リモート同期の概要

ブラウザ (DayFlow)  →  バックエンドプロキシ  →  CalDAV / Google / Outlook API

const adapter = createCalDAVAdapter({
  calendarHomeUrl: 'https://caldav.example.com/calendars/alice/',
  fetch: (url, init) =>
    fetch('/api/caldav-proxy', {
      method: 'POST',
      body: JSON.stringify({ url, init }),
    }),
});

# iCloud
CALDAV_BASE_URL=https://caldav.icloud.com/
CALDAV_USERNAME=alice@icloud.com
CALDAV_PASSWORD=xxxx-xxxx-xxxx-xxxx

# Nextcloud
# CALDAV_BASE_URL=https://nextcloud.example.com/remote.php/dav/
# CALDAV_USERNAME=alice
# CALDAV_PASSWORD=nextcloud-app-password

# Radicale
# CALDAV_BASE_URL=https://radicale.example.com/

# Fastmail
# CALDAV_BASE_URL=https://caldav.fastmail.com/dav/

export const runtime = 'nodejs';

const ALLOWED_METHODS = new Set(['PROPFIND', 'REPORT', 'PUT', 'DELETE']);

function requireEnv(name: string): string {
  const value = process.env[name];
  if (!value) throw new Error(`${name} is required`);
  return value;
}

function corsHeaders() {
  return {
    'Access-Control-Allow-Origin':
      process.env.APP_ORIGIN ?? 'http://localhost:3000',
    'Access-Control-Allow-Methods': 'POST, OPTIONS',
    'Access-Control-Allow-Headers': 'Content-Type',
    'Access-Control-Expose-Headers': 'ETag, DAV',
  };
}

export function OPTIONS() {
  return new Response(null, { status: 204, headers: corsHeaders() });
}

export async function POST(request: Request) {
  const baseUrl = requireEnv('CALDAV_BASE_URL');
  const username = requireEnv('CALDAV_USERNAME');
  const password = requireEnv('CALDAV_PASSWORD');
  const { url, init = {} } = (await request.json()) as {
    url: string;
    init?: RequestInit;
  };

  const target = new URL(url);
  const base = new URL(baseUrl);
  const method = init.method ?? 'PROPFIND';

  if (!target.href.startsWith(base.href)) {
    return new Response('Forbidden upstream URL', {
      status: 403,
      headers: corsHeaders(),
    });
  }
  if (!ALLOWED_METHODS.has(method)) {
    return new Response('Method not allowed', {
      status: 405,
      headers: corsHeaders(),
    });
  }

  const headers = new Headers(init.headers);
  headers.set(
    'Authorization',
    `Basic ${Buffer.from(`${username}:${password}`).toString('base64')}`
  );

  const upstream = await fetch(target.href, {
    method,
    headers,
    body: typeof init.body === 'string' ? init.body : undefined,
  });

  const responseHeaders = new Headers(corsHeaders());
  for (const name of ['Content-Type', 'ETag', 'DAV', 'Last-Modified']) {
    const value = upstream.headers.get(name);
    if (value) responseHeaders.set(name, value);
  }

  return new Response(await upstream.text(), {
    status: upstream.status,
    headers: responseHeaders,
  });
}

import type { CalDAVStorage } from '@dayflow/caldav';

const key = (accountId: string, name: string, id: string) =>
  `dayflow:caldav:${accountId}:${name}:${id}`;

export function createLocalCalDAVStorage(accountId: string): CalDAVStorage {
  return {
    getSyncToken: async calendarId =>
      localStorage.getItem(key(accountId, 'sync-token', calendarId)),
    setSyncToken: async (calendarId, token) => {
      const storageKey = key(accountId, 'sync-token', calendarId);
      if (token) localStorage.setItem(storageKey, token);
      else localStorage.removeItem(storageKey);
    },
    getCtag: async calendarId =>
      localStorage.getItem(key(accountId, 'ctag', calendarId)),
    setCtag: async (calendarId, ctag) => {
      localStorage.setItem(key(accountId, 'ctag', calendarId), ctag);
    },
    getEtag: async href => localStorage.getItem(key(accountId, 'etag', href)),
    setEtag: async (href, etag) => {
      localStorage.setItem(key(accountId, 'etag', href), etag);
    },
    deleteEtag: async href => {
      localStorage.removeItem(key(accountId, 'etag', href));
    },
    getEventState: async eventId =>
      JSON.parse(
        localStorage.getItem(key(accountId, 'event-state', eventId)) ?? 'null'
      ),
    setEventState: async (eventId, state) => {
      localStorage.setItem(
        key(accountId, 'event-state', eventId),
        JSON.stringify(state)
      );
    },
    deleteEventState: async eventId => {
      localStorage.removeItem(key(accountId, 'event-state', eventId));
    },
    clearCalendar: async calendarId => {
      const prefix = `dayflow:caldav:${accountId}:`;
      for (const storageKey of Object.keys(localStorage)) {
        if (!storageKey.startsWith(prefix)) continue;

