#!/usr/bin/python

# SYSTEM-DEPENDENT VARIABLES, MAY NEED TO BE EDITED.

latex = '/usr/bin/latex'
dvips = '/usr/bin/dvips'
convert = '/usr/bin/convert'

tdir = "/var/tmp/"    


import sys
import os

class presentex_help:
    '''presentex is a command-line equivalent to the web-based PHP package,
PresenTeX. It allows users to easily produce high-quality, colourful
equations with LaTeX for use in presentations, etc. It is written in
Python and uses LaTeX, dvips, and imagemagick. It should run on
Linux/UNIX/Mac systems (not sure about Windows), provided the
appropriate software packages are installed.

USAGE:

from the command line
$ presentex 'latex equation in quotes' [options]

Options are:

-f -fg --foreground: Foreground (text) colour, reported as 'r,g,b'
                     (quotes are required) where r,g,b can span the
                     integeer values [0,255]. The default is 
                     '0, 0, 0'.

-b -bg --background: Background color, reported as 'r,g,b' (quotes are
                     required) where r,g,b can span the integer values
                     [0,255]. The default is '255, 255, 255'.

-e --enlargement:    Enlargement factor. The default is "1".

-o --output: Name of output file. Extension (.jpg, .gif, .png, etc.)
                     will be interpreted by Imagemagick. Note that
                     transparency does not work for all image types,
                     but it does work for pngs and gifs. The default
                     is "./eqn.png"

-t --transparent: Option for a transparent background.

-h --help: Produces this help window

-v -a --version --about: Gets information on present version

-i --install: Gives help about setting up presentex on your computer.

EXAMPLES:

presentex '\gamma = \displaystyle{\\frac{\mathcal{A}}{g\delta\sin^2\phi}}' \
     -fg '190,75,75' -bg '200,200,200' -o 'gamma.jpg' 

presentex -t -o 'pi.gif' -e 3 '\pi = 3.14159\dots' -fg 200,20,20 -t

presentex '\\text{CH}_4+\\text{CO}_2 +\\text{SO}_4^=\\to 2\\text{HCO}_3^-+\\text{H}_2\\text{S}'


'''

class presentex_install:
    '''If you have the appropriate software installed on your computer
and presentex doesn't start up for you right away, then you should be
reading this.

At the beginning of the presentex file are a few lines that may
require editing.

1) The paths. 

You should be able to locate the following lines:

latex = '/usr/bin/latex'
dvips = '/usr/bin/dvips'
convert = '/usr/bin/convert'

If these don't match the paths on your computer, then presentex won't
work. You can check by entering 
$ which latex
at the command line (or "which dvips" or "which convert"). Replace the 
paths in this file if necessary. 

If you get a response like "no latex in (/usr/local/bin/:/usr/bin:...)
then that means that latex (or dvips, or convert) is not installed on
your system. You will have to perform that installation before proceeding.

2) The temporary directory. 

You should be able to locate the following lines:

tdir = "/var/tmp/"    

PresenTeX creates temporary files before producing the final
one. These are placed in a temporary directory within the directory
/var/tmp/. If /var/tmp/ does not exist on your system, or if you do
not have access to /var/tmp/ then you will need to change the variable
tdir to someting you can access.

'''

def version():
    print "PresenTex v.0.8, August 5, 2008."
    print "Written by Ramzi Mirshak, ramzi@dal.ca"
    sys.exit()
    

def timehash():
    import md5, time
    thash = md5.new()
    tstr = time.time()
    thash.update(str(tstr))
    tmp = repr(thash.hexdigest())
    tmp = tmp.split("\'")
    return(tmp[1])

def readargv():
    import re
    global bg
    global fg
    global size
    global trans
    global eqn
    global fname
    global ftype
    global density
    global outdir

    bg = '255,255,255'
    fg = '0,0,0'
    size = 2
    trans = 0
    eqn = '\int_{-\infty}^\infty f(x) dx = 1'
    ftype = 'png'
    fname = 'eqn'
    density = "120"
    outdir = './'

