#!/usr/bin/env python

# LSST Data Management System
# Copyright 2014-2015 AURA/LSST.
#
# This product includes software developed by the
# LSST Project (http://www.lsst.org/).
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the LSST License Statement and
# the GNU General Public License along with this program.  If not,
# see <http://www.lsstcorp.org/LegalNotices/>.

"""
Parse JSON responses from replication service

@author  Fabrice Jammes, IN2P3
"""

# -------------------------------
#  Imports of standard modules --
# -------------------------------
from enum import Enum
import logging
import typing

# ----------------------------
# Imports for other modules --
# ----------------------------
from jsonpath_ng import jsonpath
from jsonpath_ng.ext import parse

# ---------------------------------
# Local non-exported definitions --
# ---------------------------------
_LOG = logging.getLogger(__name__)

class DatabaseStatus(Enum):
    NOT_REGISTERED = -1
    REGISTERED_NOT_PUBLISHED = 0
    PUBLISHED = 1

class TransactionState(Enum):
    ABORTED = "ABORTED"
    STARTED = "STARTED"
    FINISHED = "FINISHED"

def filter_transactions(responseJson, database, states):
    """Filter transactions by state inside json response issued by replication service
    """
    transaction_ids = []
    transactions = responseJson["databases"][database]['transactions']
    _LOG.debug(states)
    if len(transactions) != 0:
        _LOG.debug(f"Transactions for database {database}")
        for trans in transactions:
            _LOG.debug("  id: %s state: %s",
                        trans['id'], trans['state'])
            state = TransactionState(trans['state'])
            if state in states:
                transaction_ids.append(trans['id'])
    return transaction_ids

def get_indexes(responseJson, existing_indexes: typing.Dict[str, set]=dict()):
    for worker, data in responseJson['workers'].items():
        table = list(data.keys())[0]
        for idx_data in data[table]:
            try:
                existing_indexes[table].add(idx_data)
            except KeyError:
                existing_indexes[table] = set(idx_data)
    return existing_indexes

def get_location(responseJson):
    """ Retrieve chunk location (host and port) inside json response issued by replication service
    """
    host = responseJson["location"]["http_host"]
    port = responseJson["location"]["http_port"]
    return (host, port)

def parse_database_status(responseJson, database, family):
    jsonpath_expr = parse('$.config.databases[?(database="{}" & family_name="{}")].is_published'.format(database, family))
    result = jsonpath_expr.find(responseJson)
    if len(result) == 0:
        status = DatabaseStatus.NOT_REGISTERED
    elif len(result) == 1:
        if result[0].value == 0:
            status = DatabaseStatus.REGISTERED_NOT_PUBLISHED
        else:
            status = DatabaseStatus.PUBLISHED
    else:
        raise ValueError("Unexpected answer from replication service", responseJson)
    return status

def raise_error(responseJson, check_retry = False):
    """Check JSON response for error
       return True if check_retry = True and if error allows retrying request
       return False if no error in JSON response
       raise exception in case of error in JSON response for a non-retriable request
    """
    retry = False
    if not responseJson["success"]:
        _LOG.critical(responseJson["error"])
        error_ext = ''
        if "error_ext" in responseJson:
            _LOG.critical(responseJson["error_ext"])
            error_ext = responseJson["error_ext"]
            if check_retry:
                retry = _check_retry(error_ext)
        if not retry:
            raise Exception(
            'Error in JSON response',
            responseJson["error"], error_ext)
    return retry

def _check_retry(error_ext):
    if "retry_allowed" in error_ext and error_ext["retry_allowed"] != 0:
        retry = True
    else:
        retry = False
    return retry