public class Basic101 : Custom.DataSource.DataSource16
{
  public Basic101(MyServices services) : base(services)
  {
    ProvideOut(() => new {
      Title = "Hello from Basic101",
      TheAnswer = 42,
    });
  }
}

// 1.1 The class must have the same name as the file
// 1.2 It must inherit from Custom.DataSource.DataSource16 
public class Basic101Commented : Custom.DataSource.DataSource16
{
  // 2.1 The constructor must have the same name as the class
  // 2.2 It must also have a parameter of type MyServices
  // 2.3 It must call the base constructor with the same parameter
  // 2.4 This ensures that any internal functionality is initialized
  public Basic101Commented(MyServices services) : base(services)
  {
    // 3.1 The ProvideOut method must be called to define the output
    // 3.2 It must be called with a lambda expression (the () => part)
    // 3.3 In this example we're just returning a single object
    // 3.4 The object can be anonymous, as shown here
    ProvideOut(() => new {
      // Our object has a Title property with a hello-message
      // and another property with the answer to life, the universe and everything
      Title = "Hello from Basic101-Commented",
      TheAnswer = 42,
    });
  }
}

// This sample uses some LINQ
using System.Linq;

public class ListBasic : Custom.DataSource.DataSource16
{
  public ListBasic(MyServices services) : base(services)
  {
    ProvideOut(() =>
      // For demo, create a few of these items using numbers 1 to 5
      Enumerable.Range(1, 5).Select(i => new {
        // Property with name "Id" is automatically used for the EntityId
        Id = i,
        // Property with name "Guid" is automatically used for the EntityGuid
        Guid = System.Guid.NewGuid(),
        Title = "Hello from ListBasic",
        FavoriteNumber = 2742,
      })
    );
  }
}

using System.Net.Http;
using System.Linq;
using System.Text.Json.Serialization;   // For JsonPropertyName

public class DataFromWebService : Custom.DataSource.DataSource16
{
  public DataFromWebService(MyServices services) : base(services)
  {
    ProvideOut(() => {
      var response = new HttpClient()
        .GetAsync("https://api.open-meteo.com/v1/forecast?latitude=52.52&longitude=13.41&current_weather=true")
        .GetAwaiter()
        .GetResult();
      response.EnsureSuccessStatusCode();
      
      var responseBody = response.Content.ReadAsStringAsync()
        .GetAwaiter()
        .GetResult();
      var result = Kit.Convert.Json.To<WeatherData>(responseBody);

      return new {
        Temperature = result.Current.Temperature,
        WindSpeed = result.Current.WindSpeed,
        WindDirection = result.Current.WindDirection,
      };
    });
  }
}

// Helper classes for JSON deserialization
// Note that we're not using most of the properties, but we have them for completeness of the tutorial
public class WeatherData
{
  public double Latitude { get; set; }
  public double Longitude { get; set; }
  [JsonPropertyName("generationtime_ms")]
  public double GenerationTimeMs { get; set; }
  [JsonPropertyName("utc_offset_seconds")]
  public int UtcOffsetSeconds { get; set; }
  public string Timezone { get; set; }
  [JsonPropertyName("timezone_abbreviation")]
  public string TimezoneAbbreviation { get; set; }
  public double Elevation { get; set; }
  [JsonPropertyName("current_weather")]
  public CurrentWeather Current { get; set; }
}

public class CurrentWeather
{
  public double Temperature { get; set; }
  public double WindSpeed { get; set; }
  public double WindDirection { get; set; }
  public int WeatherCode { get; set; }
  public int Is_Day { get; set; }
  public string Time { get; set; }
}

using System.Linq;
using ToSic.Eav.DataSource; // This namespace is for the [Configuration] attribute

public class WithConfig : Custom.DataSource.DataSource16
{
  public WithConfig(MyServices services) : base(services, "My.Magic")
  {
    ProvideOut(() => {
      var result = Enumerable.Range(1, AmountOfItems).Select(i => new {
        Title = "Hello from WithConfig #" + i,
        FavoriteColor,
      });
      return result;
    });
  }

