"use client";

import { useRef, useEffect, useState } from "react";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { useClaudeChat } from "@/hooks/use-claude-chat";
import { Send, Loader2 } from "lucide-react";

export function ClaudeChat({ campaignId }: { campaignId: string }) {
  const { messages, sendMessage, isStreaming } = useClaudeChat(campaignId);
  const [input, setInput] = useState("");
  const messagesEndRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
  }, [messages]);

  function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    if (!input.trim() || isStreaming) return;
    sendMessage(input.trim());
    setInput("");
  }

  function handleKeyDown(e: React.KeyboardEvent) {
    if (e.key === "Enter" && !e.shiftKey) {
      e.preventDefault();
      handleSubmit(e);
    }
  }

  return (
    <div className="flex flex-col h-[calc(100vh-16rem)]">
      {/* Messages */}
      <div className="flex-1 overflow-y-auto space-y-4 p-4">
        {messages.length === 0 && (
          <p className="text-center text-muted-foreground py-12">
            Chat with Claude about this campaign. Ask for edits, new variations,
            or feedback on generated content.
          </p>
        )}
        {messages.map((msg, i) => (
          <div
            key={i}
            className={`flex ${
              msg.role === "user" ? "justify-end" : "justify-start"
            }`}
          >
            <div
              className={`max-w-[80%] rounded-lg px-4 py-2 text-sm whitespace-pre-wrap ${
                msg.role === "user"
                  ? "bg-primary text-primary-foreground"
                  : "bg-muted"
              }`}
            >
              {msg.content}
              {isStreaming && i === messages.length - 1 && msg.role === "assistant" && (
                <Loader2 className="inline-block ml-1 h-3 w-3 animate-spin" />
              )}
            </div>
          </div>
        ))}
        <div ref={messagesEndRef} />
      </div>

      {/* Input */}
      <form onSubmit={handleSubmit} className="border-t p-4 flex gap-2">
        <Textarea
          value={input}
          onChange={(e) => setInput(e.target.value)}
          onKeyDown={handleKeyDown}
          placeholder="Ask Claude to modify content, regenerate hooks, give feedback..."
          className="min-h-[2.5rem] max-h-32 resize-none"
          rows={1}
        />
        <Button type="submit" size="icon" disabled={!input.trim() || isStreaming}>
          <Send className="h-4 w-4" />
        </Button>
      </form>
    </div>
  );
}