#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (C) 2013-2016 Étienne Loks  <etienne.loks_AT_peacefrogsDOTnet>

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# See the file COPYING for details.

from csv import QUOTE_ALL
import datetime
from functools import wraps
from itertools import chain
import hashlib
import os
import random
import re
import requests
import shutil
import six
import subprocess
import sys
import tempfile

from django import forms
from django.apps import apps
from django.conf import settings
from django.conf.urls import url
from django.contrib.contenttypes.models import ContentType
from django.contrib.gis.geos import GEOSGeometry
from django.contrib.sessions.backends.db import SessionStore
from django.core.cache import cache
from django.core.files import File
from django.core.validators import EMPTY_VALUES
from django.core.urlresolvers import reverse
from django.db import models
from django.http import HttpResponseRedirect
from django.utils.datastructures import MultiValueDict as BaseMultiValueDict
from django.utils.safestring import mark_safe
from django.utils.translation import ugettext_lazy as _, ugettext
from django.template.defaultfilters import slugify


class BColors:
    """
    Bash colors. Don't forget to finish your colored string with ENDC.
    """
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'


CSV_OPTIONS = {'delimiter': ',', 'quotechar': '"', 'quoting': QUOTE_ALL}


def check_rights(rights=None, redirect_url='/'):
    """
    Decorator that checks the rights to access the view.
    """

    def decorator(view_func):
        def _wrapped_view(request, *args, **kwargs):
            if not rights:
                return view_func(request, *args, **kwargs)
            if hasattr(request.user, 'ishtaruser'):
                if request.user.ishtaruser.has_right('administrator',
                                                     request.session):
                    kwargs['current_right'] = 'administrator'
                    return view_func(request, *args, **kwargs)
                for right in rights:
                    # be careful to put the more permissive rights first
                    # if granted it can allow more
                    if request.user.ishtaruser.has_right(right,
                                                         request.session):
                        kwargs['current_right'] = right
                        return view_func(request, *args, **kwargs)
            put_session_message(
                request.session.session_key,
                _(u"You don't have sufficient permissions to do this action."),
                'warning'
            )
            return HttpResponseRedirect(redirect_url)
        return _wrapped_view
    return decorator


def check_rights_condition(rights):
    """
    To be used to check in wizard condition_dict
    """
    def func(self):
        request = self.request
        if request.user.ishtaruser.has_right('administrator', request.session):
            return True
        for right in rights:
            if request.user.ishtaruser.has_right(right, request.session):
                return True
        return False
    return func


def check_model_access_control(request, model, available_perms=None):
    """
    Check access control to a model for a specific request

    :param request: the current request
    :param model: the concerned model
    :param available_perms: specific permissions to check if not specified
    "view" and "view_own" will be checked
    :return: (allowed, own) tuple
    """
    own = True  # more restrictive by default
    allowed = False
    if not request.user.is_authenticated():
        return allowed, own

    if not available_perms:
        available_perms = ['view_' + model.__name__.lower(),
                           'view_own_' + model.__name__.lower()]
    try:
        ishtaruser = request.user.ishtaruser
    except request.user._meta.model.ishtaruser.RelatedObjectDoesNotExist:
        return False, True
    if ishtaruser.has_right('administrator', session=request.session):
        allowed = True
        own = False
        return allowed, own
    for perm, lbl in model._meta.permissions:
        if perm not in available_perms:
            continue
        if ishtaruser.person.has_right(perm, session=request.session):
            allowed = True
            if "_own_" not in perm:
                own = False
                break  # max right reach
    return allowed, own


def update_data(data_1, data_2, merge=False):
    """
    Update a data directory taking account of key detail
    """
    res = {}
    if not isinstance(data_1, dict) or not isinstance(data_2, dict):
        if data_2 and not data_1:
            return data_2
        if not merge:
            return data_1
        if data_2 and data_2 != data_1:
            return data_1 + u" ; " + data_2
        return data_1
    for k in data_1:
        if k not in data_2:
            res[k] = data_1[k]
        else:
            res[k] = update_data(data_1[k], data_2[k], merge=merge)
    for k in data_2:
        if k not in data_1:
            res[k] = data_2[k]
    return res


