_range = re.compile(r"\$?([A-I]?[A-Z]\$?\d+):\$?([A-I]?[A-Z]\$?\d+)")
_re_cell_ref = re.compile(r"\$?([A-I]?[A-Z]\$?\d+)")


def _col_by_name(colname):
    """
    """
    col = 0
    pow = 1
    for i in xrange(len(colname)-1, -1, -1):
        ch = colname[i]
        col += (ord(ch) - ord('A') + 1) * pow
        pow *= 26
    return col - 1


def cell_to_rowcol(cell):
    """Convert an Excel cell reference string in A1 notation
    to numeric row/col notation.
  
    Returns: row, col, row_abs, col_abs
 
    """
    m = _re_cell_ex.match(cell)
    if not m:
        raise Exception("Error in cell format")
    col_abs, col, row_abs, row = m.groups()
    row_abs = bool(row_abs)
    col_abs = bool(col_abs)
    row = int(row) - 1
    col = _col_by_name(col)
    return row, col, row_abs, col_abs


def cell_to_rowcol2(cell):
    """Convert an Excel cell reference string in A1 notation
    to numeric row/col notation.
  
    Returns: row, col
    
    """
    m = _re_cell_ex.match(cell)
    if not m:
        raise Exception("Error in cell format")
    col_abs, col, row_abs, row = m.groups()
    # Convert base26 column string to number
    # All your Base are belong to us.
    row = int(row) - 1
    col = _col_by_name(col)
    return row, col
    
    
def rowcol_to_cell(row, col, row_abs=False, col_abs=False):
    """Convert numeric row/col notation to an Excel cell reference string in
    A1 notation.
 
    """
    d = col // 26
    m = col % 26
    chr1 = ""    # Most significant character in AA1
    if row_abs:
        row_abs = '$'
    else:
        row_abs = ''
    if col_abs:
        col_abs = '$'
    else:
        col_abs = ''
    if d > 0:
        chr1 = chr(ord('A') + d  - 1)
    chr2 = chr(ord('A') + m)
    # Zero index to 1-index
    return col_abs + chr1 + chr2 + row_abs + str(row + 1)


def cellrange_to_rowcol_pair(cellrange):
    """Convert cell range string in A1 notation to numeric row/col 
    pair.

    Returns: row1, col1, row2, col2
    
    """
    cellrange = cellrange.upper()
    # Convert a row range: '1:3'
    res = _re_row_range.match(cellrange)
    if res:
        row1 = int(res.group(1)) - 1
        col1 = 0
        row2 = int(res.group(2)) - 1
        col2 = -1
        return row1, col1, row2, col2
    # Convert a column range: 'A:A' or 'B:G'.
    # A range such as A:A is equivalent to A1:A16384, so add rows as required
    res = _re_col_range.match(cellrange)
    if res:
        col1 = _col_by_name(res.group(1))
        row1 = 0
        col2 = _col_by_name(res.group(2))
        row2 = -1
        return row1, col1, row2, col2
    # Convert a cell range: 'A1:B7'
    res = _re_cell_range.match(cellrange)
    if res:
        row1, col1 = cell_to_rowcol2(res.group(1))
        row2, col2 = cell_to_rowcol2(res.group(2))
        return row1, col1, row2, col2
    # Convert a cell reference: 'A1' or 'AD2000'
    res = _re_cell_ref.match(cellrange)
    if res:
        row1, col1 = cell_to_rowcol2(res.group(1))
        return row1, col1, row1, col1
    raise Exception("Unknown cell reference %s" % (cell))
