#!/usr/bin/env python
# ***** BEGIN LICENSE BLOCK *****
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
# ***** END LICENSE BLOCK *****
"""Support for fetching secrets from the secrets API
"""

import os
import mozharness
import urllib2
import json
from mozharness.base.log import ERROR


class SecretsMixin(object):

    def _fetch_secret(self, secret_name):
        self.info("fetching secret {} from API".format(secret_name))
        # fetch from http://taskcluster, which points to the taskcluster proxy
        # within a taskcluster task.  Outside of that environment, do not
        # use this action.
        url = "http://taskcluster/secrets/v1/secret/" + secret_name
        res = urllib2.urlopen(url)
        if res.getcode() != 200:
            self.fatal("Error fetching from secrets API:" + res.read())

        return json.load(res)['secret']['content']

    def get_secrets(self):
        """
        Get the secrets specified by the `secret_files` configuration.  This is
        a list of dictionaries, one for each secret.  The `secret_name` key
        names the key in the TaskCluster secrets API to fetch (see
        http://docs.taskcluster.net/services/secrets/).  It can contain
        %-substitutions based on the `subst` dictionary below.

        Since secrets must be JSON objects, the `content` property of the
        secret is used as the value to be written to disk.

        The `filename` key in the dictionary gives the filename to which the
        secret should be written.

        The optional `min_scm_level` key gives a minimum SCM level at which this
        secret is required.  For lower levels, the value of the 'default` key
        is used, or no secret is written.
        """
        secret_files = self.config.get('secret_files', [])

        scm_level = self.config.get('scm_level', 1)
        subst = {
            'scm-level': scm_level,
        }

        for sf in secret_files:
            filename = sf['filename']
            secret_name = sf['secret_name'] % subst
            min_scm_level = sf.get('min_scm_level', 0)
            if scm_level <= min_scm_level:
                if 'default' in sf:
                    self.info("Using default value for " + filename)
                    secret = sf['default']
                else:
                    self.info("No default for secret; not writing " + filename)
                    continue
            else:
                secret = self._fetch_secret(secret_name)

            open(filename, "w").write(secret)
