import datetime
from collections import defaultdict

from sqlalchemy import text

from app import app
from app.extensions import db
from app.models.base import Group
from app.models.mirrors import Origin, Proxy
from app.terraform import BaseAutomation


class ProxyAutomation(BaseAutomation):
    def get_subgroups(self):
        conn = db.engine.connect()
        result = conn.execute(text("""
        SELECT origin.group_id, proxy.psg, COUNT(proxy.id) FROM proxy, origin
        WHERE proxy.origin_id = origin.id
            AND proxy.destroyed IS NULL
            AND proxy.provider = :provider
        GROUP BY origin.group_id, proxy.psg;
        """), provider=self.provider)
        subgroups = defaultdict(lambda: defaultdict(lambda: 0))
        for row in result:
            subgroups[row[0]][row[1]] = row[2]
        return subgroups

    def create_missing_proxies(self):
        origins = Origin.query.all()
        for origin in origins:
            cloudfront_proxies = [
                x for x in origin.proxies
                if x.provider == self.provider and x.deprecated is None and x.destroyed is None
            ]
            if not cloudfront_proxies:
                proxy = Proxy()
                proxy.origin_id = origin.id
                proxy.provider = self.provider
                proxy.added = datetime.datetime.utcnow()
                proxy.updated = datetime.datetime.utcnow()
                db.session.add(proxy)
                db.session.commit()

    def destroy_expired_proxies(self):
        cutoff = datetime.datetime.utcnow() - datetime.timedelta(days=3)
        proxies = Proxy.query.filter(
            Proxy.destroyed == None,
            Proxy.provider == self.provider,
            Proxy.deprecated < cutoff
        ).all()
        for proxy in proxies:
            proxy.destroyed = datetime.datetime.utcnow()
            proxy.updated = datetime.datetime.utcnow()
        db.session.commit()

    def generate_terraform(self):
        self.write_terraform_config(
            self.template,
            groups=Group.query.all(),
            proxies=Proxy.query.filter(
                Proxy.provider == self.provider,
                Proxy.destroyed == None
            ).all(),
            subgroups = self.get_subgroups(),
            global_namespace=app.config['GLOBAL_NAMESPACE'],
            bypass_token=app.config['BYPASS_TOKEN'],
            **{
                k: app.config[k.upper()]
                for k in self.template_parameters
            }
        )