## 
##     Copyright (C) 1998  David Miller
##
##     Based in part on prescript 0.1 (c) 1996 Todd Reed
##  
##     This program is free software; you can redistribute it and/or modify
##     it under the terms of the GNU General Public License as published by
##     the Free Software Foundation; either version 2 of the License, or
##     (at your option) any later version.
##  
##     This program 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 General Public License for more details.
##  
##     You should have received a copy of the GNU General Public License
##     along with this program; if not, write to the Free Software
##     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
## 

import misc
from process import Line

def predict(l):
    # extract each datum into a convenient variable

    # The following three lines are a bit of a hack to make the algorithm work
    # better.  We will say that a line = mode length, when either of the
    # following  are true:
    #	   - length(x) == modeLineLength 
    #	   - x1 == rtmargin
    #
    # specifically, this hack means bullet-indents, etc will be considered
    # line feeds dispite their length not being equal to the mode length.
    LN_PL_eq_MOLEN		  = l.LN_PL_eq_MOLEN or l.RTedge_PL_eq_RTmargin
    LN_CL_eq_MOLEN		  = l.LN_CL_eq_MOLEN or l.RTedge_CL_eq_RTmargin
    lastpagelastline_eq_MOLEN = l.lastpagelastline_eq_MOLEN or l.RTedge_lastpagelastline_eq_RTmargin
    
    LS_CL_leq_AVLS		  = l.LS_CL_exactly_AVLS or l.LS_CL_lt_AVLS
    LS_CL_geq_AVLS		  = l.LS_CL_exactly_AVLS or l.LS_CL_gt_AVLS
    
    # start of algorithm, proper

    if l.LS_CL_missing:
	if lastpagelastline_eq_MOLEN: return '0','pagebreaklinefeed'	#0
	else: return '0','pagebreakparagraph'				#0
	
    if l.LS_CL_eq_MOLS and LN_PL_eq_MOLEN:
	if l.isIndented and l.LS_NL_eq_MOLS: return 'A','paragraph'	#A
	else: return 'B','linefeed'					#B

    if LN_PL_eq_MOLEN and not l.LS_CL_eq_MOLS:
	if l.isColumnbreak or l.LS_CL_missing:
	    if l.isIndented or not LN_CL_eq_MOLEN: return 'C','paragraph'#C
	    else: return 'D','linefeed'					#D

	if l.NL_AVLS_eq_1: return 'E','paragraph'			#E
	if LS_CL_leq_AVLS: return 'F','linefeed'			#F
	if l.LS_CL_gt_AVLS: return 'G','paragraph'			#G
	return 'Q','BUG!!!'						#Q

    if not LN_PL_eq_MOLEN and l.LS_CL_eq_MOLS:
	if l.isIndented and l.LS_NL_eq_MOLS: return 'H','paragraph'	#H
	else: return 'I','explicitlinefeed'				#I

    misc.myassert( "not LN_PL_eq_MOLEN and not l.LS_CL_eq_MOLS", globals(), locals() )

    if l.isColumnbreak or l.LS_CL_missing: return 'J','paragraph'	#J
    if l.NL_AVLS_eq_1: return 'K','explicitlinefeed'			#K
    if l.LS_CL_lt_AVLS: return 'L','explicitlinefeed'			#L
    if l.LS_CL_exactly_AVLS:
	if l.LS_CL_eq_LS_NL: return 'M','explicitlinefeed'		#M
	else: return 'M','paragraph'					#N
    if l.LS_CL_gt_AVLS: return 'O','paragraph'				#O
    return 'P','BUG!!'							#P
	    
def predictDocument(document):
    lpll = None
    for page in document:
	i = 0
	while i < len(page):
	    line = page[i]
	    (line.algoCase,line.prediction) = predict(line)
	    if not page.dehyphenateLine(i, lpll):
		# if a line was deleted, we are already at the next line
		# so we don't need to next i.
		i=i+1
	lpll = page[-1]