nexus/ui/src/components/ChatBranchSelector.tsx

import { GitBranch } from "lucide-react";
import { cn } from "@/lib/utils";
import type { ChatConversation } from "@paperclipai/shared";

interface ChatBranchSelectorProps {
  conversationId: string;
  branches: ChatConversation[];
  activeBranchId: string | null;
  onSelectBranch: (id: string) => void;
}

function formatDate(dateStr: string): string {
  return new Date(dateStr).toLocaleDateString(undefined, { month: "short", day: "numeric" });
}

export function ChatBranchSelector({
  conversationId,
  branches,
  activeBranchId,
  onSelectBranch,
}: ChatBranchSelectorProps) {
  if (branches.length === 0) return null;

  return (
    <div className="flex items-center gap-1 px-2 py-1 border-b border-border overflow-x-auto">
      <GitBranch className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
      <span className="text-xs text-muted-foreground shrink-0 mr-1">Branch:</span>

      {/* Original conversation */}
      <button
        type="button"
        className={cn(
          "shrink-0 rounded px-2 py-0.5 text-xs transition-colors",
          activeBranchId === null || activeBranchId === conversationId
            ? "bg-accent text-accent-foreground"
            : "hover:bg-accent/50 text-muted-foreground",
        )}
        onClick={() => onSelectBranch(conversationId)}
        title="Original conversation"
      >
        Original
      </button>

      {branches.map((branch, index) => (
        <button
          key={branch.id}
          type="button"
          className={cn(
            "shrink-0 rounded px-2 py-0.5 text-xs transition-colors",
            activeBranchId === branch.id
              ? "bg-accent text-accent-foreground"
              : "hover:bg-accent/50 text-muted-foreground",
          )}
          onClick={() => onSelectBranch(branch.id)}
          title={`Created ${formatDate(branch.createdAt)}`}
        >
          {branch.title ?? `Branch ${index + 1}`}
        </button>
      ))}
    </div>
  );
}