import requests
import time
import warnings
import dateutil.parser
import json

from .exceptions import *
from .constants import *

__version__ = (0, 0, 0)

BOT_DEV_URL = "https://github.com/bnewbold/basebasebase"
BOT_DEV_EMAIL = "bnewbold@robocracy.org"
BOT_USER_AGENT = "basebasebase/%d.%d (%s; %s)" % (
    __version__[0], __version__[1], BOT_DEV_URL, BOT_DEV_EMAIL)
DEFAULT_LANG = "en"
DEFAULT_SITE = "enwiki"


class WikibaseServer:
    '''
    This class represents a Wikibase API endpoint. It isn't called a "Site"
    because that term is ambiguous in this context.
    '''

    def __init__(self, api_url, lang=DEFAULT_LANG, auth=None, is_bot=False,
                 user_agent=BOT_USER_AGENT, maxlag=5, site=DEFAULT_SITE,
                 throttle_delay=0.):
        self.api_url = str(api_url)
        self.lang = DEFAULT_LANG

        self.throttle_delay = throttle_delay
        self.site = site

        self.is_bot = is_bot
        self.session = requests.Session()
        assert(auth is None or len(auth) == 2)
        self.session.auth = auth
        self.session.headers.update({
            'User-Agent': user_agent,
            'Api-User-Agent': user_agent
        })
        if maxlag is not None:
            self.session.params['maxlag'] = int(maxlag)
        self.session.params['format'] = 'json'
        self.session.params['uselang'] = 'user'

    def __repr__(self):
        return "<WikibaseServer at %s>" % self.api_url

    def _check_api_err(self, action, resp):

        if 'warnings' in resp:
            for k in resp['warnings']:
                warnings.warn(str((k, resp['warnings'][k])), Warning)

        if 'error' in resp:
            try:
                raise WikibaseAPIError(resp['error']['code'],
                    resp['error']['info'], action)
            except KeyError:
                raise WikibaseException(resp['error'])

    def _api_call(self, method, action, params):
        params['action'] = action
        if self.throttle_delay:
            time.sleep(self.throttle_delay)
        if method.upper() == "GET":
            resp = self.session.get(self.api_url, params=params)
        elif method.upper() == "POST":
            resp = self.session.post(self.api_url, params=params)
        else:
            raise ValueError("method must be GET or POST")
        resp_json = resp.json()
        self._check_api_err(action, resp_json)
        return resp_json

    def _post(self, action, params):
        return self._api_call("POST", action, params)

    def _get(self, action, params=dict()):
        return self._api_call("GET", action, params)

    def _get_csrf_token(self):
        resp = self._get('query', dict(meta="tokens", type="csrf"))
        return resp['query']['tokens']['csrftoken']

    def check(self):
        # Check that wikibase API calls work (instead of just "action=query")
        self._get("wbparsevalue",
            dict(datatype="time", values="1999-12-31|now"))

    def login(self, user=None, passwd=None, is_bot=None, force_http=False):
        if user is None or passwd is None:
            raise WikibaseException("Need user and pass to attempt log-in")

        if not force_http and not self.api_url.lower().startswith("https:"):
            raise WikibaseException("Cowardly refusing to log in without https")

        if is_bot is not None:
            self.is_bot = bool(is_bot)
        self.user = user
        # not keeping password around; don't need it

        # First partially log-in to get a token...
        self.session.params.pop('assert', None)
        resp = self._post("login", dict(lgname=self.user, lgpassword=passwd))
        token = resp['login']['token']

        # Then really log-in
        resp = self._post("login", dict(lgname=self.user, lgpassword=passwd, lgtoken=token))
        result = resp['login']['result']
        if result != 'Success':
            raise WikibaseAccountError(user, result)

        if self.is_bot:
            self.session.params['assert'] = 'bot'
        else:
            self.session.params['assert'] = 'user'

        # Simple ping to check that we are actually logged in
        self._get("query")

    def logout(self):
        self.user = None
        self.session.params.pop('assert', None)
        self._get("logout")

    def _get_entities(self, query, expected, site=None, lang=None, redirects=True, as_titles=False):
        
        """
        NB: doesn't handle case of multiple sites, single title
        """

        if len(query) == 0:
            return []
        params = {
            'sites': site or self.site,
            'languages': lang or self.lang,
            'redirects': redirects and "yes" or "no",
        }
        if as_titles:
            params['titles'] = '|'.join(query)
        else:
            params['ids'] = '|'.join(query)

        try:
            resp = self._get("wbgetentities", params)
        except WikibaseAPIError as wae:
            if wae.code == "no-such-entity":
                raise MissingEntityError(info=wae.info)
            else:
                raise wae

        if not 'success' in resp:
            raise WikibaseException("Expected 'success' in wbgetentities response")

        entities = resp['entities'].values()

        for e in entities:
            if 'missing' in e or e['type'] != expected:
                if 'title' in e:
                    raise MissingEntityError(title=e['title'])
                elif 'id' in e:
                    raise MissingEntityError(id=e['id'])
                else:
                    raise MissingEntityError()

