# -*- coding: utf-8 -*-

"""This module provides tools to import tabular data.

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

Example of use (run this with `cubicweb-ctl shell instance import-script.py`):

.. sourcecode:: python

  # define data generators

  GENERATORS = []

  USERS = [('Prenom', 'firstname', ()),

           ('Nom', 'surname', ()),

           ('Identifiant', 'login', ()),

           ]

  def gen_users(ctl):

      for row in ctl.get_data('utilisateurs'):

          entity = mk_entity(row, USERS)

          entity['upassword'] = u'motdepasse'

          ctl.check('login', entity['login'], None)

          ctl.store.add('CWUser', entity)

          email = {'address': row['email']}

          ctl.store.add('EmailAddress', email)

          ctl.store.relate(entity['eid'], 'use_email', email['eid'])

          ctl.store.rql('SET U in_group G WHERE G name "users", U eid %(x)s', {'x':entity['eid']})

  CHK = [('login', check_doubles, 'Utilisateurs Login',

          'Deux utilisateurs ne devraient pas avoir le même login.'),

         ]

  GENERATORS.append( (gen_users, CHK) )

  # create controller

  ctl = CWImportController(RQLObjectStore())

  ctl.askerror = True

  ctl.generators = GENERATORS

  ctl.store._checkpoint = checkpoint

  ctl.store._rql = rql

  ctl.data['utilisateurs'] = lazytable(utf8csvreader(open('users.csv')))

  # run

  ctl.run()

  sys.exit(0)

"""

__docformat__ = "restructuredtext en"

import sys, csv, traceback

from logilab.common import shellutils

def utf8csvreader(file, encoding='utf-8', separator=',', quote='"'):

    """A csv reader that accepts files with any encoding and outputs

    unicode strings."""

    for row in csv.reader(file, delimiter=separator, quotechar=quote):

        yield [item.decode(encoding) for item in row]

def lazytable(reader):

    """The first row is taken to be the header of the table and

    used to output a dict for each row of data.

    >>> data = lazytable(utf8csvreader(open(filename)))

    """

    header = reader.next()

    for row in reader:

        yield dict(zip(header, row))

# base sanitizing functions #####

def capitalize_if_unicase(txt):

    if txt.isupper() or txt.islower():

        return txt.capitalize()

    return txt

def no_space(txt):

    return txt.replace(' ','')

def no_uspace(txt):

    return txt.replace(u'\xa0','')

def no_dash(txt):

    return txt.replace('-','')

def alldigits(txt):

    if txt.isdigit():

        return txt

    else:

        return u''

def strip(txt):

    return txt.strip()

# base checks #####

def check_doubles(buckets):

    """Extract the keys that have more than one item in their bucket."""

    return [(key, len(value)) for key,value in buckets.items() if len(value) > 1]

# make entity helper #####

def mk_entity(row, map):

    """Return a dict made from sanitized mapped values.

    >>> row = {'myname': u'dupont'}

    >>> map = [('myname', u'name', (capitalize_if_unicase,))]

    >>> mk_entity(row, map)

    {'name': u'Dupont'}

    """

    res = {}

    for src, dest, funcs in map:

        res[dest] = row[src]

        for func in funcs:

            res[dest] = func(res[dest])

    return res

# object stores

class ObjectStore(object):

    """Store objects in memory for faster testing. Will not

    enforce the constraints of the schema and hence will miss

    some problems.

