#!/usr/bin/env python
# -*- encoding: utf-8 -*-

"""Group management."""

import logging

from flask import Blueprint
from flask import request
from flask import jsonify

from luncho.helpers import ForceJSON
from luncho.helpers import auth

from luncho.server import User
from luncho.server import Group
from luncho.server import db

from luncho.exceptions import LunchoException
from luncho.exceptions import ElementNotFoundException
from luncho.exceptions import AccountNotVerifiedException
from luncho.exceptions import NewMaintainerDoesNotExistException
from luncho.exceptions import UserIsNotAdminException


class UserIsNotMemberException(LunchoException):
    """The user is not the admin of the group.

    .. sourcecode:: http

       HTTP/1.1 403 Forbidden
       Content-Type: test/json

       { "status": "ERROR", "message": "User is not member of this group" }
    """
    def __init__(self):
        super(UserIsNotMemberException, self).__init__()
        self.status = 403
        self.message = 'User is not member of this group'


class SomeUsersNotFoundException(LunchoException):
    """Some users in the add list do not exist.

    .. sourcecode:: http

       HTTP/1.1 404 Not Found
       Content-Type: text/json

       { "status": "ERROR",
         "message", "Some users in the add list do not exist",
         "users": ["<username>", "<username>", ...]}
    """
    def __init__(self, users=None):
        super(SomeUsersNotFoundException, self).__init__()
        self.status = 404
        self.message = 'Some users in the add list do not exist'
        self.users = users

    def response(self):
        json = {'status': 'ERROR',
                'message': self.message}
        if self.users:
            json['users'] = self.users
        response = jsonify(json)
        response.status_code = self.status
        return response


groups = Blueprint('groups', __name__)

LOG = logging.getLogger('luncho.blueprints.groups')


@groups.route('', methods=['GET'])
@auth
def user_groups():
    """*Authenticated request*

    Return a list of the groups the user belongs or it's the owner.

    :header Authorization: Access token from `/token/`.

    :status 200: Success

        .. sourcecode:: http

            HTTP/1.1 200 OK
            Content-Type: text/json

            { "status": "OK", "groups": [ { "id": "<group id>" ,
                                            "name": "<group name>",
                                            "admin": <true if the user is
                                                admin>},
                                            ...] }

    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    """
    user = request.user
    groups = {}
    for group in user.groups:
        groups[group.id] = {'id': group.id,
                            'name': group.name,
                            'admin': group.owner == user.username}

    return jsonify(status='OK',
                   groups=groups.values())


@groups.route('', methods=['POST'])
@ForceJSON(required=['name'])
@auth
def create_group():
    """*Authenticated request*

    Create a new group. Once the group is created, the user becomes the
    administrator of the group.

    **Example request**:

    .. sourcecode:: http

       { "name": "Name for the group" }

    :header Authorization: Access token from `/token/`.

    :status 200: Success

        .. sourcecode:: http

            HTTP/1.1 200 OK
            Content-Type: text/json

            { "status": "OK", "id": <new group id> }

    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    :status 412: Account not verified
        (:py:class:`AccountNotVerifiedException`)
    """
    user = request.user
    LOG.debug('User status: {verified}'.format(verified=user.verified))

    if not user.verified:
        raise AccountNotVerifiedException()

    json = request.get_json(force=True)
    new_group = Group(name=json['name'],
                      owner=user)

    LOG.debug('Current user groups: {groups}'.format(groups=user.groups))
    user.groups.append(new_group)

    db.session.add(new_group)
    db.session.commit()

    return jsonify(status='OK',
                   id=new_group.id)


@groups.route('<groupId>/', methods=['PUT'])
@ForceJSON()
@auth
def update_group(groupId):
    """*Authenticated request*

    Update group information. The user must be the administrator of the group
    to change any information. Partial requests are accepted and missing
    fields are not changed.

    The administrator of the group can be changed by sending the
    "admin" field with the username of the new administrator.

    **Example request**:

    .. sourcecode:: http

       { "name": "new group name": "admin": "newAdmin"}

    :header Authorization: Access token from `/token/`.

