# Copyright (C) 2005-2025 Splunk Inc. All Rights Reserved.

import sys
import uuid
import time
import json
import traceback
from splunk.clilib.bundle_paths import make_splunkhome_path
sys.path.append(make_splunkhome_path(['etc', 'apps', 'SA-ITOA', 'lib']))
from itsi.itsi_utils import ITOAInterfaceUtils

from .metrics_backfill_worker import MetricsBackfillWorker

JOB_MANAGER_PAGE = '/app/itsi/job_manager?app=&filter='
KVSTORE_COLLECTION = 'itsi_metrics_backfill_queue'
DOCS_URL = '/help?location=[itsi:4.20.0]metrics_summary_index'


class MetricsBackfillQueue(object):
    def __init__(self, session_key, logger):
        self.session_key = session_key
        self.service = ITOAInterfaceUtils.service_connection(session_key, 'SA-ITOA')
        self.logger = logger
        try:
            self.queue_collection = self.service.kvstore[KVSTORE_COLLECTION]
        except KeyError:
            self.queue_collection = None

    def get_backfill_queue_info(self):
        if not self.queue_collection:
            return {}
        return self.queue_collection.data.query()

    def clear_backfill_queue(self):
        self.queue_collection.data.delete()

    def notify_of_start(self, batch_id):
        self.logger.info('Metric index backfill process has started')
        msg = {
            'severity': 'info',
            'value': ('Your summary index data is being migrated to the new ITSI metrics summary index. '
                      '[[{0}|View the import process.]] The itsi_summary_metrics index creates a more responsive UI '
                      'experience by increasing the performance of the searches dispatched by ITSI. '
                      '[[{1}|Learn more.]]').format((JOB_MANAGER_PAGE + batch_id), DOCS_URL)
        }
        self.service.messages.create(name='metric_backfill_started', **msg)

    def notify_of_finish(self, elapsed):
        self.logger.info('Metric index backfill process completed in {} minutes'.format(elapsed))
        msg = {
            'severity': 'info',
            'value': 'Metric index backfill process completed in {} minutes'.format(elapsed)
        }
        self.service.messages.create(name='metric_backfill_completed', **msg)

    def update_queue(self, backfill_queue_info, current_hour):
        backfill_queue_info['current_hour'] = current_hour
        self.queue_collection.data.update(backfill_queue_info['_key'], json.dumps(backfill_queue_info))

    def execute_backfill_queue(self, config_settings={}, summary_index_name='`get_itsi_summary_index`',
                               metrics_index_name='`get_itsi_summary_metrics_index`', sourcetype='itsi_summary:metrics'):
        """
        Main function that generates the searches that will be used to backfill data from itsi_summary index into
        the itsi_summary_metrics index (introduced in ITSI 4.6.0).

        Uses configuration settings defined in inputs.conf (or modified through UI) for how many searches or how quickly
        backfill process will run.

        @type config_settings: dict
        @param config_settings: the configuration settings from the modular input configuration (inputs.conf)
            Configurations include:
            - metrics_backfill_length: how many days back backfill should look for data
            - metrics_backfill_throttle: how long the backfill process should wait in between running searches
            - metrics_backfill_concurrent_searches: how many searches run at the same time

        :param summary_index_name: index where the data is coming from
        :param metrics_index_name: index where the data will be written to
        :param sourcetype: sourcetype to be used in the backfill events/results
        :return: Boolean indicating success or failure
        """
        try:
            backfill_queue_info = self.get_backfill_queue_info()
            if not len(backfill_queue_info):
                # queue is empty
                return False
            else:
                backfill_queue_info = backfill_queue_info[0]

            is_backfill_triggered = backfill_queue_info.get('is_backfill_triggered')
            if not is_backfill_triggered:
                return False

            batch_id = str(uuid.uuid4())

            self.notify_of_start(batch_id)
            self.logger.info('Backfill queue info: ' + str(backfill_queue_info))
            start = time.time()

            # Configuration settings come from the modular input settings. Default settings:
            # Lookback of 3 days, throttle 10s, 1 concurrent search
            hours_lookback = int(config_settings.get('metrics_backfill_length', 3)) * 24
            wait_throttle = int(config_settings.get('metrics_backfill_throttle', 10))
            concurrent_searches = int(config_settings.get('metrics_backfill_concurrent_searches', 1))
            current_hour = backfill_queue_info.get('current_hour', 1)

            workers = [MetricsBackfillWorker(self.session_key, self.logger) for w in range(concurrent_searches)]
            current_hour = 1 if current_hour < 1 else current_hour

            while current_hour < hours_lookback:
                for worker in workers:
                    if worker.is_work_done():
                        earliest = '-{}h@h'.format(current_hour)
                        latest = '-{}h@h'.format(current_hour - 1) if current_hour > 1 else 'now'
                        worker.migrate_summary_to_metrics(earliest, latest, batch_id, summary_index_name, metrics_index_name, sourcetype)
                        current_hour += 1
                        self.update_queue(backfill_queue_info, current_hour)
                # Give the indexing tier a brief break in between each backfill search
                time.sleep(wait_throttle)

            elapsed = int((time.time() - start) // 60)
            self.notify_of_finish(elapsed)
            self.clear_backfill_queue()
            return True
        except Exception as e:
            self.logger.error('Error running metrics_backfill: ' + str(e))
            self.logger.error(str(traceback.format_exc()))
            return False