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

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

:organization: Logilab

:copyright: 2001-2010 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

  from cubicweb.devtools.dataimport import *

  # 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 = 1

  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)

.. BUG fichier à une colonne pose un problème de parsing

.. TODO rollback()

"""

__docformat__ = "restructuredtext en"

import sys

import csv

import traceback

import os.path as osp

from StringIO import StringIO

from logilab.common import shellutils

from logilab.common.deprecation import deprecated

def ucsvreader_pb(filepath, encoding='utf-8', separator=',', quote='"',

                  skipfirst=False, withpb=True):

    """same as ucsvreader but a progress bar is displayed as we iter on rows"""

    if not osp.exists(filepath):

        raise Exception("file doesn't exists: %s" % filepath)

    rowcount = int(shellutils.Execute('wc -l "%s"' % filepath).out.strip().split()[0])

    if skipfirst:

        rowcount -= 1

    if withpb:

        pb = shellutils.ProgressBar(rowcount, 50)

    for urow in ucsvreader(file(filepath), encoding, separator, quote, skipfirst):

        yield urow

        if withpb:

            pb.update()

    print ' %s rows imported' % rowcount

def ucsvreader(stream, encoding='utf-8', separator=',', quote='"',

               skipfirst=False):

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

    strings

    """

    it = iter(csv.reader(stream, delimiter=separator, quotechar=quote))

    if skipfirst:

        it.next()

    for row in it:

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

utf8csvreader = deprecated('use ucsvreader instead')(ucsvreader)

def commit_every(nbit, store, it):

    for i, x in enumerate(it):

        yield x

        if nbit is not None and i % nbit:

            store.checkpoint()

    if nbit is not None:

        store.checkpoint()

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))

def mk_entity(row, map):

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

    ValidationError can be raised on unexpected values found in checkers

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

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

    >>> mk_entity(row, map)

    {'name': u'Dupont'}

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

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

    ...        ('optname', u'MARKER', (optional,))]

    >>> mk_entity(row, map)

    {'name': u'Dupont'}

    """

    res = {}

    assert isinstance(row, dict)

    assert isinstance(map, list)

    for src, dest, funcs in map:

        assert not (required in funcs and optional in funcs), "optional and required checks are exclusive"

        res[dest] = row[src]

        try:

            for func in funcs:

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

            if res[dest] is None or res[dest]==False:

                raise AssertionError('undetermined value')

        except AssertionError, err:

            if optional in funcs:

                # Forget this field if exception is coming from optional function

               del res[dest]

            else:

               raise AssertionError('error with "%s" field: %s' % (src, err))

    return res

# user interactions ############################################################

def tell(msg):

    print 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'

class catch_error(object):

    """Helper for @contextmanager decorator."""

    def __init__(self, ctl, key='unexpected error', msg=None):

        self.ctl = ctl

        self.key = key

        self.msg = msg

    def __enter__(self):

        return self

    def __exit__(self, type, value, traceback):

        if type is not None:

            if issubclass(type, (KeyboardInterrupt, SystemExit)):

                return # re-raise

            if self.ctl.catcherrors:

                self.ctl.record_error(self.key, None, type, value, traceback)

                return True # silent

# base sanitizing functions ####################################################

def capitalize_if_unicase(txt):

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

        return txt.capitalize()

    return txt

def uppercase(txt):

    return txt.upper()

def lowercase(txt):

    return txt.lower()

def no_space(txt):

    return txt.replace(' ','')

def no_uspace(txt):

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

def no_dash(txt):

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

def decimal(value):

    """cast to float but with comma replacement

    We take care of some locale format as replacing ',' by '.'"""

    value = value.replace(',', '.')

    try:

        return float(value)

    except Exception, err:

        raise AssertionError(err)

def integer(value):

    try:

        return int(value)

    except Exception, err:

        raise AssertionError(err)

def strip(txt):

    return txt.strip()

def yesno(value):

    return value.lower()[0] in 'yo1'

def isalpha(value):

    if value.isalpha():

        return value

    raise AssertionError("not all characters in the string alphabetic")

def optional(value):

    """validation error will not been raised if you add this checker in chain"""

    return value

def required(value):

    """raise AssertionError is value is empty

    This check should be often found in last position in the chain.