def move_dict_data(data, key1, key2):
    """
    Move key1 value to key2 value in a data dict
    :param data: data dict (with subdicts)
    :param key1: key to move (with __ notation for hierarchy - begining with
    "data__")
    :param key2: target key (with __ notation for hierarchy - begining with
    "data__")
    :return: result data
    """
    keys1 = key1.split('__')
    keys2 = key2.split('__')
    value = data
    for idx, key in enumerate(keys1):
        if not idx:
            if key != 'data':
                return data
            continue
        if key not in value:
            return data
        if idx == (len(keys1) - 1):  # last
            value = value.pop(key)  # remove from data
        else:
            value = value[key]

    new_value = data
    for idx, key in enumerate(keys2):
        if not idx:
            if key != 'data':
                return data
            continue
        if idx == (len(keys2) - 1):  # last
            new_value[key] = value
        else:
            if key not in new_value:
                new_value[key] = {}
            new_value = new_value[key]
    return data


def clean_empty_data(data):
    """
    Clean empty branches of a data dict
    """
    for key in data.keys():
        if data[key] in [{}, None, u""]:
            data.pop(key)
            continue
        if isinstance(data[key], dict):
            data[key] = clean_empty_data(data[key])
    return data


class MultiValueDict(BaseMultiValueDict):
    def get(self, *args, **kwargs):
        v = super(MultiValueDict, self).getlist(*args, **kwargs)
        if callable(v):
            v = v()
        if type(v) in (list, tuple) and len(v) > 1:
            v = ",".join(v)
        elif type(v) not in (int, unicode):
            v = super(MultiValueDict, self).get(*args, **kwargs)
        return v

    def getlist(self, *args, **kwargs):
        lst = super(MultiValueDict, self).getlist(*args, **kwargs)
        if type(lst) not in (tuple, list):
            lst = [lst]
        return lst


def is_downloadable(url):
    """
    Does the url contain a downloadable resource
    """
    h = requests.head(url, allow_redirects=True)
    header = h.headers
    content_type = header.get('content-type')
    if 'text' in content_type.lower():
        return False
    if 'html' in content_type.lower():
        return False
    return True


def get_current_year():
    return datetime.datetime.now().year


def get_cache(cls, extra_args=tuple(), app_label=None):
    if not app_label:
        app_label = cls._meta.app_label
    cache_key = u"{}-{}-{}".format(
        settings.PROJECT_SLUG, app_label, cls.__name__)
    for arg in extra_args:
        if not arg:
            cache_key += '-0'
        else:
            if type(arg) == dict:
                cache_key += '-' + "_".join([unicode(arg[k]) for k in arg])
            elif type(arg) in (list, tuple):
                cache_key += '-' + "_".join([unicode(v) for v in arg])
            else:
                cache_key += '-' + unicode(arg)
    cache_key = slugify(cache_key)
    if not cache_key.endswith('_current_keys') \
            and hasattr(cls, '_add_cache_key_to_refresh'):
        cls._add_cache_key_to_refresh(extra_args)
    if len(cache_key) >= 250:
        m = hashlib.md5()
        m.update(cache_key)
        cache_key = m.hexdigest()
    return cache_key, cache.get(cache_key)


def force_cached_label_changed(sender, **kwargs):
    if not kwargs.get('instance'):
        return
    kwargs['instance']._cached_label_checked = False
    cached_label_changed(sender, **kwargs)


def cached_label_changed(sender, **kwargs):
    if not kwargs.get('instance'):
        return
    instance = kwargs.get('instance')
    force_update = kwargs.get('force_update', False)

    if hasattr(instance, 'test_obj'):
        instance.test_obj.reached(sender, **kwargs)

    if not force_update and hasattr(instance, '_cached_label_checked') \
            and instance._cached_label_checked:
        return
    instance._cached_label_checked = True
    cached_labels = ['cached_label']
    if hasattr(sender, 'CACHED_LABELS'):
        cached_labels = sender.CACHED_LABELS
    changed = False
    for cached_label in cached_labels:
        lbl = getattr(instance, '_generate_' + cached_label)()
        if lbl != getattr(instance, cached_label):
            setattr(instance, cached_label, lbl)
            changed = True
    if changed:
        instance._search_updated = False
        if hasattr(instance, '_cascade_change') and instance._cascade_change:
            instance.skip_history_when_saving = True
        instance.save()
    updated = False
    if force_update or hasattr(instance, 'update_search_vector'):
        updated = instance.update_search_vector()
    if hasattr(instance, '_cached_labels_bulk_update'):
        updated = instance._cached_labels_bulk_update() or updated
    if not updated and hasattr(instance, '_get_associated_cached_labels'):
        for item in instance._get_associated_cached_labels():
            item._cascade_change = True
            if hasattr(instance, 'test_obj'):
                item.test_obj = instance.test_obj
            cached_label_changed(item.__class__, instance=item)


def regenerate_all_cached_labels(model):
    """
    When the rule for generating cached label change. Regeneration of all
    label has to be done.
    :param model: model class concerned
    """
    for item in model.all():
        item.skip_history_when_saving = True
        cached_label_changed(model, instance=item)


