import datetime
import re
from sqlalchemy import func
from szurubooru import config, db, errors
from szurubooru.util import auth, misc, files, images

class UserNotFoundError(errors.NotFoundError): pass
class UserAlreadyExistsError(errors.ValidationError): pass
class InvalidNameError(errors.ValidationError): pass
class InvalidEmailError(errors.ValidationError): pass
class InvalidPasswordError(errors.ValidationError): pass
class InvalidRankError(errors.ValidationError): pass
class InvalidAvatarError(errors.ValidationError): pass

def get_by_name(session, name):
    return session.query(db.User) \
        .filter(func.lower(db.User.name) == func.lower(name)) \
        .first()

def get_by_name_or_email(session, name_or_email):
    return session.query(db.User) \
        .filter(
            (func.lower(db.User.name) == func.lower(name_or_email))
            | (func.lower(db.User.email) == func.lower(name_or_email))) \
        .first()

def create_user(session, name, password, email, auth_user):
    user = db.User()
    update_name(session, user, name, auth_user)
    update_password(user, password)
    update_email(user, email)
    if not session.query(db.User).count():
        user.rank = 'admin'
    else:
        user.rank = config.config['default_rank']
    user.creation_time = datetime.datetime.now()
    user.avatar_style = db.User.AVATAR_GRAVATAR
    return user

def update_name(session, user, name, auth_user):
    if misc.value_exceeds_column_size(name, db.User.name):
        raise InvalidNameError('User name is too long.')
    other_user = get_by_name(session, name)
    if other_user and other_user.user_id != auth_user.user_id:
        raise UserAlreadyExistsError('User %r already exists.' % name)
    name = name.strip()
    name_regex = config.config['user_name_regex']
    if not re.match(name_regex, name):
        raise InvalidNameError(
            'User name %r must satisfy regex %r.' % (name, name_regex))
    user.name = name

def update_password(user, password):
    password_regex = config.config['password_regex']
    if not re.match(password_regex, password):
        raise InvalidPasswordError(
            'Password must satisfy regex %r.' % password_regex)
    user.password_salt = auth.create_password()
    user.password_hash = auth.get_password_hash(user.password_salt, password)

def update_email(user, email):
    email = email.strip() or None
    if email and misc.value_exceeds_column_size(email, db.User.email):
        raise InvalidEmailError('Email is too long.')
    if not misc.is_valid_email(email):
        raise InvalidEmailError('E-mail is invalid.')
    user.email = email

def update_rank(user, rank, authenticated_user):
    rank = rank.strip()
    available_ranks = config.config['ranks']
    if not rank in available_ranks:
        raise InvalidRankError(
            'Rank %r is invalid. Valid ranks: %r' % (rank, available_ranks))
    if available_ranks.index(authenticated_user.rank) \
            < available_ranks.index(rank):
        raise errors.AuthError('Trying to set higher rank than your own.')
    user.rank = rank

def update_avatar(user, avatar_style, avatar_content):
    if avatar_style == 'gravatar':
        user.avatar_style = user.AVATAR_GRAVATAR
    elif avatar_style == 'manual':
        user.avatar_style = user.AVATAR_MANUAL
        if not avatar_content:
            raise InvalidAvatarError('Avatar content missing.')
        image = images.Image(avatar_content)
        image.resize_fill(
            int(config.config['thumbnails']['avatar_width']),
            int(config.config['thumbnails']['avatar_height']))
        files.save('avatars/' + user.name.lower() + '.jpg', image.to_jpeg())
    else:
        raise InvalidAvatarError(
            'Avatar style %r is invalid. Valid avatar styles: %r.' % (
                avatar_style, ['gravatar', 'manual']))

def bump_login_time(user):
    user.last_login_time = datetime.datetime.now()

def reset_password(user):
    password = auth.create_password()
    user.password_salt = auth.create_password()
    user.password_hash = auth.get_password_hash(user.password_salt, password)
    return password