"""rewriting url from shortner with new format

Revision ID: a99f2f7c195a
Revises: 53fc3de270ae
Create Date: 2017-02-08 14:16:34.948793

"""

# revision identifiers, used by Alembic.
revision = 'a99f2f7c195a'
down_revision = 'db0c65b146bd'

from alembic import op
import json
import sqlalchemy as sa
from superset import db
from superset.legacy import cast_form_data
from sqlalchemy.ext.declarative import declarative_base
from future.standard_library import install_aliases
install_aliases()
from urllib import parse

Base = declarative_base()

def parse_querystring(qs):
    d = {}
    for k, v in parse.parse_qsl(qs):
        if not k in d:
            d[k] = v
        else:
            if isinstance(d[k], list):
                d[k].append(v)
            else:
                d[k] = [d[k], v]
    return d

class Url(Base):

    """Used for the short url feature"""

    __tablename__ = 'url'
    id = sa.Column(sa.Integer, primary_key=True)
    url = sa.Column(sa.Text)


def upgrade():
    bind = op.get_bind()
    session = db.Session(bind=bind)

    urls = session.query(Url).all()
    urls_len = len(urls)
    for i, url in enumerate(urls):
        if (
                '?form_data' not in url.url and
                '?' in url.url and
                'dbid' not in url.url and
                url.url.startswith('//superset/explore')):
            d = parse_querystring(url.url.split('?')[1])
            split = url.url.split('/')
            d['datasource'] = split[5] + '__' + split[4]
            d = cast_form_data(d)
            newurl = '/'.join(split[:-1]) + '/?form_data=' + parse.quote_plus(json.dumps(d))
            url.url = newurl
            session.merge(url)
            session.commit()
        print('Updating url ({}/{})'.format(i, urls_len))
    session.close()


def downgrade():
    pass
