import logging
import json
import re

import requests

from flask_mail import Message

from app import mail, app, OVERRIDE_CONFIG_DIRECTORY
from data import model
from util.config.validator import SSL_FILENAMES
from workers.queueworker import JobException


logger = logging.getLogger(__name__)

METHOD_TIMEOUT = app.config.get('NOTIFICATION_SEND_TIMEOUT', 10) # Seconds


class InvalidNotificationMethodException(Exception):
  pass


class CannotValidateNotificationMethodException(Exception):
  pass


class NotificationMethodPerformException(JobException):
  pass


SSLClientCert = None
if app.config['PREFERRED_URL_SCHEME'] == 'https':
  # TODO(jschorr): move this into the config provider library
  SSLClientCert = [OVERRIDE_CONFIG_DIRECTORY + f for f in SSL_FILENAMES]


class NotificationMethod(object):
  def __init__(self):
    pass

  @classmethod
  def method_name(cls):
    """
    Particular method implemented by subclasses.
    """
    raise NotImplementedError

  def validate(self, repository, config_data):
    """
    Validates that the notification can be created with the given data. Throws
    a CannotValidateNotificationMethodException on failure.
    """
    raise NotImplementedError

  def perform(self, notification_obj, event_handler, notification_data):
    """
    Performs the notification method.

    notification_obj: The noticication record itself.
    event_handler: The NotificationEvent handler.
    notification_data: The dict of notification data placed in the queue.
    """
    raise NotImplementedError

  @classmethod
  def get_method(cls, methodname):
    for subc in cls.__subclasses__():
      if subc.method_name() == methodname:
        return subc()

    raise InvalidNotificationMethodException('Unable to find method: %s' % methodname)


class QuayNotificationMethod(NotificationMethod):
  @classmethod
  def method_name(cls):
    return 'quay_notification'

  def validate(self, repository, config_data):
    status, err_message, target_users = self.find_targets(repository, config_data)
    if err_message:
       raise CannotValidateNotificationMethodException(err_message)

  def find_targets(self, repository, config_data):
    target_info = config_data['target']

    if target_info['kind'] == 'user':
      target = model.user.get_nonrobot_user(target_info['name'])
      if not target:
        # Just to be safe.
        return (True, 'Unknown user %s' % target_info['name'], [])

      return (True, None, [target])
    elif target_info['kind'] == 'org':
      target = model.organization.get_organization(target_info['name'])
      if not target:
        # Just to be safe.
        return (True, 'Unknown organization %s' % target_info['name'], None)

      # Only repositories under the organization can cause notifications to that org.
      if target_info['name'] != repository.namespace_user.username:
        return (False, 'Organization name must match repository namespace')

      return (True, None, [target])
    elif target_info['kind'] == 'team':
      # Lookup the team.
      org_team = None
      try:
        org_team = model.team.get_organization_team(repository.namespace_user.username,
                                                    target_info['name'])
      except model.InvalidTeamException:
        # Probably deleted.
        return (True, 'Unknown team %s' % target_info['name'], None)

      # Lookup the team's members
      return (True, None, model.organization.get_organization_team_members(org_team.id))


  def perform(self, notification_obj, event_handler, notification_data):
    repository = notification_obj.repository
    if not repository:
      # Probably deleted.
      return

    # Lookup the target user or team to which we'll send the notification.
    config_data = json.loads(notification_obj.config_json)
    status, err_message, target_users = self.find_targets(repository, config_data)
    if not status:
      raise NotificationMethodPerformException(err_message)

    # For each of the target users, create a notification.
    for target_user in set(target_users or []):
      model.notification.create_notification(event_handler.event_name(), target_user,
                                             metadata=notification_data['event_data'])


class EmailMethod(NotificationMethod):
  @classmethod
  def method_name(cls):
    return 'email'

  def validate(self, repository, config_data):
    email = config_data.get('email', '')
    if not email:
      raise CannotValidateNotificationMethodException('Missing e-mail address')

    record = model.repository.get_email_authorized_for_repo(repository.namespace_user.username,
                                                            repository.name, email)
    if not record or not record.confirmed:
      raise CannotValidateNotificationMethodException('The specified e-mail address '
                                                      'is not authorized to receive '
                                                      'notifications for this repository')


