Refactored handlers and provided a base class

ProjectNephos/exceptions.py

@@ -8,3 +8,7 @@ class OAuthFailure(NephosException):
 
 class FileNotFound(NephosException):
     pass
+
+
+class SubCommandNotFound(NephosException):
+    pass

ProjectNephos/handlers/base.py

@@ -0,0 +1,70 @@
+from argparse import _SubParsersAction, Namespace
+
+from ProjectNephos.config import Configuration
+from ProjectNephos.exceptions import SubCommandNotFound
+
+from logging import getLogger
+
+
+logger = getLogger(__name__)
+
+
+class BaseHandler(object):
+    """
+    This is the base class for all handlers. All common
+    functions are defined here.
+    """
+
+    def __init__(self, subcommand: str = None, config: Configuration = None):
+        """
+        Initialise the handler. This generally takes the subcommand name when calling
+        nephos from the command line. Config can also be provided in which case it will
+        initialize config as well.
+        """
+        self.subcommand = subcommand
+        self.config = config
+
+        if self.config:
+            self.init_with_config(self.config)
+
+    def init_with_config(self, config):
+        """
+        Config is generally not available during the initialisation phase. This command is
+        to be used in such a case.
+        """
+        if self.config != config and self.config is not None:
+            logger.warning(
+                "The class is already initalised with an config. Reinitializing with another one"
+            )
+        self.config = config
+
+    def init_args(self, subparser: _SubParsersAction):
+        """
+        This command takes the subparser from the calling code and initialises the
+        command line arguments for this function. This function will not be called when
+        the handler isn't called from the command line.
+        """
+        if self.subcommand is None:
+            raise SubCommandNotFound(
+                "Subcommand has not been supplied. Cannot init_args without a subcommand"
+            )
+        return subparser.add_parser(self.subcommand)
+
+    def execute_command(self):
+        """
+        Actually execute the functionality of the handler. The signature of the function
+        will be different for each handler. This will be the function called when handler
+        is not initiated from the command line.
+        """
+        raise NotImplementedError
+
+    def run(self, args: Namespace):
+        """
+        This command is only used in the case of command line invocation. This will recieve
+        the parsed command-line arguments and perform logic on them. For the most part, it
+        will use the arguments to directly call the execute_command function and pretty print
+        its output.
+
+        Its signature will not change across handlers.
+        """
+        raise NotImplementedError

ProjectNephos/handlers/channels.py

@@ -3,24 +3,24 @@
 
 from ProjectNephos.config import Configuration
 from ProjectNephos.backends import DBStorage
+from ProjectNephos.handlers.base import BaseHandler
 
 logger = getLogger(__name__)
 
 
-class ChannelHandler(object):
+class ChannelHandler(BaseHandler):
     """
     Handles creating channels.
     """
 
-    def __init__(self, subcommand):
-        self.subcommand = subcommand
-
     def init_with_config(self, config: Configuration):
-        self.config = config
+        super().init_with_config(config)
+
         self.db = DBStorage(config)
 
     def init_args(self, subparser: _SubParsersAction):
-        parser = subparser.add_parser(self.subcommand)
+        parser = super().init_args(subparser)
+
         parser.add_argument(
             "action", help="Define what action to take.", choices=["list", "add"]
         )
@@ -36,9 +36,6 @@ def init_args(self, subparser: _SubParsersAction):
         parser.add_argument("--language", action="store", help="Language of the stream")
         parser.add_argument("--source", action="store", help="Source of the video.")
 
-    def execute_command(self):
-        pass
-
     def run(self, args: Namespace):
         if args.action == "add":
             if not args.name:

ProjectNephos/handlers/init.py

@@ -5,6 +5,7 @@
     BASE_FOLDER,
     default_values,
 )
+from ProjectNephos.handlers.base import BaseHandler
 from ProjectNephos.orchestration import Server
 from argparse import _SubParsersAction, Namespace
 from logging import getLogger
@@ -16,27 +17,19 @@
 logger = getLogger(__name__)
 
 
-class InitHandler(object):
+class InitHandler(BaseHandler):
     """
     Handles startup of the project. This probably needs to be run just once.
     This performs the following tasks:
         1.  Creates all the config files and stuff.
         2.  Performs OAuth with google.
         3.  Starts an orchestration server that ensures that the recorder is always running.
             and other stuff not currently decided.
+    TODO: Passing config to this handler should override create config option.
 
-    NOTE: 1 and 2 are being handled separately as of now. They will be moved here later.
+    NOTE: 2 is being handled separately as of now. It will be moved here later.
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
-
-    def init_with_config(self, config: Configuration):
-        raise NotImplementedError
-
-    def init_args(self, subparser: _SubParsersAction):
-        subparser.add_parser(self.subcommand)
-
     def _create_config(self, config_path):
         if config_path == CONFIG_FULL_PATH_DEFAULT:
             logger.debug("Default config path is being used")

ProjectNephos/handlers/permissions.py

@@ -1,5 +1,6 @@
 from ProjectNephos.backends import DriveStorage, DBStorage
 from ProjectNephos.config import Configuration
+from ProjectNephos.handlers.base import BaseHandler
 from ProjectNephos.handlers.search import SearchHandler
 
 from argparse import _SubParsersAction, Namespace
@@ -8,7 +9,7 @@
 logger = getLogger(__name__)
 
 
-class PermissionHandler(object):
+class PermissionHandler(BaseHandler):
     """
     This class handles adding permissions to uploaded files.
 
