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# Source code for astropy.io.ascii.latex

    # Licensed under a 3-clause BSD style license - see LICENSE.rst
    """An extensible ASCII table reader and writer.

    latex.py:
      Classes to read and write LaTeX tables

    :Copyright: Smithsonian Astrophysical Observatory (2011)
    :Author: Tom Aldcroft (aldcroft@head.cfa.harvard.edu)
    """

    from __future__ import absolute_import, division, print_function

    import re

    from ...extern import six
    from . import core

    latexdicts = {'AA':  {'tabletype': 'table',
                          'header_start': r'\hline \hline', 'header_end': r'\hline',
                          'data_end': r'\hline'},
                  'doublelines': {'tabletype': 'table',
                                  'header_start': r'\hline \hline', 'header_end': r'\hline\hline',
                                  'data_end': r'\hline\hline'},
                  'template': {'tabletype': 'tabletype', 'caption': 'caption',
                               'tablealign': 'tablealign',
                               'col_align': 'col_align', 'preamble': 'preamble',
                               'header_start': 'header_start',
                               'header_end': 'header_end', 'data_start': 'data_start',
                               'data_end': 'data_end', 'tablefoot': 'tablefoot',
                               'units': {'col1': 'unit of col1', 'col2': 'unit of col2'}}
                  }

    def add_dictval_to_list(adict, key, alist):
        '''
        Add a value from a dictionary to a list

        Parameters
        ----------
        adict : dictionary
        key : hashable
        alist: list
            List where value should be added
        '''
        if key in adict:
            if isinstance(adict[key], six.string_types):
                alist.append(adict[key])
            else:
                alist.extend(adict[key])

    def find_latex_line(lines, latex):
        '''
        Find the first line which matches a patters

        Parameters
        ----------
        lines : list
            List of strings
        latex : str
            Search pattern

        Returns
        -------
        line_num : int, None
            Line number. Returns None, if no match was found

        '''
        re_string = re.compile(latex.replace('\\', '\\\\'))
        for i, line in enumerate(lines):
            if re_string.match(line):
                return i
        else:
            return None

    class LatexSplitter(core.BaseSplitter):
        '''Split LaTeX table date. Default delimiter is `&`.
        '''
        delimiter = '&'

        def process_line(self, line):
            """Remove whitespace at the beginning or end of line. Also remove
            \\ at end of line"""
            line = line.split('%')[0]
            line = line.strip()
            if line[-2:] == r'\\':
                line = line.strip(r'\\')
            else:
                raise core.InconsistentTableError(r'Lines in LaTeX table have to end with \\')
            return line

        def process_val(self, val):
            """Remove whitespace and {} at the beginning or end of value."""
            val = val.strip()
            if val and (val[0] == '{') and (val[-1] == '}'):
                val = val[1:-1]
            return val

        def join(self, vals):
            '''Join values together and add a few extra spaces for readability'''
            delimiter = ' ' + self.delimiter + ' '
            return delimiter.join(x.strip() for x in vals) + r' \\'

    class LatexHeader(core.BaseHeader):
        '''Class to read the header of Latex Tables'''
        header_start = r'\begin{tabular}'
        splitter_class = LatexSplitter

        def start_line(self, lines):
            line = find_latex_line(lines, self.header_start)
            if line:
                return line + 1
            else:
                return None

        def _get_units(self):
            units = {}
            col_units = [col.info.unit for col in self.cols]
            for name, unit in zip(self.colnames, col_units):
                if unit:
                    try:
                        units[name] = unit.to_string(format='latex_inline')
                    except AttributeError:
                        units[name] = unit
            return units

        def write(self, lines):
            if not 'col_align' in self.latex:
                self.latex['col_align'] = len(self.cols) * 'c'
            if 'tablealign' in self.latex:
                align = '[' + self.latex['tablealign'] + ']'
            else:
                align = ''
            lines.append(r'\begin{' + self.latex['tabletype'] + r'}' + align)
            add_dictval_to_list(self.latex, 'preamble', lines)
            if 'caption' in self.latex:
                lines.append(r'\caption{' + self.latex['caption'] + '}')
            lines.append(self.header_start + r'{' + self.latex['col_align'] + r'}')
            add_dictval_to_list(self.latex, 'header_start', lines)
            lines.append(self.splitter.join(self.colnames))
            units = self._get_units()
            if 'units' in self.latex:
                units.update(self.latex['units'])
            if units:
                lines.append(self.splitter.join([units.get(name, ' ') for name in self.colnames]))
            add_dictval_to_list(self.latex, 'header_end', lines)

