APIController.cs

using Microsoft.AspNetCore.Mvc;

namespace yFilesASPNET.Controllers;

public class Person
{
    public int Id { get; set; }

    public string FirstName { get; set; } = null!;

    public string LastName { get; set; } = null!;
}

public class PersonAddress
{
    public string AddressLine { get; set; } = null!;

    public string Zip { get; set; } = null!;

    public string City { get; set; } = null!;

    public string Country { get; set; } = null!;
}

public class PersonHierarchy
{
    public List<Person> Nodes { get; set; }

    public List<Link> Links { get; set; }

    public PersonHierarchy()
    {
        this.Nodes = new List<Person>();
        this.Links = new List<Link>();
    }
}

public class Link
{
    public int From { get; set; }

    public int To { get; set; }
}

public class APIController : Controller
{
    static class Cache
    {
        static Dictionary<int, Tuple<Person, PersonAddress>> cache = new Dictionary<int, Tuple<Person, PersonAddress>>();

        static void AddPerson(int id)
        {
            var person = new Person
            {
                Id = id,
                FirstName = Faker.Name.First(),
                LastName = Faker.Name.Last()
            };
            var personAddress = new PersonAddress
            {
                AddressLine = Faker.Address.StreetAddress(),
                City = Faker.Address.City(),
                Zip = Faker.Address.ZipCode(),
                Country = Faker.Address.Country()
            };
            cache.Add(id, Tuple.Create(person, personAddress));
        }

        public static Person GetPerson(int id)
        {
            if (!cache.ContainsKey(id))
            {
                AddPerson(id);
            }

            return cache[id].Item1;
        }

        public static PersonAddress GetPersonAddress(int id)
        {
            if (!cache.ContainsKey(id))
            {
                AddPerson(id);
            }

            return cache[id].Item2;
        }
    }

    static Random Rand = new Random(Environment.TickCount);

    [HttpGet]
    [Route("API/GetRoot")]
    public Person GetRoot()
    {
        return Cache.GetPerson(0);
    }

    [HttpGet]
    [Route("API/GetPerson/{id}")]
    public Person GetPerson(int id)
    {
        return Cache.GetPerson(id);
    }

    [HttpGet]
    [Route("API/GetPersonAddress/{id}")]
    public PersonAddress GetPersonAddress(int id)
    {
        return Cache.GetPersonAddress(id);
    }

    [HttpGet]
    [Route("API/GetHierarchy/{id}/{count?}/{degree?}")]
    public PersonHierarchy GetHierarchy(int id, int count = 20, int degree = 3)
    {
        // let's keep it tidy shall we?
        degree = Math.Max(1, Math.Min(5, degree));
        var hierarchy = new PersonHierarchy();
        // make sure the root is already in the collection
        hierarchy.Nodes.Add(Cache.GetPerson(0));
        var parentId = 0;
        // keep track of the node degrees
        var degrees = new Dictionary<int, int> {{0, 0}};

        for (int i = 1; i < count; i++)
        {
            parentId = Rand.Next(hierarchy.Nodes.Count);
            while (degrees[parentId] >= degree)
                parentId = Rand.Next(hierarchy.Nodes.Count);

            hierarchy.Links.Add(new Link {From = parentId, To = i});
            // include the new node
            hierarchy.Nodes.Add(Cache.GetPerson(i));
            // upstate the stats
            degrees.Add(i, 0);
            degrees[parentId]++;
        }

        return hierarchy;
    }
}