import { useEffect, useMemo } from 'react';
import type { LayoutNode } from 'officerdev';
import { WorkspaceView } from 'officerdev';
import { useDashboardState } from 'state/useDashboardState';
import { defaultLayout } from './defaultLayout';

// /calendar uses the Workspace/Panel system (like /transmission): the calendar list on the left, the
// selected calendar's agenda on the right. Both panels read the officer-caldav sidecar through the
// /api/caldav auth proxy, which holds no DAV credentials of its own.
//
// There is no :param route pair here and so no <Navigate> guard: a collection id is a DAV path with
// slashes in it, so the selection lives in ?collection= on this same route. An absent or unknown value
// resolves to the first collection inside the panels rather than by redirecting, because until the
// collection list has loaded there is no canonical URL to redirect to.

const ALLOWED_APP_TYPES = new Set<string | null>(['calendar-nav', 'calendar-view', null]);

function normalizeLayout(node: LayoutNode): LayoutNode {
  if (node.type === 'panel') {
    return ALLOWED_APP_TYPES.has(node.appType) ? node : { ...node, appType: 'calendar-view' };
  }
  const children = node.children.map((c) => {
    const fixed = normalizeLayout(c.node);
    return fixed === c.node ? c : { ...c, node: fixed };
  });
  const changed = children.some((c, i) => c !== node.children[i]);
  return changed ? { ...node, children } : node;
}

export const CalendarScreen = () => {
  const rawWorkspace = useDashboardState<LayoutNode>('screens/calendar', defaultLayout);

  const workspace = useMemo(() => {
    const fixed = normalizeLayout(rawWorkspace.value);
    if (fixed === rawWorkspace.value) return rawWorkspace;
    return { ...rawWorkspace, value: fixed };
  }, [rawWorkspace]);

  useEffect(() => {
    if (rawWorkspace.isLoaded && workspace.value !== rawWorkspace.value) {
      rawWorkspace.setValue(workspace.value);
    }
  }, [rawWorkspace.isLoaded, workspace.value, rawWorkspace.value]);

  return (
    <div className="h-full w-full pt-2">
      <WorkspaceView workspace={workspace} locked />
    </div>
  );
};