    class LatexData(core.BaseData):
        '''Class to read the data in LaTeX tables'''
        data_start = None
        data_end = r'\end{tabular}'
        splitter_class = LatexSplitter

        def start_line(self, lines):
            if self.data_start:
                return find_latex_line(lines, self.data_start)
            else:
                return self.header.start_line(lines) + 1

        def end_line(self, lines):
            if self.data_end:
                return find_latex_line(lines, self.data_end)
            else:
                return None

        def write(self, lines):
            add_dictval_to_list(self.latex, 'data_start', lines)
            core.BaseData.write(self, lines)
            add_dictval_to_list(self.latex, 'data_end', lines)
            lines.append(self.data_end)
            add_dictval_to_list(self.latex, 'tablefoot', lines)
            lines.append(r'\end{' + self.latex['tabletype'] + '}')

    class Latex(core.BaseReader):
        r'''Write and read LaTeX tables.

        This class implements some LaTeX specific commands.  Its main
        purpose is to write out a table in a form that LaTeX can compile. It
        is beyond the scope of this class to implement every possible LaTeX
        command, instead the focus is to generate a syntactically valid
        LaTeX tables.

        This class can also read simple LaTeX tables (one line per table
        row, no ``\multicolumn`` or similar constructs), specifically, it
        can read the tables that it writes.

        Reading a LaTeX table, the following keywords are accepted:

        **ignore_latex_commands** :
            Lines starting with these LaTeX commands will be treated as comments (i.e. ignored).

        When writing a LaTeX table, the some keywords can customize the
        format.  Care has to be taken here, because python interprets ``\\``
        in a string as an escape character.  In order to pass this to the
        output either format your strings as raw strings with the ``r``
        specifier or use a double ``\\\\``.

        Examples::

            caption = r'My table \label{mytable}'
            caption = 'My table \\\\label{mytable}'

        **latexdict** : Dictionary of extra parameters for the LaTeX output

            * tabletype : used for first and last line of table.
                The default is ``\\begin{table}``.  The following would generate a table,
                which spans the whole page in a two-column document::

                    ascii.write(data, sys.stdout, Writer = ascii.Latex,
                                latexdict = {'tabletype': 'table*'})

            * tablealign : positioning of table in text.
                The default is not to specify a position preference in the text.
                If, e.g. the alignment is ``ht``, then the LaTeX will be ``\\begin{table}[ht]``.

            * col_align : Alignment of columns
                If not present all columns will be centered.

            * caption : Table caption (string or list of strings)
                This will appear above the table as it is the standard in
                many scientific publications.  If you prefer a caption below
                the table, just write the full LaTeX command as
                ``latexdict['tablefoot'] = r'\caption{My table}'``

            * preamble, header_start, header_end, data_start, data_end, tablefoot: Pure LaTeX
                Each one can be a string or a list of strings. These strings
                will be inserted into the table without any further
                processing. See the examples below.

            * units : dictionary of strings
                Keys in this dictionary should be names of columns. If
                present, a line in the LaTeX table directly below the column
                names is added, which contains the values of the
                dictionary. Example::

                  from astropy.io import ascii
                  data = {'name': ['bike', 'car'], 'mass': [75,1200], 'speed': [10, 130]}
                  ascii.write(data, Writer=ascii.Latex,
                                   latexdict = {'units': {'mass': 'kg', 'speed': 'km/h'}})

                If the column has no entry in the ``units`` dictionary, it defaults
                to the **unit** attribute of the column. If this attribute is not
                specified (i.e. it is None), the unit will be written as ``' '``.

            Run the following code to see where each element of the
            dictionary is inserted in the LaTeX table::

                from astropy.io import ascii
                data = {'cola': [1,2], 'colb': [3,4]}
                ascii.write(data, Writer=ascii.Latex, latexdict=ascii.latex.latexdicts['template'])

            Some table styles are predefined in the dictionary
            ``ascii.latex.latexdicts``. The following generates in table in
            style preferred by A&A and some other journals::

                ascii.write(data, Writer=ascii.Latex, latexdict=ascii.latex.latexdicts['AA'])

            As an example, this generates a table, which spans all columns
            and is centered on the page::

                ascii.write(data, Writer=ascii.Latex, col_align='|lr|',
                            latexdict={'preamble': r'\begin{center}',
                                       'tablefoot': r'\end{center}',
                                       'tabletype': 'table*'})

