# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

import os
import re

# Override much of pygments' CMakeLexer.
# We need to parse CMake syntax definitions, not CMake code.

# For hard test cases that use much of the syntax below, see
# - module/FindPkgConfig.html (with "glib-2.0>=2.10 gtk+-2.0" and similar)
# - module/ExternalProject.html (with http:// https:// git@; also has command options -E --build)
# - manual/cmake-buildsystem.7.html (with nested $<..>; relative and absolute paths, "::")

from pygments.lexers import CMakeLexer
from pygments.token import Name, Operator, Punctuation, String, Text, Comment, Generic, Whitespace, Number
from pygments.lexer import bygroups

# Notes on regular expressions below:
# - [\.\+-] are needed for string constants like gtk+-2.0
# - Unix paths are recognized by '/'; support for Windows paths may be added if needed
# - (\\.) allows for \-escapes (used in manual/cmake-language.7)
# - $<..$<..$>..> nested occurrence in cmake-buildsystem
# - Nested variable evaluations are only supported in a limited capacity. Only
#   one level of nesting is supported and at most one nested variable can be present.

CMakeLexer.tokens["root"] = [
  (r'\b(\w+)([ \t]*)(\()', bygroups(Name.Function, Text, Name.Function), '#push'),     # fctn(
  (r'\(', Name.Function, '#push'),
  (r'\)', Name.Function, '#pop'),
  (r'\[', Punctuation, '#push'),
  (r'\]', Punctuation, '#pop'),
  (r'[|;,.=*\-]', Punctuation),
  (r'\\\\', Punctuation),                                   # used in commands/source_group
  (r'[:]', Operator),
  (r'[<>]=', Punctuation),                                  # used in FindPkgConfig.cmake
  (r'\$<', Operator, '#push'),                              # $<...>
  (r'<[^<|]+?>(\w*\.\.\.)?', Name.Variable),                # <expr>
  (r'(\$\w*\{)([^\}\$]*)?(?:(\$\w*\{)([^\}]+?)(\}))?([^\}]*?)(\})',  # ${..} $ENV{..}, possibly nested
    bygroups(Operator, Name.Tag, Operator, Name.Tag, Operator, Name.Tag, Operator)),
  (r'([A-Z]+\{)(.+?)(\})', bygroups(Operator, Name.Tag, Operator)),  # DATA{ ...}
  (r'[a-z]+(@|(://))((\\.)|[\w.+-:/\\])+', Name.Attribute),          # URL, git@, ...
  (r'/\w[\w\.\+-/\\]*', Name.Attribute),                    # absolute path
  (r'/', Name.Attribute),
  (r'\w[\w\.\+-]*/[\w.+-/\\]*', Name.Attribute),            # relative path
  (r'[A-Z]((\\.)|[\w.+-])*[a-z]((\\.)|[\w.+-])*', Name.Builtin), # initial A-Z, contains a-z
  (r'@?[A-Z][A-Z0-9_]*', Name.Constant),
  (r'[a-z_]((\\;)|(\\ )|[\w.+-])*', Name.Builtin),
  (r'[0-9][0-9\.]*', Number),
  (r'(?s)"(\\"|[^"])*"', String),                           # "string"
  (r'\.\.\.', Name.Variable),
  (r'<', Operator, '#push'),                                # <..|..> is different from <expr>
  (r'>', Operator, '#pop'),
  (r'\n', Whitespace),
  (r'[ \t]+', Whitespace),
  (r'#.*\n', Comment),
  #  (r'[^<>\])\}\|$"# \t\n]+', Name.Exception),            # fallback, for debugging only
]

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

sphinx_before_1_4 = False
sphinx_before_1_7_2 = False
try:
    from sphinx import version_info
    if version_info < (1, 4):
        sphinx_before_1_4 = True
    if version_info < (1, 7, 2):
        sphinx_before_1_7_2 = True
except ImportError:
    # The `sphinx.version_info` tuple was added in Sphinx v1.2:
    sphinx_before_1_4 = True
    sphinx_before_1_7_2 = True

if sphinx_before_1_7_2:
  # Monkey patch for sphinx generating invalid content for qcollectiongenerator
  # https://github.com/sphinx-doc/sphinx/issues/1435
  from sphinx.util.pycompat import htmlescape
  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=\"" + htmlescape(ref) + "\"" + after)
      else:
        new_items.append(item)
    return new_items
  QtHelpBuilder.build_keywords = new_build_keywords

class CMakeModule(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 as error:
            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 _cmake_index_entry:
    def __init__(self, desc):
        self.desc = desc

    def __call__(self, title, targetid, main = 'main'):
        # See https://github.com/sphinx-doc/sphinx/issues/2673
        if sphinx_before_1_4:
            return ('pair', u'%s ; %s' % (self.desc, title), targetid, main)
        else:
            return ('pair', u'%s ; %s' % (self.desc, title), targetid, main, None)

