/// <summary>
/// Generate a collection corresponding to the items' dictionary. Spatial and temporal extents
/// are computed. Fields values are summarized in stats object and value sets.
/// All Items are updated with the collection id
/// </summary>
/// <param name="id">Identifier of the collection</param>
/// <param name="description">Description of the collection</param>
/// <param name="items">Dictionary of Uri, StacItem. Uri points to the StacItem destination.</param>
/// <param name="license">License of the collection</param>
/// <param name="collectionUri">Uri of the collection. If provided, the items Uri and made relative to this one.</param>
/// <param name="assets">Assets of the collection</param>
/// <returns></returns>
public static StacCollection Create(string id,
string description,
IDictionary <Uri, StacItem> items,
string license = null,
Uri collectionUri = null,
IDictionary <string, StacAsset> assets = null)
{
var collection = new StacCollection(
id,
description,
StacExtent.Create(items.Values),
assets,
items.Select(item =>
{
Uri itemUri = item.Key;
if (collectionUri != null)
{
itemUri = collectionUri.MakeRelativeUri(item.Key);
}
if (!itemUri.IsAbsoluteUri)
{
itemUri = new Uri("./" + itemUri.OriginalString, UriKind.Relative);
}
return(StacLink.CreateObjectLink(item.Value, itemUri));
}),
license);
var usedExtensions = items.SelectMany(item => item.Value.GetDeclaredExtensions());
var summaryFunctions = usedExtensions.SelectMany(ext => ext.GetSummaryFunctions())
.GroupBy(prop => prop.Key)
.ToDictionary(key => key.Key, value => value.First().Value);
summaryFunctions.Add("gsd", new SummaryFunction <double>(null, "gsd", StacPropertiesContainerExtension.CreateRangeSummaryObject <double>));
summaryFunctions.Add("platform", new SummaryFunction <string>(null, "platform", StacPropertiesContainerExtension.CreateSummaryValueSet <string>));
summaryFunctions.Add("constellation", new SummaryFunction <string>(null, "constellation", StacPropertiesContainerExtension.CreateSummaryValueSet <string>));
summaryFunctions.Add("instruments", new SummaryFunction <string>(null, "instruments", StacPropertiesContainerExtension.CreateSummaryValueSet <string>));
collection.Summaries =
items.Values.SelectMany(item => item.Properties.Where(k => summaryFunctions.Keys.Contains(k.Key)))
.GroupBy(prop => prop.Key)
.ToDictionary(key => key.Key, value =>
{
if (summaryFunctions.ContainsKey(value.Key))
{
if (summaryFunctions[value.Key].Extension != null && !collection.StacExtensions.Contains(summaryFunctions[value.Key].Extension.Identifier))
{
collection.StacExtensions.Add(summaryFunctions[value.Key].Extension.Identifier);
}
return(summaryFunctions[value.Key].Summarize(value.Select(i => i.Value)));
}
return(null);
});
return(collection);
}
public ItemCollection(string id,
string description,
List <StacItem> stacItems) : base(id,
description,
null)
{
if (stacItems != null)
{
Features = new List <StacItem>(stacItems);
Extent = StacExtent.Create(stacItems);
}
}