# SPDX-FileCopyrightText: 2014 Alex Merry <alex.merry@kde.org>
#
# Based on cmake.py from CMake:
# SPDX-FileCopyrightText: 2000-2013 Kitware Inc., Insight Software Consortium
#
# SPDX-License-Identifier: BSD-3-Clause

import html
import os
import re

# Monkey patch for pygments reporting an error when generator expressions are
# used.
# https://bitbucket.org/birkenfeld/pygments-main/issue/942/cmake-generator-expressions-not-handled
from pygments.lexers import CMakeLexer
from pygments.token import Name, Operator
from pygments.lexer import bygroups
CMakeLexer.tokens["args"].append(('(\\$<)(.+?)(>)',
                                  bygroups(Operator, Name.Variable, Operator)))

# Monkey patch for sphinx generating invalid content for qcollectiongenerator
# https://bitbucket.org/birkenfeld/sphinx/issue/1435/qthelp-builder-should-htmlescape-keywords
try:
  from sphinxcontrib.qthelp import QtHelpBuilder
except ImportError:
  # sphinx < 4.0
  from sphinx.builders.qthelp import QtHelpBuilder
old_build_keywords = QtHelpBuilder.build_keywords
def new_build_keywords(self, title, refs, subitems):
  old_items = old_build_keywords(self, title, refs, subitems)
  new_items = []
  for item in old_items:
    before, rest = item.split("ref=\"", 1)
    ref, after = rest.split("\"")
    if ("<" in ref and ">" in ref):
      new_items.append(before + "ref=\"" + html.escape(ref) + "\"" + after)
    else:
      new_items.append(item)
  return new_items
QtHelpBuilder.build_keywords = new_build_keywords

from docutils.parsers.rst import Directive, directives
from docutils.transforms import Transform

from docutils import io, nodes

from sphinx.directives import ObjectDescription
from sphinx.domains import Domain, ObjType
from sphinx.roles import XRefRole
from sphinx.util.nodes import make_refnode
from sphinx import addnodes

class ECMModule(Directive):
    required_arguments = 1
    optional_arguments = 0
    final_argument_whitespace = True
    option_spec = {'encoding': directives.encoding}

    def __init__(self, *args, **keys):
        self.re_start = re.compile(r'^#\[(?P<eq>=*)\[\.rst:$')
        Directive.__init__(self, *args, **keys)

    def run(self):
        settings = self.state.document.settings
        if not settings.file_insertion_enabled:
            raise self.warning('"%s" directive disabled.' % self.name)

        env = self.state.document.settings.env
        rel_path, path = env.relfn2path(self.arguments[0])
        path = os.path.normpath(path)
        encoding = self.options.get('encoding', settings.input_encoding)
        e_handler = settings.input_encoding_error_handler
        try:
            settings.record_dependencies.add(path)
            f = io.FileInput(source_path=path, encoding=encoding,
                             error_handler=e_handler)
        except UnicodeEncodeError:
            msg = ('Problems with "%s" directive path:\n'
                   'Cannot encode input file path "%s" '
                   '(wrong locale?).' % (self.name, path))
            raise self.severe(msg)
        except IOError as error:
            msg = 'Problems with "%s" directive path:\n%s.' % (self.name, error)
            raise self.severe(msg)
        raw_lines = f.read().splitlines()
        f.close()
        rst = None
        lines = []
        for line in raw_lines:
            if rst is not None and rst != '#':
                # Bracket mode: check for end bracket
                pos = line.find(rst)
                if pos >= 0:
                    if line[0] == '#':
                        line = ''
                    else:
                        line = line[0:pos]
                    rst = None
            else:
                # Line mode: check for .rst start (bracket or line)
                m = self.re_start.match(line)
                if m:
                    rst = ']%s]' % m.group('eq')
                    line = ''
                elif line == '#.rst:':
                    rst = '#'
                    line = ''
                elif rst == '#':
                    if line == '#' or line[:2] == '# ':
                        line = line[2:]
                    else:
                        rst = None
                        line = ''
                elif rst is None:
                    line = ''
            lines.append(line)
        if rst is not None and rst != '#':
            raise self.warning('"%s" found unclosed bracket "#[%s[.rst:" in %s' %
                               (self.name, rst[1:-1], path))
        self.state_machine.insert_input(lines, path)
        return []

class _ecm_index_entry:
    def __init__(self, desc):
        self.desc = desc

    def __call__(self, title, targetid):
        return ('pair', u'%s ; %s' % (self.desc, title), targetid, 'main', None)

_ecm_index_objs = {
    'manual':      _ecm_index_entry('manual'),
    'module':      _ecm_index_entry('module'),
    'find-module': _ecm_index_entry('find-module'),
    'kde-module':  _ecm_index_entry('kde-module'),
    'toolchain':   _ecm_index_entry('toolchain'),
    }

def _ecm_object_inventory(env, document, line, objtype, targetid):
    inv = env.domaindata['ecm']['objects']
    if targetid in inv:
        document.reporter.warning(
            'ECM object "%s" also described in "%s".' %
            (targetid, env.doc2path(inv[targetid][0])), line=line)
    inv[targetid] = (env.docname, objtype)

class ECMTransform(Transform):