  def perform(self, notification_obj, event_handler, notification_data):
    config_data = json.loads(notification_obj.config_json)
    email = config_data.get('email', '')
    if not email:
      return

    with app.app_context():
      msg = Message(event_handler.get_summary(notification_data['event_data'], notification_data),
                    recipients=[email])
      msg.html = event_handler.get_message(notification_data['event_data'], notification_data)

      try:
          mail.send(msg)
      except Exception as ex:
        logger.exception('Email was unable to be sent: %s' % ex.message)
        raise NotificationMethodPerformException(ex.message)


class WebhookMethod(NotificationMethod):
  @classmethod
  def method_name(cls):
    return 'webhook'

  def validate(self, repository, config_data):
    url = config_data.get('url', '')
    if not url:
      raise CannotValidateNotificationMethodException('Missing webhook URL')

  def perform(self, notification_obj, event_handler, notification_data):
    config_data = json.loads(notification_obj.config_json)
    url = config_data.get('url', '')
    if not url:
      return

    payload = notification_data['event_data']
    headers = {'Content-type': 'application/json'}

    try:
      resp = requests.post(url, data=json.dumps(payload), headers=headers, cert=SSLClientCert,
                           timeout=METHOD_TIMEOUT)
      if resp.status_code/100 != 2:
        error_message = '%s response for webhook to url: %s' % (resp.status_code, url)
        logger.error(error_message)
        logger.error(resp.content)
        raise NotificationMethodPerformException(error_message)

    except requests.exceptions.RequestException as ex:
      logger.exception('Webhook was unable to be sent: %s' % ex.message)
      raise NotificationMethodPerformException(ex.message)


class FlowdockMethod(NotificationMethod):
  """ Method for sending notifications to Flowdock via the Team Inbox API:
      https://www.flowdock.com/api/team-inbox
  """
  @classmethod
  def method_name(cls):
    return 'flowdock'

  def validate(self, repository, config_data):
    token = config_data.get('flow_api_token', '')
    if not token:
      raise CannotValidateNotificationMethodException('Missing Flowdock API Token')

  def perform(self, notification_obj, event_handler, notification_data):
    config_data = json.loads(notification_obj.config_json)
    token = config_data.get('flow_api_token', '')
    if not token:
      return

    owner = model.user.get_user_or_org(notification_obj.repository.namespace_user.username)
    if not owner:
      # Something went wrong.
      return

    url = 'https://api.flowdock.com/v1/messages/team_inbox/%s' % token
    headers = {'Content-type': 'application/json'}
    payload = {
      'source': 'Quay',
      'from_address':  'support@quay.io',
      'subject': event_handler.get_summary(notification_data['event_data'], notification_data),
      'content': event_handler.get_message(notification_data['event_data'], notification_data),
      'from_name': owner.username,
      'project': (notification_obj.repository.namespace_user.username + ' ' +
                  notification_obj.repository.name),
      'tags': ['#' + event_handler.event_name()],
      'link': notification_data['event_data']['homepage']
    }

    try:
      resp = requests.post(url, data=json.dumps(payload), headers=headers, timeout=METHOD_TIMEOUT)
      if resp.status_code/100 != 2:
        error_message = '%s response for flowdock to url: %s' % (resp.status_code, url)
        logger.error(error_message)
        logger.error(resp.content)
        raise NotificationMethodPerformException(error_message)

    except requests.exceptions.RequestException as ex:
      logger.exception('Flowdock method was unable to be sent: %s' % ex.message)
      raise NotificationMethodPerformException(ex.message)


class HipchatMethod(NotificationMethod):
  """ Method for sending notifications to Hipchat via the API:
      https://www.hipchat.com/docs/apiv2/method/send_room_notification
  """
  @classmethod
  def method_name(cls):
    return 'hipchat'

  def validate(self, repository, config_data):
    if not config_data.get('notification_token', ''):
      raise CannotValidateNotificationMethodException('Missing Hipchat Room Notification Token')

    if not config_data.get('room_id', ''):
      raise CannotValidateNotificationMethodException('Missing Hipchat Room ID')

  def perform(self, notification_obj, event_handler, notification_data):
    config_data = json.loads(notification_obj.config_json)

    token = config_data.get('notification_token', '')
    room_id = config_data.get('room_id', '')

