1 files changed, 110 insertions, 0 deletions
diff --git a/src/utils/settings.py b/src/utils/settings.py
new file mode 100644
index 00000000..8040c2e8
--- /dev/null
+++ b/src/utils/settings.py
@@ -0,0 +1,110 @@
+import typing
+
+class SettingParseException(Exception):
+    pass
+
+class Setting(object):
+    example: typing.Optional[str] = None
+    def __init__(self, name: str, help: str=None, example: str=None):
+        self.name = name
+        self.help = help
+        if not example == None:
+            self.example = example
+    def parse(self, value: str) -> typing.Any:
+        return value
+
+    def get_example(self):
+        if not self.example == None:
+            return "Example: %s" % self.example
+        else:
+            return self._format_example()
+    def _format_example(self):
+        return None
+
+    def format(self, value: typing.Any):
+        return repr(value)
+
+SETTING_TRUE = ["true", "yes", "on", "y"]
+SETTING_FALSE = ["false", "no", "off", "n"]
+class BoolSetting(Setting):
+    example: typing.Optional[str] = "on"
+    def parse(self, value: str) -> typing.Any:
+        value_lower = value.lower()
+        if value_lower in SETTING_TRUE:
+            return True
+        elif value_lower in SETTING_FALSE:
+            return False
+        return None
+
+class IntSetting(Setting):
+    example: typing.Optional[str] = "10"
+    def parse(self, value: str) -> typing.Any:
+        if value == "0":
+            return 0
+        else:
+            stripped = value.lstrip("0")
+            if stripped.isdigit():
+                return int(stripped)
+        return None
+
+class IntRangeSetting(IntSetting):
+    example: typing.Optional[str] = None
+    def __init__(self, n_min: int, n_max: int, name: str, help: str=None,
+            example: str=None):
+        self._n_min = n_min
+        self._n_max = n_max
+        Setting.__init__(self, name, help, example)
+
+    def parse(self, value: str) -> typing.Any:
+        out = IntSetting.parse(self, value)
+        if not out == None and self._n_min <= out <= self._n_max:
+            return out
+        return None
+
+    def _format_example(self):
+        return "Must be between %d and %d" % (self._n_min, self._n_max)
+
+class OptionsSetting(Setting):
+    def __init__(self, options: typing.List[str], name: str, help: str=None,
+            example: str=None,
+            options_factory: typing.Callable[[], typing.List[str]]=None):
+        self._options = options
+        self._options_factory = options_factory
+        Setting.__init__(self, name, help, example)
+
+    def _get_options(self):
+        if not self._options_factory == None:
+            return self._options_factory()
+        else:
+            return self._options
+
+    def parse(self, value: str) -> typing.Any:
+        value_lower = value.lower()
+        for option in self._get_options():
+            if option.lower() == value_lower:
+                return option
+        return None
+
+    def _format_example(self):
+        options = self._get_options()
+        options_str = ["'%s'" % option for option in options]
+        return "Options: %s" % ", ".join(options_str)
+
+class FunctionSetting(Setting):
+    def __init__(self, func: typing.Callable[[str], bool], name: str,
+            help: str=None, example: str=None, format=None):
+        self._func = func
+        Setting.__init__(self, name, help, example)
+        if not format == None:
+            self.format = format # type: ignore
+
+    def parse(self, value: str) -> typing.Any:
+        return self._func(value)
+
+def sensitive_format(value: typing.Any):
+    return "*"*16
+
+class SensitiveSetting(Setting):
+    def format(self, value: typing.Any):
+        return sensitive_format(value)
+