function app() {
    return {
        inboxFiles: [],
        outboxFiles: [],
        async loadFiles() {
            const [inbox, outbox] = await Promise.all([
                fetch('/api/files?dir=inbox').then(r => r.json()),
                fetch('/api/files?dir=outbox').then(r => r.json())
            ]);
            this.inboxFiles = inbox.files || [];
            this.outboxFiles = outbox.files || [];
        },
        async upload(event, dir) {
            const file = event.target.files[0];
            const form = new FormData();
            form.append('file', file);
            form.append('dir', dir);
            await fetch('/api/upload', {method: 'POST', body: form});
            this.loadFiles();
        },
        download(id) {
            window.location.href = '/api/files/' + id + '/download';
        },
        async deleteFile(id) {
            await fetch('/api/files/' + id, {method: 'DELETE'});
            this.loadFiles();
        },
        async share(id) {
            const res = await fetch('/api/files/' + id + '/share', {method: 'POST'});
            const data = await res.json();
            alert('Share URL: ' + data.url);
        },
        async logout() {
            await fetch('/api/logout', {method: 'POST'});
            window.location.href = '/login';
        }
    };
}