/**
 * @file projectTreePrefs — the sidebar workspace list's viewer preferences, in
 * ONE localStorage key (`agenthub.sidebar.projects`): which workspaces are
 * expanded to their sessions (by lane id), the tool the list is filtered to,
 * which owner groups an admin/analyst folded, and — Settings → Worktrees —
 * whether a workspace home's Add folder suggests the repo's untracked
 * worktrees and which sources of them (`claude` = `<repo>/.claude/worktrees/*`,
 * `agenthub` = LANES_ROOT) it leaves out. A `useSyncExternalStore` reader that caches nothing
 * but the parsed blob for the current raw string, so the sidebar and Settings
 * can never disagree. Nothing here reaches the server.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { useSyncExternalStore } from "react";

export const PROJECT_TREE_KEY = "agenthub.sidebar.projects";

export interface ProjectTreePrefs {
  /** Lane id → its sessions are shown under it in the sidebar. */
  expanded: Record<string, boolean>;
  /** Show only this tool's workspaces; null = every tool. */
  tool: string | null;
  /** Server mode, admin/analyst: owner key (user id, or "none") → its group is folded. */
  collapsedOwners: Record<string, boolean>;
  showUntracked: boolean;
  hideSources: string[];
}

const DEFAULTS: ProjectTreePrefs = {
  expanded: {},
  tool: null,
  collapsedOwners: {},
  showUntracked: true,
  hideSources: [],
};
const listeners = new Set<() => void>();
let cache: { raw: string | null; value: ProjectTreePrefs } = { raw: null, value: DEFAULTS };

function readRaw(): string | null {
  try {
    return localStorage.getItem(PROJECT_TREE_KEY);
  } catch {
    return null;
  }
}

export function readProjectTreePrefs(): ProjectTreePrefs {
  const raw = readRaw();
  if (raw === cache.raw) return cache.value;
  let value = DEFAULTS;
  try {
    const parsed = raw ? (JSON.parse(raw) as Partial<ProjectTreePrefs>) : {};
    value = {
      expanded: parsed.expanded && typeof parsed.expanded === "object" ? parsed.expanded : {},
      tool: typeof parsed.tool === "string" && parsed.tool ? parsed.tool : null,
      collapsedOwners:
        parsed.collapsedOwners && typeof parsed.collapsedOwners === "object"
          ? parsed.collapsedOwners
          : {},
      showUntracked: parsed.showUntracked !== false,
      hideSources: Array.isArray(parsed.hideSources) ? parsed.hideSources : [],
    };
  } catch {
    value = DEFAULTS;
  }
  cache = { raw, value };
  return value;
}

export function writeProjectTreePrefs(patch: Partial<ProjectTreePrefs>): void {
  try {
    localStorage.setItem(PROJECT_TREE_KEY, JSON.stringify({ ...readProjectTreePrefs(), ...patch }));
  } catch {
    /* disabled storage: the tree just forgets between visits */
  }
  listeners.forEach((l) => l());
}

function subscribe(l: () => void) {
  listeners.add(l);
  return () => listeners.delete(l);
}

export function useProjectTreePrefs(): ProjectTreePrefs {
  return useSyncExternalStore(subscribe, readProjectTreePrefs);
}