oxirs-gql 0.2.4

//! GraphQL schema generation from RDF ontologies

use crate::rdf_scalars::RdfScalars;
use crate::types::*;
use anyhow::{anyhow, Result};
use oxirs_core::format::{RdfFormat, RdfParser};
use std::collections::{HashMap, HashSet};
use std::fmt::Write;

/// RDF vocabulary information extracted from an ontology
#[derive(Debug, Clone)]
pub struct RdfVocabulary {
    pub classes: HashMap<String, RdfClass>,
    pub properties: HashMap<String, RdfProperty>,
    pub namespaces: HashMap<String, String>,
}

/// RDF class information
#[derive(Debug, Clone)]
pub struct RdfClass {
    pub uri: String,
    pub label: Option<String>,
    pub comment: Option<String>,
    pub super_classes: Vec<String>,
    pub properties: Vec<String>,
}

/// RDF property information
#[derive(Debug, Clone)]
pub struct RdfProperty {
    pub uri: String,
    pub label: Option<String>,
    pub comment: Option<String>,
    pub domain: Vec<String>,
    pub range: Vec<String>,
    pub property_type: PropertyType,
    pub functional: bool,
    pub inverse_functional: bool,
}

/// Type of RDF property
#[derive(Debug, Clone, PartialEq)]
pub enum PropertyType {
    DataProperty,
    ObjectProperty,
    AnnotationProperty,
}

/// Configuration for schema generation
#[derive(Debug, Clone)]
pub struct SchemaGenerationConfig {
    pub include_deprecated: bool,
    pub max_depth: usize,
    pub custom_scalars: HashMap<String, String>,
    pub type_mappings: HashMap<String, String>,
    pub exclude_classes: HashSet<String>,
    pub exclude_properties: HashSet<String>,
    pub enable_introspection: bool,
    pub enable_mutations: bool,
    pub enable_subscriptions: bool,
}

impl Default for SchemaGenerationConfig {
    fn default() -> Self {
        Self {
            include_deprecated: false,
            max_depth: 10,
            custom_scalars: HashMap::new(),
            type_mappings: Self::default_type_mappings(),
            exclude_classes: HashSet::new(),
            exclude_properties: HashSet::new(),
            enable_introspection: true,
            enable_mutations: false,
            enable_subscriptions: false,
        }
    }
}

impl SchemaGenerationConfig {
    fn default_type_mappings() -> HashMap<String, String> {
        let mut mappings = HashMap::new();

        // XSD mappings
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#string".to_string(),
            "String".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#int".to_string(),
            "Int".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#integer".to_string(),
            "Int".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#long".to_string(),
            "Int".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#float".to_string(),
            "Float".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#double".to_string(),
            "Float".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#decimal".to_string(),
            "Float".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#boolean".to_string(),
            "Boolean".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#dateTime".to_string(),
            "DateTime".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#date".to_string(),
            "DateTime".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#time".to_string(),
            "DateTime".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#duration".to_string(),
            "Duration".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2001/XMLSchema#anyURI".to_string(),
            "IRI".to_string(),
        );

        // RDF mappings
        mappings.insert(
            "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString".to_string(),
            "LangString".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/2000/01/rdf-schema#Literal".to_string(),
            "Literal".to_string(),
        );
        mappings.insert(
            "http://www.w3.org/1999/02/22-rdf-syntax-ns#PlainLiteral".to_string(),
            "String".to_string(),
        );

        // RDFS mappings
        mappings.insert(
            "http://www.w3.org/2000/01/rdf-schema#Resource".to_string(),
            "IRI".to_string(),
        );

        mappings
    }
}

/// Schema generator that converts RDF ontologies to GraphQL schemas
pub struct SchemaGenerator {
    config: SchemaGenerationConfig,
    vocabulary: Option<RdfVocabulary>,
}

impl SchemaGenerator {
    pub fn new() -> Self {
        Self {
            config: SchemaGenerationConfig::default(),
            vocabulary: None,
        }
    }

    pub fn with_config(mut self, config: SchemaGenerationConfig) -> Self {
        self.config = config;
        self
    }

    /// Set the RDF vocabulary to generate schema from
    pub fn with_vocabulary(mut self, vocabulary: RdfVocabulary) -> Self {
        self.vocabulary = Some(vocabulary);
        self
    }

    /// Generate GraphQL schema from loaded RDF vocabulary
    pub fn generate_schema(&self) -> Result<Schema> {
        let vocabulary = self
            .vocabulary
            .as_ref()
            .ok_or_else(|| anyhow!("No vocabulary loaded"))?;

        let mut schema = Schema::new();

