Improve Tilejson typings to include properties used in Carto platform (…

…#37)

src/sources/index.ts

@@ -4,6 +4,11 @@
 
 export {SOURCE_DEFAULTS} from './base-source';
 export type {
+  VectorLayer,
+  RasterMetadataBandStats,
+  RasterBandColorinterp,
+  RasterMetadataBand,
+  RasterMetadata,
   TilejsonResult,
   GeojsonResult,
   JsonResult,

src/sources/types.ts

@@ -191,16 +191,51 @@ export interface Tilejson {
   attribution: string;
   scheme: string;
   tiles: string[];
-  properties_tiles: string[];
-  minresolution: number;
-  maxresolution: number;
   minzoom: number;
   maxzoom: number;
-  bounds: [number, number, number, number];
-  center: [number, number, number];
+  bounds: [left: number, bottom: number, right: number, top: number];
+  center: [longitute: number, latitude: number, zoom: number];
   vector_layers: VectorLayer[];
+
+  //
+  // Carto additions over standard Tilejson properties
+  //
+
+  minresolution: number;
+  maxresolution: number;
+  properties_tiles: string[];
   tilestats: Tilestats;
   tileResolution?: TileResolution;
+
+  /**
+   * Resolution of data in spatial-index dataset (e.g. H3, Quadbin).
+   *
+   * @internal
+   */
+  dataresolution?: number;
+
+  /**
+   * Array of ratios of dropped features per zoom level.
+   *
+   * Example: `[0,0,0.5]` - means that 50% of features are dropped at zoom 2 and bigger.
+   *
+   * @internal
+   */
+  fraction_dropped_per_zoom?: number[];
+
+  /**
+   * Names of bands - rasters only.
+   *
+   * @internal
+   */
+  raster_bands?: string[];
+
+  /**
+   * Raster metadata - rasters only.
+   *
+   * @internal
+   */
+  raster_metadata?: RasterMetadata;
 }
 
 export interface Tilestats {
@@ -221,12 +256,116 @@ export interface Attribute {
 }
 
 export interface VectorLayer {
+  // tilejson standard
   id: string;
   minzoom: number;
   maxzoom: number;
   fields: Record<string, string>;
+
+  // Carto additions over standard Tilejson properties
+  geometry_type?: string;
 }
 
+export type RasterMetadataBandStats = {
+  approximated_stats?: boolean;
+  min: number;
+  max: number;
+  mean: number;
+  stddev: number;
+  sum: number;
+  sum_squares: number;
+  count: number;
+
+  /**
+   * Quantiles by number of buckets.
+   *
+   * Example:
+   * ```ts
+   *   {
+   *     // for 3 buckets, first 1/3 of items lies in range [min, 20], second 1/3 is in [20, 40], and last 1/3 is in [40, max]
+   *     3: [20, 40],
+   *     4: [20, 30, 50], for 4 buckets ...
+   *   }
+   * ```
+   */
+  quantiles?: Record<number, number[]>;
+
+  /**
+   * Top values by number of values.
+   *
+   * Key of dictionary is value, value is count.
+   * Key order is random.
+   *
+   * Example:
+   * ```
+   *  {
+   *    3: 5, // means there are 5 pixels with value 3
+   *    11: 222,
+   *    12: 333, // means that 12 is most common value with count 333
+   *    ...      // (assuming 333 was largest value in dict)
+   *   }
+   * ```
+   */
+  top_values?: Record<number, number>;
+
+  /**
+   * Raster loader version.
+   */
+  version?: string;
+};
+
+export enum RasterBandColorinterp {
+  Gray = 'gray',
+  Red = 'red',
+  Green = 'green',
+  Blue = 'blue',
+  Alpha = 'alpha',
+  Palette = 'palette',
+}
+
+export type RasterMetadataBand = {
+  type: string;
+  name: string;
+  stats: RasterMetadataBandStats;
+  /**
+   * Known values:
+   *  * `palette`: use unique value and `colortable` ad default mapping
+   *  * `red`, `green`, `blue`: use the band as color channel
+   *  * `gray`: use the band as grayscale
+   */
+  colorinterp?: string | RasterBandColorinterp; // use RasterBandColorinterp, but it's external value, so let's use string
+
+  /**
+   * Default color mapping for unique values (or if coloprinterp is `palette`)
+   */
+  colortable?: Record<string, number[]>;
+
+  /**
+   * No value representation.
+   * Observed values:
+   *   * `'nan'` for `NaN`
+   *   * `number`: both as string as number, so parsing is needed
+   */
+  nodata: string | number; // 255, '0', 'nan'
+};
+
+export type RasterMetadata = {
+  block_resolution: number;
+  minresolution: number;
+  maxresolution: number;
+  nodata: number | string;
+  bands: RasterMetadataBand[];
+  bounds: [left: number, bottom: number, right: number, top: number];
+  center: [longitute: number, latitude: number, zoom: number];
+  width: number;
+  height: number;
+  block_width: number;
+  block_height: number;
+  num_blocks: number;
+  num_pixels: number;
+  pixel_resolution: number;
+};
+
 export type TilejsonResult = Tilejson & {accessToken: string};
 export type GeojsonResult = {type: 'FeatureCollection'; features: Feature[]};
 export type JsonResult = any[];