1 files changed, 102 insertions, 0 deletions
diff --git a/src/xpit_/args_helpers.py b/src/xpit_/args_helpers.py
new file mode 100644
index 0000000..1e79911
--- /dev/null
+++ b/src/xpit_/args_helpers.py
@@ -0,0 +1,102 @@
+from sys import stderr
+from . import error
+Err = error.Err
+
+def print_error(msg: str) -> None:
+    stderr.write(f"{msg}\n")
+
+def err_arg_unrecognized(arg: str) -> None:
+    print_error(f"Unrecognized argument: {arg}")
+
+ERR_UNRECOGNIZED_ARG = "ERR_UNRECOGNIZED_ARG"
+ERR_NOT_ENOUGH_ARGS = "ERR_NOT_ENOUGH_ARGS"
+
+def parse_arg(
+    argv: list[str],
+    i: int,
+    flag_value_map: dict[str, int]
+) -> tuple[str, list[str], int, Err | None]:
+    def success(
+        flag: str,
+        values: list[str],
+        new_i: int
+    ) -> tuple[str, list[str], int, Err | None]:
+        return flag, values, new_i, None
+    def fail(msg: str) -> tuple[str, list[str], int, Err | None]:
+        return "", [], 0, Err(msg)
+
+    flag: str
+    values: list[str] = []
+    arg: str = argv[i]
+    i += 1
+    if arg[0] != '-':
+        err_arg_unrecognized(arg)
+        return fail(ERR_UNRECOGNIZED_ARG)
+
+    value_index = 0
+    if arg[1] == '-':
+        # --flag
+        delimiter_index = arg.find('=')
+        if delimiter_index == -1:
+            flag = arg[2:]
+            value_index = 0
+        else:
+            flag = arg[2:delimiter_index]
+            values.append(arg[delimiter_index+1:])
+            value_index = 1
+
+    else:
+        # -f
+        flag = arg[1]
+        value_index = 0
+
+        if len(arg) != 2:
+            value = arg[2:]
+            if value[0] == '=':
+                value = value[1:]
+            values.append(value)
+            value_index += 1
+    target_flag_set_arr = None
+    value_count: int = 0
+    for flag_set in flag_value_map:
+        flag_set_arr = flag_set.split('|')
+        if flag in flag_set_arr:
+            target_flag_set_arr = flag_set_arr
+            value_count = flag_value_map[flag_set]
+            break
+    if target_flag_set_arr is None:
+        err_arg_unrecognized(flag)
+        return fail(ERR_UNRECOGNIZED_ARG)
+    while value_index < value_count:
+        if i >= len(argv):
+            print_error(f"Not enough arguments for flag '{flag}'")
+            return fail(ERR_NOT_ENOUGH_ARGS)
+        values.append(argv[i])
+        i += 1
+        value_index += 1
+
+    # NOTE: we always return the first flag in the flag-set for normalization
+    return success(target_flag_set_arr[0], values, i)
+
+def parse_generic(
+    flag_value_map: dict[str, int],
+    argv: list[str],
+    i: int
+) -> dict[str, list[str]] | None:
+    res: dict[str, list[str]] = {}
+    while i < len(argv):
+        arg = argv[i]
+        if len(arg) >= 2:
+            flag, values, i, err = parse_arg(argv, i, flag_value_map)
+            if err is not None:
+                return None
+
+            res[flag] = values
+            #if not callback(flag, values):
+            #    return False
+        else:
+            err_arg_unrecognized(arg)
+            return None
+
+    return res
+