_cmake_index_objs = {
    'command':    _cmake_index_entry('command'),
    'cpack_gen':  _cmake_index_entry('cpack generator'),
    'envvar':     _cmake_index_entry('envvar'),
    'generator':  _cmake_index_entry('generator'),
    'genex':      _cmake_index_entry('genex'),
    'guide':      _cmake_index_entry('guide'),
    'manual':     _cmake_index_entry('manual'),
    'module':     _cmake_index_entry('module'),
    'policy':     _cmake_index_entry('policy'),
    'prop_cache': _cmake_index_entry('cache property'),
    'prop_dir':   _cmake_index_entry('directory property'),
    'prop_gbl':   _cmake_index_entry('global property'),
    'prop_inst':  _cmake_index_entry('installed file property'),
    'prop_sf':    _cmake_index_entry('source file property'),
    'prop_test':  _cmake_index_entry('test property'),
    'prop_tgt':   _cmake_index_entry('target property'),
    'variable':   _cmake_index_entry('variable'),
    }

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

class CMakeTransform(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<$]
           or fall back to the document basename if no such line exists.
           The cmake --help-*-list commands also depend on this convention.
           Return the title or False if the document file does not exist.
        """
        env = self.document.settings.env
        title = self.titles.get(docname)
        if title is None:
            fname = os.path.join(env.srcdir, docname+'.rst')
            try:
                f = open(fname, 'r')
            except IOError:
                title = False
            else:
                for line in f:
                    if len(line) > 0 and (line[0].isalnum() or line[0] == '<' or line[0] == '$'):
                        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 cmake domain objects.
        objtype, sep, tail = env.docname.partition('/')
        make_index_entry = _cmake_index_objs.get(objtype)
        if make_index_entry:
            title = self.parse_title(env.docname)
            # Insert the object link target.
            if objtype == 'command':
                targetname = title.lower()
            elif objtype == 'guide' and not tail.endswith('/index'):
                targetname = tail
            else:
                if objtype == 'genex':
                    m = CMakeXRefRole._re_genex.match(title)
                    if m:
                        title = m.group(1)
                targetname = title
            targetid = '%s:%s' % (objtype, targetname)
            targetnode = nodes.target('', '', ids=[targetid])
            self.document.note_explicit_target(targetnode)
            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 cmake domain object inventory
            _cmake_object_inventory(env, self.document, 1, objtype, targetid)

class CMakeObject(ObjectDescription):

    def handle_signature(self, sig, signode):
        # called from sphinx.directives.ObjectDescription.run()
        signode += addnodes.desc_name(sig, sig)
        if self.objtype == 'genex':
            m = CMakeXRefRole._re_genex.match(sig)
            if m:
                sig = m.group(1)
        return sig

    def add_target_and_index(self, name, sig, signode):
        if self.objtype == 'command':
           targetname = name.lower()
        else:
           targetname = name
        targetid = '%s:%s' % (self.objtype, targetname)
        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)
            _cmake_object_inventory(self.env, self.state.document,
                                    self.lineno, self.objtype, targetid)

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

class CMakeXRefRole(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*\(([^()]*)\)$', re.DOTALL)
    _re_genex = re.compile(r'^\$<([^<>:]+)(:[^<>]+)?>$', re.DOTALL)
    _re_guide = re.compile(r'^([^<>/]+)/([^<>]*)$', re.DOTALL)

    def __call__(self, typ, rawtext, text, *args, **keys):
        # Translate CMake command cross-references of the form:
        #  `command_name(SUB_COMMAND)`
        # to have an explicit target:
        #  `command_name(SUB_COMMAND) <command_name>`
        if typ == 'cmake:command':
            m = CMakeXRefRole._re_sub.match(text)
            if m:
                text = '%s <%s>' % (text, m.group(1))
        elif typ == 'cmake:genex':
            m = CMakeXRefRole._re_genex.match(text)
            if m:
                text = '%s <%s>' % (text, m.group(1))
        elif typ == 'cmake:guide':
            m = CMakeXRefRole._re_guide.match(text)
            if m:
                text = '%s <%s>' % (m.group(2), text)
        # CMake cross-reference targets frequently contain '<' so escape
        # any explicit `<target>` with '<' not preceded by whitespace.
        while True:
            m = CMakeXRefRole._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)