    >>> store = ObjectStore()

    >>> user = {'login': 'johndoe'}

    >>> store.add('CWUser', user)

    >>> group = {'name': 'unknown'}

    >>> store.add('CWUser', group)

    >>> store.relate(user['eid'], 'in_group', group['eid'])

    """

    def __init__(self):

        self.items = []

        self.eids = {}

        self.types = {}

        self.relations = set()

        self.indexes = {}

        self._rql = None

        self._checkpoint = None

    def _put(self, type, item):

        self.items.append(item)

        return len(self.items) - 1

    def add(self, type, item):

        assert isinstance(item, dict), item

        eid = item['eid'] = self._put(type, item)

        self.eids[eid] = item

        self.types.setdefault(type, []).append(eid)

    def relate(self, eid_from, rtype, eid_to):

        eids_valid = (eid_from < len(self.items) and eid_to <= len(self.items))

        assert eids_valid, 'eid error %s %s' % (eid_from, eid_to)

        self.relations.add( (eid_from, rtype, eid_to) )

    def build_index(self, name, type, func):

        index = {}

        for eid in self.types[type]:

            index.setdefault(func(self.eids[eid]), []).append(eid)

        self.indexes[name] = index

    def get_many(self, name, key):

        return self.indexes[name].get(key, [])

    def get_one(self, name, key):

        eids = self.indexes[name].get(key, [])

        assert len(eids) == 1

        return eids[0]

    def find(self, type, key, value):

        for idx in self.types[type]:

            item = self.items[idx]

            if item[key] == value:

                yield item

    def rql(self, query, args):

        if self._rql:

            return self._rql(query, args)

    def checkpoint(self):

        if self._checkpoint:

            self._checkpoint()

class RQLObjectStore(ObjectStore):

    """ObjectStore that works with an actual RQL repository."""

    def _put(self, type, item):

        query = ('INSERT %s X: ' % type) + ', '.join(['X %s %%(%s)s' % (key,key) for key in item])

        return self.rql(query, item)[0][0]

    def relate(self, eid_from, rtype, eid_to):

        query = 'SET X %s Y WHERE X eid %%(from)s, Y eid %%(to)s' % rtype

        self.rql(query, {'from': int(eid_from), 'to': int(eid_to)})

        self.relations.add( (eid_from, rtype, eid_to) )

# import controller #####

class CWImportController(object):

    """Controller of the data import process.

    >>> ctl = CWImportController(store)

    >>> ctl.generators = list_of_data_generators

    >>> ctl.data = dict_of_data_tables

    >>> ctl.run()

    """

    def __init__(self, store):

        self.store = store

        self.generators = None

        self.data = {}

        self.errors = None

        self.askerror = False

    def check(self, type, key, value):

        self._checks.setdefault(type, {}).setdefault(key, []).append(value)

    def check_map(self, entity, key, map, default):

        try:

            entity[key] = map[entity[key]]

        except KeyError:

            self.check(key, entity[key], None)

            entity[key] = default

    def run(self):

        self.errors = {}

        for func, checks in self.generators:

            self._checks = {}

            func_name = func.__name__[4:]

            question = 'Importation de %s' % func_name

            self.tell(question)

            try:

                func(self)

            except:

                import StringIO

                tmp = StringIO.StringIO()

                traceback.print_exc(file=tmp)

                print tmp.getvalue()

                self.errors[func_name] = ('Erreur lors de la transformation',

                                          tmp.getvalue().splitlines())

            for key, func, title, help in checks:

                buckets = self._checks.get(key)

                if buckets:

                    err = func(buckets)

                    if err:

                        self.errors[title] = (help, err)

            self.store.checkpoint()

        errors = sum(len(err[1]) for err in self.errors.values())

        self.tell('Importation terminée. (%i objets, %i types, %i relations et %i erreurs).'

                  % (len(self.store.eids), len(self.store.types),

                     len(self.store.relations), errors))

        if self.errors and self.askerror and confirm('Afficher les erreurs ?'):

            import pprint

            pprint.pprint(self.errors)

    def get_data(self, key):

        return self.data.get(key)

    def index(self, name, key, value):

        self.store.indexes.setdefault(name, {}).setdefault(key, []).append(value)

    def tell(self, msg):

        self._tell(msg)

def confirm(question):

    """A confirm function that asks for yes/no/abort and exits on abort."""

    answer = shellutils.ASK.ask(question, ('Y','n','abort'), 'Y')

    if answer == 'abort':

        sys.exit(1)

    return answer == 'Y'