lib.ExecContext.create(): Add method

Add a class method to instantiate an ExecContext by its URI.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/ExecContext.py

@@ -1,7 +1,12 @@
 # -*- coding: utf-8 -*-
 
-import abc
+from __future__ import annotations
-from typing import NamedTuple
+
+import abc, re
+from typing import NamedTuple, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from typing import Self
 
 class Result(NamedTuple):
 
@@ -93,3 +98,18 @@ class ExecContext(abc.ABC):
 
     async def sudo(self, cmd: list[str], mod_env: dict[str, str] = {}, opts: list[str]=[], verbose: bool|None=None) -> Result:
         return await self._sudo(cmd, mod_env, opts, self._verbose(verbose))
+
+    @classmethod
+    def create(cls, uri: str, *args, **kwargs) -> Self:
+        tokens = re.split(r'://', uri)
+        schema = tokens[0]
+        match schema:
+            case 'local':
+                from .ec.Local import Local
+                return Local(uri, *args, **kwargs)
+            case 'ssh':
+                from .SSHClient import ssh_client
+                return ssh_client(uri, *args, **kwargs)
+            case _:
+                pass
+        raise Exception(f'Can\'t create execution context for {uri} with unknown schema "{schema}"')