import bcrypt
import logging
import dateutil.parser
import operator

from database import *
from util.validation import (validate_email, validate_username,
                             validate_password)


logger = logging.getLogger(__name__)


class DataModelException(Exception):
  pass


def create_user(username, password, email):
  pw_hash = bcrypt.hashpw(password, bcrypt.gensalt())

  if not validate_email(email):
    raise DataModelException('Invalid email address: %s' % email)
  if not validate_username(username):
    raise DataModelException('Invalid username: %s' % username)
  if not validate_password(password):
    raise DataModelException('Invalid password, password must be at least ' +
                             '8 characters and contain no whitespace.')

  try:
    new_user = User.create(username=username, password_hash=pw_hash,
                           email=email)
    return new_user
  except Exception as ex:
    raise DataModelException(ex.message)


def create_confirm_email_code(user):
  code = EmailConfirmation.create(user=user, email_confirm=True)
  return code


def confirm_user_email(code):
  code = EmailConfirmation.get(EmailConfirmation.code == code,
                               EmailConfirmation.email_confirm == True)

  user = code.user
  user.verified = True
  user.save()

  code.delete_instance()

  return user


def get_user(username):
  try:
    return User.get(User.username == username)
  except User.DoesNotExist:
    return None


def get_matching_users(username_prefix):
  query = User.select().where(User.username ** (username_prefix + '%'))
  return list(query.limit(10))


def verify_user(username, password):
  try:
    fetched = User.get(User.username == username)
  except User.DoesNotExist:
    return None

  if bcrypt.hashpw(password, fetched.password_hash) == fetched.password_hash:
    return fetched

  # We weren't able to authorize the user
  return None


def create_access_token(user, repository):
  new_token = AccessToken.create(user=user, repository=repository)
  return new_token


def verify_token(code, namespace_name, repository_name):
  joined = AccessToken.select(AccessToken, Repository).join(Repository)
  tokens = list(joined.where(AccessToken.code == code,
                             Repository.namespace == namespace_name,
                             Repository.name == repository_name))
  if tokens:
    return tokens[0]
  return None


def get_token(code):
  return AccessToken.get(AccessToken.code == code)


def get_visible_repositories(username=None):
  query = Repository.select().distinct().join(Visibility)
  or_clauses = [(Visibility.name == 'public')]

  if username:
    with_perms = query.switch(Repository).join(RepositoryPermission,
                                               JOIN_LEFT_OUTER)
    query = with_perms.join(User)
    or_clauses.append(User.username == username)

  return query.where(reduce(operator.or_, or_clauses))


def get_matching_repositories(repo_term, username=None):
  visible = get_visible_repositories(username)
  search_clauses = (Repository.name ** ('%' + repo_term + '%') |
                    Repository.namespace ** ('%' + repo_term + '%') |
                    Repository.description ** ('%' + repo_term + '%'))


  final = visible.where(search_clauses).limit(10)
  return list(final)


def change_password(user, new_password):
  pw_hash = bcrypt.hashpw(new_password, bcrypt.gensalt())
  user.password_hash = pw_hash
  user.save()


def update_email(user, new_email):
  user.email = new_email
  user.verified = False
  user.save()


def get_all_user_permissions(user):
  select = User.select(User, Repository, RepositoryPermission, Role)
  with_repo = select.join(RepositoryPermission).join(Repository)
  with_role = with_repo.switch(RepositoryPermission).join(Role)
  return with_role.where(User.username == user.username)


def get_all_repo_users(namespace_name, repository_name):
  select = RepositoryPermission.select(User.username, Role.name,
                                       RepositoryPermission)
  with_user = select.join(User)
  with_role = with_user.switch(RepositoryPermission).join(Role)
  with_repo = with_role.switch(RepositoryPermission).join(Repository)
  return with_repo.where(Repository.namespace == namespace_name,
                         Repository.name == repository_name)


def get_repository(namespace_name, repository_name):
  try:
    return Repository.get(Repository.name == repository_name,
                          Repository.namespace == namespace_name)
  except Repository.DoesNotExist:
    return None


def repository_is_public(namespace_name, repository_name):
  joined = Repository.select().join(Visibility)
  query = joined.where(Repository.namespace == namespace_name,
                       Repository.name == repository_name,
                       Visibility.name == 'public')
  return len(list(query)) > 0


def set_repository_visibility(repo, visibility):
  visibility_obj = Visibility.get(name=visibility)
  if not visibility_obj:
    return

  repo.visibility = visibility_obj
  repo.save()
  

def create_repository(namespace, name, owner):
  private = Visibility.get(name='private')
  repo = Repository.create(namespace=namespace, name=name,
                           visibility=private)
  admin = Role.get(name='admin')
  permission = RepositoryPermission.create(user=owner, repository=repo,
                                           role=admin)
  return repo


def create_image(image_id, repository):
  new_image = Image.create(image_id=image_id, repository=repository)
  return new_image


def set_image_checksum(image_id, repository, checksum):
  fetched = Image.get(Image.image_id == image_id,
                      Image.repository == repository)
  fetched.checksum = checksum
  fetched.save()
  return fetched