        const value = localStorage.getItem(storageKey);
        const isCalendarKey =
          storageKey === key(accountId, 'sync-token', calendarId) ||
          storageKey === key(accountId, 'ctag', calendarId) ||
          storageKey.startsWith(key(accountId, 'etag', calendarId));
        let isEventStateForCalendar = false;
        if (storageKey.startsWith(`${prefix}event-state:`) && value) {
          try {
            isEventStateForCalendar =
              JSON.parse(value).calendarId === calendarId;
          } catch {
            isEventStateForCalendar = false;
          }
        }

        if (isCalendarKey || isEventStateForCalendar) {
          localStorage.removeItem(storageKey);
        }
      }
    },
  };
}

import { useEffect, useRef } from 'react';
import {
  DayFlowCalendar,
  createMonthView,
  useCalendarApp,
} from '@dayflow/react';
import {
  ICLOUD_CALDAV_SERVER,
  attachCalDAVToDayFlow,
  createCalDAVAdapter,
  createCalDAVAdapterFromServer,
  createCalDAVSync,
  createNamespacedCalDAVEventId,
  nextcloudConfig,
  type CalDAVDayFlowController,
  type CalDAVSyncStatus,
} from '@dayflow/caldav';
import { createLocalCalDAVStorage } from './caldav-storage';

type Provider = 'icloud' | 'nextcloud';

type Props = {
  accountId: string;
  provider: Provider;
  nextcloudHost?: string;
  nextcloudUsername?: string;
  onStatusChange?: (status: CalDAVSyncStatus) => void;
};

export function CalDAVCalendar({
  accountId,
  provider,
  nextcloudHost,
  nextcloudUsername,
  onStatusChange,
}: Props) {
  const calendar = useCalendarApp({
    views: [createMonthView()],
    calendars: [],
    events: [],
  });
  const controllerRef = useRef<CalDAVDayFlowController | null>(null);

  useEffect(() => {
    let disposed = false;

    const proxiedFetch = (url: string, init?: RequestInit) =>
      fetch('/api/caldav', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ url, init }),
      });

    async function startSync() {
      const adapter =
        provider === 'icloud'
          ? await createCalDAVAdapterFromServer(ICLOUD_CALDAV_SERVER, {
              fetch: proxiedFetch,
            })
          : createCalDAVAdapter({
              ...nextcloudConfig(nextcloudHost!, nextcloudUsername!),
              fetch: proxiedFetch,
            });

      if (disposed) return;

      const sync = createCalDAVSync({
        adapter,
        storage: createLocalCalDAVStorage(accountId),
      });

      const controller = attachCalDAVToDayFlow(calendar.app, sync, {
        writable: true,
        refreshOnVisibleRangeChange: true,
        createEventId: createNamespacedCalDAVEventId,
        eventMode: {
          recurring: 'read-only',
        },
        getInitialSnapshot: async () => {
          const cached = await loadCachedCalDAVSnapshot(accountId);
          return cached ?? { calendars: [], events: [] };
        },
        onSyncComplete: async delta => {
          await persistSyncedDayFlowState(accountId, calendar.app);
          console.info('CalDAV sync complete', delta);
        },
        onWriteComplete: async () => {
          await persistSyncedDayFlowState(accountId, calendar.app);
        },
        onError: (error, context) => {
          console.error('CalDAV sync failed', context, error);
          onStatusChange?.(controller.getStatus());
        },
      });

      controllerRef.current = controller;
      await controller.start();
      onStatusChange?.(controller.getStatus());
    }

    startSync().catch(error => {
      console.error('Failed to start CalDAV sync', error);
    });

    return () => {
      disposed = true;
      controllerRef.current?.stop();
      controllerRef.current = null;
    };
  }, [
    accountId,
    calendar.app,
    nextcloudHost,
    nextcloudUsername,
    onStatusChange,
    provider,
  ]);

  return <DayFlowCalendar calendar={calendar} />;
}

import type { ICalendarApp } from '@dayflow/core';

async function loadCachedCalDAVSnapshot(accountId: string) {
  // IndexedDB、Supabase、バックエンドなどから { calendars, events } を返します。
  // キャッシュがない場合は null を返します。
  return null;
}

async function persistSyncedDayFlowState(accountId: string, app: ICalendarApp) {
  // app.getCalendars() と app.getAllEvents() をローカルストアに永続化します。
  // 同期メタデータのみを保存する CalDAVStorage とは分けてください。
}