#
# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
# or more contributor license agreements. Licensed under the Elastic License 2.0;
# you may not use this file except in compliance with the Elastic License 2.0.
#
"""This module allows to remove recently deleted documents from Elastic Enterprise Search.

    Documents that were deleted in Network Drives will still be available in
    Elastic Enterprise Search until a full sync happens, or until this module is used.
"""
import os

from . import constant
from .base_command import BaseCommand
from .files import Files
from .utils import (group_files_by_folder_path,
                    split_documents_into_equal_chunks)


class DeletionSyncCommand(BaseCommand):
    """DeletionSyncCommand class allows to remove instances of specific files.

    It provides a way to remove those files from Elastic Enterprise Search
    that were deleted in Network Drives Server instance."""

    def __init__(self, args):
        super().__init__(args)
        self.logger.debug("Initializing the deletion sync class")
        self.server_name = self.config.get_value("network_drive.server_name")

    def get_deleted_files(self, drive_name, ids):
        """Fetches the ids of deleted files from the Network Drives
        :param drive_name: service name of the Network Drives
        :param ids: structure containing id's of all files
        Returns:
            ids_list: list of file ids that got deleted from Network Drives
        """
        file_details = ids["delete_keys"].get("files")
        file_structure = group_files_by_folder_path(file_details)
        ids_list = []
        if not file_details:
            self.logger.info(f"No files found to be deleted for drive: {drive_name}")
            return []

        deleted_folders = []
        visited_folders = []

        smb_connection = self.network_drive_client.connect()
        if not smb_connection:
            raise ConnectionError("Unknown error while connecting to network drives")

        files = Files(self.logger, self.config, self.network_drive_client)
        for file_id, file_path in file_details.items():
            folder_path, file_name = os.path.split(file_path)
            if folder_path in deleted_folders:
                ids_list.append(file_id)
                continue
            if folder_path in visited_folders:
                continue
            folder_deleted = files.is_file_present_on_network_drive(
                smb_connection,
                drive_name,
                folder_path,
                file_structure,
                ids_list,
                visited_folders,
                deleted_folders,
            )
            if folder_deleted:
                ids_list.append(file_id)

        return ids_list

    def sync_deleted_files(self, ids_list, ids):
        """Invokes delete documents api for the deleted files ids to remove them from
        workplace search.
        :param ids_list: list of ids of files to be deleted from Enterprise Search
        :param ids: structure containing ids of all files
        Returns:
            ids: updated structure containing ids of all files after performing deletion
        """
        if ids_list:
            for chunk in split_documents_into_equal_chunks(ids_list, constant.BATCH_SIZE):
                self.workplace_search_custom_client.delete_documents(chunk)
            for id in ids_list:
                ids["global_keys"]["files"].pop(id)
        return ids

    def execute(self):
        """Runs the deletion sync logic"""

        self.logger.info("Starting the deletion sync..")

        ids = self.local_storage.load_storage()
        self.logger.info(f"Starting the deletion sync for drive: {self.server_name}")
        if ids["delete_keys"].get("files"):
            deleted_ids = self.get_deleted_files(self.server_name, ids)
            ids = self.sync_deleted_files(deleted_ids, ids)
            self.logger.info("Completed the syncing of deleted files")
        else:
            self.logger.debug(f"No objects present to be deleted for the drive: {self.server_name}")
        ids["delete_keys"] = {}
        self.logger.info("Updating the local storage")
        self.local_storage.update_storage(ids)