import logging
import io
import os.path
import tarfile
import base64
import json
import requests
import re

from flask.ext.mail import Message
from app import mail, app, get_app_url
from data import model

logger = logging.getLogger(__name__)

class InvalidNotificationMethodException(Exception):
  pass

class CannotValidateNotificationMethodException(Exception):
  pass


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, event_handler, notification_data):
    """
    Performs the notification method.

    notification: 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.get_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.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:
        return (False, 'Organization name must match repository namespace')

      return (True, None, [target])
    elif target_info['kind'] == 'team':
      # Lookup the team.
      team = None
      try:
        team = model.get_organization_team(repository.namespace, 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.get_organization_team_members(team.id))


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

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

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


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.get_email_authorized_for_repo(repository.namespace, 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, event_handler, notification_data):
    config_data = json.loads(notification.config_json)
    email = config_data.get('email', '')
    if not email:
      return False

    msg = Message(event_handler.get_summary(notification_data['event_data'], notification_data),
                  sender='support@quay.io',
                  recipients=[email])
    msg.html = event_handler.get_message(notification_data['event_data'], notification_data)

    try:
      with app.app_context():
        mail.send(msg)
    except Exception as ex:
      logger.exception('Email was unable to be sent: %s' % ex.message)
      return False      

    return True


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, event_handler, notification_data):
    config_data = json.loads(notification.config_json)
    url = config_data.get('url', '')
    if not url:
      return False

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

    try:
      resp = requests.post(url, data=json.dumps(payload), headers=headers)
      if resp.status_code/100 != 2:
        logger.error('%s response for webhook to url: %s' % (resp.status_code,
                                                             url))
        return False

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

    return True


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, event_handler, notification_data):
    config_data = json.loads(notification.config_json)
    token = config_data.get('flow_api_token', '')
    if not token:
      return False

    owner = model.get_user(notification.repository.namespace)
    if not owner:
      # Something went wrong.
      return False

    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.repository.namespace + ' ' + notification.repository.name,
      'tags': ['#' + event_handler.event_name()],
      'link': notification_data['event_data']['homepage']
    }

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

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

    return True


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, event_handler, notification_data):
    config_data = json.loads(notification.config_json)

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

    if not token or not room_id:
      return False

    owner = model.get_user(notification.repository.namespace)
    if not owner:
      # Something went wrong.
      return False

    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',
      '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)
      if resp.status_code/100 != 2:
        logger.error('%s response for hipchat to url: %s' % (resp.status_code,
                                                              url))
        logger.error(resp.content)
        return False

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

    return True


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('token', ''):
      raise CannotValidateNotificationMethodException('Missing Slack Token')

    if not config_data.get('subdomain', '').isalnum():
      raise CannotValidateNotificationMethodException('Missing Slack Subdomain Name')

  def formatForSlack(self, message):
    message = message.replace('\n', '')
    message = re.sub(r'\s+', ' ', message)
    message = message.replace('<br>', '\n')
    message = re.sub(r'<a href="(.+)">(.+)</a>', '<\\1|\\2>', message)
    return message

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

    token = config_data.get('token', '')
    subdomain = config_data.get('subdomain', '')

    if not token or not subdomain:
      return False

    owner = model.get_user(notification.repository.namespace)
    if not owner:
      # Something went wrong.
      return False

    url = 'https://%s.slack.com/services/hooks/incoming-webhook?token=%s' % (subdomain, token)

    level = event_handler.get_level(notification_data['event_data'], notification_data)
    color = {
      'info': '#ffffff',
      'warning': 'warning',
      'error': 'danger',
      '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.formatForSlack(message),
          'color': color
        }
      ]
    }

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

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

    return True