#!/usr/bin/env python
#
# Copyright 2011 Ville Rantanen
#
# This program 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 3 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

'''SC based CSV editor.'''

__author__ = "Ville Rantanen"

__version__ = "0.1"

import sys,os
import csv
from argparse import ArgumentParser 
import unicodedata, re
import subprocess
import shutil

def which(program):
    import os
    def is_exe(fpath):
        return os.path.isfile(fpath) and os.access(fpath, os.X_OK)

    fpath, fname = os.path.split(program)
    if fpath:
        if is_exe(program):
            return program
    else:
        for path in os.environ["PATH"].split(os.pathsep):
            exe_file = os.path.join(path, program)
            if is_exe(exe_file):
                return exe_file

    return None

class SCReader:
    """ Class for reading SC files.
    
    """ 
    def __init__(self,fileobject):
        self.file=fileobject
        self.parserre=re.compile('.* ([A-Z]+)([0-9]+) = (.*)')
    
    def _parse_row(self,string):
        col=None
        row=None
        content=None
        m=self.parserre.match(string.strip())
        if m:
            col=self.alpha_to_column(m.group(1))
            row=self.try_int(m.group(2))
            content=m.group(3)
        return col,row,content
    
    def try_int(self,string):
    
        try:
            return int(string)
        except:
            return string
    
    def alpha_to_column(self,alpha):
        ''' Returns a column number from spreadsheet column alphabet '''
        n=0
        o=0
        for char in alpha[::-1]:
            o+=(ord(char.upper())-64)*(26**n)
            n+=1
        return int(o-1)
        
    
    def next(self):
        ''' Returns the next row in the table, three items: column, row, content'''
        return self._parse_row(self.reader.next())

    def __iter__(self):
        for row in self.file:
            yield self._parse_row(row)

class SCWriter:
    """ Class for writing SC files.
    
    """ 
    def __init__(self,fileobject):
        self.file=fileobject
        self.row=0
        self.col=0
        self.col_lengths=[]
    
    def parse_row(self,string):
        
        self.col=0
        for el in row:
            self.write_element(self.row,self.col,el)
            if len(self.col_lengths) <= self.col:
                self.col_lengths.append(max(len(el),8))
            else:
                self.col_lengths[self.col]=max(len(el),self.col_lengths[self.col])
            self.col+=1
        self.row+=1
    
    def write_element(self,row,col,content):
        
        colalpha=self.column_to_alpha(col)
        content=content.strip('"')
        
        if self.is_num(content):
            self.file.write('let '+colalpha+str(row)+' = ' + str(self.to_num(content))+'\n')
        else:
            self.file.write('rightstring '+colalpha+str(row)+' = "' + content + '"\n')
                
    
    def column_to_alpha(self,column):
        ''' Returns a column alphabet from column number '''
        o=chr(column+64+1)
        if column>25:
            return self.column_to_alpha((column / 26) -1) + self.column_to_alpha(column % 26);
        return o
    
    def write_row(self,row):
        ''' Writes a row as a SC file part '''
        self.parse_row(row)
    
    def write_formats(self):
        
        for col in range(len(self.col_lengths)):
            self.file.write('format '+self.column_to_alpha(col)+' '+str(self.col_lengths[col])+' 2 0\n')
    
    def is_num(self,string):
        ''' returns the True if string can be converted to number safely '''
        try:
            num=int(string)
            return True
        except:
            pass

        try:
            num=float(string)
            return True
        except:
            pass
        
        return False

    def to_num(self,string):
        ''' returns the number in the correct data type if string can be converted to number safely '''
        try:
            num=int(string)
            return num
        except:
            pass

        try:
            num=float(string)
            return num
        except:
            pass
        
        return string

def setup_options():
    ''' Setup the command line options '''
    
    parser=ArgumentParser()
    parser.add_argument("-v",action='version', version=__version__)
    parser.add_argument("--version",action='version', version=__version__)
    parser.add_argument("-b",action="store_false",dest="backup",default=True,
                      help="Do not create a backup file.")
    parser.add_argument("-i",type=str,dest="delimiter",default="\t",
                      help="Input delimiter for the CSV, default: [tab]")
    parser.add_argument("-D",action="store_true",dest="debug",default=False,
                      help="Debug mode, i.e. do not delete the SC file.")
    parser.add_argument("csv",type=str,action="store",
                      help="CSV file to edit")
    options=parser.parse_args()
    return options                
 
def csv_write(screader,fileout):
    ''' writes a CSV from SCReader iterator '''
    content=[]
    rows=0
    cols=0
    for row in screader:
        if row[0]!=None:
            content.append(row)
            rows=max(row[1],rows)
            cols=max(row[0],cols)
    table=[]
    for r in range(rows+1):
        table.append([])
        for c in range(cols+1):
            table[r].append('')
    for e in content:
        table[e[1]][e[0]]=e[2]
    for row in table:
        fileout.write('\t'.join(row)+'\n')

 
if not which('sc'):
    print('You don\'t seem to have "sc" installed!')
    print('sudo apt-get install sc')
    sys.exit(1)

opts=setup_options()

f_bkp=opts.csv+'.bkp'
f_sc=opts.csv+'.sc'
f_sc_tmp=opts.csv+'.sc.tmp'

# copy a backup file
if opts.backup:
    shutil.copyfile(opts.csv, f_bkp)

# Convert CSV -> SC
f_sc_w=open(f_sc,'wt')
f_csv_r=open(opts.csv,'rt')
csv_reader = csv.reader(f_csv_r,
                        delimiter=opts.delimiter,
                        doublequote=False,
                        escapechar='\\',
                        quoting=csv.QUOTE_NONE)
sc_writer=SCWriter(f_sc_w)
for row in csv_reader:
    if len(row)>0:
        sc_writer.write_row(row)
sc_writer.write_formats()
f_sc_w.close()
f_csv_r.close()

# Launch sc
subprocess.call(['sc',f_sc])
# Calculate values

process = subprocess.Popen(['sc','-v','-P','%',f_sc], shell=False, stdout=subprocess.PIPE)
f_cs_tmp_w=open(f_sc_tmp,'wt')
for l in process.stdout.readlines():
    f_cs_tmp_w.write(l)
f_cs_tmp_w.close()

# Convert SC -> CSV
f_sc_r=open(f_sc_tmp,'rt')
f_csv_w=open(opts.csv,'wt')
sc_reader=SCReader(f_sc_r)
csv_write(sc_reader,f_csv_w)
f_sc_r.close()
f_csv_w.close()

# Delete SC if not in debug mode
if not opts.debug:
    os.remove(f_sc)
    os.remove(f_sc_tmp)
    if os.path.isfile(f_sc+'~'):
        os.remove(f_sc+'~')