        // Add RDF-specific scalar types
        schema.add_type(GraphQLType::Scalar(RdfScalars::iri()));
        schema.add_type(GraphQLType::Scalar(RdfScalars::literal()));
        schema.add_type(GraphQLType::Scalar(RdfScalars::datetime()));
        schema.add_type(GraphQLType::Scalar(RdfScalars::duration()));
        schema.add_type(GraphQLType::Scalar(RdfScalars::geolocation()));
        schema.add_type(GraphQLType::Scalar(RdfScalars::lang_string()));

        // Generate object types from RDF classes
        for (class_uri, rdf_class) in &vocabulary.classes {
            if self.config.exclude_classes.contains(class_uri) {
                continue;
            }

            let object_type = self.generate_object_type_from_class(rdf_class, vocabulary)?;
            schema.add_type(GraphQLType::Object(object_type));
        }

        // Generate Query type
        let query_type = self.generate_query_type(vocabulary)?;
        schema.add_type(GraphQLType::Object(query_type));
        schema.set_query_type("Query".to_string());

        // Generate Mutation type if enabled
        if self.config.enable_mutations {
            let mutation_type = self.generate_mutation_type(vocabulary)?;
            schema.add_type(GraphQLType::Object(mutation_type));
            schema.set_mutation_type("Mutation".to_string());
        }

        // Generate Subscription type if enabled
        if self.config.enable_subscriptions {
            let subscription_type = self.generate_subscription_type(vocabulary)?;
            schema.add_type(GraphQLType::Object(subscription_type));
            schema.set_subscription_type("Subscription".to_string());
        }

        Ok(schema)
    }

    /// Generate GraphQL schema SDL from RDF ontology
    pub async fn generate_from_ontology(&self, ontology_uri: &str) -> Result<String> {
        // Load and parse real RDF ontology from URI
        let vocabulary = self.load_ontology_from_uri(ontology_uri).await?;

        let schema_with_vocab = Self::new()
            .with_config(self.config.clone())
            .with_vocabulary(vocabulary);

        let schema = schema_with_vocab.generate_schema()?;
        Ok(self.schema_to_sdl(&schema))
    }

    /// Generate GraphQL schema from RDF store containing ontology data
    pub fn generate_from_store(&self, store: &crate::RdfStore) -> Result<String> {
        let vocabulary = self.extract_vocabulary_from_store(store)?;

        let schema_with_vocab = Self::new()
            .with_config(self.config.clone())
            .with_vocabulary(vocabulary);

        let schema = schema_with_vocab.generate_schema()?;
        Ok(self.schema_to_sdl(&schema))
    }

    /// Extract RDF vocabulary from a store using SPARQL queries
    pub fn extract_vocabulary_from_store(&self, store: &crate::RdfStore) -> Result<RdfVocabulary> {
        let mut classes = HashMap::new();
        let mut properties = HashMap::new();
        let mut namespaces = HashMap::new();

        // Extract namespaces
        namespaces.insert(
            "rdf".to_string(),
            "http://www.w3.org/1999/02/22-rdf-syntax-ns#".to_string(),
        );
        namespaces.insert(
            "rdfs".to_string(),
            "http://www.w3.org/2000/01/rdf-schema#".to_string(),
        );
        namespaces.insert(
            "owl".to_string(),
            "http://www.w3.org/2002/07/owl#".to_string(),
        );

        // Extract classes using SPARQL
        let class_query = r#"
            PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
            PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
            PREFIX owl: <http://www.w3.org/2002/07/owl#>
            
            SELECT DISTINCT ?class ?label ?comment ?superClass
            WHERE {
                {
                    ?class a rdfs:Class .
                } UNION {
                    ?class a owl:Class .
                }
                OPTIONAL { ?class rdfs:label ?label }
                OPTIONAL { ?class rdfs:comment ?comment }
                OPTIONAL { ?class rdfs:subClassOf ?superClass }
                FILTER(!isBlank(?class))
            }
        "#;

        if let Ok(results) = store.query(class_query) {
            self.process_class_results(results, &mut classes)?;
        }

        // Extract properties using SPARQL
        let property_query = r#"
            PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
            PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
            PREFIX owl: <http://www.w3.org/2002/07/owl#>
            
