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

#

# Copyright IRI (c) 2013

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# This software is governed by the CeCILL-B license under French law and

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#

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from rdflib.plugins.sparql.processor import prepareQuery

from rdflib.term import URIRef

from p4l.models.data import Language, Record

from p4l.models import signals

class QueryCache(object):

    def __init__(self, *args, **kwargs):

        self.__query_cache = {}

    def get_sparql_query(self, query, namespaces_dict):

        return self.__query_cache.get(query, False) \

            or self.__query_cache.setdefault(query, prepareQuery(query, initNs=namespaces_dict))

def convert_bool(val):

    if val == True or val == False:

        return val

    if val is None:

        return False

    if isinstance(val, basestring):

        if len(val) == 0:

            return False

        if val[0].lower() in ['t','y','1','o']:

            return True

        else:

            return False        

    return bool(val)

class RecordParser(object):

    def __init__(self, query_cache = None):

        self.query_cache = None

        if self.query_cache is None:

            self.query_cache = QueryCache()        

    def extract_single_value_form_graph(self, graph, q, bindings={}, index=0, convert=lambda v:unicode(v) if v is not None else None, default=None):

        '''

        Extract a single value form an rdf graph.

        :param graph: the rdflib.Graph object to parse

        :param q: the SPARQL query used to extact the data from the graph

        :param bindings: Optional binding values for the query

        :param index: zero based index of the result to extract

        :param convert: Either a single method of a map of method to apply to the data to extract 

        :param default: The default value to return if no result is returned by the query

        @return: None or a single value        

        '''

        return next(self.extract_multiple_values_from_graph(graph, q, bindings, index, convert), default)

    def extract_multiple_values_from_graph(self, graph, q, bindings={}, index=0, convert=lambda v:unicode(v) if v is not None else None):

        '''

        Extract multiple values from a rdf graph.

        :param graph: the rdflib.Graph object to parse

        :param q: the SPARQL query used to extact the data from the graph

        :param bindings: Optional binding values for the query

        :param index:  zero based index of the result to extract

        :param convert: The default value to return if no result is returned by the query

        @return: an iterator on the extracted values

        '''

        index_list = index

        if isinstance(index, int):

            index_list = range(index+1)

        if hasattr(convert, '__call__'):

            convert_dict = dict((k, convert) for k in index_list)

        else:

            convert_dict = convert

        convert_dict = dict((k, f if hasattr(f,'__call__') else lambda v:unicode(v) if v is not None else None) for k,f in convert_dict.iteritems())

        for row in graph.query(self.query_cache.get_sparql_query(q, dict(graph.namespaces())), initBindings=bindings):

            if len(row) < len(index_list):

                break

            else:

                res = dict([ (k, convert_dict.get(k, lambda v:unicode(v) if v is not None else None)(v)) for k, v in zip(index_list, row)])

                if isinstance(index, int):

                    yield res[index]

                else:

                    yield res

    def convert_bool(self, val):

        if val == True or val == False:

            return val

        if val is None:

            return False

        if isinstance(val, basestring):

            if len(val) == 0:

                return False

            if val[0].lower() in ['t','y','1','o']:

                return True

            else:

                return False        

        return bool(val)

    def add_to_related_collection(self, coll, graph, fields, q, bindings={},  convert=lambda v: unicode(v) if v is not None else None, through_fields=None):

        '''

        This method add new object to a related object collection by extracting data from an rdflib.Graph.

        :param coll: The collection to add the new objects into. This must be a related collection (cf. django)

        :param graph: The graph from wich data is extracted

        :param fields: The list of fields to extract

        :param q: The SPAQL query. The order and number of the binding parameters of the query must be equals to the one descibed in the ``fields`` parameter.

        :param bindings: Binding for the SPARQL qery

        :param convert: map of methods or simple method  to convert data extracted form the graph.

        :param through_fields: the list (in order) of the througt table used to make a relation between the main object and an "external" object.

