# python 2.5 compat

from __future__ import with_statement

from cm.utils.cache import memoize

######

## This module requires pandoc v > 1.0 (pandoc & markdown executables) 

######

from subprocess import Popen, PIPE, call

import os

from tempfile import mkstemp

import StringIO

import tidy

PANDOC_BIN = "pandoc"

PANDOC_OPTIONS = "--sanitize-html "

MARKDOWN2PDF_BIN = "markdown2pdf"

# make sure binaries are available

from cm.utils.system import bin_search

bin_search(PANDOC_BIN)

bin_search(MARKDOWN2PDF_BIN)

# pandoc capabilities

INPUT_FORMATS = ['native', 'markdown', 'rst', 'html', 'latex']

OUTPUT_FORMATS = ['native', 'html', 's5', 'docbook', 'opendocument', 'odt', 'latex', 'context', 'texinfo', 'man', 'markdown', 'rst', 'mediawiki', 'rtf']

# add pdf output using markdown2pdf

OUTPUT_FORMATS.append('pdf')

# input formats

CHOICES_INPUT_FORMATS = [(f, f) for f in ['markdown', 'rst', 'html']]

DEFAULT_INPUT_FORMAT = 'markdown'

_PANDOC_ENCODING = 'utf8'

@memoize

def pandoc_convert(content, from_format, to_format, full=False):

    """

    Convert markdown content to pdf

    >>> res = pandoc_convert('<span>dssd', 'html', 'pdf')

    """

    # pandoc does not react well when html is not valid

    # use tidy to clean html  

    if from_format == 'html':

        content = do_tidy(content)

    # if to_format is pdf: use markdown2pdf

    if to_format == 'pdf':        

        if from_format != 'markdown':

            content = pandoc_convert(content, from_format, 'markdown', True)

        return pandoc_markdown2pdf(content)

    return pandoc_pandoc(content, from_format, to_format, full)

def content_or_file_name(content, file_name):

    if not content and not file_name:

        raise Exception('You should provide either a content or a file_name')

    if content and file_name:

        raise Exception('You should not provide a content AND a file_name')

    if file_name:

        fp = file(file_name)

        content = fp.read()

        fp.close()

    return content

@memoize

def do_tidy(content=None, file_name=None):

    """

    Tidy (html) content

    >>> res = do_tidy('<span>sdd')

    """

    content = content_or_file_name(content, file_name)

    tidy_options = dict(output_xhtml=1, 

                        add_xml_decl=0, 

                        indent=0, 

                        tidy_mark=0,

                        input_encoding='utf8',

                        output_encoding='utf8',

                        )

    tidyied_content = tidy.parseString(content.encode('utf8'), **tidy_options)

    tidyied_content = str(tidyied_content)

    if content and not tidyied_content.strip():

        raise Exception('Content could not be tidyfied') 

    return str(tidyied_content).decode('utf8')

def get_filetemp(mode="r"):

    (fd, fname) = mkstemp()

    return (os.fdopen(fd, mode), fname)

# build absolute address for latex header file

_tmp_ = __file__.split(os.path.sep)[:-1]

_tmp_.append('latex_header.txt')

_tmp_.insert(0, os.path.sep)

LATEX_HEADER_PATH = os.path.join(*_tmp_)

if not os.path.isfile(LATEX_HEADER_PATH):

    raise Exception('LATEX_HEADER_PATH is not a file!')

@memoize

def pandoc_markdown2pdf(content=None, file_name=None):

    """

    Convert markdown content to pdf

    >>> pdf_content = pandoc_markdown2pdf('# dssd')

    """

    content = content_or_file_name(content, file_name)

    # write file to disk

    temp_file, input_temp_name = get_filetemp('w')

    fp_error, error_temp_name = get_filetemp('w')

    temp_file.write(content.encode(_PANDOC_ENCODING))

    temp_file.close()

    # custom latex header

    cust_head_tex = " --custom-header=%s " %LATEX_HEADER_PATH

    # use markdown2pdf

    retcode = call(MARKDOWN2PDF_BIN + cust_head_tex + ' ' + input_temp_name, shell=True, stderr=fp_error)

    fp_error.close()

    fp_error = file(error_temp_name)

    error = fp_error.read()

    fp_error.close()

    os.remove(input_temp_name)

    os.remove(error_temp_name)

    if retcode:

        raise Exception(error)

    output_temp_name = input_temp_name + '.pdf'

    fp_output = file(output_temp_name)

    pdf_content = fp_output.read()

    fp_output.close()

    os.remove(output_temp_name)

    return pdf_content

# TODO: manage images in pandoc (?)

# TODO: use tidy to cleanup html

@memoize

def pandoc_pandoc(content, from_format, to_format, full=False):

    """

    Convert content (should be unicode) from from_format to to_format

    (if full: includes header & co [html, latex])

    Returns out (unicode), err

    >>> res, err = pandoc_pandoc(u'# sdsd', 'markdown', 'html', False)

    >>> print err

    None

    >>> res.replace("\\n","")

    u'<h1 id="sdsd">sdsd</h1>'

    >>> res, err = pandoc_pandoc(u'# sdsd', 'markdown', 'html', True)

    >>> print err

    None

    """

    # verify formats

    if from_format not in INPUT_FORMATS:

        raise Exception("Input format [%s] is not a supported format [%s]" % (from_format, ' '.join(INPUT_FORMATS)))

    if to_format not in OUTPUT_FORMATS:

        raise Exception("Output format [%s] is not a supported format [%s]" % (to_format, ' '.join(OUTPUT_FORMATS)))

    if type(content) != unicode:

        raise Exception('Content is not in unicode format!')

    # temp file

    input_file, input_temp_name = get_filetemp('w')

    output_temp_fp, output_temp_name = get_filetemp()

    output_temp_fp.close()

    error_temp_fp, error_temp_name = get_filetemp('w')

    error_temp_fp.close()

    input_file.write(content.encode(_PANDOC_ENCODING))

    input_file.close()

    # pandoc arguments and command line

    cmd_args = ' %s -o %s ' %(PANDOC_OPTIONS,output_temp_name) 

    if full:

        cmd_args += ' -s '

    cmd_args += ' -f %s ' % from_format

    cmd_args += ' -t %s ' % to_format

    cmd_args += ' %s ' % input_temp_name

    cmd = PANDOC_BIN + ' ' + cmd_args

    #from socommons.converters.new_conv import controlled_Popen 

    #controlled_Popen(cmd, stderr=file(error_temp_name,'w'))

    fp_error = file(error_temp_name,'w')

    retcode = call(cmd, shell=True, stderr=fp_error)

    fp_error.close()

    fp_error = file(error_temp_name)

    error = fp_error.read()

    fp_error.close()

    fp_output = file(output_temp_name)

    stdoutdata = fp_output.read()

    fp_output.close()

    # cleanup

    os.remove(output_temp_name)

    os.remove(input_temp_name)

    os.remove(error_temp_name)

    if retcode:

        raise Exception(error)

    # try converting to unicode

    try:

        stdoutdata = stdoutdata.decode(_PANDOC_ENCODING)

    except UnicodeDecodeError:

        # this will fail for binary output formats such as odt

        # return result without conversion then

        pass

    return stdoutdata

if __name__ == "__main__":

    import doctest

    doctest.testmod()