Add schema bundling tools and multi-dialect publish workflow

Create tooling to bundle JSON schema fragments (from PR #226) into
single-file schemas and convert to draft-07, 2019-09, and 2020-12
dialects. The 2020-12 output enables OpenAPI 3.1 compatibility.
New files:
- standard/schema/root.json: fragment entry point
- tools/: bundle_schema, convert_dialect, patch_schema
- requirements.txt
- .github/workflows/publish-schema.yml: CI pipeline publishing
  all three dialect versions to gh-pages

Author: awarde96

.github/workflows/publish-schema.yml

@@ -0,0 +1,52 @@
+name: Publish schema
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - 'standard/schema/**'
+      - 'tools/**'
+
+jobs:
+  bundle-and-publish:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.x'
+
+    - name: Install dependencies
+      run: pip install -r requirements.txt
+
+    - name: Bundle schema fragments
+      run: python -m tools.bundle_schema --schema-dir standard/schema --root /schemas/coveragejson --out dist/bundle.json
+
+    - name: Convert to draft-07
+      run: |
+        python -m tools.convert_dialect dist/bundle.json --dialect draft-07 --out dist/draft-07/coveragejson.json
+        python -m tools.patch_schema dist/draft-07/coveragejson.json --set-id "https://schemas.opengis.net/covjson/1.0/coveragejson.json"
+
+    - name: Convert to 2019-09
+      run: |
+        python -m tools.convert_dialect dist/bundle.json --dialect 2019-09 --out dist/2019-09/coveragejson.json
+        python -m tools.patch_schema dist/2019-09/coveragejson.json --set-id "https://schemas.opengis.net/covjson/1.0/coveragejson.json"
+
+    - name: Convert to 2020-12
+      run: |
+        python -m tools.convert_dialect dist/bundle.json --dialect 2020-12 --out dist/2020-12/coveragejson.json
+        python -m tools.patch_schema dist/2020-12/coveragejson.json --set-id "https://schemas.opengis.net/covjson/1.0/coveragejson.json"
+
+    - name: Remove intermediate bundle
+      run: rm dist/bundle.json
+
+    - name: Publish to GitHub Pages
+      uses: peaceiris/actions-gh-pages@v4
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: ./dist
+        publish_branch: gh-pages

requirements.txt

@@ -0,0 +1 @@
+jsonschema

standard/schema/root.json

@@ -0,0 +1,81 @@
+{
+    "$id": "/schemas/coveragejson",
+    "description": "A CoverageJSON object",
+    "type": "object",
+    "properties": {
+        "type": {
+            "enum": [
+                "Domain",
+                "NdArray",
+                "TiledNdArray",
+                "Coverage",
+                "CoverageCollection"
+            ]
+        }
+    },
+    "required": [
+        "type"
+    ],
+    "allOf": [
+        {
+            "if": {
+                "properties": {
+                    "type": {
+                        "const": "Domain"
+                    }
+                }
+            },
+            "then": {
+                "$ref": "/schemas/domain"
+            }
+        },
+        {
+            "if": {
+                "properties": {
+                    "type": {
+                        "const": "NdArray"
+                    }
+                }
+            },
+            "then": {
+                "$ref": "/schemas/ndArray"
+            }
+        },
+        {
+            "if": {
+                "properties": {
+                    "type": {
+                        "const": "TiledNdArray"
+                    }
+                }
+            },
+            "then": {
+                "$ref": "/schemas/tiledNdArray"
+            }
+        },
+        {
+            "if": {
+                "properties": {
+                    "type": {
+                        "const": "Coverage"
+                    }
+                }
+            },
+            "then": {
+                "$ref": "/schemas/coverage"
+            }
+        },
+        {
+            "if": {
+                "properties": {
+                    "type": {
+                        "const": "CoverageCollection"
+                    }
+                }
+            },
+            "then": {
+                "$ref": "/schemas/coverageCollection"
+            }
+        }
+    ]
+}

tools/__init__.py

@@ -0,0 +1,87 @@
+# Bundles all referenced schema fragments into a single root schema.
+# Adapted from https://github.com/covjson/covjson-validator/blob/main/tools/bundle_schema.py
+#
+# Follows the method described in:
+# https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-00#section-9.3.1
+
+import argparse
+import json
+import copy
+import os
+
+
+def walk_dict(obj, match_key, fn):
+    """Recursively walk a dict and call fn(obj, key, value) for every match_key found."""
+    for key, value in list(obj.items()):
+        if key == match_key:
+            fn(obj, key, value)
+        elif isinstance(value, dict):
+            walk_dict(value, match_key, fn)
+        elif isinstance(value, list):
+            for item in value:
+                if isinstance(item, dict):
+                    walk_dict(item, match_key, fn)
+
+
+def create_schema_store(schema_dir):
+    """Load all JSON schema fragments from a directory into a dict keyed by $id."""
+    schema_store = {}
+    for entry in os.scandir(schema_dir):
+        if entry.is_file() and entry.path.endswith(".json"):
+            with open(entry.path) as f:
+                schema = json.load(f)
+            if "$id" in schema:
+                schema_store[schema["$id"]] = schema
+    return schema_store
+
+
+def bundle_schema(schema_store, root_schema_id):
+    """Bundle all referenced schemas into the root schema using $defs."""
+    root_schema = copy.deepcopy(schema_store[root_schema_id])
+
+    # Collect all referenced schema IDs recursively
+    refs = set()
+
+    def record_ref(obj, key, value):
+        if value in schema_store:
+            refs.add(value)
+
+    done = set()
+    todo = {root_schema_id}
+    while todo:
+        for schema_id in todo:
+            walk_dict(schema_store[schema_id], "$ref", record_ref)
+            done.add(schema_id)
+        todo = refs - done
+
+    # Remove self-reference if present
+    refs.discard(root_schema_id)
+
+    # Embed referenced schemas under $defs
+    if refs:
+        defs = root_schema.setdefault("$defs", {})
+        for schema_id in sorted(refs):
+            defs[schema_id] = copy.deepcopy(schema_store[schema_id])
+
+    return root_schema
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Bundle CoverageJSON schema fragments into a single file")
+    parser.add_argument("--schema-dir", default="standard/schema",
+                        help="Directory containing schema fragment JSON files")
+    parser.add_argument("--root", default="/schemas/coveragejson",
+                        help="$id of the root schema fragment")
+    parser.add_argument("--out", default="dist/coveragejson.json",
+                        help="Output file path")
+    args = parser.parse_args()
+
+    store = create_schema_store(args.schema_dir)
+    schema = bundle_schema(store, args.root)
+
+    os.makedirs(os.path.dirname(args.out), exist_ok=True)
+    with open(args.out, "w") as f:
+        json.dump(schema, f, indent=2)
+        f.write("\n")
+
+    print(f"Bundled schema written to {args.out}")