# -*- coding: utf-8 -*-
from __future__ import unicode_literals

"""
Include Pygments highlighted code with reStructuredText
=======================================================

:author: Colin Dunklau

Use this plugin to make writing coding tutorials easier! You can
maintain the example source files separately from the actual article.

"""

import os.path

from docutils import io, nodes, statemachine, utils
from docutils.utils.error_reporting import SafeString, ErrorString
from docutils.parsers.rst import directives, Directive

from pelican.rstdirectives import Pygments


class CodeInclude(Directive):
    """
    Include content read from a separate source file, and highlight
    it with the given lexer (using pelican.rstdirectives.CodeBlock)

    The encoding of the included file can be specified. Only a part
    of the given file argument may be included by specifying start
    and end line. Hard tabs will be replaced with ``tab-width``
    spaces.
    """

    required_arguments = 1
    optional_arguments = 0
    final_argument_whitespace = True
    option_spec = {'lexer': directives.unchanged,
                   'encoding': directives.encoding,
                   'tab-width': int,
                   'start-line': int,
                   'end-line': int}

    def run(self):
        """Include a file as part of the content of this reST file."""
        if not self.state.document.settings.file_insertion_enabled:
            raise self.warning('"%s" directive disabled.' % self.name)
        source = self.state_machine.input_lines.source(
            self.lineno - self.state_machine.input_offset - 1)
        source_dir = os.path.dirname(os.path.abspath(source))

        path = directives.path(self.arguments[0])
        path = os.path.normpath(os.path.join(source_dir, path))
        path = utils.relative_path(None, path)
        path = nodes.reprunicode(path)

        encoding = self.options.get(
            'encoding', self.state.document.settings.input_encoding)
        e_handler = self.state.document.settings.input_encoding_error_handler
        tab_width = self.options.get(
            'tab-width', self.state.document.settings.tab_width)

        try:
            self.state.document.settings.record_dependencies.add(path)
            include_file = io.FileInput(source_path=path,
                                        encoding=encoding,
                                        error_handler=e_handler)
        except UnicodeEncodeError as error:
            raise self.severe('Problems with "%s" directive path:\n'
                              'Cannot encode input file path "%s" '
                              '(wrong locale?).' %
                              (self.name, SafeString(path)))
        except IOError as error:
            raise self.severe('Problems with "%s" directive path:\n%s.' %
                              (self.name, ErrorString(error)))
        startline = self.options.get('start-line', None)
        endline = self.options.get('end-line', None)
        try:
            if startline or (endline is not None):
                lines = include_file.readlines()
                rawtext = ''.join(lines[startline:endline])
            else:
                rawtext = include_file.read()
        except UnicodeError as error:
            raise self.severe('Problem with "%s" directive:\n%s' %
                              (self.name, ErrorString(error)))

        include_lines = statemachine.string2lines(rawtext, tab_width,
                                                  convert_whitespace=True)

        # default lexer to 'text'
        lexer = self.options.get('lexer', 'text')

        self.options['source'] = path
        codeblock = Pygments(self.name,
                             [lexer],  # arguments
                             {},  # no options for this directive
                             include_lines,  # content
                             self.lineno,
                             self.content_offset,
                             self.block_text,
                             self.state,
                             self.state_machine)
        return codeblock.run()


def register():
    directives.register_directive('code-include', CodeInclude)