    """

    if bool(value):

        return value

    raise AssertionError("required")

@deprecated('use required(value)')

def nonempty(value):

    return required(value)

@deprecated('use integer(value)')

def alldigits(txt):

    if txt.isdigit():

        return txt

    else:

        return u''

# base integrity checking functions ############################################

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]

def check_doubles_not_none(buckets):

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

    return [(key, len(value)) for key,value in buckets.items() if key is not None and len(value) > 1]

# object stores #################################################################

class ObjectStore(object):

    """Store objects in memory for *faster* validation (development mode)

    But it 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 is not a dict but a %s' % type(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):

        """Add new relation (reverse type support is available)

        >>> 1,2 = eid_from, eid_to

        >>> self.relate(eid_from, 'in_group', eid_to)

        1, 'in_group', 2

        >>> self.relate(eid_from, 'reverse_in_group', eid_to)

        2, 'in_group', 1

        """

        if rtype.startswith('reverse_'):

            eid_from, eid_to = eid_to, eid_from

            rtype = rtype[8:]

        relation = eid_from, rtype, eid_to

        self.relations.add(relation)

        return relation

    def build_index(self, name, type, func=None):

        index = {}

        if func is None or not callable(func):

            func = lambda x: x['eid']

        for eid in self.types[type]:

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

        assert index, "new index '%s' cannot be empty" % name

        self.indexes[name] = index

    def build_rqlindex(self, name, type, key, rql, rql_params=False, func=None):

        """build an index by rql query

        rql should return eid in first column

        ctl.store.build_index('index_name', 'users', 'login', 'Any U WHERE U is CWUser')

        """

        rset = self.rql(rql, rql_params or {})

        for entity in rset.entities():

            getattr(entity, key) # autopopulate entity with key attribute

            self.eids[entity.eid] = dict(entity)

            if entity.eid not in self.types.setdefault(type, []):

                self.types[type].append(entity.eid)

        assert self.types[type], "new index type '%s' cannot be empty (0 record found)" % type

        # Build index with specified key

        func = lambda x: x[key]

        self.build_index(name, type, func)

    @deprecated('get_many() deprecated. Use fetch() instead')

    def get_many(self, name, key):

        return self.fetch(name, key, unique=False)

    @deprecated('get_one() deprecated. Use fetch(..., unique=True) instead')

    def get_one(self, name, key):

        return self.fetch(name, key, unique=True)

    def fetch(self, name, key, unique=False, decorator=None):

        """

            decorator is a callable method or an iterator of callable methods (usually a lambda function)

            decorator=lambda x: x[:1] (first value is returned)

            We can use validation check function available in _entity

        """

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

        if decorator is not None:

            if not hasattr(decorator, '__iter__'):

                decorator = (decorator,)

            for f in decorator:

                eids = f(eids)

        if unique:

            assert len(eids) == 1, u'expected a single one value for key "%s" in index "%s". Got %i' % (key, name, len(eids))

            eids = eids[0] # FIXME maybe it's better to keep an iterator here ?

        return eids

    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, *args):

        if self._rql is not None:

            return self._rql(*args)

    def checkpoint(self):

        pass

class RQLObjectStore(ObjectStore):

    """ObjectStore that works with an actual RQL repository (production mode)"""

    _rql = None # bw compat

    def __init__(self, session=None, checkpoint=None):

        ObjectStore.__init__(self)

        if session is not None:

            if not hasattr(session, 'set_pool'):

                # connection

                cnx = session

                session = session.request()

                session.set_pool = lambda : None

                checkpoint = checkpoint or cnx.commit

            self.session = session