SHORTIFY_STR = ugettext(" (...)")


def shortify(lbl, number=20):
    if not lbl:
        lbl = ''
    if len(lbl) <= number:
        return lbl
    return lbl[:number - len(SHORTIFY_STR)] + SHORTIFY_STR


def mode(array):
    most = max(list(map(array.count, array)))
    return list(set(filter(lambda x: array.count(x) == most, array)))


def disable_for_loaddata(signal_handler):
    """
    Decorator that turns off signal handlers when loading fixture data.
    """

    @wraps(signal_handler)
    def wrapper(*args, **kwargs):
        if kwargs.get('raw'):
            return
        signal_handler(*args, **kwargs)
    return wrapper


def _get_image_link(doc):
    from ishtar_common.models import IshtarSiteProfile

    # manage missing images
    if not doc.thumbnail or not doc.thumbnail.url or not doc.image \
            or not doc.image.url:
        return ""

    item = None
    for related_key in doc.__class__.RELATED_MODELS:
        q = getattr(doc, related_key)
        if q.count():
            item = q.all()[0]
            break
    if not item:
        # image attached to nothing...
        return ""

    item_class_name = unicode(item.__class__._meta.verbose_name)

    if item.__class__.__name__ == "ArchaeologicalSite":
        item_class_name = unicode(IshtarSiteProfile.get_default_site_label())

    return mark_safe(u"""
    <div class="col col-lg-3">
    <div class="card">
        <div id="lightgallery-rand-img">
            <a href="{}">
                <img class="card-img-top" src="{}"/>
            </a>
        </div>
        <div class="card-body">
            <h4 class="card-title">{}</h4>
            <p class="card-text">{}</p>
            <a href="#" onclick="load_window(\'{}\')" class="btn btn-info">
                <i class="fa fa-info-circle" aria-hidden="true"></i> {}
            </a>
            <a href="." title="{}" class="btn btn-secondary">
                <i class="fa fa-random" aria-hidden="true"></i>
            </a><br/>
        </div>
    </div>
    </div>
    <script type="text/javascript">
        lightGallery(document.getElementById('lightgallery-rand-img'));
    </script>""".format(
        doc.image.url,
        doc.thumbnail.url,
        item_class_name,
        unicode(item),
        reverse(item.SHOW_URL, args=[item.pk, '']),
        unicode(_(u"Information")),
        unicode(_(u"Load another random image?"))))


def get_random_item_image_link(request):
    from ishtar_common.models import Document

    if not hasattr(request.user, 'ishtaruser'):
        return ''

    ishtar_user = request.user.ishtaruser
    if not ishtar_user.has_right('ishtar_common.view_document',
                                 session=request.session):
        return ''

    q = Document.objects.filter(
        thumbnail__isnull=False,
        image__isnull=False
    ).exclude(thumbnail='').exclude(image='')

    total = q.count()
    if not total:
        return ''

    image_nb = random.randint(0, total - 1)
    return _get_image_link(q.all()[image_nb])


def convert_coordinates_to_point(x, y, z=None, srid=4326):
    if z:
        geom = GEOSGeometry('POINT({} {} {})'.format(x, y, z), srid=srid)
    else:
        geom = GEOSGeometry('POINT({} {})'.format(x, y), srid=srid)
    if not geom.valid:
        raise forms.ValidationError(geom.valid_reason)
    return geom