    marker = 1
    if(len(sys.argv)==2):
        if(sys.argv[1] == '-h' or sys.argv[1] == '--help'):
            help(presentex_help)
            sys.exit()
        if(sys.argv[1] == '-i' or sys.argv[1] == '--install'):
            help(presentex_install)
            sys.exit()
        if(sys.argv[1] == '-v' or sys.argv[1] == '--version' or sys.argv[1] == '-a' or sys.argv[1] == '--about'):
            version()


    while(marker < len(sys.argv)):
        entry = sys.argv[marker]
        if entry == '-t' or entry == '--transparent':
            trans = 1
            marker = marker + 1
        elif entry == '-b' or entry == '-bg' or entry == '--background':
            bg = sys.argv[marker+1]
            marker = marker + 2
        elif entry == '-f' or entry == '-fg' or entry == '--foreground':
            fg = sys.argv[marker+1]
            marker = marker + 2
        elif entry == '-e' or entry == '--enlargement':
            size = float(sys.argv[marker+1])
            marker = marker + 2
        elif entry == '-o' or entry == '--output':
            fname = sys.argv[marker+1]
            marker = marker + 2
        elif re.match("^\-", entry):
            print "Input error: " + " ".join(sys.argv)
            str = ""
            for i in range(0,marker):
                str = str + sys.argv[i] + " "
            str = re.sub("."," ", str)
            str = str + "^^"
            print "             " + str + " Unknown paramter"
            sys.exit()
        else: 
            eqn = entry
            marker = marker + 1

    parts = fname.split('/')
    if(len(parts) > 1):
        outdir = '/'.join(parts[0:-1]) + '/'
        fname = parts[-1]
    parts = fname.split('.')
    if(len(parts) > 1):
        ftype = parts[1]
        fname = parts[0]
    
    if(marker == 1):
        print "There were no input arguments. You may want to enter presentex --help"
        sys.exit()

def main():


    readargv()

    bgcols = bg.split(',')
    fgcols = fg.split(',')
    for i in range(0,len(bgcols)):
        bgcols[i] = str(round(float(bgcols[i])/255*10000)/10000)
        fgcols[i] = str(round(float(fgcols[i])/255*10000)/10000)
    bg2 = ",".join(bgcols)
    fg2 = ",".join(fgcols)
    

    wd = os.getcwd()

    tempdir = tdir + timehash() + "/"
    os.mkdir(tempdir)
    os.chdir(tempdir)


    latexfile = '\documentclass{article}' + "\n" + '\usepackage{color,amsmath,amssymb}' + "\n" + '\pagecolor[rgb]{' + bg2 + '}' + "\n" + "\\" + 'begin{document}' + "\n" + '\color[rgb]{' + fg2 + '}' + "\n" + "\\" + 'thispagestyle{empty}' + "\n" + '\Huge' + "\n" + '\[ ' + eqn + '\]' + "\n" + '\end{document}'


    fout = open(tempdir + fname + ".tex",'w')
    fout.write(latexfile)
    fout.close()

    os.popen(latex + " --interaction=nonstopmode " + tempdir + fname).read()
    os.popen(dvips + " -q -x " + str(size*1000) + " -E " + fname + ".dvi -o " + fname + ".ps")
    if(trans):
        bgcols = bg.split(',')
        rgbbg = '#'
        for i in range (0,len(bgcols)):
            bgcols[i] = int(float(bgcols[i]))
            rgbbg = rgbbg + ('%02x' % bgcols[i])
            # that's it! '%02x' means zero-padded, 2-digit hex values
        os.popen(convert + " -transparent \"" + rgbbg + "\" -crop 0x0 -density " + density + " "+ fname + ".ps " + fname + "." + ftype)
    else:
        os.popen(convert + " -crop 0x0 -density " + density + " "+ fname + ".ps " + fname + "." + ftype)

    os.chdir(wd)
    os.system("cp " + tempdir + fname + "." + ftype + " " + outdir + fname + "." + ftype)
    
    if(outdir == "./"):
        print "Image written to \"" + fname + "." + ftype + "\""
    else:
        print "Image written to \"" + outdir + fname + "." + ftype + "\""

    os.system("rm -r " + tempdir)

if __name__ == "__main__":
    main()