        **caption** : Set table caption
            Shorthand for::

                latexdict['caption'] = caption

        **col_align** : Set the column alignment.
            If not present this will be auto-generated for centered
            columns. Shorthand for::

                latexdict['col_align'] = col_align

        '''
        _format_name = 'latex'
        _io_registry_format_aliases = ['latex']
        _io_registry_suffix = '.tex'
        _description = 'LaTeX table'

        header_class = LatexHeader
        data_class = LatexData

        def __init__(self, ignore_latex_commands=['hline', 'vspace', 'tableline'],
                     latexdict={}, caption='', col_align=None):

            super(Latex, self).__init__()

            self.latex = {}
            # The latex dict drives the format of the table and needs to be shared
            # with data and header
            self.header.latex = self.latex
            self.data.latex = self.latex
            self.latex['tabletype'] = 'table'
            self.latex.update(latexdict)
            if caption:
                self.latex['caption'] = caption
            if col_align:
                self.latex['col_align'] = col_align

            self.ignore_latex_commands = ignore_latex_commands
            self.header.comment = '%|' + '|'.join(
                [r'\\' + command for command in self.ignore_latex_commands])
            self.data.comment = self.header.comment

        def write(self, table=None):
            self.header.start_line = None
            self.data.start_line = None
            return core.BaseReader.write(self, table=table)

    class AASTexHeaderSplitter(LatexSplitter):
        '''Extract column names from a `deluxetable`_.

        This splitter expects the following LaTeX code **in a single line**:

            \tablehead{\colhead{col1} & ... & \colhead{coln}}
        '''
        def process_line(self, line):
            """extract column names from tablehead
            """
            line = line.split('%')[0]
            line = line.replace(r'\tablehead', '')
            line = line.strip()
            if (line[0] == '{') and (line[-1] == '}'):
                line = line[1:-1]
            else:
                raise core.InconsistentTableError(r'\tablehead is missing {}')
            return line.replace(r'\colhead', '')

        def join(self, vals):
            return ' & '.join([r'\colhead{' + str(x) + '}' for x in vals])

    class AASTexHeader(LatexHeader):
        '''In a `deluxetable
        <http://fits.gsfc.nasa.gov/standard30/deluxetable.sty>`_ some header
        keywords differ from standard LaTeX.

        This header is modified to take that into account.
        '''
        header_start = r'\tablehead'
        splitter_class = AASTexHeaderSplitter

        def start_line(self, lines):
            return find_latex_line(lines, r'\tablehead')

        def write(self, lines):
            if not 'col_align' in self.latex:
                self.latex['col_align'] = len(self.cols) * 'c'
            if 'tablealign' in self.latex:
                align = '[' + self.latex['tablealign'] + ']'
            else:
                align = ''
            lines.append(r'\begin{' + self.latex['tabletype'] + r'}{' + self.latex['col_align'] + r'}'
                           + align)
            add_dictval_to_list(self.latex, 'preamble', lines)
            if 'caption' in self.latex:
                lines.append(r'\tablecaption{' + self.latex['caption'] + '}')
            tablehead = ' & '.join([r'\colhead{' + name + '}' for name in self.colnames])
            units = self._get_units()
            if 'units' in self.latex:
                units.update(self.latex['units'])
            if units:
                tablehead += r'\\ ' + self.splitter.join([units.get(name, ' ')
                                                          for name in self.colnames])
            lines.append(r'\tablehead{' + tablehead + '}')

    class AASTexData(LatexData):
        '''In a `deluxetable`_ the data is enclosed in `\startdata` and `\enddata`
        '''
        data_start = r'\startdata'
        data_end = r'\enddata'

        def start_line(self, lines):
            return find_latex_line(lines, self.data_start) + 1

        def write(self, lines):
            lines.append(self.data_start)
            core.BaseData.write(self, lines)
            lines.append(self.data_end)
            add_dictval_to_list(self.latex, 'tablefoot', lines)
            lines.append(r'\end{' + self.latex['tabletype'] + r'}')

    class AASTex(Latex):
        '''Write and read AASTeX tables.

        This class implements some AASTeX specific commands.
        AASTeX is used for the AAS (American Astronomical Society)
        publications like ApJ, ApJL and AJ.

        It derives from the ``Latex`` reader and accepts the same
        keywords.  However, the keywords ``header_start``, ``header_end``,
        ``data_start`` and ``data_end`` in ``latexdict`` have no effect.
        '''

        _format_name = 'aastex'
        _io_registry_format_aliases = ['aastex']
        _io_registry_suffix = ''  # AASTex inherits from Latex, so override this class attr
        _description = 'AASTeX deluxetable used for AAS journals'

        header_class = AASTexHeader
        data_class = AASTexData

        def __init__(self, **kwargs):
            super(AASTex, self).__init__(**kwargs)
            # check if tabletype was explicitly set by the user
            if not (('latexdict' in kwargs) and ('tabletype' in kwargs['latexdict'])):
                self.latex['tabletype'] = 'deluxetable'