  // This attribute [Configuration] creates a configuration "FavoriteColor"
  // In this example [Configuration] already knows about the fallback.
  // * The property getter calls Configuration.GetThis()
  // * GetThis() will automatically use the property name "FavoriteColor" to look up the config
  // * Calling an empty GetThis() will always return a string,
  //   so it's ideal for string-properties where the Fallback was specified before
  [Configuration(Fallback = "magenta")]
  public string FavoriteColor { get { return Configuration.GetThis(); } }

  // This attribute [Configuration] creates configuration "AmountOfItems"
  // * The property getter calls Configuration.GetThis()
  // * GetThis() will automatically use the property name "AmountOfItems" to look up the config
  //   and will use the default value of 1 if it was not specified
  [Configuration]
  public int AmountOfItems { get { return Configuration.GetThis(1); } }
}

using System.Linq;

public class KeepOdd : Custom.DataSource.DataSource16
{
  public KeepOdd(MyServices services) : base(services)
  {
    ProvideOut(() => {
      // Make sure we have an In stream - otherwise return an error
      var inStream = TryGetIn();
      if (inStream == null) return Error.TryGetInFailed();

      // Return only odd items
      return inStream.Where(e => e.EntityId % 2 == 1);
    });
  }
}

using System.Linq;

public class KeepOdd : Custom.DataSource.DataSource16
{
  public KeepOdd(MyServices services) : base(services)
  {
    ProvideOut(() => {
      // Make sure we have an In stream - otherwise return an error
      var inStream = TryGetIn();
      if (inStream == null) return Error.TryGetInFailed();

      // Return only odd items
      return inStream.Where(e => e.EntityId % 2 == 1);
    });
  }
}

// This sample uses Enumerable.Repeat, which needs this namespace
using System.Linq;

public class ListMultiStream : Custom.DataSource.DataSource16
{
  public ListMultiStream(MyServices services) : base(services)
  {
    // First stream "Settings" containing just one item
    ProvideOut(() => new {
      Title = "Settings Entity",
      PageSize = 50,
      ShowStuff = true,
    }, name: "Settings");

    // A second stream on the normal (unnamed) "Default"
    ProvideOut(() => Enumerable.Range(1, 5).Select(i => new {
        Id = i,
        guid = System.Guid.NewGuid(),
        Title = "Hello from ListMultiStream",
        FavoriteNumber = 2742,
      })
    );
  }
}

using System.Linq;

public class SplitOddEven : Custom.DataSource.DataSource16
{
  public SplitOddEven(MyServices services) : base(services)
  {
    ProvideOut(() => TryGetIn());
    ProvideOut(() => Split().Odd, name: "Odd");
    ProvideOut(() => Split().Even, name: "Even");
  }

  private Cache Split() {
    // If already cached (eg. it's retrieving Even after Odd was already retrieved), return cache
    if (_cache != null)
      return _cache;

    // Make sure we have an In stream - otherwise return an error
    var inStream = TryGetIn();
    if (inStream == null) return new Cache { Odd = Error.TryGetInFailed(), Even = Error.TryGetInFailed() };

    // Build cache so we don't have to re-calculate when retrieving other streams
    return _cache = new Cache {
      Odd = inStream.Where(e => e.EntityId % 2 == 1),
      Even = inStream.Where(e => e.EntityId % 2 == 0)
    };
  }

  private Cache _cache;

  private class Cache {
    public object Odd;
    public object Even;
  }
}

using System.Linq;
using ToSic.Eav.DataSources;

public class Authors : Custom.DataSource.DataSource16
{
  public Authors(MyServices services) : base(services)
  {
    ProvideOut(() => {
      // Get the app data
      var appData = Kit.Data.GetAppSource();

      // Get the Content-Type Filter DataSource
      var contentTypeFilter = Kit.Data.GetSource<EntityTypeFilter>(attach: appData, parameters: new { TypeName = "Persons"});

      // Return all the items after filtering
      return contentTypeFilter.List;
    });
  }
}