"""
========
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] http://projects.scipy.org/numpy/wiki/CodingStyleGuidelines#docstring-standard

"""

import sphinx

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

import os, re, pydoc
from .docscrape_sphinx import get_doc_object, SphinxDocString
from pandas.compat import u, callable
from sphinx.util.compat import Directive
import inspect

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)

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

    if app.config.numpydoc_edit_link and hasattr(obj, '__name__') and \
           obj.__name__:
        if hasattr(obj, '__module__'):
            v = dict(full_name=u("%s.%s") % (obj.__module__, obj.__name__))
        else:
            v = dict(full_name=obj.__name__)
        lines += [u(''), u('.. htmlonly::'), '']
        lines += [u('    %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(u(r'^.. \[([a-z0-9_.-])\]'), 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(u(r'^\d+$'), r):
                    new_r = u("R%d") % (reference_offset[0] + int(r))
                else:
                    new_r = u("%s%d") % (r, reference_offset[0])
                lines[i] = lines[i].replace(u('[%s]_') % r,
                                            u('[%s]_') % new_r)
                lines[i] = lines[i].replace(u('.. [%s]') % r,
                                            u('.. [%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 (callable(obj) or hasattr(obj, '__argspec_is_invalid_')): return
    if not hasattr(obj, '__doc__'): return

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

def setup(app, get_doc_object_=get_doc_object):
    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)

    # 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 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',
    }

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

