"use client";

import { useState } from "react";
import { Sparkles, Loader2, Check, Copy, Shrink, Zap, Wand2, ListFilter, FileText } from "lucide-react";

interface AIPanelProps {
  // For text operations (polish/expand/shorten/fix)
  selectedText: string;
  onApplyText: (text: string) => void;
  // For summary/tags generation
  title: string;
  content: string;
  onApplyMeta?: (data: { summary?: string; tags?: string }) => void;
}

export default function AIPanel({ selectedText, onApplyText, title, content, onApplyMeta }: AIPanelProps) {
  const [loading, setLoading] = useState<string | null>(null);
  const [result, setResult] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);

  const runAction = async (action: string) => {
    setLoading(action);
    setError(null);
    setResult(null);
    try {
      const body: Record<string, string> = { action };
      if (["polish", "expand", "shorten", "fix"].includes(action) && selectedText) {
        body.text = selectedText;
      } else if (["summary", "tags"].includes(action)) {
        body.title = title;
        body.content = content;
      }
      const res = await fetch("/api/ai", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(body),
      });
      if (!res.ok) throw new Error((await res.json()).error || "AI error");
      const data = await res.json();
      setResult(data.result);
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : "请求失败");
    } finally {
      setLoading(null);
    }
  };

  const apply = () => {
    if (!result) return;
    if (loading && ["summary", "tags"].includes(loading)) {
      // For tags: parse and apply
      if (loading === "tags" && onApplyMeta) {
        onApplyMeta({ tags: result });
      } else if (loading === "summary" && onApplyMeta) {
        onApplyMeta({ summary: result });
      }
    } else {
      onApplyText(result);
    }
    setResult(null);
  };

  const textActions = [
    { id: "polish", label: "润色", icon: Wand2, desc: "让文字更流畅" },
    { id: "expand", label: "扩写", icon: Zap, desc: "增加细节论述" },
    { id: "shorten", label: "缩写", icon: Shrink, desc: "精简核心信息" },
    { id: "fix", label: "纠错", icon: Check, desc: "修正错别字语法" },
  ];

  const metaActions = [
    { id: "summary", label: "生成摘要", icon: FileText },
    { id: "tags", label: "提取标签", icon: ListFilter },
  ];

  return (
    <div>
      <h3 className="text-[11px] font-medium text-muted uppercase tracking-wider mb-3">AI 助手</h3>

      <div className="bg-card border border-line rounded-lg overflow-hidden">
        {/* Text operations */}
        <div className="p-3 border-b border-line/50">
          <div className="text-[10px] font-medium text-muted/70 uppercase mb-2">文本处理</div>
          <div className="space-y-1">
            {textActions.map((a) => (
              <button
                key={a.id}
                type="button"
                disabled={!!loading}
                onClick={() => runAction(a.id)}
                className={`w-full flex items-center gap-2 px-2.5 py-1.5 text-[12px] rounded transition-colors ${
                  selectedText
                    ? "text-text/70 hover:text-accent hover:bg-accent/4"
                    : "text-muted/30 cursor-not-allowed"
                }`}
                title={selectedText ? a.desc : "请先选中文字"}
              >
                {loading === a.id ? (
                  <Loader2 size={13} className="animate-spin shrink-0" />
                ) : (
                  <a.icon size={13} className="shrink-0" />
                )}
                <span>{a.label}</span>
              </button>
            ))}
          </div>
        </div>

        {/* Meta generation */}
        <div className="p-3">
          <div className="text-[10px] font-medium text-muted/70 uppercase mb-2">元信息生成</div>
          <div className="space-y-1">
            {metaActions.map((a) => (
              <button
                key={a.id}
                type="button"
                disabled={!!loading || !title}
                onClick={() => runAction(a.id)}
                className={`w-full flex items-center gap-2 px-2.5 py-1.5 text-[12px] rounded transition-colors ${
                  title
                    ? "text-text/70 hover:text-accent hover:bg-accent/4"
                    : "text-muted/30 cursor-not-allowed"
                }`}
              >
                {loading === a.id ? (
                  <Loader2 size={13} className="animate-spin shrink-0" />
                ) : (
                  <a.icon size={13} className="shrink-0" />
                )}
                <span>{a.label}</span>
              </button>
            ))}
          </div>
        </div>
      </div>

      {/* Result panel */}
      {(result || error) && (
        <div className="mt-3 p-3 bg-card border border-line rounded-lg">
          {error ? (
            <div className="text-[12px] text-danger">{error}</div>
          ) : (
            <>
              <div className="text-[12px] text-text/80 leading-relaxed max-h-[200px] overflow-y-auto whitespace-pre-wrap">
                {result}
              </div>
              <div className="flex items-center gap-2 mt-2">
                <button
                  type="button"
                  onClick={apply}
                  className="flex items-center gap-1 px-2.5 py-1 text-[11px] font-medium rounded bg-accent text-white hover:bg-accent-hover transition-colors"
                >
                  <Copy size={11} /> 应用
                </button>
                <button
                  type="button"
                  onClick={() => setResult(null)}
                  className="px-2.5 py-1 text-[11px] rounded border border-line text-muted hover:bg-surface transition-colors"
                >
                  忽略
                </button>
              </div>
            </>
          )}
        </div>
      )}

      {/* API key tip */}
      {!selectedText && !title && (
        <p className="mt-3 text-[10px] text-muted/50 leading-relaxed">
          选中文字后可使用润色/扩写/缩写/纠错。填写标题后可生成摘要和标签。
        </p>
      )}
    </div>
  );
}