import re
import io
from datetime import datetime, date
from typing import List, Optional

import config
from workers.ccp.repository import CCPImportRepository
from services.s3_client import S3Client

from workers.base_worker import BaseWorker
from utils import db_utils, encoding
from workers.prs.models import PRSDataFile
from models.projects_import_info import ProjectsImportInfo

FILE_REGEX = r"^ccp\/ccp_(?P<type>grps_projects|po_details_UK-IE|po_details_GSA|expense_hierarchy|budgets|po_details_ibe-it-nav-po-tr|po_details_ca-latam-us)_(?P<timestamp>.*)\.tsv"  # noqa: E501

FILE_ORDER = {
    "grps_projects": 1,
    "budgets": 2,
    "expense_hierarchy": 3,
    "po_details_uk-ie": 4,
    "po_details_gsa": 5,
    "po_details_ibe-it-nav-po-tr": 6,
    "po_details_ca-latam-us": 7
}

TABLE_NAME_MAPS = {
    "grps_projects": "RawCCPProjects",
    "budgets": "RawCCPBudgets",
    "expense_hierarchy": "RawCCPExpenseHierarchy",
    "po_details_uk-ie": "RawCCPPurchaseOrders",
    "po_details_gsa": "RawCCPPurchaseOrders",
    # "po_details_ibe-it-nav-po-tr": "RawCCPPurchaseOrders",
    # "po_details_ca-latam-us": "RawCCPPurchaseOrders",
}


class CCPDataImportError(Exception):
    details: str

    def __init__(self, details: str):
        self.details = details


class CCPDataImporter(BaseWorker):
    client: S3Client
    repository = CCPImportRepository()
    worker_name = "CCPDataImporter"

    def should_log_exceptions(self):
        return True

    def execute(self):
        self.logger.info("CCP Data import", "Started")

        self.client = S3Client(config.SFTP_BUCKET)

        self.__prepare_database_for_import()

        raw_ccp_purchase_orders_number = self.repository.count_raw_ccp_purchase_orders()
        self.logger.info("CCP Data import", f"RawCCPPurchaseOrders after preparing db {raw_ccp_purchase_orders_number}")

        last_import = ProjectsImportInfo.get_imported_ccp_date() or date.min
        aws_files = self.__get_file_list()
        most_recent_files = sorted(aws_files, key=lambda x: x.timestamp, reverse=True)[:5]

        files_to_import = list(
            filter(lambda x: x.type.lower() in TABLE_NAME_MAPS and x.timestamp.date() > last_import, most_recent_files)
        )
        if not files_to_import:
            files_names = ", ".join([file.file_name for file in aws_files])
            error_details = f"No data files found since {last_import}. Got: {files_names}"
            self.logger.error("CCP Data import error", error_details)
            raise CCPDataImportError(error_details)
        for item in files_to_import:
            file_object = self.client.get_object(item.file_name, encoding.UTF8).replace("\n\r\n", "\n")
            with io.StringIO(file_object) as file:
                if item.is_update_strategy():
                    db_utils.update_data_from(
                        file=file, table_name=TABLE_NAME_MAPS[item.type.lower()], without_header=True
                    )
                else:
                    db_utils.import_data_from(
                        file=file, table_name=TABLE_NAME_MAPS[item.type.lower()], without_header=True
                    )

        ProjectsImportInfo.update_imported_ccp_date()
        self.logger.success("CCP Data import", "Finished!")

    def __get_file_list(self) -> List[PRSDataFile]:
        files = self.client.get_objects_list("ccp/")
        data = [self.__map_from_file(file["Key"]) for file in files]
        data = [item for item in data if item is not None]
        data.sort(key=lambda x: FILE_ORDER[x.type.lower()])
        return data

    def __map_from_file(self, file_name: str) -> Optional[PRSDataFile]:
        match = re.compile(FILE_REGEX, re.IGNORECASE).match(file_name)
        if not match:
            if not file_name.endswith(".trg"):
                self.logger.error("CCP Data file error", f"Invalid file name: {file_name}")
            return None
        type = match.group("type")
        timestamp = match.group("timestamp")

        try:
            timestamp = datetime.strptime(timestamp, "%Y%m%d")
        except ValueError:
            self.logger.error("CCP Data file error", f"Invalid date format: {timestamp}")
            return None
        return PRSDataFile(type, timestamp, file_name)

    def __prepare_database_for_import(self):
        self.repository.truncate_raw_ccp_purchase_orders()