            SELECT DISTINCT ?property ?label ?comment ?domain ?range ?type
            WHERE {
                {
                    ?property a rdf:Property .
                    BIND("AnnotationProperty" as ?type)
                } UNION {
                    ?property a rdfs:Property .
                    BIND("DataProperty" as ?type)
                } UNION {
                    ?property a owl:DatatypeProperty .
                    BIND("DataProperty" as ?type)
                } UNION {
                    ?property a owl:ObjectProperty .
                    BIND("ObjectProperty" as ?type)
                } UNION {
                    ?property a owl:AnnotationProperty .
                    BIND("AnnotationProperty" as ?type)
                }
                OPTIONAL { ?property rdfs:label ?label }
                OPTIONAL { ?property rdfs:comment ?comment }
                OPTIONAL { ?property rdfs:domain ?domain }
                OPTIONAL { ?property rdfs:range ?range }
                FILTER(!isBlank(?property))
            }
        "#;

        if let Ok(results) = store.query(property_query) {
            self.process_property_results(results, &mut properties)?;
        }

        // Link properties to classes
        self.link_properties_to_classes(&mut classes, &properties);

        Ok(RdfVocabulary {
            classes,
            properties,
            namespaces,
        })
    }

    fn process_class_results(
        &self,
        results: oxirs_core::query::QueryResults,
        classes: &mut HashMap<String, RdfClass>,
    ) -> Result<()> {
        use oxirs_core::query::QueryResults;

        if let QueryResults::Solutions(solutions) = results {
            for solution in solutions {
                if let Some(class_term) = solution.get(
                    &oxirs_core::model::Variable::new("class")
                        .expect("hardcoded variable name should be valid"),
                ) {
                    let class_uri = class_term.to_string();

                    let label = solution
                        .get(
                            &oxirs_core::model::Variable::new("label")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .and_then(|t| self.extract_literal_value(&t.to_string()));

                    let comment = solution
                        .get(
                            &oxirs_core::model::Variable::new("comment")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .and_then(|t| self.extract_literal_value(&t.to_string()));

                    let super_class = solution
                        .get(
                            &oxirs_core::model::Variable::new("superClass")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .map(|t| t.to_string());

                    // Get or create class entry
                    let rdf_class = classes
                        .entry(class_uri.clone())
                        .or_insert_with(|| RdfClass {
                            uri: class_uri.clone(),
                            label: None,
                            comment: None,
                            super_classes: Vec::new(),
                            properties: Vec::new(),
                        });

                    // Update class information
                    if label.is_some() {
                        rdf_class.label = label;
                    }
                    if comment.is_some() {
                        rdf_class.comment = comment;
                    }
                    if let Some(sc) = super_class {
                        if !rdf_class.super_classes.contains(&sc) {
                            rdf_class.super_classes.push(sc);
                        }
                    }
                }
            }
        }

        Ok(())
    }

    fn process_property_results(
        &self,
        results: oxirs_core::query::QueryResults,
        properties: &mut HashMap<String, RdfProperty>,
    ) -> Result<()> {
        use oxirs_core::query::QueryResults;

        if let QueryResults::Solutions(solutions) = results {
            for solution in solutions {
                if let Some(property_term) = solution.get(
                    &oxirs_core::model::Variable::new("property")
                        .expect("hardcoded variable name should be valid"),
                ) {
                    let property_uri = property_term.to_string();

                    let label = solution
                        .get(
                            &oxirs_core::model::Variable::new("label")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .and_then(|t| self.extract_literal_value(&t.to_string()));

                    let comment = solution
                        .get(
                            &oxirs_core::model::Variable::new("comment")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .and_then(|t| self.extract_literal_value(&t.to_string()));

                    let domain = solution
                        .get(
                            &oxirs_core::model::Variable::new("domain")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .map(|t| t.to_string());

                    let range = solution
                        .get(
                            &oxirs_core::model::Variable::new("range")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .map(|t| t.to_string());

                    let property_type = solution
                        .get(
                            &oxirs_core::model::Variable::new("type")
                                .expect("hardcoded variable name should be valid"),
                        )
                        .map(|t| t.to_string())
                        .and_then(|s| self.extract_literal_value(&s))
                        .unwrap_or_else(|| "AnnotationProperty".to_string());

                    let prop_type = match property_type.as_str() {
                        "DataProperty" => PropertyType::DataProperty,
                        "ObjectProperty" => PropertyType::ObjectProperty,
                        _ => PropertyType::AnnotationProperty,
                    };

                    // Get or create property entry
                    let rdf_property =
                        properties
                            .entry(property_uri.clone())
                            .or_insert_with(|| RdfProperty {
                                uri: property_uri.clone(),
                                label: None,
                                comment: None,
                                domain: Vec::new(),
                                range: Vec::new(),
                                property_type: prop_type,
                                functional: false,
                                inverse_functional: false,
                            });

