"use client";

import { useEffect, useState } from "react";

import { api } from "@/lib/api/client";
import type { InjectionResponse } from "./injection";

export interface UseInjection {
  data: InjectionResponse | null;
  loading: boolean;
  error: string | null;
}

// 本章注入透明（B0 读端点）：挂载时拉一次确定性 SelectionTrace。
// 只读、无 LLM、无 commit——展示「选了谁/为什么」。失败给可读文案不抛。
export function useInjection(
  projectId: string,
  chapterNo: number,
): UseInjection {
  const [data, setData] = useState<InjectionResponse | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    let cancelled = false;
    setLoading(true);
    setError(null);

    void (async () => {
      const { data: body, error: err } = await api.GET(
        "/projects/{project_id}/chapters/{chapter_no}/injection",
        { params: { path: { project_id: projectId, chapter_no: chapterNo } } },
      );
      if (cancelled) return;
      if (err || !body) {
        setError("注入信息暂不可用");
        setData(null);
      } else {
        setData(body);
      }
      setLoading(false);
    })();

    return () => {
      cancelled = true;
    };
  }, [projectId, chapterNo]);

  return { data, loading, error };
}