"use client";

import { useCallback, useEffect, useRef, useState } from "react";
import { errorMessage, getExecutionView, listScriptBuilds } from "@/lib/api";
import { isTerminalStatus, type BuildSummary, type ExecutionViewV8 } from "@/lib/types";

const RUN_QUERY_KEY = "run";
const LAST_RUN_STORAGE_KEY = "script-build:last-run";

export function initialBuildId(builds: BuildSummary[], search: string, storedId?: string | null) {
  const queryId = new URLSearchParams(search).get(RUN_QUERY_KEY)?.trim();
  if (queryId) return queryId;
  const remembered = storedId?.trim();
  if (remembered && builds.some((build) => build.id === remembered)) return remembered;
  return builds[0]?.id || "";
}

export function useExecutionView() {
  const [builds, setBuilds] = useState<BuildSummary[]>([]);
  const [selectedId, setSelectedId] = useState("");
  const [view, setView] = useState<ExecutionViewV8 | null>(null);
  const [loading, setLoading] = useState(true);
  const [refreshing, setRefreshing] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const generation = useRef(0);

  const loadView = useCallback(async (id: string, signal?: AbortSignal, quiet = false) => {
    const requestId = ++generation.current;
    quiet ? setRefreshing(true) : setLoading(true);
    try {
      if (!id) throw new Error("请输入真实 Run ID");
      const data = await getExecutionView(id, signal);
      if (requestId !== generation.current) return;
      setView(data);
      setError(null);
      const loadedId = String(data.header.id);
      setSelectedId(loadedId);
      rememberBuildId(loadedId);
    } catch (requestError) {
      if (signal?.aborted || requestId !== generation.current) return;
      if (quiet && view) {
        setError(`刷新失败，保留 ${view.capturedAt} 的快照：${errorMessage(requestError)}`);
      } else {
        setView(null);
        setError(`无法读取构建 #${id}：${errorMessage(requestError)}`);
      }
    } finally {
      if (requestId === generation.current) { setLoading(false); setRefreshing(false); }
    }
  }, [view]);

  useEffect(() => {
    const controller = new AbortController();
    void listScriptBuilds(controller.signal)
      .then((items) => {
        setBuilds(items);
        const preferred = initialBuildId(items, window.location.search, readRememberedBuildId());
        setSelectedId(preferred);
        if (!preferred) throw new Error("当前没有可读取的真实构建记录");
        return loadView(preferred, controller.signal);
      })
      .catch((listError) => { if (!controller.signal.aborted) { setView(null); setLoading(false); setError(`无法读取真实构建列表：${errorMessage(listError)}`); } });
    return () => controller.abort();
  }, []);

  useEffect(() => {
    if (!view || isTerminalStatus(view.header.status)) return;
    const timer = window.setTimeout(() => void loadView(String(view.header.id), undefined, true), 3000);
    return () => window.clearTimeout(timer);
  }, [view?.capturedAt, view?.header.id, view?.header.status, loadView]);

  const selectBuild = useCallback((id: string) => {
    const normalized = id.trim();
    if (!normalized) return;
    setSelectedId(normalized); setView(null); setError(null);
    void loadView(normalized);
  }, [loadView]);

  return { builds, selectedId, view, loading, refreshing, error, selectBuild };
}

function readRememberedBuildId() {
  try {
    return window.localStorage.getItem(LAST_RUN_STORAGE_KEY);
  } catch {
    return null;
  }
}

function rememberBuildId(id: string) {
  try {
    window.localStorage.setItem(LAST_RUN_STORAGE_KEY, id);
  } catch {
    // URL persistence still works when storage is unavailable.
  }
  const url = new URL(window.location.href);
  if (url.searchParams.get(RUN_QUERY_KEY) === id) return;
  url.searchParams.set(RUN_QUERY_KEY, id);
  window.history.replaceState(window.history.state, "", url);
}