                    // Update property information
                    if label.is_some() {
                        rdf_property.label = label;
                    }
                    if comment.is_some() {
                        rdf_property.comment = comment;
                    }
                    if let Some(d) = domain {
                        if !rdf_property.domain.contains(&d) {
                            rdf_property.domain.push(d);
                        }
                    }
                    if let Some(r) = range {
                        if !rdf_property.range.contains(&r) {
                            rdf_property.range.push(r);
                        }
                    }
                }
            }
        }

        Ok(())
    }

    fn extract_literal_value(&self, term_str: &str) -> Option<String> {
        // Extract literal value from RDF term string format
        if let Some(stripped) = term_str.strip_prefix('"') {
            if let Some(end_quote) = stripped.find('"') {
                return Some(stripped[..end_quote].to_string());
            }
        }
        None
    }

    fn link_properties_to_classes(
        &self,
        classes: &mut HashMap<String, RdfClass>,
        properties: &HashMap<String, RdfProperty>,
    ) {
        for (property_uri, property) in properties {
            for domain_class in &property.domain {
                if let Some(class) = classes.get_mut(domain_class) {
                    if !class.properties.contains(property_uri) {
                        class.properties.push(property_uri.clone());
                    }
                }
            }
        }
    }

    fn generate_object_type_from_class(
        &self,
        rdf_class: &RdfClass,
        vocabulary: &RdfVocabulary,
    ) -> Result<ObjectType> {
        let type_name = self.uri_to_graphql_name(&rdf_class.uri);
        let mut object_type = ObjectType::new(type_name);

        if let Some(ref comment) = rdf_class.comment {
            object_type = object_type.with_description(comment.clone());
        }

        // Add ID field
        object_type = object_type.with_field(
            "id".to_string(),
            FieldType::new(
                "id".to_string(),
                GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::id()))),
            )
            .with_description("The unique identifier of this resource".to_string()),
        );

        // Add URI field
        object_type = object_type.with_field(
            "uri".to_string(),
            FieldType::new(
                "uri".to_string(),
                GraphQLType::NonNull(Box::new(GraphQLType::Scalar(RdfScalars::iri()))),
            )
            .with_description("The IRI of this resource".to_string()),
        );

        // Add fields from properties
        for property_uri in &rdf_class.properties {
            if self.config.exclude_properties.contains(property_uri) {
                continue;
            }

            if let Some(property) = vocabulary.properties.get(property_uri) {
                let field = self.generate_field_from_property(property, vocabulary)?;
                let field_name = self.uri_to_graphql_name(&property.uri);
                object_type = object_type.with_field(field_name, field);
            }
        }

        Ok(object_type)
    }

    fn generate_field_from_property(
        &self,
        property: &RdfProperty,
        vocabulary: &RdfVocabulary,
    ) -> Result<FieldType> {
        let field_name = self.uri_to_graphql_name(&property.uri);

        let field_type = match property.property_type {
            PropertyType::DataProperty => self.generate_scalar_type_from_range(&property.range)?,
            PropertyType::ObjectProperty => {
                self.generate_object_type_from_range(&property.range, vocabulary)?
            }
            PropertyType::AnnotationProperty => GraphQLType::Scalar(BuiltinScalars::string()),
        };

        // Make non-functional properties lists
        let final_type = if property.functional {
            field_type
        } else {
            GraphQLType::List(Box::new(field_type))
        };

        let mut field = FieldType::new(field_name, final_type);

        if let Some(ref comment) = property.comment {
            field = field.with_description(comment.clone());
        }

        // Add filter arguments for object properties
        if matches!(property.property_type, PropertyType::ObjectProperty) {
            field = field.with_argument(
                "where".to_string(),
                ArgumentType::new(
                    "where".to_string(),
                    GraphQLType::Scalar(BuiltinScalars::string()),
                )
                .with_description("SPARQL filter condition".to_string()),
            );

            field = field.with_argument(
                "limit".to_string(),
                ArgumentType::new(
                    "limit".to_string(),
                    GraphQLType::Scalar(BuiltinScalars::int()),
                )
                .with_default_value(crate::ast::Value::IntValue(10))
                .with_description("Maximum number of results".to_string()),
            );

            field = field.with_argument(
                "offset".to_string(),
                ArgumentType::new(
                    "offset".to_string(),
                    GraphQLType::Scalar(BuiltinScalars::int()),
                )
                .with_default_value(crate::ast::Value::IntValue(0))
                .with_description("Number of results to skip".to_string()),
            );
        }

