From e8c0450423e132ef5f75916f8c05dfa71d2fc5d8 Mon Sep 17 00:00:00 2001
From: "Krzysztof (Chris) Bernat" <chris.bernat@telespazio.com>
Date: Wed, 27 Sep 2017 19:21:37 +0100
Subject: [PATCH] #337 initial state for Data Source Status reporting

---
 cate/core/ds.py  | 22 ++++++++++++++++++++++
 cate/ds/local.py | 23 ++++++++++++++---------
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/cate/core/ds.py b/cate/core/ds.py
index 78bf76e48..dc4bad212 100644
--- a/cate/core/ds.py
+++ b/cate/core/ds.py
@@ -80,6 +80,7 @@
 
 import glob
 from abc import ABCMeta, abstractmethod
+from enum import Enum
 from math import ceil, sqrt
 from typing import Sequence, Optional, Union, Tuple, Any
 
@@ -137,6 +138,13 @@ def protocols(self) -> []:
     def data_store(self) -> 'DataStore':
         """The data store to which this data source belongs."""
 
+    @property
+    def status(self) -> 'DataSourceStatus':
+        """
+        Return information about data source accessibility
+        """
+        return DataSourceStatus.READY
+
     # TODO (forman): issue #399 - remove "ds_id", see TODO on "DataStore.query()"
     def matches(self, ds_id: str = None, query_expr: str = None) -> bool:
         """
@@ -330,6 +338,20 @@ def _repr_html_(self):
         """Provide an HTML representation of this object for IPython."""
 
 
+class DataSourceStatus(Enum):
+    """
+    Enum stating current state of Data Source accessibility.
+     * READY - data is complete and ready to use
+     * ERROR - data initialization process has been interrupted, causing that data source is incomplete or/and corrupted
+     * PROCESSING - data source initialization process is in progress.
+     * CANCELLED - data initialization process has been intentionally interrupted by user
+    """
+    READY = "READY",
+    ERROR = "ERROR",
+    PROCESSING = "PROCESSING",
+    CANCELLED = "CANCELLED"
+
+
 class DataStore(metaclass=ABCMeta):
     """
     Represents a data store of data sources.
diff --git a/cate/ds/local.py b/cate/ds/local.py
index 20604862a..29498b58c 100644
--- a/cate/ds/local.py
+++ b/cate/ds/local.py
@@ -53,7 +53,7 @@
 
 from cate.conf import get_config_value, get_data_stores_path
 from cate.conf.defaults import NETCDF_COMPRESSION_LEVEL
-from cate.core.ds import DATA_STORE_REGISTRY, DataStore, DataSource, open_xarray_dataset
+from cate.core.ds import DATA_STORE_REGISTRY, DataSourceStatus, DataStore, DataSource, open_xarray_dataset
 from cate.core.types import Polygon, PolygonLike, TimeRange, TimeRangeLike, VarNames, VarNamesLike
 from cate.util.monitor import Monitor
 
@@ -79,8 +79,8 @@ def add_to_data_store_registry():
 # TODO (kbernat): document this class
 class LocalDataSource(DataSource):
     """
-
-    :param ds_id:
+    Local Data Source implementation provides access to locally stored data sets.
+    :param ds_id: unique ID of data source
     :param files:
     :param data_store:
     :param temporal_coverage:
@@ -131,7 +131,7 @@ def __init__(self,
                  'standard_name': ''
                  } for var_name in self._variables]
 
-        self._is_complete = True
+        self._state = DataSourceStatus.READY
 
     def _resolve_file_path(self, path) -> Sequence:
         return glob(os.path.join(self._data_store.data_store_path, path))
@@ -540,6 +540,10 @@ def spatial_coverage(self):
     def data_store(self) -> DataStore:
         return self._data_store
 
+    @property
+    def status(self) -> DataSourceStatus:
+        return self._status
+
     @property
     def id(self) -> str:
         return self._id
@@ -562,7 +566,7 @@ def is_complete(self) -> bool:
         Return a DataSource creation state
         :return:
         """
-        return self._is_complete
+        return self._state is DataSourceStatus.READY
 
     @property
     def is_empty(self) -> bool:
@@ -574,11 +578,12 @@ def is_empty(self) -> bool:
 
     def set_completed(self, state: bool):
         """
-        Sets state of DataSource creation/completion
-        :param state: Is DataSource completed
-        :return:
+        Sets state of DataSource completion
         """
-        self._is_complete = state
+        if state:
+            self._state = DataSourceStatus.READY
+        else:
+            self._state = DataSourceStatus.PROCESSING
 
     def _repr_html_(self):
         import html