        '''

        for val in self.extract_multiple_values_from_graph(graph, q, bindings=bindings, index=fields, convert=convert):

            if through_fields:                

                new_obj_val = dict([(k,v) for k,v in val.iteritems() if k not in through_fields])

            else:

                new_obj_val = val

            if hasattr(coll, 'through'):

                new_obj_rel, _ = coll.model.objects.get_or_create(**new_obj_val)

                if through_fields:

                    through_vals = {coll.source_field_name: coll.instance, coll.target_field_name: new_obj_rel}

                    through_vals.update(dict([(k,v) for k,v in val.iteritems() if k in through_fields]))

                    coll.through.objects.create(**through_vals)

                    new_obj = None

                else:

                    new_obj = new_obj_rel

            else:

                new_obj = coll.create(**new_obj_val)

            if new_obj:

                coll.add(new_obj)

    def build_record(self, graph, delete=True):

        record_uri = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?s WHERE { ?s rdf:type iiep:Record .}")

        record_identifier = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s dct:identifier ?o .}", bindings={'s':URIRef(record_uri)})

        if delete:

            Record.objects.filter(identifier=record_identifier).delete()

        record = Record()

        record.uri = record_uri

        record.identifier = record_identifier

        record.notes = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:notes ?o .}", bindings={'s':URIRef(record.uri)})

        record.recordType = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s dct:type ?o .}", bindings={'s':URIRef(record.uri)})

        record.isDocumentPart = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:isDocumentPart ?o .}", bindings={'s':URIRef(record.uri)}, convert=self.convert_bool, default=False)

        record.hidden = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:hidden ?o .}", bindings={'s':URIRef(record.uri)}, convert=self.convert_bool, default=False)

        record.restricted = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:restricted ?o .}", bindings={'s':URIRef(record.uri)}, convert=self.convert_bool, default=False)

        record.editionStatement = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:editionStatement ?o .}", bindings={'s':URIRef(record.uri)})

        record.corporateAuthorLabel = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s iiep:corporateAuthorLabel ?o .}", bindings={'s':URIRef(record.uri)})

        language = self.extract_single_value_form_graph(graph,"SELECT DISTINCT ?o WHERE { ?s dct:language ?o .}", bindings={'s':URIRef(record.uri)})

        if language:

            record.language, _ = Language.objects.get_or_create(uri=language)

        record.save()

        self.add_to_related_collection(record.otherLanguages, graph,  ['uri'], "SELECT ?o WHERE { ?s iiep:otherLanguage ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.subjects, graph, ['uri'], "SELECT ?o WHERE { ?s dct:subject ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.themes, graph, ['uri'], "SELECT ?o WHERE { ?s iiep:theme ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.countries, graph,  ['uri'], "SELECT ?o WHERE { ?s iiep:country ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.authors, graph, ['name'], "SELECT ?o WHERE { ?s iiep:author ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.subjectPersons, graph, ['name'], "SELECT ?o WHERE { ?s iiep:subjectPerson ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(record.projectNames, graph, ['uri'], "SELECT ?o WHERE { ?s iiep:projectName ?o . }")

        self.add_to_related_collection(record.audiences, graph,  ['uri'], "SELECT ?o WHERE { ?s dct:audience ?o .}", bindings={'s':URIRef(record.uri)})

        self.add_to_related_collection(

            record.periodicals,

            graph, 

            ['label','lang'],

            "SELECT DISTINCT ?o  ( lang(?o) as ?l) WHERE { ?s iiep:periodical ?o .}",

            bindings={'s':URIRef(record.uri)}

        )

        self.add_to_related_collection(

            record.meetings,

            graph, 

            ['label', 'meetingNumber', 'meetingPlace', 'meetingDate', 'meetingYear', 'lang'],

            "SELECT ?l ?mn ?mp ?md ?my (lang(COALESCE(?l,?nm, ?mp,?md,?my)) as ?lang) WHERE { [iiep:meeting ?bnode]. OPTIONAL { ?bnode rdfs:label ?l }. OPTIONAL { ?bnode iiep:meetingNumber ?mn }. OPTIONAL { ?bnode iiep:meetingPlace ?mp }.  OPTIONAL { ?bnode iiep:meetingDate ?md }. OPTIONAL { ?bnode iiep:meetingYear ?my }}",

            convert={'meetingYear' : lambda y: int(y) if y is not None else None}

        )

        self.add_to_related_collection(

            record.series,

            graph, 

            ['title', 'volume', 'lang'],

            "SELECT ?t ?vol (lang(COALESCE(?t,?vol)) as ?lang) WHERE { [iiep:serie ?bnode]. OPTIONAL { ?bnode dct:title ?t }. OPTIONAL { ?bnode iiep:volume ?vol } }",