    # Run this transform early since we insert nodes we want
    # treated as if they were written in the documents.
    default_priority = 210

    def __init__(self, document, startnode):
        Transform.__init__(self, document, startnode)
        self.titles = {}

    def parse_title(self, docname):
        """Parse a document title as the first line starting in [A-Za-z0-9<]
           or fall back to the document basename if no such line exists.
           Return the title or False if the document file does not exist.
        """
        env = self.document.settings.env
        title = self.titles.get(docname)
        if title is None:
            fname = os.path.join(env.srcdir, docname+'.rst')
            try:
                f = open(fname, 'r')
            except IOError:
                title = False
            else:
                for line in f:
                    if len(line) > 0 and (line[0].isalnum() or line[0] == '<'):
                        title = line.rstrip()
                        break
                f.close()
                if title is None:
                    title = os.path.basename(docname)
            self.titles[docname] = title
        return title

    def apply(self):
        env = self.document.settings.env

        # Treat some documents as ecm domain objects.
        objtype, sep, tail = env.docname.rpartition('/')
        make_index_entry = _ecm_index_objs.get(objtype)
        if make_index_entry:
            title = self.parse_title(env.docname)
            # Insert the object link target.
            targetid = '%s:%s' % (objtype, title)
            targetnode = nodes.target('', '', ids=[targetid])
            self.document.insert(0, targetnode)
            # Insert the object index entry.
            indexnode = addnodes.index()
            indexnode['entries'] = [make_index_entry(title, targetid)]
            self.document.insert(0, indexnode)
            # Add to ecm domain object inventory
            _ecm_object_inventory(env, self.document, 1, objtype, targetid)

class ECMObject(ObjectDescription):

    def handle_signature(self, sig, signode):
        # called from sphinx.directives.ObjectDescription.run()
        signode += addnodes.desc_name(sig, sig)
        return sig

    def add_target_and_index(self, name, sig, signode):
        targetid = '%s:%s' % (self.objtype, name)
        if targetid not in self.state.document.ids:
            signode['names'].append(targetid)
            signode['ids'].append(targetid)
            signode['first'] = (not self.names)
            self.state.document.note_explicit_target(signode)
            _ecm_object_inventory(self.env, self.state.document,
                                    self.lineno, self.objtype, targetid)

        make_index_entry = _ecm_index_objs.get(self.objtype)
        if make_index_entry:
            self.indexnode['entries'].append(make_index_entry(name, targetid))

class ECMXRefRole(XRefRole):

    # See sphinx.util.nodes.explicit_title_re; \x00 escapes '<'.
    _re = re.compile(r'^(.+?)(\s*)(?<!\x00)<(.*?)>$', re.DOTALL)
    _re_sub = re.compile(r'^([^()\s]+)\s*\(([^()]*)\)$', re.DOTALL)

    def __call__(self, typ, rawtext, text, *args, **keys):
        # CMake cross-reference targets may contain '<' so escape
        # any explicit `<target>` with '<' not preceded by whitespace.
        while True:
            m = ECMXRefRole._re.match(text)
            if m and len(m.group(2)) == 0:
                text = '%s\x00<%s>' % (m.group(1), m.group(3))
            else:
                break
        return XRefRole.__call__(self, typ, rawtext, text, *args, **keys)

class ECMDomain(Domain):
    """ECM domain."""
    name = 'ecm'
    label = 'ECM'
    object_types = {
        'module':      ObjType('module',      'module'),
        'kde-module':  ObjType('kde-module',  'kde-module'),
        'find-module': ObjType('find-module', 'find-module'),
        'manual':      ObjType('manual',      'manual'),
        'toolchain':   ObjType('toolchain',   'toolchain'),
    }
    directives = {}
    roles = {
        'module':      XRefRole(),
        'kde-module':  XRefRole(),
        'find-module': XRefRole(),
        'manual':      XRefRole(),
        'toolchain':   XRefRole(),
    }
    initial_data = {
        'objects': {},  # fullname -> docname, objtype
    }

    def clear_doc(self, docname):
        to_clear = []
        for fullname, (fn, _) in self.data['objects'].items():
            if fn == docname:
                to_clear.append(fullname)
        for fullname in to_clear:
            del self.data['objects'][fullname]

    def resolve_xref(self, env, fromdocname, builder,
                     typ, target, node, contnode):
        targetid = '%s:%s' % (typ, target)
        obj = self.data['objects'].get(targetid)
        if obj is None:
            # TODO: warn somehow?
            return None
        return make_refnode(builder, fromdocname, obj[0], targetid,
                            contnode, target)

    def get_objects(self):
        for refname, (docname, type) in self.data['objects'].items():
            yield (refname, refname, type, docname, refname, 1)

def setup(app):
    app.add_directive('ecm-module', ECMModule)
    app.add_transform(ECMTransform)
    app.add_domain(ECMDomain)