    # We cannot insert index nodes using the result_nodes method
    # because CMakeXRefRole is processed before substitution_reference
    # nodes are evaluated so target nodes (with 'ids' fields) would be
    # duplicated in each evaluated substitution replacement.  The
    # docutils substitution transform does not allow this.  Instead we
    # use our own CMakeXRefTransform below to add index entries after
    # substitutions are completed.
    #
    # def result_nodes(self, document, env, node, is_ref):
    #     pass

class CMakeXRefTransform(Transform):

    # Run this transform early since we insert nodes we want
    # treated as if they were written in the documents, but
    # after the sphinx (210) and docutils (220) substitutions.
    default_priority = 221

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

        # Find CMake cross-reference nodes and add index and target
        # nodes for them.
        for ref in self.document.traverse(addnodes.pending_xref):
            if not ref['refdomain'] == 'cmake':
                continue

            objtype = ref['reftype']
            make_index_entry = _cmake_index_objs.get(objtype)
            if not make_index_entry:
                continue

            objname = ref['reftarget']
            if objtype == 'guide' and CMakeXRefRole._re_guide.match(objname):
                # Do not index cross-references to guide sections.
                continue

            targetnum = env.new_serialno('index-%s:%s' % (objtype, objname))

            targetid = 'index-%s-%s:%s' % (targetnum, objtype, objname)
            targetnode = nodes.target('', '', ids=[targetid])
            self.document.note_explicit_target(targetnode)

            indexnode = addnodes.index()
            indexnode['entries'] = [make_index_entry(objname, targetid, '')]
            ref.replace_self([indexnode, targetnode, ref])

class CMakeDomain(Domain):
    """CMake domain."""
    name = 'cmake'
    label = 'CMake'
    object_types = {
        'command':    ObjType('command',    'command'),
        'cpack_gen':  ObjType('cpack_gen',  'cpack_gen'),
        'envvar':     ObjType('envvar',     'envvar'),
        'generator':  ObjType('generator',  'generator'),
        'genex':      ObjType('genex',      'genex'),
        'guide':      ObjType('guide',      'guide'),
        'variable':   ObjType('variable',   'variable'),
        'module':     ObjType('module',     'module'),
        'policy':     ObjType('policy',     'policy'),
        'prop_cache': ObjType('prop_cache', 'prop_cache'),
        'prop_dir':   ObjType('prop_dir',   'prop_dir'),
        'prop_gbl':   ObjType('prop_gbl',   'prop_gbl'),
        'prop_inst':  ObjType('prop_inst',  'prop_inst'),
        'prop_sf':    ObjType('prop_sf',    'prop_sf'),
        'prop_test':  ObjType('prop_test',  'prop_test'),
        'prop_tgt':   ObjType('prop_tgt',   'prop_tgt'),
        'manual':     ObjType('manual',     'manual'),
    }
    directives = {
        'command':    CMakeObject,
        'envvar':     CMakeObject,
        'genex':      CMakeObject,
        'variable':   CMakeObject,
        # Other object types cannot be created except by the CMakeTransform
        # 'generator':  CMakeObject,
        # 'module':     CMakeObject,
        # 'policy':     CMakeObject,
        # 'prop_cache': CMakeObject,
        # 'prop_dir':   CMakeObject,
        # 'prop_gbl':   CMakeObject,
        # 'prop_inst':  CMakeObject,
        # 'prop_sf':    CMakeObject,
        # 'prop_test':  CMakeObject,
        # 'prop_tgt':   CMakeObject,
        # 'manual':     CMakeObject,
    }
    roles = {
        'command':    CMakeXRefRole(fix_parens = True, lowercase = True),
        'cpack_gen':  CMakeXRefRole(),
        'envvar':     CMakeXRefRole(),
        'generator':  CMakeXRefRole(),
        'genex':      CMakeXRefRole(),
        'guide':      CMakeXRefRole(),
        'variable':   CMakeXRefRole(),
        'module':     CMakeXRefRole(),
        'policy':     CMakeXRefRole(),
        'prop_cache': CMakeXRefRole(),
        'prop_dir':   CMakeXRefRole(),
        'prop_gbl':   CMakeXRefRole(),
        'prop_inst':  CMakeXRefRole(),
        'prop_sf':    CMakeXRefRole(),
        'prop_test':  CMakeXRefRole(),
        'prop_tgt':   CMakeXRefRole(),
        'manual':     CMakeXRefRole(),
    }
    initial_data = {
        'objects': {},  # fullname -> docname, objtype
    }

    def clear_doc(self, docname):
        to_clear = set()
        for fullname, (fn, _) in self.data['objects'].items():
            if fn == docname:
                to_clear.add(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('cmake-module', CMakeModule)
    app.add_transform(CMakeTransform)
    app.add_transform(CMakeXRefTransform)
    app.add_domain(CMakeDomain)