From 5c67bf774d14294b9ee8f2700be0dea5d90f43f8 Mon Sep 17 00:00:00 2001
From: Matthias Mohr <m.mohr@uni-muenster.de>
Date: Tue, 11 Apr 2023 19:28:20 +0200
Subject: [PATCH] Draft for equi7 support #301

---
 docs/geotiff.md                    |  2 +-
 src/components/maps/projManager.js | 36 ++++++++++++++++++++++++------
 src/formats/geotiff.js             | 10 ++++++++-
 3 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/docs/geotiff.md b/docs/geotiff.md
index 625abb82c..26ce28050 100644
--- a/docs/geotiff.md
+++ b/docs/geotiff.md
@@ -19,7 +19,7 @@ What is required by back-ends to give users an ideal experience with GeoTiff ima
     1. The no-data value either in `file:nodata` (deprecated) or in `nodata` in `raster:bands`
 	2. The `minimum` and `maximum` values per band in the `statistics` object in `raster:bands`
 	3. A band `name` either in `raster:bands` (unspecified) or `eo:bands`
-	4. The projection in `proj:epsg` (recommended), `proj:wkt2` (not well suported by OpenLayers) or `proj:proj4` (deprecated by STAC)
+	4. The projection in `proj:epsg` (recommended), `proj:wkt2` (not suported by OpenLayers), or `equi7:proj` (proprietary).
 	5. The `type` must be set to the corresponding media type (see below)
 8. For synchronous execution, the `Content-Type` in the header of the response must be set to the corresponding media type (see below)
 
diff --git a/src/components/maps/projManager.js b/src/components/maps/projManager.js
index 684fc3dc6..38a47d59d 100644
--- a/src/components/maps/projManager.js
+++ b/src/components/maps/projManager.js
@@ -34,14 +34,36 @@ export default class ProjManager {
 		}
 	}
 
-	// Get projection details from STAC (todo: add collection support)
-	static async addFromStac(stac) {
-		if (Utils.isObject(stac) && Utils.isObject(stac.properties)) {
-			if (stac.properties['proj:epsg']) {
-				return await ProjManager.get(stac.properties['proj:epsg']);
+	static async addFromStacItem(stac) {
+		if (Utils.isObject(stac)) {
+			return await this.addFromStacObject(stac.properties, stac.id);
+		}
+		return null;
+	}
+	static async addFromStacCollection(stac) {
+		if (Utils.isObject(stac)) {
+			// Todo: Handle arrays in summaries...
+			// return await this.addFromStacObject(stac.summaries, stac.id);
+		}
+		return null;
+	}
+
+	// Get projection details from STAC Asset
+	static async addFromStacAsset(asset) {
+		return await this.addFromStacObject(asset, asset.href);
+	}
+
+	// Get projection details from STAC Asset
+	static async addFromStacObject(obj, id) {
+		if (Utils.isObject(obj)) {
+			if (obj['proj:epsg']) {
+				return await ProjManager.get(obj['proj:epsg']);
+			}
+			else if (obj['equi7:proj']) {
+				return ProjManager.add(id, obj['equi7:proj']);
 			}
-			else if (stac.properties['proj:wkt2']) {
-				return ProjManager.add(stac.id, stac.properties['proj:wkt2']);
+			else if (obj['proj:wkt2']) {
+				return ProjManager.add(id, obj['proj:wkt2']);
 			}
 		}
 		return null;
diff --git a/src/formats/geotiff.js b/src/formats/geotiff.js
index 4602252c4..a9636c89e 100644
--- a/src/formats/geotiff.js
+++ b/src/formats/geotiff.js
@@ -49,7 +49,15 @@ class GeoTIFF extends SupportedFormat {
 		let stacHasExtent = this.stac && (this.stac.geometry || this.stac.extent);
 
 		// Get projection from STAC
-		this.projection = await ProjManager.addFromStac(this.stac);
+		if (this.stac.type === 'Feature') {
+			this.projection = await ProjManager.addFromStacItem(this.stac);
+		}
+		else if (this.stac.type === 'Collection') {
+			this.projection = await ProjManager.addFromStacCollection(this.stac);
+		}
+		else {
+			this.projection = await ProjManager.addFromStacAsset(this.stac);
+		}
 
 		// Get nodata from STAC file:nodata
 		if (Array.isArray(this['file:nodata']) && this['file:nodata'].length > 0) {