#!/usr/bin/env python
from __future__ import division, print_function

"""
This script generates a file to use for building authorea papers, and then runs
latex on them.

Requires python >= 2.6 (3.x should work, too)

The key assumptions are:
* ``layout.md`` exists in the article (I think it always does in Authorea)
* ``preamble.tex`` and/or``header.tex``, ``title.tex``, and
  ``bibliobgraphy/biblio.bib`` exist (I think these are created normally in a
    new Authorea article)
* ``posttitle.tex`` exists.  This one you'll have to create, containing
  everything you want after the title but before the beginning of the document.

"""

import os
import subprocess


#lots of dobule-{}'s are here because we use it as a formatting template below
MAIN_TEMPLATE = r"""
{preamblein}

{headerin}


\begin{{document}}

{titlecontent}

{sectioninputs}

\bibliography{{{bibloc}}}{{}}

\end{{document}}
"""

FIGURE_TEMPLATE=r"""
\begin{figure}[h!]
\begin{center}
\includegraphics[width=1\columnwidth]{<figfn>}
<caption>
\end{center}
\end{figure}
""".replace('{', '{{').replace('}', '}}').replace('<', '{').replace('>', '}')


def get_input_string(filename, localdir):
    if filename.endswith('.tex'):
        filename = filename[:-4]

    return r'\input{' + os.path.join(os.path.abspath(localdir), filename) + '}'


def get_figure_string(filename, localdir):
    figdir, figfn = os.path.split(filename)
    figdir = os.path.join(localdir, figdir)

    print('rep', figfn)

    figfnbase = os.path.splitext(figfn)[0]
    figfn = os.path.join(figdir, figfn)
    pdffn = os.path.join(figdir, figfnbase + '.pdf')
    epsfn = os.path.join(figdir, figfnbase + '.eps')

    if not os.path.exists(pdffn):
        pdffn = None
    if not os.path.exists(epsfn):
        epsfn = None

    if pdffn or epsfn:
        figfn = os.path.join(figdir, figfnbase)

    figfn = os.path.abspath(figfn)

    capfn = os.path.join(figdir, 'caption.tex')
    if os.path.exists(capfn):
        caption = r'\caption{ \protect\input{' + os.path.abspath(capfn) + '}}'
    else:
        caption = ''

    return FIGURE_TEMPLATE.format(**locals())


def build_authorea_latex(localdir, builddir, latex_exec, bibtex_exec, outname,
                         usetitle, dobibtex, npostbibcalls, openwith):
    if not os.path.exists(builddir):
        os.mkdir(builddir)

    if not os.path.isdir(builddir):
        raise IOError('Requested build directory {0} is a file, not a '
                      'directory'.format(builddir))

    # generate the main tex file as a string
    if os.path.exists('preamble.tex'):
        preamblein = get_input_string('preamble', localdir)
    else:
        preamblein = ''
    if os.path.exists('header.tex'):
        headerin = get_input_string('header', localdir)
    else:
        headerin = ''

    if not headerin and not preamblein:
        print("Neither preable nor header found!  Proceeding, but that's rather weird")

    bibloc = os.path.join(os.path.abspath(localdir), 'bibliography', 'biblio')

    titlecontent = []
    if usetitle:
        titlecontent.append(r'\title{' + get_input_string('title', localdir) + '}')
    if os.path.exists(os.path.join(os.path.abspath(localdir), 'posttitle.tex')):
        titlecontent.append(get_input_string('posttitle', localdir))
    titlecontent = '\n'.join(titlecontent)

    sectioninputs = []
    with open(os.path.join(localdir, 'layout.md')) as f:
        for l in f:
            ls = l.strip()
            if ls == '':
                pass
            elif ls.startswith('figures'):
                sectioninputs.append(get_figure_string(ls, localdir))
            else:
                sectioninputs.append(get_input_string(ls, localdir))
    sectioninputs = '\n'.join(sectioninputs)

    maintexstr = MAIN_TEMPLATE.format(**locals())

    #now save that string out as a file
    outname = outname if outname.endswith('.tex') else (outname + '.tex')
    outtexpath = os.path.join(builddir, outname)
    with open(outtexpath, 'w') as f:
        f.write(maintexstr)

    if outname.endswith('.tex'):
        outname = outname[:-4]

    #now actually run latex/bibtex
    args = [latex_exec, outname + '.tex']
    print('\n\RUNNING THIS COMMAND: "{0}"\n'.format(' '.join([latex_exec, outname + '.tex'])))
    subprocess.check_call(args, cwd=builddir)
    if dobibtex:
        args = [bibtex_exec, outname]
        print('\n\RUNNING THIS COMMAND: "{0}"\n'.format(' '.join([latex_exec, outname + '.tex'])))
        subprocess.check_call(args, cwd=builddir)
    for _ in range(npostbibcalls):
        args = [latex_exec, outname + '.tex']
        print('\n\RUNNING THIS COMMAND: "{0}"\n'.format(' '.join([latex_exec, outname + '.tex'])))
        subprocess.check_call(args, cwd=builddir)

    #launch the result if necessary
    resultfn = outtexpath[:-4] + ('.pdf' if 'pdf' in latex_exec else '.dvi')
    if openwith:
        args = openwith.split(' ')
        args.append(resultfn)
        print('\nLaunching as:' + str(args), '\n')
        subprocess.check_call(args)
    else:
        msg = '\nBuild completed.  You can see the result in "{0}": "{1}"'
        print(msg.format(builddir, resultfn), '\n')


if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser(description='Local builder for authorea papers.')

    parser.add_argument('localdir', nargs='?', default='.',
                        help='The directory to actually search for the authorea'
                             ' files in. Default to the current directory.')
    parser.add_argument('--build-dir', '-d', default='authorea_build',
                        help='the directory to build the paper in')
    parser.add_argument('--latex', '-l', default='pdflatex',
                        help='The executable to use for the latex build step.')
    parser.add_argument('--bibtex', '-b', default='bibtex',
                        help='The executable to use for the bibtex build step.')
    parser.add_argument('--filename', '-f', default='authorea_paper',
                        help='The name to use for the output tex file.')
    parser.add_argument('--no-bibtex', action='store_false', dest='usebibtex',
                        help='Provide this to not run bibtex.')
    parser.add_argument('--no-title', action='store_false', dest='usetitle',
                        help='Provide this to skip the title command.')
    parser.add_argument('--n-runs-after-bibtex', '-n', type=int, default=3,
                        help='The number of times to call latex after bibtex.')
    parser.add_argument('--open-with', '-o', default=None,
                        help='An executable to launch the output file with. '
                             'Default is to not do anything with it.')

    args = parser.parse_args()

    build_authorea_latex(args.localdir, args.build_dir, args.latex, args.bibtex,
                         args.filename, args.usetitle, args.usebibtex,
                         args.n_runs_after_bibtex, args.open_with)