def post_save_point(sender, **kwargs):
    """
    Convert raw x, y, z point to real geo field
    """
    if not kwargs.get('instance'):
        return
    instance = kwargs.get('instance')
    point = None
    point_2d = None
    if instance.x and instance.y and \
            instance.spatial_reference_system and \
            instance.spatial_reference_system.auth_name == 'EPSG' and \
            instance.spatial_reference_system.srid != 0:
        point_2d = convert_coordinates_to_point(
            instance.x, instance.y, srid=instance.spatial_reference_system.srid)
        if instance.z:
            point = convert_coordinates_to_point(
                instance.x, instance.y, instance.z,
                srid=instance.spatial_reference_system.srid)
    if point_2d != instance.point_2d or point != instance.point:
        instance.point = point
        instance.point_2d = point_2d
        instance.skip_history_when_saving = True
        instance.save()
    return


def create_slug(model, name, slug_attr='slug', max_length=100):
    base_slug = slugify(name)
    slug = base_slug[:max_length]
    final_slug = None
    idx = 1
    while not final_slug:
        if slug and not model.objects.filter(**{slug_attr:slug}).exists():
            final_slug = slug
            break
        slug = base_slug[:(max_length - 1 - len(str(idx)))] + "-" + str(idx)
        idx += 1
    return final_slug


def get_all_field_names(model):
    return list(set(chain.from_iterable(
        (field.name, field.attname) if hasattr(field, 'attname') else (
         field.name,)
        for field in model._meta.get_fields()
        if not (field.many_to_one and field.related_model is None)
    )))


def get_all_related_m2m_objects_with_model(model):
    return [
        (f, f.model if f.model != model else None)
        for f in model._meta.get_fields(include_hidden=True)
        if f.many_to_many and f.auto_created
    ]


def get_all_related_many_to_many_objects(model):
    return [
        f for f in model._meta.get_fields(include_hidden=True)
        if f.many_to_many and f.auto_created
    ]


def get_all_related_objects(model):
    return [
        f for f in model._meta.get_fields()
        if (f.one_to_many or f.one_to_one)
        and f.auto_created and not f.concrete
    ]


def num2col(n):
    string = ""
    while n > 0:
        n, remainder = divmod(n - 1, 26)
        string = chr(65 + remainder) + string
    return string


def merge_tsvectors(vectors):
    """
    Parse tsvector to merge them in one string
    :param vectors: list of tsvector string
    :return: merged tsvector
    """
    result_dict = {}
    for vector in vectors:
        if not vector:
            continue

        current_position = 0
        if result_dict:
            for key in result_dict:
                max_position = max(result_dict[key])
                if max_position > current_position:
                    current_position = max_position

        for dct_member in vector.split(" "):
            splitted = dct_member.split(':')
            key = ":".join(splitted[:-1])
            positions = splitted[-1]
            key = key[1:-1]  # remove quotes
            positions = [int(pos) + current_position
                         for pos in positions.split(',')]
            if key in result_dict:
                result_dict[key] += positions
            else:
                result_dict[key] = positions

    # {'lamelie': [1, 42, 5]} => {'lamelie': "1,42,5"}
    result_dict = {k: ",".join([str(val) for val in result_dict[k]])
                   for k in result_dict}
    # {'lamelie': "1,5", "hagarde": "2", "regarde": "4"} =>
    # "'lamelie':1,5 'hagarde':2 'regarde':4"
    result = " ".join(["'{}':{}".format(k, result_dict[k])
                       for k in result_dict])

    return result


def put_session_message(session_key, message, message_type):
    session = SessionStore(session_key=session_key)
    messages = []
    if 'messages' in session:
        messages = session['messages'][:]
    messages.append((unicode(message), message_type))
    session['messages'] = messages
    session.save()


def put_session_var(session_key, key, value):
    session = SessionStore(session_key=session_key)
    session[key] = value
    session.save()


def get_session_var(session_key, key):
    session = SessionStore(session_key=session_key)
    if key not in session:
        return
    return session[key]


def clean_session_cache(session):
    # clean session cache
    cache_key_list = 'sessionlist-{}'.format(session.session_key)
    key_list = cache.get(cache_key_list, [])
    for key in key_list:
        cache.set(key, None, settings.CACHE_TIMEOUT)
    cache.set(cache_key_list, [], settings.CACHE_TIMEOUT)


def get_field_labels_from_path(model, path):
    """
    :param model: base model
    :param path: list of attribute starting from the base model
    :return: list of labels
    """
    labels = []
    for key in path:
        try:
            field = model._meta.get_field(key)
        except:
            labels.append(key)
            continue
        if hasattr(field, 'verbose_name'):
            labels.append(field.verbose_name)
        else:
            labels.append(key)
    return labels