    :status 200: Success
    :status 400: Request not in JSON format
        (:py:class:`RequestMustBeJSONException`)
    :status 403: User is not the group administrator
        (:py:class:`UserIsNotAdminException`)
    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 404: New administrator does not exist
        (:py:class:`NewMaintainerDoesNotExistException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    """
    user = request.user
    group = Group.query.get(groupId)
    if not group:
        raise ElementNotFoundException('Group')

    if not group.owner == user.username:
        raise UserIsNotAdminException()

    LOG.debug('Group = {group}'.format(group=group))

    json = request.get_json(force=True)
    if 'name' in json:
        group.name = json['name']

    if 'admin' in json:
        new_maintainer = User.query.get(json['admin'])
        if not new_maintainer:
            raise NewMaintainerDoesNotExistException()

        group.owner = new_maintainer.username
        LOG.debug("new owner of {group} = {new_maintainer}".format(
            group=group, new_maintainer=new_maintainer))

    db.session.commit()
    return jsonify(status='OK')


@groups.route('<groupId>/', methods=['DELETE'])
@auth
def delete_group(groupId):
    """*Authenticated request*

    Delete a group. Only the administrator of the group can delete it.

    :param groupId: The group Id

    :header Authorization: Access token from `/token/`.

    :status 200: Success
    :status 403: User is not the group administrator
        (:py:class:`UserIsNotAdminException`)
    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    """
    user = request.user
    group = Group.query.get(groupId)
    if not group:
        raise ElementNotFoundException('Group')

    if not group.owner == user.username:
        raise UserIsNotAdminException()

    db.session.delete(group)
    db.session.commit()

    return jsonify(status='OK')


@groups.route('<groupId>/users/', methods=['PUT'])
@ForceJSON(required=['usernames'])
@auth
def add_users_to_group(groupId):
    """*Authenticated request*

    Add users to the group. Only the group administrator can add users to
    their groups.

    :param groupId: The group Id

    **Example request**:

    .. sourcecode:: http

        { "usernames": ["<username>", "<username>", ...] }

    :header Authorization: Access token from `/token/`.

    :status 200: Success
    :status 400: Request not in JSON format
        (:py:class:`RequestMustBeJSONException`)
    :status 403: User is not the group administrator
        (:py:class:`UserIsNotAdminException`)
    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 404: Incomplete request, some users not found; users that couldn't
        be found will return in the "missing" field.
        (:py:class:`SomeUsersNotFoundException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    """
    user = request.user
    group = Group.query.get(groupId)
    if not group:
        raise ElementNotFoundException('Group')

    if not group.owner == user.username:
        raise UserIsNotAdminException()

    json = request.get_json(force=True)
    unknown = []
    for user in json['usernames']:
        user_obj = User.query.get(user)
        if not user_obj:
            unknown.append(user)
            continue

        user_obj.groups.append(group)

    if unknown:
        raise SomeUsersNotFoundException(unknown)

    return jsonify(status='OK')


@groups.route('<groupId>/users/', methods=['GET'])
@auth
def list_group_members(groupId):
    """*Authenticated request*

    Return a list of the users in the group. The user must be part of the
    group to request this list.

    :parma groupId: The group Id

    :header Authorization: Access token from `/token/`.

    :status 200: Success

        .. sourcecode:: http

            HTTP/1.1 200 OK
            Content-Type: text/json

            { "status": "OK", "users": [ { "username": "<username>",
                                            "full_name": "<full name>"},
                                            ...] }

    :status 403: The user is not a member of the group
        (:py:class:`UserIsNotMemberException`)
    :status 404: User not found (via token)
        (:py:class:`UserNotFoundException`)
    :status 412: Authorization required
        (:py:class:`AuthorizationRequiredException`)
    """
    user = request.user
    group = Group.query.get(groupId)
    if not group:
        raise ElementNotFoundException('Group')

    LOG.debug('user groups: {groups}'.format(groups=user.groups))

    if group not in user.groups:
        raise UserIsNotMemberException()

    users = []
    for user in group.users:
        users.append({'username': user.username,
                      'full_name': user.fullname})

    return jsonify(status='OK', users=users)