1 files changed, 59 insertions, 0 deletions
diff --git a/iredis/warning.py b/iredis/warning.py
new file mode 100644
index 0000000..bb8231e
--- /dev/null
+++ b/iredis/warning.py
@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+
+import sys
+import click
+from .commands import dangerous_commands
+
+
+class ConfirmBoolParamType(click.ParamType):
+    name = "confirmation"
+
+    def convert(self, value, param, ctx):
+        if isinstance(value, bool):
+            return bool(value)
+        value = value.lower()
+        if value in ("yes", "y"):
+            return True
+        elif value in ("no", "n"):
+            return False
+        self.fail("%s is not a valid boolean" % value, param, ctx)
+
+    def __repr__(self):
+        return "BOOL"
+
+
+BOOLEAN_TYPE = ConfirmBoolParamType()
+
+
+def is_dangerous(command):
+    """
+    :return : return True, reason str if command is dangerous;
+        return False, None otherwise.
+    """
+    reason = dangerous_commands.get(command)
+    return reason is not None, reason
+
+
+def prompt(*args, **kwargs):
+    """Prompt the user for input and handle any abort exceptions."""
+    try:
+        return click.prompt(*args, **kwargs)
+    except click.Abort:
+        return False
+
+
+def confirm_dangerous_command(upper_command):
+    """Check if the query is destructive and prompts the user to confirm.
+
+    Returns:
+    * None if the query is non-destructive or we can't prompt the user.
+    * True if the query is destructive and the user wants to proceed.
+    * False if the query is destructive and the user doesn't want to proceed.
+
+    """
+    dangerous, reason = is_dangerous(upper_command)
+    prompt_text = f"{reason}.\n" "Do you want to proceed? (y/n)"
+    if dangerous and sys.stdin.isatty():
+        return prompt(prompt_text, type=BOOLEAN_TYPE)