def create_default_areas(models=None, verbose=False):
    # can be used on migrations if models are provided
    if not models:
        from ishtar_common.models import Area, Town, Department, State
    else:
        Area = models['area']
        Town = models['town']
        Department = models['department']
        State = models['state']

    areas = {}

    idx = 0
    for state in State.objects.all():
        slug = 'state-' + slugify(state.label)
        area, created = Area.objects.get_or_create(
            txt_idx=slug, defaults={'label': state.label})
        areas['state-{}'.format(state.pk)] = area
        if created:
            idx += 1
    if verbose:
        print("\n* {} state areas added".format(idx))

    idx, idx2 = 0, 0
    for dep in Department.objects.all():
        slug = 'dep-' + slugify(dep.label)
        area, created = Area.objects.get_or_create(
            txt_idx=slug, defaults={'label': dep.label})
        areas['dep-' + dep.number] = area
        if created:
            idx += 1
        if not dep.state_id:
            continue
        state_slug = 'state-{}'.format(dep.state_id)
        if state_slug not in areas:
            continue
        if area.parent and area.parent.pk == areas[state_slug].pk:
            continue
        idx2 += 1
        area.parent = areas[state_slug]
        area.save()
    if verbose:
        print(
            "* {} department areas added with {} associations to state".format(
                idx, idx2)
        )

    idx = 0
    for town in Town.objects.all():
        if not town.numero_insee or len(town.numero_insee) != 5:
            continue
        code_dep = 'dep-' + town.numero_insee[:2]
        code_dep_dom = 'dep-' + town.numero_insee[:3]
        if code_dep in areas:
            if not areas[code_dep].towns.filter(pk=town.pk).count():
                areas[code_dep].towns.add(town)
                idx += 1
        elif code_dep_dom in areas:
            if not areas[code_dep_dom].towns.filter(pk=town.pk).count():
                areas[code_dep_dom].towns.add(town)
                idx += 1

    if verbose:
        print("* {} town associated to department area".format(idx))


def get_relations_for_graph(rel_model, obj_pk, above_relations=None,
                            equal_relations=None, treated=None, styles=None):
    """
    Get all above and equal relations of an object (get all child and parent
    relations)
    :param rel_model: the relation model concerned
    :param obj_pk: id of an object with relations
    :param above_relations: list of current above_relations
    :param equal_relations: list of current equal_relations
    :param treated: treated relation list to prevent circular call
    :param styles: current styles
    :return: above and equal relations list (each containing lists of two
    members)
    """
    if not above_relations:
        above_relations = []
    if not equal_relations:
        equal_relations = []
    if not treated:
        treated = []
    if not styles:
        styles = {}
    if obj_pk in treated:
        return above_relations, equal_relations, styles

    treated.append(obj_pk)
    q = rel_model.objects.filter(
        left_record_id=obj_pk,
        relation_type__logical_relation__isnull=False
    ).values('right_record_id', 'relation_type__logical_relation')
    if not q.count():
        return [], []
    for relation in q.all():
        logical_relation = relation['relation_type__logical_relation']
        right_record = relation['right_record_id']
        if not logical_relation:
            continue
        elif logical_relation == 'above'and \
                (obj_pk, right_record) not in above_relations:
            above_relations.append((obj_pk, right_record))
        elif logical_relation == 'bellow' and \
                (right_record, obj_pk) not in above_relations:
            above_relations.append((right_record, obj_pk))
        elif logical_relation == 'equal' and \
                (right_record, obj_pk) not in equal_relations and \
                (obj_pk, right_record) not in equal_relations:
            equal_relations.append((obj_pk, right_record))
        else:
            continue
        ar, er, substyles = get_relations_for_graph(
            rel_model, right_record, above_relations, equal_relations, treated,
            styles
        )
        styles.update(substyles)
        error_style = "color=red"
        for r in ar:
            if r not in above_relations:
                above_relations.append(r)
            reverse_rel = tuple(reversed(r))
            if reverse_rel in above_relations:
                # circular
                if r not in styles:
                    styles[r] = []
                if reverse_rel not in styles:
                    styles[reverse_rel] = []

                if error_style not in styles[r]:
                    styles[r].append(error_style)
                if error_style not in styles[reverse_rel]:
                    styles[reverse_rel].append(error_style)
            if r[0] == r[1]:
                # same entity
                if r not in styles:
                    styles[r] = []
                if error_style not in styles[r]:
                    styles[r].append("color=red")
        for r in er:
            if r not in equal_relations:
                equal_relations.append(r)
    return above_relations, equal_relations, styles


def generate_relation_graph(obj, debug=False):
    if not settings.DOT_BINARY:
        return

    model = obj.__class__
    rel_model = model._meta.get_field('right_relations').related_model

