"""
========
numpydoc
========

Sphinx extension that handles docstrings in the Numpy standard format. [1]

It will:

- Convert Parameters etc. sections to field lists.
- Convert See Also section to a See also entry.
- Renumber references.
- Extract the signature from the docstring, if it can't be determined otherwise.

.. [1] https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt

"""

import re, pydoc
import sphinx
import inspect
import collections

if sphinx.__version__ < "1.0.1":
    raise RuntimeError("Sphinx 1.0.1 or newer is required")

from .docscrape_sphinx import get_doc_object, SphinxDocString
from sphinx.util.compat import Directive

sixu = lambda s: str(s, "unicode_escape")


def mangle_docstrings(app, what, name, obj, options, lines, reference_offset=[0]):

    cfg = dict(
        use_plots=app.config.numpydoc_use_plots,
        show_class_members=app.config.numpydoc_show_class_members,
        class_members_toctree=app.config.numpydoc_class_members_toctree,
    )

    if what == "module":
        # Strip top title
        title_re = re.compile(
            sixu("^\\s*[#*=]{4,}\\n[a-z0-9 -]+\\n[#*=]{4,}\\s*"), re.I | re.S
        )
        lines[:] = title_re.sub(sixu(""), sixu("\n").join(lines)).split(sixu("\n"))
    else:
        doc = get_doc_object(obj, what, sixu("\n").join(lines), config=cfg)
        doc = str(doc)
        lines[:] = doc.split(sixu("\n"))

    if app.config.numpydoc_edit_link and hasattr(obj, "__name__") and obj.__name__:
        if hasattr(obj, "__module__"):
            v = dict(full_name=sixu("%s.%s") % (obj.__module__, obj.__name__))
        else:
            v = dict(full_name=obj.__name__)
        lines += [sixu(""), sixu(".. htmlonly::"), sixu("")]
        lines += [
            sixu("    %s") % x for x in (app.config.numpydoc_edit_link % v).split("\n")
        ]

    # replace reference numbers so that there are no duplicates
    references = []
    for line in lines:
        line = line.strip()
        m = re.match(sixu("^.. \\[([a-z0-9_.-])\\]"), line, re.I)
        if m:
            references.append(m.group(1))

    # start renaming from the longest string, to avoid overwriting parts
    references.sort(key=lambda x: -len(x))
    if references:
        for i, line in enumerate(lines):
            for r in references:
                if re.match(sixu("^\\d+$"), r):
                    new_r = sixu("R%d") % (reference_offset[0] + int(r))
                else:
                    new_r = sixu("%s%d") % (r, reference_offset[0])
                lines[i] = lines[i].replace(sixu("[%s]_") % r, sixu("[%s]_") % new_r)
                lines[i] = lines[i].replace(
                    sixu(".. [%s]") % r, sixu(".. [%s]") % new_r
                )

    reference_offset[0] += len(references)


def mangle_signature(app, what, name, obj, options, sig, retann):
    # Do not try to inspect classes that don't define `__init__`
    if inspect.isclass(obj) and (
        not hasattr(obj, "__init__")
        or "initializes x; see " in pydoc.getdoc(obj.__init__)
    ):
        return "", ""

    if not (
        isinstance(obj, collections.Callable) or hasattr(obj, "__argspec_is_invalid_")
    ):
        return
    if not hasattr(obj, "__doc__"):
        return

    doc = SphinxDocString(pydoc.getdoc(obj))
    if doc["Signature"]:
        sig = re.sub(sixu("^[^(]*"), sixu(""), doc["Signature"])
        return sig, sixu("")


def setup(app, get_doc_object_=get_doc_object):
    if not hasattr(app, "add_config_value"):
        return  # probably called by nose, better bail out

    global get_doc_object
    get_doc_object = get_doc_object_

    app.connect("autodoc-process-docstring", mangle_docstrings)
    app.connect("autodoc-process-signature", mangle_signature)
    app.add_config_value("numpydoc_edit_link", None, False)
    app.add_config_value("numpydoc_use_plots", None, False)
    app.add_config_value("numpydoc_show_class_members", True, True)
    app.add_config_value("numpydoc_class_members_toctree", True, True)

    # Extra mangling domains
    app.add_domain(NumpyPythonDomain)
    app.add_domain(NumpyCDomain)


# ------------------------------------------------------------------------------
# Docstring-mangling domains
# ------------------------------------------------------------------------------

from docutils.statemachine import ViewList
from sphinx.domains.c import CDomain
from sphinx.domains.python import PythonDomain


class ManglingDomainBase(object):
    directive_mangling_map = {}

    def __init__(self, *a, **kw):
        super(ManglingDomainBase, self).__init__(*a, **kw)
        self.wrap_mangling_directives()

    def wrap_mangling_directives(self):
        for name, objtype in list(self.directive_mangling_map.items()):
            self.directives[name] = wrap_mangling_directive(
                self.directives[name], objtype
            )


class NumpyPythonDomain(ManglingDomainBase, PythonDomain):
    name = "np"
    directive_mangling_map = {
        "function": "function",
        "class": "class",
        "exception": "class",
        "method": "function",
        "classmethod": "function",
        "staticmethod": "function",
        "attribute": "attribute",
    }
    indices = []


class NumpyCDomain(ManglingDomainBase, CDomain):
    name = "np-c"
    directive_mangling_map = {
        "function": "function",
        "member": "attribute",
        "macro": "function",
        "type": "class",
        "var": "object",
    }


def wrap_mangling_directive(base_directive, objtype):
    class directive(base_directive):
        def run(self):
            env = self.state.document.settings.env

            name = None
            if self.arguments:
                m = re.match(r"^(.*\s+)?(.*?)(\(.*)?", self.arguments[0])
                name = m.group(2).strip()

            if not name:
                name = self.arguments[0]

            lines = list(self.content)
            mangle_docstrings(env.app, objtype, name, None, None, lines)
            self.content = ViewList(lines, self.content.parent)

            return base_directive.run(self)

    return directive