@@ -19,19 +20,16 @@ class PermissionHandler(object):
     NOTE: Mechanism to tag file while uploading has not yet been implemented.
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
-
     def init_with_config(self, config: Configuration):
-        self.config = config
+        super().init_with_config(config)
+
         self.backend = DriveStorage(config)
         self.db = DBStorage(config)
-
-        self.search = SearchHandler("search")
-        self.search.init_with_config(config)
+        self.search = SearchHandler(config=config)
 
     def init_args(self, subparser: _SubParsersAction) -> None:
-        parser = subparser.add_parser(self.subcommand)
+        parser = super().init_args(subparser)
+
         parser.add_argument(
             "action", help="Define what action to take.", choices=["list", "add"]
         )

ProjectNephos/handlers/process.py

@@ -1,15 +1,16 @@
-from ProjectNephos.config import Configuration
 from ProjectNephos.exceptions import FileNotFound
+from ProjectNephos.handlers.base import BaseHandler
 
 from argparse import _SubParsersAction, Namespace
 from logging import getLogger
 from os.path import isfile
 import ffmpy
 
+
 logger = getLogger(__name__)
 
 
-class ProcessHandler(object):
+class ProcessHandler(BaseHandler):
     """
     This class handles conversion of downloaded data. The recorded data will most likely
     be compressed to save space. The only functionality this class provides as of now is to
@@ -20,14 +21,8 @@ class ProcessHandler(object):
     sure to name it correctly
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
-
-    def init_with_config(self, config: Configuration):
-        self.config = config
-
     def init_args(self, subparser: _SubParsersAction):
-        parser = subparser.add_parser(self.subcommand)
+        parser = super().init_args(subparser)
 
         parser.add_argument(
             "input_file", action="store", help="The file that has to be transformed"
@@ -47,7 +42,5 @@ def run(self, args: Namespace):
         ff.run()
 
     def execute_command(self, input_file, output_file):
-        ff = ffmpy.FFmpeg(
-                inputs={input_file: None}, outputs={output_file: None}
-        )
-        ff.run()
+        ff = ffmpy.FFmpeg(inputs={input_file: None}, outputs={output_file: None})
+        ff.run()

ProjectNephos/handlers/search.py

@@ -1,13 +1,15 @@
 from ProjectNephos.backends import DriveStorage
 from ProjectNephos.config import Configuration
+from ProjectNephos.handlers.base import BaseHandler
 
 from argparse import _SubParsersAction, Namespace
 from logging import getLogger
 
+
 logger = getLogger(__name__)
 
 
-class SearchHandler(object):
+class SearchHandler(BaseHandler):
     """
     This class does the searching. You provide it with search parameters and
     it find all matching files and their corresponding ids.
@@ -26,15 +28,14 @@ class SearchHandler(object):
      More fine-grained controls will be added later.
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
-
     def init_with_config(self, config: Configuration):
-        self.config = config
+        super().init_with_config(config)
+
         self.backend = DriveStorage(config)
 
     def init_args(self, subparser: _SubParsersAction) -> None:
-        parser = subparser.add_parser(self.subcommand)
+        parser = super().init_args(subparser)
+
         parser.add_argument("--name", action="store", help="Search for a name")
         parser.add_argument(
             "--tags", action="store", nargs="*", help="Tags you want to search for"

ProjectNephos/handlers/tag.py

@@ -1,5 +1,6 @@
 from ProjectNephos.backends import DriveStorage
 from ProjectNephos.config import Configuration
+from ProjectNephos.handlers.base import BaseHandler
 from ProjectNephos.handlers.search import SearchHandler
 
 from argparse import _SubParsersAction, Namespace
@@ -8,7 +9,7 @@
 logger = getLogger(__name__)
 
 
-class TagHandler(object):
+class TagHandler(BaseHandler):
     """
     This class is used to tag *uploaded* files. Tags currently are just strings
     that are added in the file's description field.
@@ -21,18 +22,15 @@ class TagHandler(object):
     NOTE: Mechanism to tag file while uploading has not yet been implemented.
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
-
     def init_with_config(self, config: Configuration):
-        self.config = config
-        self.backend = DriveStorage(config)
+        super().init_with_config(config)
 
-        self.search = SearchHandler("search")
-        self.search.init_with_config(config)
+        self.backend = DriveStorage(config)
+        self.search = SearchHandler(config=config)
 
     def init_args(self, subparser: _SubParsersAction) -> None:
-        parser = subparser.add_parser(self.subcommand)
+        parser = super().init_args(subparser)
+
         parser.add_argument(
             "--for_name",
             action="store",

ProjectNephos/handlers/upload.py

@@ -1,29 +1,31 @@
 from ProjectNephos.backends import DriveStorage
 from ProjectNephos.config import Configuration
+from ProjectNephos.handlers.base import BaseHandler
+
 from argparse import _SubParsersAction, Namespace
 from logging import getLogger
 from os import path
 
+
 logger = getLogger(__name__)
 
 
-class UploadHandler(object):
+class UploadHandler(BaseHandler):
     """
     Upload files to google drive. Really, that's it. You supply it a file or
     a list of files and this will upload it for you. Raises errors on non-existant
     files based on the --ignore-errors argument.
     """
 
-    def __init__(self, subcommand: str):
-        self.subcommand = subcommand
+    def init_with_config(self, config: Configuration):
+        super().init_with_config(config)
+
+        self.backend = DriveStorage(config)
 
     def init_args(self, subparser: _SubParsersAction) -> None:
-        parser = subparser.add_parser(self.subcommand)
-        parser.add_argument("files", nargs="+", help="Files you want to upload.")
+        parser = super().init_args(subparser)
 
-    def init_with_config(self, config: Configuration):
-        self.config = config
-        self.backend = DriveStorage(config)
+        parser.add_argument("files", nargs="+", help="Files you want to upload.")
 
     def execute_command(self, filepath):
         return self.backend.write(filepath)