    # get relations
    above_relations, equal_relations, styles = get_relations_for_graph(
        rel_model, obj.pk)
    print(styles)
    if not above_relations and not equal_relations:
        obj.relation_image = None
        obj.save()
        return

    # generate dotfile
    dot_str = "digraph relations {\nnode [shape=box];\n"
    rel_str = ""
    described = []
    for list, directed in ((above_relations, True),
                           (equal_relations, False)):
        if directed:
            rel_str += "subgraph Dir {\n"
        else:
            rel_str += "subgraph NoDir {\nedge [dir=none,style=dashed];\n"
        for left_pk, right_pk in list:
            if left_pk not in described:
                described.append(left_pk)
                left = model.objects.get(pk=left_pk)
                style = 'label="{}"'.format(left.relation_label)
                if left.pk == obj.pk:
                    style += ',style=filled,fillcolor="#C6C0C0"'
                dot_str += u'item{}[{}];\n'.format(left.pk, style)
            if right_pk not in described:
                described.append(right_pk)
                right = model.objects.get(pk=right_pk)
                style = 'label="{}"'.format(right.relation_label)
                if right.pk == obj.pk:
                    style += ',style=filled,fillcolor="#C6C0C0"'
                dot_str += u'item{}[{}];\n'.format(right.pk, style)
            if not directed:  # on the same level
                rel_str += u"{{rank = same; item{}; item{};}}\n".format(
                    left_pk, right_pk)
            style = ""
            if (left_pk, right_pk) in styles:
                style = " [{}]".format(", ".join(styles[(left_pk, right_pk)]))
            rel_str += u'item{} -> item{}{};\n'.format(left_pk, right_pk, style)
        rel_str += "}\n"
    dot_str += rel_str + "\n}"

    tempdir = tempfile.mkdtemp("-ishtardot")
    dot_name = tempdir + os.path.sep + "relations.dot"
    with open(dot_name, 'w') as dot_file:
        dot_file.write(dot_str)

    # execute dot program
    args = (settings.DOT_BINARY, "-Tsvg", dot_name)

    svg_tmp_name = tempdir + os.path.sep + "relations.svg"

    with open(svg_tmp_name, "w") as svg_file:
        popen = subprocess.Popen(args, stdout=svg_file)
        popen.wait()

    with open(svg_tmp_name, "r") as svg_file:
        django_file = File(svg_file)
        obj.relation_image.save("relations.svg", django_file, save=True)

    if debug:
        print(u"DOT file: {}. Tmp SVG file: {}.".format(dot_name, svg_tmp_name))
        return
    shutil.rmtree(tempdir)


def create_default_json_fields(model):
    """
    Create default json field configuration in existing database
    :param model: model concerned
    """
    from ishtar_common.models import JsonDataField

    def _get_keys(data, current_path=""):
        keys = []
        for key in data.keys():
            if type(data[key]) == dict:
                keys += _get_keys(data[key], current_path + key + "__")
                continue
            keys.append(current_path + key)
        return keys

    keys = []
    for item in model.objects.all():
        for key in _get_keys(item.data):
            if key not in keys:
                keys.append(key)

    content_type = ContentType.objects.get_for_model(model)
    for key in keys:
        JsonDataField.objects.get_or_create(
            content_type=content_type, key=key,
            defaults={
                'name': u" ".join(key.split('__')).capitalize(),
                'value_type': 'T',
                'display': False
            }
        )


def get_urls_for_model(model, views, own=False, autocomplete=False,
                       ):
    """
    Generate get and show url for a model
    """
    urls = [
        url(r'show-{}(?:/(?P<pk>.+))?/(?P<type>.+)?$'.format(model.SLUG),
            check_rights(['view_' + model.SLUG, 'view_own_' + model.SLUG])(
                getattr(views, 'show_' + model.SLUG)),
            name="show-" + model.SLUG),
        url(r'^display-{}/(?P<pk>.+)/$'.format(model.SLUG),
            check_rights(['view_' + model.SLUG, 'view_own_' + model.SLUG])(
                getattr(views, 'display_' + model.SLUG)),
            name='display-' + model.SLUG),
    ]
    if own:
        urls += [
            url(r'get-{}/own/(?P<type>.+)?$'.format(model.SLUG),
                check_rights(['view_' + model.SLUG, 'view_own_' + model.SLUG])(
                    getattr(views, 'get_' + model.SLUG)),
                name="get-own-" + model.SLUG, kwargs={'force_own': True}),
        ]

