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""" 

Wrappers for lucene Fields and Documents. 

""" 

 

from future_builtins import map, zip 

import datetime, calendar 

import collections 

import lucene 

from .queries import Query 

 

class Field(object): 

    """Saved parameters which can generate lucene Fields given values. 

     

    :param name: name of field 

    :param store,index,termvector: field parameters, expressed as bools or strs, with lucene defaults 

    :param analyzed,omitNorms: additional index boolean settings 

    :param withPositions,withOffsets: additional termvector boolean settings 

    :param attrs: additional attributes to set on the field 

    """ 

    def __init__(self, name, store=False, index='analyzed', termvector=False, analyzed=False, omitNorms=False, withPositions=False, withOffsets=False, **attrs): 

        self.name, self.attrs = name, attrs 

        if isinstance(store, bool): 

            store = 'yes' if store else 'no' 

        self.store = lucene.Field.Store.valueOf(store.upper()) 

        if isinstance(index, bool): 

            self.index = lucene.Field.Index.toIndex(index, analyzed, omitNorms) 

        else: 

            self.index = lucene.Field.Index.valueOf(index.upper()) 

        if isinstance(termvector, bool): 

            self.termvector = lucene.Field.TermVector.toTermVector(termvector, withOffsets, withPositions) 

        else: 

            self.termvector = lucene.Field.TermVector.valueOf(termvector.upper()) 

        next(Field.items(self, ' ')) # validate settings 

    def items(self, *values): 

        "Generate lucene Fields suitable for adding to a document." 

        for value in values: 

            if isinstance(value, basestring): 

                field = lucene.Field(self.name, value, self.store, self.index, self.termvector) 

            elif isinstance(value, lucene.JArray_byte): 

                field = lucene.Field(self.name, value) 

            else: 

                field = lucene.Field(self.name, value, self.termvector) 

            for name, value in self.attrs.items(): 

                setattr(field, name, value) 

            yield field 

 

class FormatField(Field): 

    """Field which uses string formatting on its values. 

     

    :param format: format string 

    """ 

    def __init__(self, name, format='{0}', **kwargs): 

        Field.__init__(self, name, **kwargs) 

        self.format = format.format 

    def items(self, *values): 

        "Generate fields with formatted values." 

        return Field.items(self, *map(self.format, values)) 

 

class NestedField(Field): 

    """Field which indexes every component into its own field. 

    Original value may be stored for convenience. 

     

    :param sep: field separator used on name and values 

    """ 

    def __init__(self, name, sep='.', index=True, **kwargs): 

        Field.__init__(self, name, index=index, **kwargs) 

        self.sep = sep 

        self.names = tuple(self.values(name)) 

    def values(self, value): 

        "Generate component field values in order." 

        value = value.split(self.sep) 

        for index in range(1, len(value) + 1): 

            yield self.sep.join(value[:index]) 

    def items(self, *values): 

        "Generate indexed component fields." 

        if self.store.stored: 

            for value in values: 

                yield lucene.Field(self.name, value, self.store, lucene.Field.Index.NO) 

        for value in values: 

            for index, text in enumerate(self.values(value)): 

                yield lucene.Field(self.names[index], text, lucene.Field.Store.NO, self.index, self.termvector) 

    def prefix(self, value): 

        "Return prefix query of the closest possible prefixed field." 

        index = value.count(self.sep) 

        return Query.prefix(self.names[index], value) 

    def range(self, start, stop, lower=True, upper=False): 

        "Return range query of the closest possible prefixed field." 

        index = max(value.count(self.sep) for value in (start, stop) if value is not None) 

        return Query.range(self.names[index], start, stop, lower, upper) 

 

class NumericField(Field): 

    """Field which indexes numbers in a prefix tree. 

     

    :param name: name of field 

    :param step: precision step 

    """ 

    def __init__(self, name, step=None, store=False, index=True): 

        Field.__init__(self, name, store) 

        self.step = step or lucene.NumericUtils.PRECISION_STEP_DEFAULT 

        self.index = index 

    def items(self, *values): 

        "Generate lucene NumericFields suitable for adding to a document." 

        for value in values: 

            field = lucene.NumericField(self.name, self.step, self.store, self.index) 

            if isinstance(value, float): 

                field.doubleValue = value 

            else: 

                field.longValue = long(value) 

            yield field 

    def numeric(self, cls, start, stop, lower, upper): 

        if isinstance(start, float) or isinstance(stop, float): 

            start, stop = (value if value is None else lucene.Double(value) for value in (start, stop)) 

            return cls.newDoubleRange(self.name, self.step, start, stop, lower, upper) 

        if start is not None: 

            start = None if start < lucene.Long.MIN_VALUE else lucene.Long(long(start)) 

        if stop is not None: 

            stop = None if stop > lucene.Long.MAX_VALUE else lucene.Long(long(stop)) 

        return cls.newLongRange(self.name, self.step, start, stop, lower, upper) 

    def range(self, start, stop, lower=True, upper=False): 

        "Return lucene NumericRangeQuery." 

        return self.numeric(lucene.NumericRangeQuery, start, stop, lower, upper) 

    def term(self, value): 

        "Return range query to match single term." 

        return self.range(value, value, upper=True) 

    def filter(self, start, stop, lower=True, upper=False): 

        "Return lucene NumericRangeFilter." 

        return self.numeric(lucene.NumericRangeFilter, start, stop, lower, upper) 

 

class DateTimeField(NumericField): 

    """Field which indexes datetimes as a NumericField of timestamps. 

    Supports datetimes, dates, and any prefix of time tuples. 

