import uuid

from sqlalchemy import (desc, text)

from app import db
from app.models import (Template, TemplateHistory)
from app.dao.dao_utils import (
    transactional,
    version_class
)


@transactional
@version_class(Template, TemplateHistory)
def dao_create_template(template):
    template.id = uuid.uuid4()  # must be set now so version history model can use same id
    template.archived = False
    db.session.add(template)


@transactional
@version_class(Template, TemplateHistory)
def dao_update_template(template):
    db.session.add(template)


def dao_get_template_by_id_and_service_id(template_id, service_id, version=None):
    if version is not None:
        return TemplateHistory.query.filter_by(
            id=template_id,
            service_id=service_id,
            version=version).one()
    return Template.query.filter_by(id=template_id, service_id=service_id).one()


def dao_get_template_by_id(template_id, version=None):
    if version is not None:
        return TemplateHistory.query.filter_by(
            id=template_id,
            version=version).one()
    return Template.query.filter_by(id=template_id).one()


def dao_get_all_templates_for_service(service_id):
    return Template.query.filter_by(
        service_id=service_id,
        archived=False
    ).order_by(
        desc(Template.created_at)
    ).all()


def dao_get_template_versions(service_id, template_id):
    return TemplateHistory.query.filter_by(
        service_id=service_id, id=template_id
    ).order_by(
        desc(TemplateHistory.version)
    ).all()


def dao_get_templates_by_for_cache(cache):
    if not cache or len(cache) == 0:
        return []
    txt = "( " + " Union all ".join(
        "select '{}'::text as template_id, {} as count".format(x.decode(),
                                                               y.decode()) for x, y in cache) + " ) as cache"
    txt = "Select t.id as template_id, t.template_type, t.name, cache.count from templates t,  " + \
          txt + " where t.id::text = cache.template_id order by t.name"
    stmt = text(txt)

    return db.session.execute(stmt).fetchall()