'''Staff management.'''

import time
from sqlalchemy.sql import case, or_, and_, select, func, null

import strings
import model
import misc
import staff_interface
import config, config_defaults
from util import WakaError, local
from template import Template

# Cache of staff personnel objects.
__staff = {}

# Staff class types.
ADMIN = 'admin'
GLOBAL_MOD = 'globmod'
MODERATOR = 'mod'
CLASSES = (ADMIN, GLOBAL_MOD, MODERATOR)

# Login cookie expire times (in seconds).
SAVED_LOGIN_EXPIRE = 365 * 24 * 3600
UNSAVED_LOGIN_EXPIRE = 3600

# Staff Accounts and Logins
class LoginData(object):
    '''Class for interfacing with prefetched login data.'''

    def __init__(self, user, addr):
        self.__addr = addr
        self.__crypt = misc.hide_critical_data\
                       (','.join((user.password, remote)), config.SECRET)
        self.__username = user.username
        self.__cstring = ','.join((self.username, self.crypt()))

    def make_cookie(self, save_login=False):
        misc.make_cookies(admin=self.__cstring)

        if save_login:
            misc.make_cookies(wakaadminsave='1', wakaadmin=crypt,
                              expires=time.time()+SAVED_LOGIN_EXPIRE)
        else:
            misc.make_cookies(wakaadminsave='0', wakaadmin=crypt,
                              expires=time.time()+UNSAVED_LOGIN_EXPIRE)


    def get_crypt(self):
        '''Encrypted <password + MAC> string for login credentials.'''

        return self.__crypt

    def get_cookie_str(self):
        return self.__cstring

    def get_addr(self):
        return self.__addr

    def get_username(self):
        return self.__username

    cookie_str = property(get_cookie_str)
    crypt = property(get_crypt)
    addr = property(get_addr)
    username = property(get_username)

def get_staff(username):
    '''Generate (or get) a cached staff object for initializing and
    updating account information.'''

    if username in __staff:
        return __staff[username]

    # Class for representing staff
    class StaffMember(object):
        def __init__(self, username):
            session = model.Session()
            table = model.account
            table.create(bind=model.engine, checkfirst=True)
            sql = table.select().where(table.c.username == username)
            row = session.execute(sql).fetchone()
            self.__table = table

            if row is None:
                WakaError('Staff not found.')

            # Grab parameters from database. Password is pre-encrypted.
            self.__username = username
            self.__password = row.password
            self.__class = row.account
            self.__reign = row.reign.split(',')
            self.__disabled = row.disabled
            self.__update_dict = {}

            # Not logged in yet.
            self.__login_data = None

        def __update_db(self, **kwargs):
            self.__update_dict += kwargs

        def get_username(self):
            return self.__username

        def get_password(self):
            return self.__password

        def set_password(self, new):
            table = self.__table
            # TODO: Sanity checks

            kwargs = {'password' : new}
            self.__update_db(**kwargs)
            self.__password = new

        def get_reign(self):
            return self.__reign

        def set_reign(self, board_list):
            reign_str = ','.join(board_list)
            kwargs = {'reign' : reign_str}
            self.__update_db(**kwargs)

            self.__reign = board_list

        def get_class(self):
            return self.__class

        def set_class(self, new):
            if new in CLASSES:
                kwargs = {'account' : new}
                self.__update_db(**kwargs)
                self.__class = new
            else:
                raise WakaError('Invalid class name %s' % new)

        def get_login_data(self):
            return self.__login_data

        def get_disabled(self):
            return self.__disabled

        def set_disabled(self, disable):
            if disable:
                kwargs = {'disabled' : 1}
            else:
                kwargs = {'disabled' : 0}
            self.__disabled = disable

            self.__update_db(**kwargs)

        def login_host(self, ip):
            login_data = LoginData(self.username, ip)
            self.__login_data = login_data
            return login_data

        def logout_user(self):
            self.__login_data = None

        def flush_db(self):
            session = model.Session()
            table = self.__table

            if len(self.__update_dict) > 0:
                db_update = table.update().where(self.username == username)\
                                 .values(**self.__update_dict)

        account = property(get_class, set_class)
        username = property(get_username)
        password = property(get_password, set_password)
        reign = property(get_reign, set_reign)
        disabled = property(get_disabled, set_disabled)

    staff_obj = StaffMember(username)
    __staff[username] = staff_obj
    return staff_obj

def add_staff(username, pt_password, account, reign):
    session = model.Session()
    table = model.account
    password = misc.hide_critical_data(pt_password, config.SECRET)
    reign_str = ','.join(reign)

    sql = table.insert().values(username=username, password=password,
                                account=account, reign=reign_str,
                                disabled=0)
    session.execute(sql)

def del_staff(username):
    session = model.Session()
    table = model.account
    sql = table.delete(table.c.username == username)
    session.execute(sql)

    try:
        del __staff[username]
    except AttributeError:
        pass

def edit_staff(mpass, username, clear_pass=None, new_class=None,
               reign=None):

    staff_obj = get_staff(username)

    if clear_pass:
        staff_obj.password = misc.hide_critical_data(clear_pass,
                                                     config.SECRET)

    if new_class and new_class in CLASSES:
        staff_obj.account = new_class

    if reign:
        staff_obj.reign = reign

    staff_obj.flush_db()

def staff_exist():
    session = model.Session()
    table = model.account
    table.create(bind=model.engine, checkfirst=True)
    sql = select([func.count()], table)
    row = session.execute(sql).fetchone()

    if row[0] == 0:
        return False
    else:
        return True


def do_login(username=None, password=None, save_login=False,
             admin_cookie=None, nexttask='mpanel'):

    bad_pass = False
    staff_entry = None

    if len(__staff) == 0 and not staff_exist():
        return staff_interface.make_first_time_setup_gateway()
    elif username and password:
        # Login via login form entry.
        try:
            staff_entry = get_staff(username)
        except WakaError:
            # Bad username.
            bad_pass = True
        else:
            crypt_pass = misc.hide_critical_data(staff_entry.password,
                                                 config.SECRET)
            if crypt_pass == staff_entry.password:
                staff_entry.login_host(remote)
            else:
                bad_pass = True
    elif admin_cookie:
        # Attempt automatic login.
        staff_entry = check_password(admin_cookie, nexttask)
    else:
        # No login credentials given.
        bad_pass = True

    if bad_pass:
        return staff_interface.make_login_panel()
    else:
        login = staff_entry.login_data
        login.make_cookie(save_login=save_login)
        return staff_interface.make_admin_panel(login.cookie, nexttask)

def do_logout(admin):
    # Clear login cache.
    try:
        user = check_password(admin)
        user.logout_user()
    except WakaError:
        pass

    # Clear login cookies.
    misc.make_cookies(wakaadmin='', wakaadminsave='0', expires=0)

def check_password(cookie_str, editing=None):
    (username, crypt) = cookie_str.split(',')
    staff_entry = get_staff(username)
    cache = staff_entry.login_data

    if cache and cache.addr == remote:
        # The host is already logged in.
        pass
    elif crypt != misc.hide_critical_data(','.join([staff_entry.password,
                                                    remote]), config.SECRET):
        WakaError(S_WRONGPASS)
    else:
        # NOTE: This will overwrite the current network address login.
        staff_entry.login_host(remote)

    return staff_entry

def crypt_pass(cleartext):
    remote = local.environ['REMOTE_ADDR']
    return misc.hide_critical_data(','.join((cleartext, remote)),
                                            config.SECRET)