# Copyright 2018 TrilioData Inc.
# All Rights Reserved.

from sqlalchemy.sql.expression import asc

from oslo_log import log as logging
import six.moves.urllib.parse as urlparse
from dmapi.db.sqlalchemy import api as db_api
from dmapi.db.sqlalchemy import api_models
from dmapi import exception
from dmapi.objects import base
from dmapi.objects import fields
from dmapi import conf 


CONF = conf.CONF
LOG = logging.getLogger(__name__)


def _parse_netloc(netloc):
    """Parse a user:pass@host:port and return a dict suitable for formatting
    a cell mapping template.
    """
    these = {
        'username': None,
        'password': None,
        'hostname': None,
        'port': None,
    }

    if '@' in netloc:
        userpass, hostport = netloc.split('@', 1)
    else:
        hostport = netloc
        userpass = ''

    if hostport.startswith('['):
        host_end = hostport.find(']')
        if host_end < 0:
            raise ValueError('Invalid IPv6 URL')
        these['hostname'] = hostport[1:host_end]
        these['port'] = hostport[host_end + 1:]
    elif ':' in hostport:
        these['hostname'], these['port'] = hostport.split(':', 1)
    else:
        these['hostname'] = hostport

    if ':' in userpass:
        these['username'], these['password'] = userpass.split(':', 1)
    else:
        these['username'] = userpass

    return these


@base.ContegoObjectRegistry.register
class CellMapping(base.ContegoObject):
    CELL0_UUID = '00000000-0000-0000-0000-000000000000'

    fields = {
        'id': fields.IntegerField(read_only=True),
        'uuid': fields.UUIDField(),
        'name': fields.StringField(nullable=True),
        'transport_url': fields.StringField(),
        'database_connection': fields.StringField(),
        }


    @staticmethod
    def _format_url(url, default):
        default_url = urlparse.urlparse(default)

        subs = {
            'username': default_url.username,
            'password': default_url.password,
            'hostname': default_url.hostname,
            'port': default_url.port,
            'scheme': default_url.scheme,
            'query': default_url.query,
            'fragment': default_url.fragment,
            'path': default_url.path.lstrip('/'),
        }

        if ',' in default_url.netloc:
            netlocs = default_url.netloc.split(',')
            index = 0
            for netloc in netlocs:
                index += 1
                these = _parse_netloc(netloc)
                for key in these:
                    subs['%s%i' % (key, index)] = these[key]

        return url.format(**subs)

    @staticmethod
    def format_db_url(url):

        # For older releases where DB contains connection string
        if url is not None and '{' not in url:
            return url

        if CONF.database.connection is None:
            if '{' in url:
                LOG.error('Cell mapping database_connection is a template, '
                          'but [database]/connection is not set')
            return url
        try:
            return CellMapping._format_url(url, CONF.database.connection)
        except Exception:
            LOG.exception('Failed to parse [database]/connection to '
                          'format cell mapping')
            return url

    @staticmethod
    def format_mq_url(url):

        # For older releases where DB contains connection string
        if url is not None and '{' not in url:
            return url

        if CONF.transport_url is None:
            if '{' in url:
                LOG.error('Cell mapping transport_url is a template, but '
                          '[DEFAULT]/transport_url is not set')
            return url
        try:
            return CellMapping._format_url(url, CONF.transport_url)
        except Exception:
            LOG.exception('Failed to parse [DEFAULT]/transport_url to '
                          'format cell mapping')
            return url

    @staticmethod
    def _from_db_object(context, cell_mapping, db_cell_mapping):
        for key in cell_mapping.fields:
            val = db_cell_mapping[key]
            if key == 'database_connection':
                val = cell_mapping.format_db_url(val)
            elif key == 'transport_url':
                val = cell_mapping.format_mq_url(val)
            setattr(cell_mapping, key, val)
        cell_mapping.obj_reset_changes()
        cell_mapping._context = context
        return cell_mapping