# coding=utf-8
#
# Copyright © 2016 Intel Corporation
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
#
# Authors:
#    Jani Nikula <jani.nikula@intel.com>
#
# Please make sure this works on both python2 and python3.
#

import codecs
import os
import subprocess
import sys
import re
import glob

from docutils import nodes, statemachine
from docutils.statemachine import ViewList
from docutils.parsers.rst import directives, Directive

import sphinx
from sphinx.util import logging
from sphinx.util.docutils import switch_source_input


__version__  = '1.0'
logger = logging.getLogger('kerneldoc')


class KernelDocDirective(Directive):
    """Extract kernel-doc comments from the specified file"""
    required_argument = 1
    optional_arguments = 4
    option_spec = {
        'doc': directives.unchanged_required,
        'functions': directives.unchanged,
        'export': directives.unchanged,
        'internal': directives.unchanged,
    }
    has_content = False

    def run(self):
        env = self.state.document.settings.env
        cmd = env.config.kerneldoc_bin + ['-rst', '-enable-lineno']

        # Pass through the warnings-as-errors flag
        if env.config.kerneldoc_werror:
            cmd += ['-Werror']

        filename = env.config.kerneldoc_srctree + '/' + self.arguments[0]
        export_file_patterns = []

        # Tell sphinx of the dependency
        env.note_dependency(os.path.abspath(filename))

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

        # FIXME: make this nicer and more robust against errors
        if 'export' in self.options:
            cmd += ['-export']
            export_file_patterns = str(self.options.get('export')).split()
        elif 'internal' in self.options:
            cmd += ['-internal']
            export_file_patterns = str(self.options.get('internal')).split()
        elif 'doc' in self.options:
            cmd += ['-function', str(self.options.get('doc'))]
        elif 'functions' in self.options:
            functions = self.options.get('functions').split()
            if functions:
                for f in functions:
                    cmd += ['-function', f]
            else:
                cmd += ['-no-doc-sections']

        for pattern in export_file_patterns:
            for f in glob.glob(env.config.kerneldoc_srctree + '/' + pattern):
                env.note_dependency(os.path.abspath(f))
                cmd += ['-export-file', f]

        cmd += [filename]

        try:
            logger.verbose('calling kernel-doc \'%s\'' % (" ".join(cmd)))

            p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            out, err = p.communicate()

            out, err = codecs.decode(out, 'utf-8'), codecs.decode(err, 'utf-8')

            if p.returncode != 0:
                sys.stderr.write(err)

                logger.warning(
                    'kernel-doc \'%s\' failed with return code %d' %
                    (" ".join(cmd), p.returncode)
                )
                return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]
            elif env.config.kerneldoc_verbosity > 0:
                sys.stderr.write(err)

            lines = statemachine.string2lines(out, tab_width, convert_whitespace=True)
            result = ViewList()

            lineoffset = 0;
            line_regex = re.compile(r"^(?:\.\.|#define) LINENO ([0-9]+)$")
            for line in lines:
                match = line_regex.search(line)
                if match:
                    # sphinx counts lines from 0
                    lineoffset = int(match.group(1)) - 1
                    # we must eat our comments since the upset the markup
                else:
                    result.append(line, filename, lineoffset)
                    lineoffset += 1

            node = nodes.section()
            self.do_parse(result, node)

            return node.children

        except Exception as e:  # pylint: disable=W0703
            logger.warning('kernel-doc \'%s\' processing failed with: %s' %
                           (" ".join(cmd), str(e)))
            return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]

    def do_parse(self, result, node):
        with switch_source_input(self.state, result):
            self.state.nested_parse(result, 0, node, match_titles=1)


def setup(app):
    app.add_config_value('kerneldoc_bin', None, 'env')
    app.add_config_value('kerneldoc_srctree', None, 'env')
    app.add_config_value('kerneldoc_verbosity', 1, 'env')
    app.add_config_value('kerneldoc_werror', 0, 'env')

    app.add_directive('kernel-doc', KernelDocDirective)

    return dict(
        version = __version__,
        parallel_read_safe = True,
        parallel_write_safe = True
    )