    """ 

    def timestamp(self, date): 

        "Return utc timestamp from date or time tuple." 

        if isinstance(date, datetime.date): 

            return calendar.timegm(date.timetuple()) + getattr(date, 'microsecond', 0) * 1e-6 

        return float(calendar.timegm(tuple(date) + (None, 1, 1, 0, 0, 0)[len(date):])) 

    def items(self, *dates): 

        "Generate lucene NumericFields of timestamps." 

        return NumericField.items(self, *map(self.timestamp, dates)) 

    def range(self, start, stop, lower=True, upper=False): 

        "Return NumericRangeQuery of timestamps." 

        start, stop = (date and self.timestamp(date) for date in (start, stop)) 

        return NumericField.range(self, start, stop, lower, upper) 

    def prefix(self, date): 

        "Return range query which matches the date prefix." 

        if isinstance(date, datetime.date): 

            date = date.timetuple()[:6 if isinstance(date, datetime.datetime) else 3] 

        if len(date) == 2 and date[1] == 12: # month must be valid 

            return self.range(date, (date[0]+1, 1)) 

        return self.range(date, tuple(date[:-1]) + (date[-1]+1,)) 

    def duration(self, date, days=0, **delta): 

        """Return date range query within time span of date. 

         

        :param date: origin date or tuple 

        :param days,delta: timedelta parameters 

        """ 

        if not isinstance(date, datetime.date): 

            date = datetime.datetime(*(tuple(date) + (None, 1, 1)[len(date):])) 

        delta = datetime.timedelta(days, **delta) 

        return self.range(*sorted([date, date + delta]), upper=True) 

    def within(self, days=0, weeks=0, utc=True, **delta): 

        """Return date range query within current time and delta. 

        If the delta is an exact number of days, then dates will be used. 

         

        :param days,weeks: number of days to offset from today 

        :param utc: optionally use utc instead of local time 

        :param delta: additional timedelta parameters 

        """ 

        date = datetime.datetime.utcnow() if utc else datetime.datetime.now() 

        if not (isinstance(days + weeks, float) or delta): 

            date = date.date() 

        return self.duration(date, days, weeks=weeks, **delta) 

 

class Document(dict): 

    "Multimapping of field names to values, but default getters return the first value." 

    def __init__(self, doc): 

        for field in doc.getFields(): 

            self.setdefault(field.name(), []).append(field.binaryValue.string_ if field.binary else field.stringValue()) 

    def __getitem__(self, name): 

        return dict.__getitem__(self, name)[0] 

    def get(self, name, default=None): 

        return dict.get(self, name, [default])[0] 

    def getlist(self, name): 

        "Return list of all values for given field." 

        return dict.get(self, name, []) 

    def dict(self, *names, **defaults): 

        """Return dict representation of document. 

         

        :param names: names of multi-valued fields to return as a list 

        :param defaults: include only given fields, using default values as necessary 

        """ 

        defaults.update((name, self[name]) for name in (defaults or self) if name in self) 

        defaults.update((name, self.getlist(name)) for name in names) 

        return defaults 

 

class Hit(Document): 

    "A Document with an id and score, from a search result." 

    def __init__(self, doc, id, score): 

        Document.__init__(self, doc) 

        self.id, self.score = id, score 

    def dict(self, *names, **defaults): 

        "Return dict representation of document with __id__ and __score__." 

        result = Document.dict(self, *names, **defaults) 

        result.update(__id__=self.id, __score__=self.score) 

        return result 

 

class Hits(object): 

    """Search results: lazily evaluated and memory efficient. 

    Provides a read-only sequence interface to hit objects. 

     

    :param searcher: `IndexSearcher`_ which can retrieve documents 

    :param ids: ordered doc ids 

    :param scores: ordered doc scores 

    :param count: total number of hits 

    :param maxscore: maximum score 

    :param fields: optional field selectors 

    """ 

    def __init__(self, searcher, ids, scores, count=None, maxscore=None, fields=None): 

        self.searcher = searcher 

        self.ids, self.scores = ids, scores 

        self.count, self.maxscore = count, maxscore 

        self.fields = lucene.MapFieldSelector(fields) if isinstance(fields, collections.Iterable) else fields 

    def __len__(self): 

        return len(self.ids) 

    def __getitem__(self, index): 

        id, score = self.ids[index], self.scores[index] 

        if isinstance(index, slice): 

            return type(self)(self.searcher, id, score, self.count, self.maxscore, self.fields) 

        return Hit(self.searcher.doc(id, self.fields), id, score) 

    def items(self): 

        "Generate zipped ids and scores." 

        return zip(self.ids, self.scores) 

    def groupby(self, func): 

        "Return ordered list of `Hits`_ grouped by value of function applied to doc ids." 

        groups = {} 

        for id, score in self.items(): 

            value = func(id) 

            try: 

                group = groups[value] 

            except KeyError: 

                group = groups[value] = type(self)(self.searcher, [], [], fields=self.fields) 

                group.index, group.value = len(groups), value 

            group.ids.append(id) 

            group.scores.append(score) 

        return sorted(groups.values(), key=lambda group: group.__dict__.pop('index')) 

    def filter(self, func): 

        "Return `Hits`_ filtered by function applied to doc ids." 

        ids, scores = [], [] 

        for id, score in self.items(): 

            if func(id): 

                ids.append(id) 

                scores.append(score) 

        return type(self)(self.searcher, ids, scores, fields=self.fields) 

    def sorted(self, key, reverse=False): 

        "Return `Hits`_ sorted by key function applied to doc ids." 

        ids = sorted(self.ids, key=key, reverse=reverse) 

        scores = list(map(dict(self.items()).__getitem__, ids)) 

        return type(self)(self.searcher, ids, scores, self.count, self.maxscore, self.fields)