# -------------------------------------------------------------------------
#   Copyright (c) 2019 Intel Corporation Intellectual Property
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#
# -------------------------------------------------------------------------


from __future__ import print_function
from os import environ
import logging
import requests
from requests.exceptions import HTTPError


QUERY_API_VERSION = '/api/v1/query'
QUERY_RANGE_API_VERSION = '/api/v1/query_range'
LIST_OF_ENV_VARIABLES = ["DATA_ENDPOINT"]
MAP_ENV_VARIABLES = dict()
LOG = logging.getLogger(__name__)


def set_log_config():
    logging.basicConfig(format='%(asctime)s ::%(filename)s :: %(funcName)s :: %(levelname)s :: %(message)s',
                    datefmt='%m-%d-%Y %I:%M:%S%p',
                    level=logging.DEBUG,
                    filename='promql_api.log',
                    filemode='a')
    LOG.info("Set the log configs.")


def load_and_validate_env_vars(list_of_env_vars):
    LOG.info("Loading the env variables ...")
    for env_var in list_of_env_vars:
        if env_var in environ:
            LOG.info("Found env variable: {} ".format(env_var.upper()))
            MAP_ENV_VARIABLES[env_var.upper()] = environ.get(env_var)
        else:
            #MAP_ENV_VARIABLES['DATA_ENDPOINT']='http://127.0.0.1:9090' # to be deleted
            LOG.error("Env var: {} not found ! ".format(env_var.upper()))
            raise KeyError("Env variable: {} not found ! ".format(env_var.upper()))


def query(QUERY_STRING):
    """
    Input parameters:
        QUERY_STRING : a list of the query strings like ['irate(collectd_cpufreq{exported_instance="otconap7",cpufreq="1"}[2m])']
    Return:
        returns a list of  result sets corresponding to each of the query strings..
        SAMPLE O/P:
        [{'metric': {'cpufreq': '1',
             'endpoint': 'collectd-prometheus',
             'exported_instance': 'otconap7',
             'instance': '172.25.103.1:9103',
             'job': 'collectd',
             'namespace': 'edge1',
             'pod': 'plundering-liger-collectd-wz7xg',
             'service': 'collectd'},
        'value': [1559177169.415, '119727200']}]
    """
    set_log_config()
    load_and_validate_env_vars(LIST_OF_ENV_VARIABLES)
    LOG.info("Forming the get request ...")
    list_of_substrings = []
    params_map = {}
    list_of_result_sets = []
    list_of_substrings.append(MAP_ENV_VARIABLES['DATA_ENDPOINT'])
    list_of_substrings.append(QUERY_API_VERSION)
    url = ''.join(list_of_substrings)

    for each_query_string in QUERY_STRING:
        params_map['query'] = each_query_string
        try:
            LOG.info('API request::: URL: {} '.format(url))
            LOG.info('API request::: params: {} '.format(params_map))
            response = requests.get(url, params=params_map)
            response.raise_for_status() # This might raise HTTPError which is handled in except block
        except HTTPError as http_err:
            if response.json()['status'] == "error":
                LOG.error("::::ERROR OCCURED::::")
                LOG.error("::::ERROR TYPE:::: {}".format(response.json()['errorType']))
                LOG.error("::::ERROR:::: {}".format(response.json()['error']))
                list_of_result_sets.append(dict({'error':response.json()['error'],
                                                'errorType' : response.json()['errorType']}))
            print(f'Check logs..HTTP error occurred: {http_err}')

        except Exception as err:
            print(f'Check logs..Other error occurred: {err}')

        else:
            if response.json()['status'] == "error":
                LOG.error("::::ERROR OCCURED!::::")
                LOG.error("::::ERROR TYPE:::: {}".format(response.json()['errorType']))
                LOG.error("::::ERROR:::: {}".format(response.json()['error']))
                list_of_result_sets.append(response.json()['error'])
                list_of_result_sets.append(dict({'error':response.json()['error'],
                                                'errorType' : response.json()['errorType']}))
            else:
                results = response.json()['data']['result']
                LOG.info('::::::::::RESULTS::::::::::::: {}'.format(each_query_string))
                for each_result in results:
                    LOG.info(each_result)
                list_of_result_sets.append(results)
    return list_of_result_sets


def validate_parameters(map_of_parameters):
    for k,v in map_of_parameters.items():
        if k not in ['query', 'start', 'end', 'step', 'timeout']:
            LOG.error('Parameter : \'{}\' not supported by query_range'.format(k))
            LOG.info('Valid parameters :: \'query\', \'start\', \'end\', \'step\', \'timeout\'')
            raise Exception('Parameter : \'{}\' not supported by query_range. Check logs'.format(k))
        if not isinstance(k,str):
            LOG.error(':: Key Paramter : \'{}\' NOT a string! Keys should be string ::'.format(k))
            raise Exception(':: Key Paramter : \'{}\' NOT a string! Keys should be string ::'.format(k))
        if not isinstance(v,str):
            LOG.error(':: Value Paramter of key: \'{}\' NOT a string! Values should be string ::'.format(k))
            raise Exception(':: Value Paramter of key: \'{}\' NOT a string! Values should be string ::'.format(k))
    return True


def query_range(map_of_parameters):
    list_of_result_sets = []
    set_log_config()
    if validate_parameters(map_of_parameters):
        LOG.info(':::Validation of map_of_parameters done::')
    load_and_validate_env_vars(LIST_OF_ENV_VARIABLES)
    LOG.info("Forming the query_range request ...")

    list_of_substrings = []
    list_of_substrings.append(MAP_ENV_VARIABLES['DATA_ENDPOINT'])
    list_of_substrings.append(QUERY_RANGE_API_VERSION)
    url = ''.join(list_of_substrings)

    try:
        LOG.info('API request::: URL: {} '.format(url))
        LOG.info('API request::: params: {} '.format(map_of_parameters))
        response = requests.get(url, params=map_of_parameters)
        response.raise_for_status() # This might raise HTTPError which is handled in except block
    except HTTPError as http_err:
        if response.json()['status'] == "error":
            LOG.error("::::ERROR OCCURED::::")
            LOG.error("::::ERROR TYPE:::: {}".format(response.json()['errorType']))
            LOG.error("::::ERROR:::: {}".format(response.json()['error']))
        print(f'Check logs..HTTP error occurred: {http_err}')
    except Exception as err:
            print(f'Check logs..Other error occurred: {err}')
    else:
        if response.json()['status'] == "error":
            LOG.error("::::ERROR OCCURED!::::")
            LOG.error("::::ERROR TYPE:::: {}".format(response.json()['errorType']))
            LOG.error("::::ERROR:::: {}".format(response.json()['error']))
            list_of_result_sets.append(response.json()['error'])
            list_of_result_sets.append(dict({'error':response.json()['error'],
                                                'errorType' : response.json()['errorType']}))
        else:
            results = response.json()['data']['result']
            LOG.info('::::::::::RESULTS OF QUERY_RANGE::::::::::::: {}'.format(map_of_parameters))
            list_of_result_sets.append(results)

    return list_of_result_sets