refactor prompt completion

This just splits the file completion.py into several files, one for each
Completer subclass.

1 files changed, 41 insertions, 0 deletions

diff --git a/alot/completion/argparse.py b/alot/completion/argparse.py
new file mode 100644
index 00000000..ac15b2c6
--- /dev/null
+++ b/alot/completion/argparse.py
@@ -0,0 +1,41 @@
+# Copyright (C) 2011-2019  Patrick Totzke <patricktotzke@gmail.com>
+# This file is released under the GNU GPL, version 3 or a later revision.
+# For further details see the COPYING file
+
+import argparse
+from .completer import Completer
+from ..utils import argparse as cargparse
+
+
+class ArgparseOptionCompleter(Completer):
+    """completes option parameters for a given argparse.Parser"""
+    def __init__(self, parser):
+        """
+        :param parser: the option parser we look up parameter and  choices from
+        :type parser: `argparse.ArgumentParser`
+        """
+        self.parser = parser
+        self.actions = parser._optionals._actions
+
+    def complete(self, original, pos):
+        pref = original[:pos]
+
+        res = []
+        for act in self.actions:
+            if '=' in pref:
+                optionstring = pref[:pref.rfind('=') + 1]
+                # get choices
+                if 'choices' in act.__dict__:
+                    # TODO: respect prefix
+                    choices = act.choices or []
+                    res = res + [optionstring + a for a in choices]
+            else:
+                for optionstring in act.option_strings:
+                    if optionstring.startswith(pref):
+                        # append '=' for options that await a string value
+                        if isinstance(act, (argparse._StoreAction,
+                                            cargparse.BooleanAction)):
+                            optionstring += '='
+                        res.append(optionstring)
+
+        return [(a, len(a)) for a in res]