        )

        self.add_to_related_collection(

            record.subjectCorporateBodies,

            graph,

            ['uri'],

            "SELECT ?o WHERE { ?s iiep:subjectCorporateBody ?o. }",

            bindings={'s':URIRef(record.uri)}

        )

        self.add_to_related_collection(

            record.subjectMeetings,

            graph,

            ['label', 'meetingNumber', 'meetingPlace', 'meetingDate', 'meetingYear'],

            "SELECT ?l ?mn ?mp ?md ?my WHERE { [iiep:subjectMeeting ?bnode]. OPTIONAL { ?bnode rdfs:label ?l }. OPTIONAL { ?bnode iiep:meetingNumber ?mn }. OPTIONAL { ?bnode iiep:meetingPlace ?mp }.  OPTIONAL { ?bnode iiep:meetingDate ?md }. OPTIONAL { ?bnode iiep:meetingYear ?my }}",            

            convert={'meetingYear' : lambda y: int(y) if y is not None else None}

        )

        self.add_to_related_collection(

            record.corporateAuthors,

            graph,

            ['uri'],

            "SELECT ?o WHERE { ?s iiep:corporateAuthor ?o.}",

            bindings={'s':URIRef(record.uri)}            

        )

        self.add_to_related_collection(

            record.issns,

            graph,

            ['issn', 'lang'],

            "SELECT ?issn (lang(COALESCE(?issn)) as ?lang) WHERE { ?s iiep:issn ?issn . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.isbns,

            graph,

            ['isbn', 'lang'],

            "SELECT ?isbn (lang(COALESCE(?isbn)) as ?lang) WHERE { ?s iiep:isbn ?isbn . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.documentCodes,

            graph,

            ['documentCode', 'lang'],

            "SELECT ?c (lang(COALESCE(?c)) as ?lang) WHERE { ?s iiep:documentCode ?c . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.titles,

            graph,

            ['title', 'lang'],

            "SELECT ?t (lang(COALESCE(?t)) as ?lang) WHERE { ?s dct:title ?t . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.abstracts,

            graph,

            ['abstract', 'lang'],

            "SELECT ?t (lang(COALESCE(?t)) as ?lang) WHERE { ?s dct:abstract ?t . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.addedTitles,

            graph,

            ['title', 'lang'],

            "SELECT ?t (lang(COALESCE(?t)) as ?lang) WHERE { ?s iiep:addedTitle ?t . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.titlesMainDocument,

            graph,

            ['title', 'lang'],

            "SELECT ?t (lang(COALESCE(?t)) as ?lang) WHERE { ?s iiep:titleMainDocument ?t . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.imprints,

            graph,

            ['imprintCity', 'publisher', 'imprintDate', 'lang'],

            "SELECT ?c ?p ?d (lang(COALESCE(?c, ?p, ?d)) as ?lang) WHERE { [ iiep:imprint ?bnode ]. OPTIONAL { ?bnode iiep:imprintCity ?c }. OPTIONAL { ?bnode dct:publisher ?p }. OPTIONAL { ?bnode iiep:imprintDate ?d }}",

        )

        self.add_to_related_collection(

            record.collations,

            graph,

            ['collation', 'lang'],

            "SELECT ?c (lang(COALESCE(?c)) as ?lang) WHERE { ?s iiep:collation ?c . }",

            bindings={'s':URIRef(record.uri)},

        )

        self.add_to_related_collection(

            record.volumeIssues,

            graph,

            ['volume', 'number', 'lang'],

            "SELECT ?v ?n (lang(COALESCE(?v, ?n)) as ?lang) WHERE { [ iiep:volumeIssue ?bnode ]. OPTIONAL { ?bnode iiep:volume ?v }. OPTIONAL { ?bnode iiep:number ?n }}",

        )

        self.add_to_related_collection(

            record.urls,

            graph,

            ['address', 'display'],

            "SELECT ?a ?d WHERE { [ iiep:url ?bnode ]. OPTIONAL { ?bnode iiep:address ?a }. OPTIONAL { ?bnode iiep:display ?d }.}",

        )

        signals.record_saved.send(Record, instance=record, created=True)

        return record