        return entities

    def get_items(self, query, **kwargs):
        if len(query) == 0:
            return []
        as_titles = False
        if type(query[0]) is int:
            # Convert list of ints to QIDs
            query = ["Q%d" % x for x in query]
        elif type(query[0]) is str and query[0][0] in "P" and query[0][1:].isdigit():
            raise ValueError("query must be a list of QIDs, not PIDs")
        elif not (type(query[0]) is str and query[0][0] in "Q" and query[0][1:].isdigit()):
            # Must be list of titles
            as_titles = True

        try:
            entities = self._get_entities(query, as_titles=as_titles, expected='item', **kwargs)
        except MissingItemError as wee:
            # Case entity error to item error
            raise MissingItemError(id=wee.id, title=wee.title)
        items = [WikibaseItem.from_dict(e) for e in entities]
        return items

    def get_item(self, query, **kwargs):
        return self.get_items((query, ), **kwargs)[0]

    def get_properties(self, query, **kwargs):
        if len(query) == 0:
            return []

        if type(query[0]) is int:
            # Convert list of ints to PIDs
            query = ["P%d" % x for x in query]
        elif not (type(query[0]) is str and query[0][0] in "P" and query[0][1:].isdigit()):
            raise ValueError("query must be a list of PIDs")

        try:
            entities = self._get_entities(query, as_titles=False, expected='property', **kwargs)
        except MissingEntityError as wee:
            # Case entity error to item error
            raise MissingPropertyError(id=wee.id, title=wee.title)
        items = [WikibaseProperty.from_dict(e) for e in entities]
        return items

    def get_property(self, query, **kwargs):
        return self.get_properties((query, ), **kwargs)

    def _search_entities(self, query, etype, limit=7, lang=None):
        resp = self._get("wbsearchentities",
            dict(search=query, language=lang or self.lang, type=etype,
                 limit=limit))
        if not 'success' in resp:
            raise WikibaseException("Expected 'success'")
        results = resp['search']
        return [dict(id=r['id'],
                     label=r['label'],
                     #description=r['description'],
                     url=r['url']) for r in results]

    def search_items(self, query, fetch=False, lang=None, **kwargs):
        lang = lang or self.lang
        results = self._search_entities(query, 'item', lang=lang, **kwargs)
        if not fetch:
            return results
        return self.get_items([short['id'] for short in results], lang=lang)

    def search_properties(self, query, fetch=False, lang=None, **kwargs):
        lang = lang or self.lang
        results = self._search_entities(query, 'property', lang=lang, **kwargs)
        if not fetch:
            return results
        return get_properties([short['id'] for short in results], lang=lang)

    def create(self, thing):
        if not isinstance(thing, (WikibaseEntity, WikibaseStatement)):
            raise ValueError(
                "Takes one of: WikibaseItem, WikibaseProperty, WikibaseStatement")
        thing.create(self)

    def save(self, thing):
        if not isinstance(thing, (WikibaseEntity, WikibaseStatement)):
            raise ValueError(
                "Takes one of: WikibaseItem, WikibaseProperty, WikibaseStatement")
        thing.save(self)

class WikibaseEntity:
    '''
    Base class for WikibaseItem and WikibaseProperty
    '''

    def __init__(self, labels=[], descriptions=[], aliases=[], dbid=None,
                 rev=None, rev_timestamp=None, statements=[], lang=DEFAULT_LANG):
        if type(labels) is str:
            labels = {DEFAULT_LANG: {"language": DEFAULT_LANG, "value": labels}}
        if type(descriptions) is str:
            descriptions = {DEFAULT_LANG: {"language": DEFAULT_LANG, "value": descriptions}}
        if type(aliases) is str:
            aliases = (aliases, )
        if type(aliases) in (list, tuple):
            aliases = {DEFAULT_LANG:
                [{"language": DEFAULT_LANG, "value": al} for al in aliases]
            }
        self.labels = labels
        self.descriptions = descriptions
        self.aliases = aliases
        self.dbid = dbid
        self.rev = rev
        self.rev_timestamp = rev_timestamp
        self.statements = statements
        self.entity_type = None

    @classmethod
    def from_dict(cls, j):
        we = cls(
            dbid=j['id'],
            rev=j['lastrevid'],
            rev_timestamp=dateutil.parser.parse(j['modified']),
            aliases=j['aliases'],
            descriptions=j['descriptions'],
        )
        claims = j['claims']
        for prop in claims:
            for c in claims[prop]:
                we.statements.append(WikibaseStatement.from_dict(c))
        return we

    def to_dict(self, new=False):
        d = dict()
        d['labels'] = self.labels
        d['descriptions'] = self.descriptions
        d['aliases'] = self.aliases
        if self.entity_type:
            d['type'] = self.entity_type
        d['statements'] = [s.to_dict() for s in self.statements]
        if not new:
            if self.dbid:
                d['id'] = self.dbid
            if self.rev:
                d['lastrevid'] = self.rev
        return d

