"""

    AUTHOR:

        Khushal P Soonderji

    DATE:

        Thursday, 5th Dec., 2024

    OBJECTIVE:

        To provide a way to retrieve the list of holidays from NSE and to check if today is a holiday.

        NOTE: This method involves web scraping. It is good for proof-of-concept development, but it is recommended that
        more professional data-sources be used when the product starts becoming mature.

    REFERENCES:

        N/A

    DOWNLOADS:

        N/A

"""


#   *****************************************************************************************************************
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# To make sibling directories accessible for imports:
import sys
from time import timezone
sys.path.append(".")
sys.path.append("..")

# System-level activities:
import io

# My utils:
from utils_v2.string import json
from utils_v2.date_time import date_time

# NSE-related utils:
from utils_v2.nse.controllers.base import AsyncNSEBase
from utils_v2.nse.models.api_call import NSEApiResponse

# To make REST-ful API calls:
import httpx

# To work with date and time:
import datetime

# To work with datatypes:
from typing import Any, List

# For asynchronous activities:
import asyncio

# For debugging:
import inspect


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# --- Nothing Yet


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# --- Nothing Yet


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# ***                                                  FUNCTIONS                                                    ***
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class NSETradingHolidayCalendar(AsyncNSEBase):

    def __init__(
            self,
            http_client: httpx.AsyncClient,
            debug = True,
            debug_prefix = "NSE (Hol) | ",
            debug_only_errors = True
    ):

        # Pass on the initialization to the parent:
        super().__init__(
            base_url = r"https://www.nseindia.com/resources/exchange-communication-holidays",
            data_url = r"https://www.nseindia.com/api/holiday-master?type=trading",
            http_client = http_client,
            debug = debug,
            debug_prefix = debug_prefix,
            debug_only_errors = debug_only_errors
        )

    async def get_data(
            self,
            return_raw: bool = False,
    ) -> NSEApiResponse:

        """
        To get the data of the holiday calendar.
        :param return_raw: Whether you want the raw JSON from NSE or you want it formatted.
        :return: The raw or formatted event calendar data in the 'data' field of the response model.
        """

        # Make the API call:
        api_response = await self.get()

        # If the API call was successful:
        if api_response.httpCode in [200]:
            api_response.success = True
            if return_raw: api_response.data = await api_response.get_json()
            else:
                try: api_response.data = self.format_data(
                    raw_json = await api_response.get_json(),
                    timestamp = date_time.get_current_utc_date_time(as_string = True),
                    raise_exception = True
                )
                except Exception as exception:
                    api_response.exception = exception
                    api_response.success = False

        # Done here:
        return api_response

    @staticmethod
    def format_data(
            raw_json: dict,
            timestamp: datetime.datetime = None,
            raise_exception: bool = False
    ) -> List[dict] | None:

        """
        We format the data here to be able to retrieve it properly later.
        :param raw_json: The raw data as scraped from NSE.
        :param timestamp: The timestamp at which the data was scraped. This shall be useful for data retrieval from the
            database, later.
        :param raise_exception: If set to True, any exception will be propagated. If set to False, any exception will be
            suppressed internally.
        :return: The formatted data if successful, else None.
        """

        # Can't do anything if the chain itself is null:
        if raw_json is None: return raw_json

        # Start by assuming failure:
        formatted_data = None

        # Ensure that we've got a proper timestamp:
        if timestamp is None: timestamp = date_time.get_current_utc_date_time(as_string = False)

        try:

            # Start by creating an empty dict:
            formatted_data = {}

            # Process each category in the original data
            for category, events in raw_json.items():
                for event in events:
                    trading_date = event["tradingDate"]

