import logging
import json

from datetime import datetime, timedelta

from flask import request

from app import app, dockerfile_build_queue
from data import model
from data.database import db
from auth.auth_context import get_authenticated_user
from endpoints.notificationhelper import spawn_notification
from util.names import escape_tag
from util.morecollections import AttrDict


logger = logging.getLogger(__name__)

MAX_BUILD_QUEUE_RATE_ITEMS = app.config.get('MAX_BUILD_QUEUE_RATE_ITEMS', -1)
MAX_BUILD_QUEUE_RATE_SECS = app.config.get('MAX_BUILD_QUEUE_RATE_SECS', -1)


class MaximumBuildsQueuedException(Exception):
  """
  This exception is raised when a build is requested, but the incoming build
  would exceed the configured maximum build rate.
  """
  pass


def start_build(repository, prepared_build, pull_robot_name=None):
  if repository.kind.name != 'image':
    raise Exception('Attempt to start a build for application repository %s' % repository.id)

  if MAX_BUILD_QUEUE_RATE_ITEMS > 0 and MAX_BUILD_QUEUE_RATE_SECS > 0:
    queue_item_canonical_name = [repository.namespace_user.username, repository.name]
    now = datetime.utcnow()
    available_min = now - timedelta(seconds=MAX_BUILD_QUEUE_RATE_SECS)
    available_builds = dockerfile_build_queue.num_available_jobs_between(available_min,
                                                                         now,
                                                                         queue_item_canonical_name)
    if available_builds >= MAX_BUILD_QUEUE_RATE_ITEMS:
      raise MaximumBuildsQueuedException()

  host = app.config['SERVER_HOSTNAME']
  repo_path = '%s/%s/%s' % (host, repository.namespace_user.username, repository.name)

  new_token = model.token.create_access_token(repository, 'write', kind='build-worker',
                                              friendly_name='Repository Build Token')
  logger.debug('Creating build %s with repo %s tags %s',
               prepared_build.build_name, repo_path, prepared_build.tags)

  job_config = {
    'docker_tags': prepared_build.tags,
    'registry': host,
    'build_subdir': prepared_build.subdirectory,
    'trigger_metadata': prepared_build.metadata or {},
    'is_manual': prepared_build.is_manual,
    'manual_user': get_authenticated_user().username if get_authenticated_user() else None,
    'archive_url': prepared_build.archive_url
  }

  with app.config['DB_TRANSACTION_FACTORY'](db):
    build_request = model.build.create_repository_build(repository, new_token, job_config,
                                                        prepared_build.dockerfile_id,
                                                        prepared_build.build_name,
                                                        prepared_build.trigger,
                                                        pull_robot_name=pull_robot_name)

    pull_creds = model.user.get_pull_credentials(pull_robot_name) if pull_robot_name else None

    json_data = json.dumps({
      'build_uuid': build_request.uuid,
      'pull_credentials': pull_creds
    })

    queue_id = dockerfile_build_queue.put([repository.namespace_user.username, repository.name],
                                          json_data,
                                          retries_remaining=3)

    build_request.queue_id = queue_id
    build_request.save()

  # Add the build to the repo's log and spawn the build_queued notification.
  event_log_metadata = {
    'build_id': build_request.uuid,
    'docker_tags': prepared_build.tags,
    'repo': repository.name,
    'namespace': repository.namespace_user.username,
    'is_manual': prepared_build.is_manual,
    'manual_user': get_authenticated_user().username if get_authenticated_user() else None
  }

  if prepared_build.trigger:
    event_log_metadata['trigger_id'] = prepared_build.trigger.uuid
    event_log_metadata['trigger_kind'] = prepared_build.trigger.service.name
    event_log_metadata['trigger_metadata'] = prepared_build.metadata or {}

  model.log.log_action('build_dockerfile', repository.namespace_user.username,
                       ip=request.remote_addr, metadata=event_log_metadata, repository=repository)

  # TODO(jzelinskie): remove when more endpoints have been converted to using interfaces
  repo = AttrDict({
    'namespace_name': repository.namespace_user.username,
    'name': repository.name,
  })

  spawn_notification(repo, 'build_queued', event_log_metadata,
                     subpage='build/%s' % build_request.uuid,
                     pathargs=['build', build_request.uuid])

  return build_request


class PreparedBuild(object):
  """ Class which holds all the information about a prepared build. The build queuing service
      will use this result to actually invoke the build.
  """
  def __init__(self, trigger=None):
    self._dockerfile_id = None
    self._archive_url = None
    self._tags = None
    self._build_name = None
    self._subdirectory = None
    self._metadata = None
    self._trigger = trigger
    self._is_manual = None

  @staticmethod
  def get_display_name(sha):
    return sha[0:7]

  def tags_from_ref(self, ref, default_branch=None):
    branch = ref.split('/', 2)[-1]
    tags = {branch}

    if branch == default_branch:
      tags.add('latest')

    self.tags = tags

  def name_from_sha(self, sha):
    self.build_name = PreparedBuild.get_display_name(sha)

  @property
  def is_manual(self):
    if self._is_manual is None:
      raise Exception('Property is_manual not set')

    return self._is_manual

  @is_manual.setter
  def is_manual(self, value):
    if self._is_manual is not None:
      raise Exception('Property is_manual already set')

    self._is_manual = value

  @property
  def trigger(self):
    return self._trigger

  @property
  def archive_url(self):
    return self._archive_url

  @archive_url.setter
  def archive_url(self, value):
    if self._archive_url:
      raise Exception('Property archive_url already set')

    self._archive_url = value

  @property
  def dockerfile_id(self):
    return self._dockerfile_id

  @dockerfile_id.setter
  def dockerfile_id(self, value):
    if self._dockerfile_id:
      raise Exception('Property dockerfile_id already set')

    self._dockerfile_id = value

  @property
  def tags(self):
    if not self._tags:
      raise Exception('Missing property tags')

    return self._tags

  @tags.setter
  def tags(self, value):
    if self._tags:
      raise Exception('Property tags already set')

    self._tags = [escape_tag(tag, default='latest') for tag in value]

  @property
  def build_name(self):
    if not self._build_name:
      raise Exception('Missing property build_name')

    return self._build_name

  @build_name.setter
  def build_name(self, value):
    if self._build_name:
      raise Exception('Property build_name already set')

    self._build_name = value

  @property
  def subdirectory(self):
    if self._subdirectory is None:
      raise Exception('Missing property subdirectory')

    return self._subdirectory

  @subdirectory.setter
  def subdirectory(self, value):
    if self._subdirectory:
      raise Exception('Property subdirectory already set')

    self._subdirectory = value

  @property
  def metadata(self):
    if self._metadata is None:
      raise Exception('Missing property metadata')

    return self._metadata

  @metadata.setter
  def metadata(self, value):
    if self._metadata:
      raise Exception('Property metadata already set')

    self._metadata = value