from datetime import datetime
from os import getenv
from wsgiref import simple_server

import falcon
from falcon import media
import jsonhandler

from google.cloud import datastore


credentials_path = getenv('GCLOUD_DATASTORE_CREDENTIALS_PATH')
datastore_client = datastore.Client.from_service_account_json(credentials_path)

entity_kind = 'spider-results'


def get_compact_results(client):
    query = client.query(kind=entity_kind,
                                    order=['-created'],
                                    #projection=['created', 'meta', 'score'],
                                    )

    out = []
    for entity in query.fetch(eventual=True):
        
        # handle creation date in different ways, depending on whether the lib returns
        # a str, int, or datetime.datetime
        created = entity.get('created')
        dt = ''
        if type(created) == datetime:
            dt = created
        elif type(created) == int:
            dt = datetime.utcfromtimestamp(created / 1000000)
        elif type(created) == str:
            dt = datetime.utcfromtimestamp(int(created) / 1000000)

        out.append({
            'input_url': entity.key.name,
            'created': dt.isoformat(),
            'meta': entity.get('meta'),
            'score': entity.get('score'),
        })
    return out
    

class LastUpdated(object):

    def on_get(self, req, resp):
        """
        Informs about the most recent update to the spider results data
        """
        query = datastore_client.query(kind=entity_kind,
                                       order=['-created'],
                                       projection=['created'])
        items = list(query.fetch(limit=1, eventual=True))
        ts = int(items[0].get('created')) / 1000000
        dt = datetime.utcfromtimestamp(ts).isoformat()

        maxage = 60 * 60  # one hour in seconds
        resp.cache_control = ["max_age=%d" % maxage]
        resp.media = {
            "last_updated": dt
        }


class CompactResults(object):

    def on_get(self, req, resp):
        """
        Returns compact sites overview and score
        """
        out = get_compact_results(datastore_client)

        maxage = 6 * 60 * 60  # six hours in seconds
        resp.cache_control = ["max_age=%d" % maxage]
        resp.media = out


handlers = media.Handlers({
    'application/json': jsonhandler.JSONHandler(),
})

app = falcon.API()

app.req_options.media_handlers = handlers
app.resp_options.media_handlers = handlers

app.add_route('/api/v1/spider-results/last-updated/', LastUpdated())
app.add_route('/api/v1/spider-results/compact/', CompactResults())

if __name__ == '__main__':
    httpd = simple_server.make_server('127.0.0.1', 5000, app)
    httpd.serve_forever()