    urls += [
        url(r'get-{}/(?P<type>.+)?$'.format(model.SLUG),
            check_rights(['view_' + model.SLUG, 'view_own_' + model.SLUG])(
                getattr(views, 'get_' + model.SLUG)),
            name="get-" + model.SLUG),
    ]

    if autocomplete:
        urls += [
            url(r'autocomplete-{}/$'.format(model.SLUG),
                check_rights(['view_' + model.SLUG, 'view_own_' + model.SLUG])(
                    getattr(views, 'autocomplete_' + model.SLUG)),
                name='autocomplete-' + model.SLUG),
        ]

    return urls


def m2m_historization_changed(sender, **kwargs):
    obj = kwargs.get('instance', None)
    if not obj:
        return
    hist_values = obj.history_m2m or {}
    for attr in obj.HISTORICAL_M2M:
        values = []
        for value in getattr(obj, attr).all():
            if not hasattr(value, "history_compress"):
                continue
            values.append(value.history_compress())
        hist_values[attr] = values
    obj.history_m2m = hist_values
    if getattr(obj, 'skip_history_when_saving', False):
        # assume the last modifier is good...
        q = obj.history.filter(
            history_modifier_id=obj.history_modifier_id,
        ).order_by('-history_date', '-history_id')
        if q.count():
            hist = q.all()[0]
            hist.history_m2m = hist_values
            hist.history_date = hist.last_modified = datetime.datetime.now()
            hist.save()
            obj.skip_history_when_saving = True
    elif not obj.history_modifier:
        obj.skip_history_when_saving = True
    obj.save()


def max_size_help():
    msg = unicode(_(u"The maximum supported file size is {} Mo.")).format(
        settings.MAX_UPLOAD_SIZE
    )
    return msg


def find_all_symlink(dirname):
    for name in os.listdir(dirname):
        if name not in (os.curdir, os.pardir):
            full = os.path.join(dirname, name)
            if os.path.islink(full):
                yield full, os.readlink(full)


MEDIA_RE = [
    re.compile(r"_[a-zA-Z0-9]{7}\-[0-9]"),
    re.compile(r"_[a-zA-Z0-9]{7}"),
]


def simplify_name(full_path_name, check_existing=False):
    """
    Simplify a file name by removing auto save suffixes

    :param full_path_name: full path name
    :param check_existing: prevent to give name of an existing file
    :return:
    """
    name_exp = full_path_name.split(os.sep)
    path = os.sep.join(name_exp[0:-1])
    name = name_exp[-1]
    current_name = name[:]
    ext = ""
    if u"." in name:  # remove extension if have one
        names = name.split(u".")
        name = u".".join(names[0:-1])
        ext = u"." + names[-1]

    while u"_" in name and len(name) > 15:
        oldname = name[:]
        for regex in MEDIA_RE:
            match = None
            for m in regex.finditer(name):  # get the last match
                match = m
            if match:
                new_name = name.replace(match.group(), '')
                full_new_name = os.sep.join([path, new_name + ext])
                if not check_existing or not os.path.isfile(full_new_name):
                    # do not take the place of another file
                    name = new_name[:]
                    break
        if oldname == name:
            break
    return path, current_name, name + ext


def rename_and_simplify_media_name(full_path_name, rename=True):
    """
    Simplify the name if possible
    :param full_path_name: full path name
    :param rename: rename file if True (default: True)
    :return: new full path name (or old if not changed), modified
    """
    if not os.path.exists(full_path_name) or not os.path.isfile(full_path_name):
        return full_path_name, False

    path, current_name, name = simplify_name(full_path_name,
                                             check_existing=True)
    if current_name == name:
        return full_path_name, False

    full_new_name = os.sep.join([path, name])
    if rename:
        os.rename(full_path_name, full_new_name)
    return full_new_name, True


def get_file_fields():
    """
    Get all fields which are inherited from FileField
    """
    all_models = apps.get_models()
    fields = []
    for model in all_models:
        for field in model._meta.get_fields():
            if isinstance(field, models.FileField):
                fields.append(field)
    return fields


def get_used_media(exclude=None, limit=None,
                   return_object_and_field=False, debug=False):
    """
    Get media which are still used in models

