Extract interface for gridded modeldata reader

pyaerocom/io/cams2_83/reader.py

@@ -14,6 +14,7 @@
 from pyaerocom import const
 from pyaerocom.griddeddata import GriddedData
 from pyaerocom.io.cams2_83.models import ModelData, ModelName, RunType
+from pyaerocom.io.gridded_reader import GriddedReader
 
 # from pyaerocom.units_helpers import UALIASES
 
@@ -220,7 +221,7 @@
     return new_paths
 
 
-class ReadCAMS2_83:
+class ReadCAMS2_83(GriddedReader):
     FREQ_CODES = dict(hour="hourly", day="daily", month="monthly", fullrun="yearly")
     REVERSE_FREQ_CODES = {val: key for key, val in FREQ_CODES.items()}
 
@@ -291,6 +292,20 @@
         self.model = ModelName[model]
         self.forecast_day = int(day)
 
+    @property
+    def years_avail(self):
+        return np.unique(
+            reader.daterange.values.astype("datetime64[Y]").astype("int") + 1970
+        ).astype("str")
+
+    @property
+    def ts_types(self):
+        return self.REVERSE_FREQ_CODES.keys()
+
+    @property
+    def vars_provided(self):
+        return AEROCOM_NAMES.values()
+
     @property
     def run_type(self):
         if self._run_type is None:
@@ -443,6 +458,11 @@
     data_id = "CAMS2-83.EMEP.day0.AN"
     reader = ReadCAMS2_83(data_dir=data_dir, data_id=data_id)
     reader.daterange = ("2021-12-01", "2021-12-04")
+    print(
+        np.unique(reader.daterange.values.astype("datetime64[Y]").astype("int") + 1970).astype(
+            "str"
+        )
+    )
     print(reader.filepaths)
     # dates = ("2021-12-01", "2021-12-04")
 

pyaerocom/io/gridded_reader.py

@@ -0,0 +1,82 @@
+import abc
+from typing import Iterator
+
+from pyaerocom.griddeddata import GriddedData
+
+
+class GriddedReader(abc.ABC):
+    """Abstract base class for griddel model reader used for collocation"""
+
+    @property
+    @abc.abstractmethod
+    def data_id(self) -> str:
+        """
+        Data ID of dataset
+        """
+        pass
+
+    @property
+    @abc.abstractmethod
+    def ts_types(self) -> Iterator[str]:
+        """
+        List of available frequencies
+
+        Raises
+        ------
+        AttributeError
+            if :attr:`data_dir` is not set.
+
+        Returns
+        -------
+        list
+            list of available frequencies
+
+        """
+        pass
+
+    @property
+    @abc.abstractmethod
+    def years_avail(self) -> Iterator[str]:
+        """
+        Years available in dataset
+        """
+        pass
+
+    @property
+    @abc.abstractmethod
+    def vars_provided(self) -> Iterator[str]:
+        """Variables provided by this dataset"""
+        pass
+
+    @abc.abstractmethod
+    def has_var(self, var_name) -> bool:
+        """Check if variable is supported
+
+        Parameters
+        ----------
+        var_name : str
+            variable to be checked
+
+        Returns
+        -------
+        bool
+        """
+        pass
+
+    @abc.abstractmethod
+    def read_var(self, var_name, ts_type=None, **kwargs) -> GriddedData:
+        """Load data for given variable.
+
+        Parameters
+        ----------
+        var_name : str
+            Variable to be read
+        ts_type : str
+            Temporal resolution of data to read. Supported are
+            "hourly", "daily", "monthly" , "yearly".
+
+        Returns
+        -------
+        GriddedData
+        """
+        pass