# copyright 2013 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

# contact http://www.logilab.fr -- mailto:contact@logilab.fr

#

# This program is free software: you can redistribute it and/or modify it under

# the terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# This program is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with this program. If not, see <http://www.gnu.org/licenses/>.

"""Instrumentation utilities"""

import os

try:

    import pygraphviz

except ImportError:

    pygraphviz = None

from cubicweb.cwvreg import CWRegistryStore

from cubicweb.devtools.devctl import DevConfiguration

ALL_COLORS = [

    "00FF00", "0000FF", "FFFF00", "FF00FF", "00FFFF", "000000",

    "800000", "008000", "000080", "808000", "800080", "008080", "808080",

    "C00000", "00C000", "0000C0", "C0C000", "C000C0", "00C0C0", "C0C0C0",

    "400000", "004000", "000040", "404000", "400040", "004040", "404040",

    "200000", "002000", "000020", "202000", "200020", "002020", "202020",

    "600000", "006000", "000060", "606000", "600060", "006060", "606060",

    "A00000", "00A000", "0000A0", "A0A000", "A000A0", "00A0A0", "A0A0A0",

    "E00000", "00E000", "0000E0", "E0E000", "E000E0", "00E0E0", "E0E0E0",

    ]

_COLORS = {}

def get_color(key):

    try:

        return _COLORS[key]

    except KeyError:

        _COLORS[key] = '#'+ALL_COLORS[len(_COLORS) % len(ALL_COLORS)]

        return _COLORS[key]

def warn(msg, *args):

    print 'WARNING: %s' % (msg % args)

def info(msg):

    print 'INFO: ' + msg

class PropagationAnalyzer(object):

    """Abstract propagation analyzer, providing utility function to extract

    entities involved in propagation from a schema, as well as propagation

    rules from hooks (provided they use intrumentalized sets, see

    :class:`CubeTracerSet`).

    Concrete classes should at least define `prop_rel` class attribute and

    implements the `is_root` method.

    See `localperms` or `nosylist` cubes for example usage (`ccplugin` module).

    """

    prop_rel = None # name of the propagation relation

    def init(self, cube):

        """Initialize analyze for the given cube, returning the (already loaded)

        vregistry and a set of entities which we're interested in.

        """

        config = DevConfiguration(cube)

        schema = config.load_schema()

        vreg = CWRegistryStore(config)

        vreg.set_schema(schema) # set_schema triggers objects registrations

        eschemas = set(eschema for eschema in schema.entities()

                       if self.should_include(eschema))

        return vreg, eschemas

    def is_root(self, eschema):

        """Return `True` if given entity schema is a root of the graph"""

        raise NotImplementedError()

    def should_include(self, eschema):

        """Return `True` if given entity schema should be included by the graph.

        """

        if self.prop_rel in eschema.subjrels or self.is_root(eschema):

            return True

        return False

    def prop_edges(self, s_rels, o_rels, eschemas):

        """Return a set of edges where propagation has been detected.

        Each edge is defined by a 4-uple (from node, to node, rtype, package)

        where `rtype` is the relation type bringing from <from node> to <to

        node> and `package` is the cube adding the rule to the propagation

        control set (see see :class:`CubeTracerSet`).

        """

        schema = iter(eschemas).next().schema

        prop_edges = set()

        for rtype in s_rels:

            found = False

            for subj, obj in schema.rschema(rtype).rdefs:

                if subj in eschemas and obj in eschemas:

                    found = True

                    prop_edges.add( (subj, obj, rtype, s_rels.value_cube[rtype]) )

            if not found:

                warn('no rdef match for %s', rtype)

        for rtype in o_rels:

            found = False

            for subj, obj in schema.rschema(rtype).rdefs:

                if subj in eschemas and obj in eschemas:

                    found = True

                    prop_edges.add( (obj, subj, rtype, o_rels.value_cube[rtype]) )

            if not found:

                warn('no rdef match for %s', rtype)

        return prop_edges

    def detect_problems(self, eschemas, edges):

        """Given the set of analyzed entity schemas and edges between them,

        return a set of entity schemas where a problem has been detected.

        """

        problematic = set()

        for eschema in eschemas:

            if self.has_problem(eschema, edges):

                problematic.add(eschema)

        not_problematic = set(eschemas).difference(problematic)

        if not_problematic:

            info('nothing problematic in: %s' %

                 ', '.join(e.type for e in not_problematic))

        return problematic

    def has_problem(self, eschema, edges):

        """Return `True` if the given schema is considered problematic,

        considering base propagation rules.

        """

        root = self.is_root(eschema)

        has_prop_rel = self.prop_rel in eschema.subjrels

        # root but no propagation relation

        if root and not has_prop_rel:

            warn('%s is root but miss %s', eschema, self.prop_rel)

            return True

        # propagated but without propagation relation / not propagated but

        # with propagation relation

        if not has_prop_rel and \

                any(edge for edge in edges if edge[1] == eschema):

            warn("%s miss %s but is reached by propagation",

                 eschema, self.prop_rel)

            return True

        elif has_prop_rel and not root:

            rdef = eschema.rdef(self.prop_rel, takefirst=True)

            edges = [edge for edge in edges if edge[1] == eschema]

            if not edges:

                warn("%s has %s but isn't reached by "

                     "propagation", eschema, self.prop_rel)

                return True

            # require_permission relation / propagation rule not added by

            # the same cube

            elif not any(edge for edge in edges if edge[-1] == rdef.package):

                warn('%s has %s relation / propagation rule'

                     ' not added by the same cube (%s / %s)', eschema,

                     self.prop_rel, rdef.package, edges[0][-1])

                return True

        return False

    def init_graph(self, eschemas, edges, problematic):

        """Initialize and return graph, adding given nodes (entity schemas) and

        edges between them.

        Require pygraphviz installed.

        """

        if pygraphviz is None:

            raise RuntimeError('pygraphviz is not installed')

        graph = pygraphviz.AGraph(strict=False, directed=True)

        for eschema in eschemas:

            if eschema in problematic:

                params = {'color': '#ff0000', 'fontcolor': '#ff0000'}

            else:

                params = {}#'color': get_color(eschema.package)}

            graph.add_node(eschema.type, **params)

        for subj, obj, rtype, package in edges:

            graph.add_edge(str(subj), str(obj), label=rtype,

                           color=get_color(package))

        return graph

    def add_colors_legend(self, graph):

        """Add a legend of used colors to the graph."""

        for package, color in sorted(_COLORS.iteritems()):

            graph.add_node(package, color=color, fontcolor=color, shape='record')

class CubeTracerSet(object):

    """Dumb set implementation whose purpose is to keep track of which cube is

    being loaded when something is added to the set.

    Results will be found in the `value_cube` attribute dictionary.

    See `localperms` or `nosylist` cubes for example usage (`hooks` module).

    """

    def __init__(self, vreg, wrapped):

        self.vreg = vreg

        self.wrapped = wrapped

        self.value_cube = {}

    def add(self, value):

        self.wrapped.add(value)

        cube = self.vreg.currently_loading_cube

        if value in self.value_cube:

            warn('%s is propagated by cube %s and cube %s',

                 value, self.value_cube[value], cube)

        else:

            self.value_cube[value] = cube

    def __iter__(self):

        return iter(self.wrapped)

    def __ior__(self, other):

        for value in other:

            self.add(value)

        return self

    def __ror__(self, other):

        other |= self.wrapped

        return other