def set_image_metadata(image_id, namespace_name, repository_name,
                       created_date_str, comment, parent=None):
  joined = Image.select().join(Repository)
  image_list = list(joined.where(Repository.name == repository_name,
                                 Repository.namespace == namespace_name,
                                 Image.image_id == image_id))

  if not image_list:
    raise DataModelException('No image with specified id and repository')

  fetched = image_list[0]
  fetched.created = dateutil.parser.parse(created_date_str)
  fetched.comment = comment

  if parent:
    fetched.ancestors = '%s%s/' % (parent.ancestors, parent.id)

  fetched.save()
  return fetched


def get_repository_images(namespace_name, repository_name):
  joined = Image.select().join(Repository)
  return joined.where(Repository.name == repository_name,
                      Repository.namespace == namespace_name)


def list_repository_tags(namespace_name, repository_name):
  select = RepositoryTag.select(RepositoryTag, Image)
  with_repo = select.join(Repository)
  with_image = with_repo.switch(RepositoryTag).join(Image)
  return with_image.where(Repository.name == repository_name,
                          Repository.namespace == namespace_name)


def get_tag_image(namespace_name, repository_name, tag_name):
  joined = Image.select().join(RepositoryTag).join(Repository)
  fetched = joined.where(Repository.name == repository_name,
                         Repository.namespace == namespace_name,
                         RepositoryTag.name == tag_name)

  if not fetched:
    raise DataModelException('Unable to find image for tag.')

  return fetched[0]


def get_image_by_id(image_id):
  return Image.get(Image.image_id == image_id)


def get_parent_images(image_obj):
  """ Returns a list of parent Image objects in chronilogical order. """
  parents = image_obj.ancestors
  parent_db_ids = parents.strip('/').split('/')

  or_clauses = [(Image.id == db_id) for db_id in parent_db_ids]
  parent_images = Image.select().where(reduce(operator.or_, or_clauses))
  id_to_image = {unicode(image.id): image for image in parent_images}

  return [id_to_image[parent_id] for parent_id in parent_db_ids]


def create_or_update_tag(namespace_name, repository_name, tag_name,
                         tag_image_id):
  repo = Repository.get(Repository.name == repository_name,
                        Repository.namespace == namespace_name)
  image = Image.get(Image.image_id == tag_image_id)

  try:
    tag = RepositoryTag.get(RepositoryTag.repository == repo,
                            RepositoryTag.name == tag_name)
    tag.image = image
    tag.save()
  except RepositoryTag.DoesNotExist:
    tag = RepositoryTag.create(repository=repo, image=image, name=tag_name)

  return tag


def delete_tag(namespace_name, repository_name, tag_name):
  repo = Repository.get(Repository.name == repository_name,
                        Repository.namespace == namespace_name)
  tag = RepositoryTag.get(RepositoryTag.repository == repo,
                          RepositoryTag.name == tag_name)
  tag.delete_instance()


def delete_all_repository_tags(namespace_name, repository_name):
  repo = Repository.get(Repository.name == repository_name,
                        Repository.namespace == namespace_name)
  RepositoryTag.delete().where(RepositoryTag.repository == repo)


def get_user_repo_permissions(user, repository):
  select = RepositoryPermission.select()
  return select.where(RepositoryPermission.user == user,
                      RepositoryPermission.repository == repository)


def user_permission_repo_query(username, namespace_name, repository_name):
  selected = RepositoryPermission.select(User, Repository, Role,
                                         RepositoryPermission)
  with_user = selected.join(User)
  with_role = with_user.switch(RepositoryPermission).join(Role)
  with_repo = with_role.switch(RepositoryPermission).join(Repository)
  return with_repo.where(Repository.name == repository_name,
                         Repository.namespace == namespace_name,
                         User.username == username)


def get_user_reponame_permission(username, namespace_name, repository_name):
  fetched = list(user_permission_repo_query(username, namespace_name,
                                            repository_name))
  if not fetched:
    raise DataModelException('User does not have permission for repo.')

  return fetched[0]


def set_user_repo_permission(username, namespace_name, repository_name,
                             role_name):
  if username == namespace_name:
    raise DataModelException('Namespace owner must always be admin.')

  user = User.get(User.username == username)
  repo = Repository.get(Repository.name == repository_name,
                        Repository.namespace == namespace_name)
  new_role = Role.get(Role.name == role_name)

  # Fetch any existing permission for this user on the repo
  try:
    perm = RepositoryPermission.get(RepositoryPermission.user == user,
                                    RepositoryPermission.repository == repo)
    perm.role = new_role
    perm.save()
    return perm
  except RepositoryPermission.DoesNotExist:
    new_perm = RepositoryPermission.create(repository=repo, user=user,
                                           role=new_role)
    return new_perm


def delete_user_permission(username, namespace_name, repository_name):
  if username == namespace_name:
    raise DataModelException('Namespace owner must always be admin.')

  fetched = list(user_permission_repo_query(username, namespace_name,
                                            repository_name))
  if not fetched:
    raise DataModelException('User does not have permission for repo.')

  fetched[0].delete_instance()