    def add_statement(self, statement):
        raise NotImplementedError

    def add_label(self, label):
        raise NotImplementedError

    def add_alias(self, label):
        raise NotImplementedError

    def create(self, srv, summary=None):
        # TODO: first have to traverse statements and find/sync any properties?
        if summary is None:
            summary = "Created new Entity"
        data = self.to_dict(new=True)
        srv._post("wbeditentity", {
            "bot": srv.is_bot,
            "new": self.entity_type,
            "token": srv._get_csrf_token(),
            "summary": summary,
            "data": data,
        })

    def save(self, srv, summary=None):
        if summary is None:
            summary = "Changes to existing Entity"
        data = self.to_dict(new=True)
        srv._post("wbeditentity", {
            "bot": srv.is_bot,
            "new": self.entity_type,
            "token": srv._get_csrf_token(),
            "summary": summary,
            "data": data,
        })

class WikibaseItem(WikibaseEntity):

    def __init__(self, *args, **kwargs):
        self.sitelinks = kwargs.pop('sitelinks', [])
        super().__init__(*args, **kwargs)
        self.entity_type = "item"

    def __repr__(self):
        return "<WikibaseItem %s>" % self.qid()

    @classmethod
    def from_dict(cls, d):
        wi = super().from_dict(d)
        wi.sitelinks = d['sitelinks']
        return wi

    def to_dict(self):
        d = super().to_dict()
        d['sitelinks'] = self.sitelinks
        return d

    def qid(self):
        if self.dbid:
            assert self.dbid.startswith("Q")
        return self.dbid

class WikibaseProperty(WikibaseEntity):

    def __init__(self,*args, **kwargs):
        self.datatype = kwargs.pop('datatype', None)
        super().__init__(*args, **kwargs)
        self.entity_type = "property"

    def __repr__(self):
        return "<WikibaseProperty %s>" % self.pid()

    @classmethod
    def from_dict(cls, d):
        wp = super().from_dict(d)
        wp.datatype = d['datatype']
        return wp

    def to_dict(self):
        d = super().to_dict()
        d['datatype'] = self.datatype
        return d

    def pid(self):
        if self.dbid:
            assert self.dbid.startswith("P")
        return self.dbid

class WikibaseStatement:

    def __init__(self, qualifiers=[], references=[],
                 rank='normal', mainsnak=None, guid=None):
        self.guid = guid
        self.mainsnak = mainsnak
        self.qualifiers = qualifiers
        self.references = references
        self.rank = rank

    def __repr__(self):
        if self.property:
            return "<WikibaseStatement %s is %s>" % (self.property.pid, self.value)
        else:
            return "<WikibaseStatement (empty)>"

    @classmethod
    def from_dict(cls, d):
        if not d['type'] == 'statement':
            raise WikibaseException("Tried to parse a non-statement claim?")
        quals = []
        for prop_set in d.get('qualifiers', {}).values():
            quals.extend([WikibaseSnak.from_dict(q) for q in prop_set])
        # TODO: handle references hashes
        refs = []
        for ref in d.get("references", []):
            # We get a list of lists; deep!
            snaks_lists = ref.get("snaks", {}).values()
            snaks = []
            for sl in snaks_lists:
                snaks.extend(sl)
            refs.append([WikibaseSnak.from_dict(q) for q in snaks])
        ws = cls(
            mainsnak=WikibaseSnak.from_dict(d['mainsnak']),
            guid=d['id'],
            rank=d['rank'],
            qualifiers=quals,
            references=refs,
        )
        return ws

    def to_dict(self):
        d = {
            "type": "statement",
            "references": [[snak.to_dict() for snak in snaklist] for snaklist in self.references],
            "qualifiers": [snak.to_dict() for snak in self.qualifiers],
        }
        if self.mainsnak is not None:
            d['mainsnak'] = self.mainsnak.to_dict()
        if self.rank is not None:
            d['rank'] = self.rank
        if self.guid is not None:
            d['guid'] = self.guid
        return d

class WikibaseSnak:

    def __init__(self, property=None, value=None, snaktype=None, hash=None, datatype=None):
        if snaktype is None:
            if value is None:
                snaktype = "novalue"
            else:
                snaktype = "somevalue"
        self.property = property
        self.snaktype = snaktype
        self.datatype = datatype
        self.value = value
        self.hash = None

    def __repr__(self):
        return "<WikibaseSnak %s has %s>" % (
            self.property, self.snaktype)

    @classmethod
    def from_dict(cls, d):
        ws = cls(
            property=d['property'],
            snaktype=d['snaktype'],
            hash=d.get('hash', None),
        )
        if ws.snaktype == 'value':
            ws.datatype = d['datatype']
            if ws.datatype == "wikibase-item":
                ws.value = "Q%d" % int(d['datavalue']['value']['numeric-id'])
            if ws.datatype == "wikibase-property":
                ws.value = "P%d" % int(d['datavalue']['value']['numeric-id'])
            else:
                ws.value = d['datavalue']['value']
        return ws

    def to_dict(self):
        d = {'snaktype': self.snaktype}
        if self.hash:
            d['hash'] = self.hash
        if self.value is not None:
            d['value'] = self.value
        if self.datatype is not None:
            d['datatype'] = self.datatype
        if self.property is not None:
            d['property'] = self.property
        return {}