    if not token or not room_id:
      return

    owner = model.user.get_user_or_org(notification_obj.repository.namespace_user.username)
    if not owner:
      # Something went wrong.
      return

    url = 'https://api.hipchat.com/v2/room/%s/notification?auth_token=%s' % (room_id, token)

    level = event_handler.get_level(notification_data['event_data'], notification_data)
    color = {
      'info': 'gray',
      'warning': 'yellow',
      'error': 'red',
      'success': 'green',
      'primary': 'purple'
    }.get(level, 'gray')

    headers = {'Content-type': 'application/json'}
    payload = {
      'color': color,
      'message': event_handler.get_message(notification_data['event_data'], notification_data),
      'notify': level == 'error',
      'message_format': 'html',
    }

    try:
      resp = requests.post(url, data=json.dumps(payload), headers=headers, timeout=METHOD_TIMEOUT)
      if resp.status_code/100 != 2:
        error_message = '%s response for hipchat to url: %s' % (resp.status_code, url)
        logger.error(error_message)
        logger.error(resp.content)
        raise NotificationMethodPerformException(error_message)

    except requests.exceptions.RequestException as ex:
      logger.exception('Hipchat method was unable to be sent: %s' % ex.message)
      raise NotificationMethodPerformException(ex.message)


from HTMLParser import HTMLParser

class SlackAdjuster(HTMLParser):
  def __init__(self):
    self.reset()
    self.result = []

  def handle_data(self, d):
    self.result.append(d)

  def get_attr(self, attrs, name):
    for attr in attrs:
      if attr[0] == name:
        return attr[1]

    return ''

  def handle_starttag(self, tag, attrs):
    if tag == 'a':
      self.result.append('<%s|' % (self.get_attr(attrs, 'href'), ))

    if tag == 'i':
      self.result.append('_')

    if tag == 'b' or tag == 'strong':
      self.result.append('*')

    if tag == 'img':
      self.result.append('')

  def handle_endtag(self, tag):
    if tag == 'a':
      self.result.append('>')

    if tag == 'b' or tag == 'strong':
      self.result.append('*')

    if tag == 'i':
      self.result.append('_')

  def get_data(self):
    return ''.join(self.result)

def adjust_tags(html):
  s = SlackAdjuster()
  s.feed(html)
  return s.get_data()


class SlackMethod(NotificationMethod):
  """ Method for sending notifications to Slack via the API:
      https://api.slack.com/docs/attachments
  """
  @classmethod
  def method_name(cls):
    return 'slack'

  def validate(self, repository, config_data):
    if not config_data.get('url', ''):
      raise CannotValidateNotificationMethodException('Missing Slack Callback URL')

  def format_for_slack(self, message):
    message = message.replace('\n', '')
    message = re.sub(r'\s+', ' ', message)
    message = message.replace('<br>', '\n')
    return adjust_tags(message)

  def perform(self, notification_obj, event_handler, notification_data):
    config_data = json.loads(notification_obj.config_json)

    url = config_data.get('url', '')
    if not url:
      return

    owner = model.user.get_user_or_org(notification_obj.repository.namespace_user.username)
    if not owner:
      # Something went wrong.
      return

    level = event_handler.get_level(notification_data['event_data'], notification_data)
    color = {
      'info': '#ffffff',
      'warning': 'warning',
      'error': 'danger',
      'success': 'good',
      'primary': 'good'
    }.get(level, '#ffffff')

    summary = event_handler.get_summary(notification_data['event_data'], notification_data)
    message = event_handler.get_message(notification_data['event_data'], notification_data)

    headers = {'Content-type': 'application/json'}
    payload = {
      'text': summary,
      'username': 'quayiobot',
      'attachments': [
        {
          'fallback': summary,
          'text': self.format_for_slack(message),
          'color': color,
          'mrkdwn_in': ["text"]
        }
      ]
    }

    try:
      resp = requests.post(url, data=json.dumps(payload), headers=headers, timeout=METHOD_TIMEOUT)
      if resp.status_code/100 != 2:
        error_message = '%s response for Slack to url: %s' % (resp.status_code, url)
        logger.error(error_message)
        logger.error(resp.content)
        raise NotificationMethodPerformException(error_message)

    except requests.exceptions.RequestException as ex:
      logger.exception('Slack method was unable to be sent: %s', ex.message)
      raise NotificationMethodPerformException(ex.message)