import typing
import json
import datetime
from abc import ABC, abstractmethod
from marshmallow import ValidationError
from string import ascii_letters, digits

from BreCal.schemas.model import Ship, Shipcall, Berth, User, Participant, ShipcallType
from BreCal.database.sql_handler import execute_sql_query_standalone    
from BreCal.database.sql_queries import SQLQuery
from BreCal.impl.participant import GetParticipant
from BreCal.impl.ships import GetShips
from BreCal.impl.berths import GetBerths

from BreCal.database.enums import ParticipantType, ParticipantFlag
from BreCal.validators.input_validation_utils import check_if_user_is_bsmd_type, check_if_ship_id_is_valid, check_if_berth_id_is_valid, check_if_participant_ids_are_valid, check_if_participant_ids_and_types_are_valid, get_shipcall_id_dictionary, get_participant_type_from_user_data
from BreCal.database.sql_handler import execute_sql_query_standalone
from BreCal.validators.validation_base_utils import check_if_int_is_valid_flag
from BreCal.validators.validation_base_utils import check_if_string_has_special_characters
import werkzeug

class InputValidationShip():
    """
    This class combines a complex set of individual input validation functions into a joint object.
    It uses static methods, so the object does not need to be instantiated, but functions can be called immediately.

    Example:
        InputValidationShip.evaluate(user_data, loadedModel, content)

    When the data violates one of the rules, a marshmallow.ValidationError is raised, which details the issues. 
    """
    def __init__(self) -> None:
        pass

    @staticmethod
    def evaluate_post_data(user_data:dict, loadedModel:dict, content:dict):
        # 1.) Only users of type BSMD are allowed to POST
        InputValidationShip.check_user_is_bsmd_type(user_data)

        # 2.) The ship IMOs are used as matching keys. They must be unique in the database. 
        InputValidationShip.check_ship_imo_already_exists(loadedModel)

        # 3.) Check for reasonable Values (see BreCal.schemas.model.ShipSchema)
        InputValidationShip.optionally_evaluate_bollard_pull_value(content)
        return
    
    @staticmethod
    def evaluate_put_data(user_data:dict, loadedModel:dict, content:dict):
        # 1.) Only users of type BSMD are allowed to PUT
        InputValidationShip.check_user_is_bsmd_type(user_data)

        # 2.) ID field is mandatory
        InputValidationShip.content_contains_ship_id(content)

        # 3.) The IMO number field may not be changed
        InputValidationShip.put_content_may_not_contain_imo_number(content)

        # 4.) Check for reasonable Values (see BreCal.schemas.model.ShipSchema)
        InputValidationShip.optionally_evaluate_bollard_pull_value(content)
        return
    
    @staticmethod
    def evaluate_delete_data(user_data:dict, ship_id:int):
        # 1.) Only users of type BSMD are allowed to PUT
        InputValidationShip.check_user_is_bsmd_type(user_data)

        # 2.) The dataset entry may not be deleted already
        InputValidationShip.check_if_entry_is_already_deleted(ship_id)
        return
    
    @staticmethod
    def optionally_evaluate_bollard_pull_value(content:dict):
        bollard_pull = content.get("bollard_pull",None)
        is_tug = content.get("is_tug", False) # default to 'False', so the bollard pull entry fails unless the property is also actively set

        if bollard_pull is not None:
            if not is_tug:
                raise ValidationError(f"'bollard_pull' is only allowed, when a ship is a tug ('is_tug').")

            if (not (0 < bollard_pull < 500)) & (is_tug):
                raise ValidationError(f"when a ship is a tug, the bollard pull must be 0 < value < 500. ")

    @staticmethod
    def check_user_is_bsmd_type(user_data:dict):
        is_bsmd = check_if_user_is_bsmd_type(user_data)
        if not is_bsmd:
            raise ValidationError(f"current user does not belong to BSMD. Cannot post, put or delete ships. Found user data: {user_data}")
        
    @staticmethod
    def check_ship_imo_already_exists(loadedModel:dict):
        # get the ships, convert them to a list of JSON dictionaries
        response, status_code, header = GetShips(token=None)
        ships = json.loads(response)

        # extract only the 'imo' values
        ship_imos = [ship.get("imo") for ship in ships]

        # check, if the imo in the POST-request already exists in the list
        imo_already_exists = loadedModel.get("imo") in ship_imos
        if imo_already_exists:
            raise ValidationError(f"the provided ship IMO {loadedModel.get('imo')} already exists. A ship may only be added, if there is no other ship with the same IMO number.")
        return
    
    @staticmethod
    def put_content_may_not_contain_imo_number(content:dict):
        # IMO is a required field, so it will never be None outside of tests. If so, there is no violation
        put_data_ship_imo = content.get("imo",None)
        if put_data_ship_imo is None:
            return
        
        # grab the ship by its ID and compare, whether the IMO is unchanged
        ship = execute_sql_query_standalone(SQLQuery.get_ship_by_id(), param={"id":content.get("id")}, command_type="single", model=Ship)

        if put_data_ship_imo != ship.imo:
            raise ValidationError(f"The IMO number field may not be changed since it serves the purpose of a primary (matching) key.")
        return
    
    @staticmethod
    def content_contains_ship_id(content:dict):
        put_data_ship_id = content.get('id',None)
        if put_data_ship_id is None:
            raise ValidationError(f"The id field is required.")
        return
    
    @staticmethod
    def check_if_entry_is_already_deleted(ship_id:int):
        """
        When calling a delete request for ships, the dataset may not be deleted already. This method
        makes sure, that the request contains and ID, has a matching entry in the database, and the
        database entry may not have a deletion state already.
        """
        if ship_id is None:
            raise ValidationError(f"The ship_id must be provided.")
        
        response, status_code, header = GetShips(token=None)
        ships = json.loads(response)
        existing_database_entries = [ship for ship in ships if ship.get("id")==ship_id]
        if len(existing_database_entries)==0:
            raise ValidationError(f"Could not find a ship with the specified ID. Selected: {ship_id}")

        existing_database_entry = existing_database_entries[0]

        deletion_state = existing_database_entry.get("deleted",None)
        if deletion_state:
            raise ValidationError(f"The selected ship entry is already deleted.")
        return