#!/bin/bash
# docker-dangerous-guard.sh — Block dangerous Docker operations
#
# Prevents: docker system prune -a, docker rm -f on running containers,
#           docker run --privileged, docker exec as root on production containers.
#
# TRIGGER: PreToolUse
# MATCHER: "Bash"
#
# Usage:
# {
#   "hooks": {
#     "PreToolUse": [{
#       "matcher": "Bash",
#       "hooks": [{ "type": "command", "command": "~/.claude/hooks/docker-dangerous-guard.sh" }]
#     }]
#   }
# }

INPUT=$(cat)
COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command // empty' 2>/dev/null)
[ -z "$COMMAND" ] && exit 0

# Block docker system prune -a (removes all images)
if echo "$COMMAND" | grep -qE 'docker\s+system\s+prune\s+.*-a'; then
  echo "BLOCKED: docker system prune -a removes all unused images." >&2
  echo "  Use 'docker system prune' (without -a) to keep tagged images." >&2
  exit 2
fi

# Block docker run --privileged
if echo "$COMMAND" | grep -qE 'docker\s+run\s+.*--privileged'; then
  echo "BLOCKED: --privileged gives full host access to the container." >&2
  exit 2
fi

# Warn on docker rm -f (force remove)
if echo "$COMMAND" | grep -qE 'docker\s+(rm|container\s+rm)\s+.*-f'; then
  echo "WARNING: Force-removing container. Data in the container will be lost." >&2
fi

# Block docker run with host network and port 22/80/443
if echo "$COMMAND" | grep -qE 'docker\s+run.*--network\s+host'; then
  echo "WARNING: --network host exposes all container ports on the host." >&2
fi

exit 0