Create schema specific to the version to validate

[samirromdhani]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• A PR or issue has been opened in all impacted repositories (if any)

Does this PR already have an issue describing the problem?

Fixes #2818

What kind of change does this PR introduce?

What is the current behavior?

What is the new behavior (if this is a feature change)?

Does this PR introduce a breaking change or deprecate an API?

• Yes
• No

If yes, please check if the following requirements are fulfilled

• The Breaking Change or Deprecated label has been added
• The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Other information:

• Some extension XSD files reference IIDM XSD files from other versions (xs:import + schemaLocation), which can impact schema resolution . To handle this, extractSchemaLocations and getSupportedExtensionsByIIdmVersion were added.
• To make version validation strict, we verify the root namespace first, then run XSD validation, this is handled by readRootNamespace and checkNamespace

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
80.6% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rolnico]

you can factorise this code in a small utility method used for the two properties

[rolnico]

Rename to createSchemaFactoryInstance to mirror createXMLInputFactoryInstance

[rolnico]

Add Javadoc for this method to explain its specificities.

Also, add a warning that it loads the full network file in memory.

[rolnico]

Suggested change

	String actualNs = readRootNamespace(xmlBytes);
	boolean matches = actualNs.equals(validationVersion.getNamespaceURI())
	|| validationVersion.supportEquipmentValidationLevel() && actualNs.equals(validationVersion.getNamespaceURI(false));
	if (!matches) {
	throw new PowsyblException("Namespace mismatch: expected validation version " + validationVersion.toString(".") + ", found namespace " + actualNs);
	String actualNamespace = readRootNamespace(xmlBytes);
	boolean matches = actualNamespace.equals(validationVersion.getNamespaceURI())
	|| validationVersion.supportEquipmentValidationLevel() && actualNamespace.equals(validationVersion.getNamespaceURI(false));
	if (!matches) {
	throw new PowsyblException("Namespace mismatch: expected validation version " + validationVersion.toString(".") + ", found namespace " + actualNamespace);

[rolnico]

Good idea to illustrate with a small example!
Could you do the same with the other methods (when possible and useful)?

[rolnico]

This does could be outside the try/catch as it does not throw an IOException

[rolnico]

Suggested change

	// XSD validation
	Schema schema;
	if (extensionsSupplier == DefaultExtensionsSupplier.getInstance()) {
	schema = DEFAULT_SCHEMAS_SUPPLIER.get().computeIfAbsent(version, v -> createSchema(DefaultExtensionsSupplier.getInstance(), v));
	} else {
	schema = createSchema(extensionsSupplier, version);
	}
	// XSD validation
	Schema schema = extensionsSupplier == DefaultExtensionsSupplier.getInstance() ?
	DEFAULT_SCHEMAS_SUPPLIER.get().computeIfAbsent(version, v -> createSchema(DefaultExtensionsSupplier.getInstance(), v)) :
	createSchema(extensionsSupplier, version);

[rolnico]

This method could be factorized with the existing one.
You might want to keep working on arrays instead of lists for efficiency (to be tested if possible)

[rolnico]

Is this check even necessary? There might be a better way to do this, avoiding loading the whole file in memory (which you are doing by creating the array of bytes).

For example something like this:

    public static void validate(InputStream is, IidmVersion version, ExtensionsSupplier extensionsSupplier) {
        Objects.requireNonNull(is);
        Objects.requireNonNull(version);
        Objects.requireNonNull(extensionsSupplier);

        // XSD validation
        Schema schema = extensionsSupplier == DefaultExtensionsSupplier.getInstance() ?
            DEFAULT_SCHEMAS_SUPPLIER.get().computeIfAbsent(version, v -> createSchema(DefaultExtensionsSupplier.getInstance(), v)) :
            createSchema(extensionsSupplier, version);
        try {
            XMLFilter xmlFilter = getXMLFilter(version);
            SAXSource saxSource = new SAXSource(xmlFilter, new InputSource(is));
            schema.newValidator().validate(saxSource);
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        } catch (SAXException e) {
            throw new UncheckedSaxException(e);
        } catch (ParserConfigurationException e) {
            throw new UncheckedParserConfigurationException(e);
        }
    }

    private static XMLFilter getXMLFilter(IidmVersion validationVersion) throws ParserConfigurationException, SAXException {
        XMLFilter filter = new XMLFilterImpl() {
            private boolean rootSeen = false;

            @Override
            public void startElement(String uri, String localName, String qName, Attributes atts)
                throws SAXException {
                if (!rootSeen) {
                    checkNamespace(uri, validationVersion);
                    rootSeen = true;
                }
                super.startElement(uri, localName, qName, atts);
            }
        };

        XMLReader xmlReader = SAXParserFactory.newNSInstance().newSAXParser().getXMLReader();
        filter.setParent(xmlReader);
        return filter;
    }

    private static void checkNamespace(String actualNamespace, IidmVersion validationVersion) {
        boolean matches = actualNamespace.equals(validationVersion.getNamespaceURI())
            || validationVersion.supportEquipmentValidationLevel() && actualNamespace.equals(validationVersion.getNamespaceURI(false));
        if (!matches) {
            throw new PowsyblException("Namespace mismatch: expected validation version " + validationVersion.toString(".") + ", found namespace " + actualNamespace);
        }
    }

Note: this is an example, this has to be checked/improved/validated!