import { useCallback, useEffect, useState } from "react";

/** comments：评论；works：TA的作品；list：搜索结果 / hashtag / 标签列表 */
export type SidePanelTab = "comments" | "works" | "list";

// 侧栏开关沿用评论区原来的 localStorage 键；停在哪个标签页、是否处于作者模式只在本次会话内记住，
// 这样下次从首页点进来不会莫名其妙停在作者模式。
// 切换作品时播放页会整体重新挂载，靠这些存储把状态带到下一个作品。
const OPEN_KEY = "aweme_player_comments_open";
const TAB_KEY = "aweme_player_panel_tab";
const AUTHOR_MODE_KEY = "aweme_player_author_mode";

function readStorage(storage: () => Storage, key: string): string | null {
  try {
    return storage().getItem(key);
  } catch {
    return null;
  }
}

function writeStorage(
  storage: () => Storage,
  key: string,
  value: string | null,
) {
  try {
    if (value === null) storage().removeItem(key);
    else storage().setItem(key, value);
  } catch {}
}

const local = () => window.localStorage;
const session = () => window.sessionStorage;

export function isPortraitViewport(): boolean {
  return (
    typeof window !== "undefined" &&
    window.matchMedia("(orientation: portrait)").matches
  );
}

/**
 * 侧栏状态与作者模式。
 * 作者模式和侧栏开关是分开的：打开「TA的作品」进入作者模式（上下切换在该作者的作品里移动），
 * 关掉侧栏不会退出，只有点顶部提示的 ✕、或切到「搜索结果 / #hashtag」列表才退出。
 */
export function useSidePanelState(authorSecUid: string | undefined) {
  const [open, setOpen] = useState(false);
  const [tab, setTab] = useState<SidePanelTab>("comments");
  // 处于作者模式时记下是哪位作者；切到别的作者的作品（例如浏览器后退）时自动不生效
  const [authorModeFor, setAuthorModeFor] = useState<string | null>(null);
  const [restored, setRestored] = useState(false);
  const [mounted, setMounted] = useState(false);

  useEffect(() => {
    setOpen(readStorage(local, OPEN_KEY) === "true");
    const savedTab = readStorage(session, TAB_KEY);
    setTab(savedTab === "works" || savedTab === "list" ? savedTab : "comments");
    setAuthorModeFor(readStorage(session, AUTHOR_MODE_KEY));
    setRestored(true);
    // 恢复完成后再开启过渡动画，避免进入页面时侧栏滑入
    requestAnimationFrame(() => {
      requestAnimationFrame(() => setMounted(true));
    });
  }, []);

  useEffect(() => {
    if (!restored) return;
    writeStorage(local, OPEN_KEY, String(open));
    writeStorage(session, TAB_KEY, tab);
    writeStorage(session, AUTHOR_MODE_KEY, authorModeFor);
  }, [open, tab, authorModeFor, restored]);

  // 切到哪个列表标签页，上下切换就改用哪个列表的顺序；「评论」不影响顺序
  const applyTabMode = useCallback(
    (nextTab: SidePanelTab) => {
      if (nextTab === "works" && authorSecUid) setAuthorModeFor(authorSecUid);
      else if (nextTab === "list") setAuthorModeFor(null);
    },
    [authorSecUid],
  );

  const selectTab = useCallback(
    (nextTab: SidePanelTab) => {
      setTab(nextTab);
      applyTabMode(nextTab);
    },
    [applyTabMode],
  );

  const show = useCallback(
    (nextTab: SidePanelTab) => {
      selectTab(nextTab);
      setOpen(true);
    },
    [selectTab],
  );

  const close = useCallback(() => setOpen(false), []);

  /** 打开到指定标签页；已经打开在这个标签页时则关闭（关闭不影响顺序） */
  const toggle = useCallback(
    (nextTab: SidePanelTab) => {
      if (open && tab === nextTab) close();
      else show(nextTab);
    },
    [close, open, show, tab],
  );

  const exitAuthorMode = useCallback(() => setAuthorModeFor(null), []);

  return {
    open,
    tab,
    mounted,
    /** 上下切换在当前作者的作品里移动 */
    authorMode: Boolean(authorSecUid) && authorModeFor === authorSecUid,
    /** 已从存储里恢复完状态（之后才能安全地自动打开侧栏） */
    restored,
    selectTab,
    show,
    close,
    toggle,
    exitAuthorMode,
  };
}