    :param exclude: exclude fields, ex: ['ishtar_common.Import.imported_file',
    'ishtar_common.Import.imported_images']
    :param limit: limit to some fields
    :param return_object_and_field: return associated object and field name
    :return: list of media filename or if return_object_and_field is set to
    True return (object, file field name, media filename)
    """

    if return_object_and_field:
        media = []
    else:
        media = set()
    for field in get_file_fields():
        if exclude and unicode(field) in exclude:
            continue
        if limit and unicode(field) not in limit:
            continue
        is_null = {'%s__isnull' % field.name: True}
        is_empty = {'%s' % field.name: ''}

        storage = field.storage
        if debug:
            print("")
        q = field.model.objects.values('id', field.name)\
            .exclude(**is_empty).exclude(**is_null)
        ln = q.count()
        for idx, res in enumerate(q):
            value = res[field.name]
            if debug:
                sys.stdout.write("* get_used_media {}: {}/{}\r".format(
                    field, idx, ln))
                sys.stdout.flush()
            if value not in EMPTY_VALUES:
                if return_object_and_field:
                    media.append((
                        field.model.objects.get(pk=res['id']),
                        field.name,
                        storage.path(value)
                    ))
                else:
                    media.add(storage.path(value))
    return media


def get_all_media(exclude=None, debug=False):
    """
    Get all media from MEDIA_ROOT
    """

    if not exclude:
        exclude = []

    media = set()
    full_dirs = list(os.walk(six.text_type(settings.MEDIA_ROOT)))
    ln_full = len(full_dirs)
    for idx_main, full_dir in enumerate(full_dirs):
        root, dirs, files = full_dir
        ln = len(files)
        if debug:
            print("")
        for idx, name in enumerate(files):
            if debug:
                sys.stdout.write("* get_all_media {} ({}/{}): {}/{}\r".format(
                    root.encode('utf-8'), idx_main, ln_full, idx, ln))
                sys.stdout.flush()
            path = os.path.abspath(os.path.join(root, name))
            relpath = os.path.relpath(path, settings.MEDIA_ROOT)
            in_exclude = False
            for e in exclude:
                if re.match(r'^%s$' % re.escape(e).replace('\\*', '.*'),
                            relpath):
                    in_exclude = True
                    break

            if not in_exclude:
                media.add(path)
        else:
            if debug:
                sys.stdout.write("* get_all_media {} ({}/{})\r".format(
                    root.encode('utf-8'), idx_main, ln_full))
    return media


def get_unused_media(exclude=None):
    """
    Get media which are not used in models
    """

    if not exclude:
        exclude = []

    all_media = get_all_media(exclude)
    used_media = get_used_media()

    return [x for x in all_media if x not in used_media]


def remove_unused_media():
    """
    Remove unused media
    """
    remove_media(get_unused_media())


def remove_media(files):
    """
    Delete file from media dir
    """
    for filename in files:
        os.remove(os.path.join(settings.MEDIA_ROOT, filename))


def remove_empty_dirs(path=None):
    """
    Recursively delete empty directories; return True if everything was deleted.
    """

    if not path:
        path = settings.MEDIA_ROOT

    if not os.path.isdir(path):
        return False

    listdir = [os.path.join(path, filename) for filename in os.listdir(path)]

    if all(list(map(remove_empty_dirs, listdir))):
        os.rmdir(path)
        return True
    else:
        return False


def try_fix_file(filename, make_copy=True):
    """
    Try to find a file with a similar name on the same dir.

    :param filename: filename (full path)
    :param make_copy: make the copy of the similar file found
    :return: name of the similar file found or None
    """
    path, current_name, simplified_ref_name = simplify_name(
        filename, check_existing=False)

    # check existing files in the path
    for file in sorted(list(os.listdir(path))):
        full_file = os.sep.join([path, file])
        if not os.path.isfile(full_file):  # must be a file
            continue
        _, _, name = simplify_name(full_file, check_existing=False)
        if simplified_ref_name.lower() == name.lower():
            # a candidate is found
            if make_copy:
                shutil.copy2(full_file, filename)
            return file