                    # If the tradingDate is not in the dictionary, initialize it
                    if trading_date not in formatted_data:
                        formatted_data[trading_date] = {
                            "scrapeTs": timestamp,
                            "date": date_time.to_timezone(
                                date_time.as_if_timezone(
                                    datetime.datetime.strptime(trading_date, "%d-%b-%Y"),
                                    timezone = date_time.TIMEZONE_IST
                                ),
                                timezone = date_time.TIMEZONE_UTC
                            ),
                            "weekDay": event["weekDay"],
                            "event": event["description"],
                            "morningSession": event["morning_session"],
                            "eveningSession": event["evening_session"],
                            "holidayType": []
                        }

                    # Add the current category to the "type" list
                    formatted_data[trading_date]["holidayType"].append(category)

            # Now we get rid of the unnecessary keys and make it a list:
            formatted_data = [v for v in formatted_data.values()]

        # If something goes wrong:
        except Exception as exception:
            formatted_data = None
            if raise_exception: raise

        # Done here:
        return formatted_data

    async def is_holiday(
            self,
            timestamp: datetime.datetime
    ) -> NSEApiResponse:

        """
        Checks if a given date is a trading holiday, or not.
        :param timestamp: The datetime instance that you want to check for it being a holiday. Preferably make it an
            aware instance. If a naive instance is passed, it will be assumed to be in UTC.
        :return: True if it is a holiday, False if it isn't. Can be None if something goes wrong in fetching the data.
            The value will be in the 'data' field of the response model.
        """

        # We first prepare UTC and IST versions of the incoming datetime:
        timestamp_utc = date_time.to_timezone(timestamp, timezone = date_time.TIMEZONE_UTC)
        timestamp_ist = date_time.to_timezone(timestamp_utc, timezone = date_time.TIMEZONE_IST)

        # If this day is a weekend, it is a holiday by default:
        ist_dow = timestamp_ist.weekday()
        if ist_dow in [5, 6]: return NSEApiResponse(
            action = inspect.stack()[0].function,
            url = None,
            method = None,
            success = True,
            data = True,
            message = f"Weekend ({'Saturday' if ist_dow == 5 else 'Sunday'})"
        )

        # First we fetch the data from NSE:
        api_response = await self.get_data(return_raw = False)
        api_response.action = inspect.stack()[0].function
        if not api_response.success: return api_response

        # Now we check if our date to check is in the list:
        holidays_list = [h["date"].date() for h in api_response.data]
        api_response.data = True if timestamp_utc.date() in holidays_list else False

        # Done here:
        return api_response


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if __name__ == "__main__":

    async def main():

        # Create an HTTP client:
        test_client = httpx.AsyncClient(
            limits = httpx.Limits(
                max_connections = 100,  # ............ Maximum number of connections allowed in the pool.
                max_keepalive_connections = 50,  # ... Maximum number of connections that can be kept alive.
            ),
            timeout = httpx.Timeout(
                pool = 120.0,  # .... Time to wait for a free connection from the pool.
                connect = 2.5,  # ... Time to wait for establishing a connection to the server.
                write = 10.0,  # .... Time to wait for sending data.
                read = 2.5  # ....... Time to wait for receiving data.
            )
        )

        # Create an instance of the scraper, and refresh its cookies:
        my_nse = NSETradingHolidayCalendar(http_client = test_client)

        # Get and show the data:
        api_response = await my_nse.get_data(return_raw = False)
        print("SUMMARY:", api_response.to_markdown(), "\n---\n\n")
        if api_response.success: print("HOLIDAY CALENDAR:", json.to_string(api_response.data, default = str))
        print("\n---\n\n")

        # Check for a holiday:
        date_to_check = date_time.parse_date_time(
            input_value = "2024-12-25 00:00:00",
            date_formats = ["%Y-%m-%d %H:%M:%S"],
            timezone = date_time.TIMEZONE_IST
        )
        api_response = await my_nse.is_holiday(date_to_check)
        print("SUMMARY:", api_response.to_markdown(), "\n---\n\n")
        print("DATETIME:", date_to_check)
        print("IS HOLIDAY:", api_response.data)

    asyncio.run(main())