Source code for metloom.pointdata.csas

"""
Data reader for the Center for Snow and Avalanche Studies
"""
from metloom.pointdata import CSVPointData, StationInfo
from metloom.variables import CSASVariables
import os
from datetime import datetime, timedelta




class InvalidDateRange(Exception):
    """
    Exception to indicate there is no know data for the available date range
    """





class CSASStationInfo(StationInfo):
    # Name, id, lat, long, elevation, http path
    SENATOR_BECK = ("Senator Beck Study Plot", "SBSP", 37.90688, -107.72627, 12186,
                    "2023/11/SBSP_1hr_2003-2009.csv")
    SWAMP_ANGEL = ("Swamp Angel Study Plot", "SASP", 37.90691, -107.71132, 11060,
                   "2023/11/SASP_1hr_2003-2009.csv")
    PUTNEY = ("Putney Study Plot", "PTSP", 37.89233, -107.69577, 12323,
              "2025/05/PTSP_1hr.csv")
    SENATOR_BECK_STREAM_GAUGE = ("Senator Beck Stream Gauge", "SBSG", 37.90678,
                                 -107.70943, 11030, "2025/05/SBSG_1hr.csv")





class CSASMet(CSVPointData):
    """
    """
    CURRENT_AVAILABLE_YEAR = 2024
    ALLOWED_VARIABLES = CSASVariables
    ALLOWED_STATIONS = CSASStationInfo

    # Data is in Mountain time
    UTC_OFFSET_HOURS = -7

    URL = "https://snowstudies.org/wp-content/uploads/"
    DATASOURCE = "CSAS"
    DOI = ""

    def _file_urls(self, station_id, start, end):
        """
        Navigate the system using dates. Data for SASP and SBSP is stored in
        two csvs. 2003-2009 and 2010-2023. Not sure what happens when the
        next year is made available. This function will grab the necessary urls
        depending on the requested data
        """
        urls = []

        if station_id in ['SASP', 'SBSP']:
            current_available_year = self.CURRENT_AVAILABLE_YEAR

            if start.year <= 2009:
                urls.append(os.path.join(self.URL, self._station_info.path))

            # Account for later file use or even straddling thge data
            if start.year > 2009 or end.year > 2009:  # TODO: add to the info enum?
                partial = str(self._station_info.path).replace("2003", "2010")
                partial = partial.replace('2009', str(current_available_year))
                # Change the subdirectory in the url
                filename = partial.replace('2023/11/', '2025/05/')

                urls.append(os.path.join(self.URL, filename))

            if start.year < 2003 or end.year > current_available_year:
                raise InvalidDateRange(f"CSAS data is only available from 2003-"
                                       f"{current_available_year}")
        else:
            urls.append(os.path.join(self.URL, self._station_info.path))

        return urls

    @staticmethod
    def _parse_datetime(row):
        # Julian day is not zero based Jan 1 == DOY 1
        dt = timedelta(days=int(row['DOY']) - 1, hours=int(row['Hour'] / 100))
        return datetime(int(row['Year']), 1, 1) + dt

    def _assign_datetime(self, resp_df):
        resp_df['datetime'] = resp_df.apply(lambda row: self._parse_datetime(row),
                                            axis=1)
        return resp_df.set_index('datetime')