1 files changed, 113 insertions, 0 deletions
diff --git a/src/utils/parse/spec.py b/src/utils/parse/spec.py
new file mode 100644
index 00000000..2cde7410
--- /dev/null
+++ b/src/utils/parse/spec.py
@@ -0,0 +1,113 @@
+import enum, typing
+from .time import duration
+
+class SpecArgumentContext(enum.IntFlag):
+    CHANNEL = 1
+    PRIVATE = 2
+    ALL = 3
+
+class SpecArgumentType(object):
+    context = SpecArgumentContext.ALL
+
+    def __init__(self, type_name: str, name: typing.Optional[str], exported: str):
+        self.type = type_name
+        self._name = name
+        self.exported = exported
+
+    def name(self) -> typing.Optional[str]:
+        return self._name
+    def simple(self, args: typing.List[str]) -> typing.Tuple[typing.Any, int]:
+        return None, -1
+    def error(self) -> typing.Optional[str]:
+        return None
+
+class SpecArgumentTypeWord(SpecArgumentType):
+    def simple(self, args: typing.List[str]) -> typing.Tuple[typing.Any, int]:
+        if args:
+            return args[0], 1
+        return None, 1
+class SpecArgumentTypeWordLower(SpecArgumentTypeWord):
+    def simple(self, args: typing.List[str]) -> typing.Tuple[typing.Any, int]:
+        out = SpecArgumentTypeWord.simple(self, args)
+        if out[0]:
+            return out[0].lower(), out[1]
+        return out
+
+class SpecArgumentTypeString(SpecArgumentType):
+    def name(self):
+        return "%s ..." % SpecArgumentType.name(self)
+    def simple(self, args: typing.List[str]) -> typing.Tuple[typing.Any, int]:
+        return " ".join(args), len(args)
+
+class SpecArgumentTypeDuration(SpecArgumentType):
+    def name(self):
+        return "+%s" % (SpecArgumentType.name(self) or "duration")
+    def simple(self, args: typing.List[str]) -> typing.Tuple[typing.Any, int]:
+        if args:
+            return duration(args[0]), 1
+        return None, 1
+    def error(self) -> typing.Optional[str]:
+        return "Invalid timeframe"
+
+class SpecArgumentPrivateType(SpecArgumentType):
+    context = SpecArgumentContext.PRIVATE
+
+SPEC_ARGUMENT_TYPES = {
+    "word": SpecArgumentTypeWord,
+    "wordlower": SpecArgumentTypeWordLower,
+    "string": SpecArgumentTypeString,
+    "duration": SpecArgumentTypeDuration
+}
+
+class SpecArgument(object):
+    def __init__(self, optional: bool, types: typing.List[SpecArgumentType]):
+        self.optional = optional
+        self.types = types
+
+def argument_spec(spec: str) -> typing.List[SpecArgument]:
+    out: typing.List[SpecArgument] = []
+    for spec_argument in spec.split(" "):
+        optional = spec_argument[0] == "?"
+
+        argument_types: typing.List[SpecArgumentType] = []
+        for argument_type in spec_argument[1:].split("|"):
+            exported = ""
+            if "~" in argument_type:
+                exported = argument_type.split("~", 1)[1]
+                argument_type = argument_type.replace("~", "", 1)
+
+            argument_type_name: typing.Optional[str] = None
+            name_end = argument_type.find(">")
+            if argument_type.startswith("<") and name_end > 0:
+                argument_type_name = argument_type[1:name_end]
+                argument_type = argument_type[name_end+1:]
+
+            argument_type_class = SpecArgumentType
+            if argument_type in SPEC_ARGUMENT_TYPES:
+                argument_type_class = SPEC_ARGUMENT_TYPES[argument_type]
+            elif exported:
+                argument_type_class = SpecArgumentPrivateType
+
+            argument_types.append(argument_type_class(argument_type,
+                argument_type_name, exported))
+        out.append(SpecArgument(optional, argument_types))
+    return out
+
+def argument_spec_human(spec: typing.List[SpecArgument],
+        context: SpecArgumentContext=SpecArgumentContext.ALL) -> str:
+    out: typing.List[str] = []
+    for spec_argument in spec:
+        names: typing.List[str] = []
+        for argument_type in spec_argument.types:
+            if not (context&argument_type.context) == 0:
+                name = argument_type.name() or argument_type.type
+                if name:
+                    names.append(name)
+
+        if names:
+            if spec_argument.optional:
+                format = "[%s]"
+            else:
+                format = "<%s>"
+            out.append(format % "|".join(names))
+    return " ".join(out)