        Ok(field)
    }

    fn generate_scalar_type_from_range(&self, range: &[String]) -> Result<GraphQLType> {
        if range.is_empty() {
            return Ok(GraphQLType::Scalar(BuiltinScalars::string()));
        }

        for range_uri in range {
            if let Some(mapped_type) = self.config.type_mappings.get(range_uri) {
                return match mapped_type.as_str() {
                    "String" => Ok(GraphQLType::Scalar(BuiltinScalars::string())),
                    "Int" => Ok(GraphQLType::Scalar(BuiltinScalars::int())),
                    "Float" => Ok(GraphQLType::Scalar(BuiltinScalars::float())),
                    "Boolean" => Ok(GraphQLType::Scalar(BuiltinScalars::boolean())),
                    "ID" => Ok(GraphQLType::Scalar(BuiltinScalars::id())),
                    "IRI" => Ok(GraphQLType::Scalar(RdfScalars::iri())),
                    "Literal" => Ok(GraphQLType::Scalar(RdfScalars::literal())),
                    "DateTime" => Ok(GraphQLType::Scalar(RdfScalars::datetime())),
                    "Duration" => Ok(GraphQLType::Scalar(RdfScalars::duration())),
                    "GeoLocation" => Ok(GraphQLType::Scalar(RdfScalars::geolocation())),
                    "LangString" => Ok(GraphQLType::Scalar(RdfScalars::lang_string())),
                    _ => Ok(GraphQLType::Scalar(BuiltinScalars::string())),
                };
            }
        }

        // Default to Literal for unknown ranges
        Ok(GraphQLType::Scalar(RdfScalars::literal()))
    }

    fn generate_object_type_from_range(
        &self,
        range: &[String],
        vocabulary: &RdfVocabulary,
    ) -> Result<GraphQLType> {
        if range.is_empty() {
            return Ok(GraphQLType::Scalar(RdfScalars::iri()));
        }

        // For now, return the first valid class in range
        for range_uri in range {
            if vocabulary.classes.contains_key(range_uri) {
                let type_name = self.uri_to_graphql_name(range_uri);
                // We assume the type will be generated elsewhere
                return Ok(GraphQLType::Object(ObjectType::new(type_name)));
            }
        }

        // Default to IRI if no class found
        Ok(GraphQLType::Scalar(RdfScalars::iri()))
    }

    fn generate_query_type(&self, vocabulary: &RdfVocabulary) -> Result<ObjectType> {
        let mut query_type = ObjectType::new("Query".to_string())
            .with_description("The root query type for accessing RDF data".to_string());

        // Add root field for each class
        for (class_uri, rdf_class) in &vocabulary.classes {
            if self.config.exclude_classes.contains(class_uri) {
                continue;
            }

            let type_name = self.uri_to_graphql_name(&rdf_class.uri);
            let field_name = self.pluralize(&self.to_camel_case(&type_name));

            // Collection query
            query_type = query_type.with_field(
                field_name.clone(),
                FieldType::new(
                    field_name.clone(),
                    GraphQLType::List(Box::new(GraphQLType::Object(ObjectType::new(
                        type_name.clone(),
                    )))),
                )
                .with_description(format!("Query all instances of {type_name}"))
                .with_argument(
                    "where".to_string(),
                    ArgumentType::new(
                        "where".to_string(),
                        GraphQLType::Scalar(BuiltinScalars::string()),
                    )
                    .with_description("SPARQL filter condition".to_string()),
                )
                .with_argument(
                    "limit".to_string(),
                    ArgumentType::new(
                        "limit".to_string(),
                        GraphQLType::Scalar(BuiltinScalars::int()),
                    )
                    .with_default_value(crate::ast::Value::IntValue(10))
                    .with_description("Maximum number of results".to_string()),
                )
                .with_argument(
                    "offset".to_string(),
                    ArgumentType::new(
                        "offset".to_string(),
                        GraphQLType::Scalar(BuiltinScalars::int()),
                    )
                    .with_default_value(crate::ast::Value::IntValue(0))
                    .with_description("Number of results to skip".to_string()),
                ),
            );

            // Single item query
            let singular_field = self.to_camel_case(&type_name);
            query_type = query_type.with_field(
                singular_field.clone(),
                FieldType::new(
                    singular_field.clone(),
                    GraphQLType::Object(ObjectType::new(type_name.clone())),
                )
                .with_description(format!("Query a single {type_name} by ID"))
                .with_argument(
                    "id".to_string(),
                    ArgumentType::new(
                        "id".to_string(),
                        GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::id()))),
                    )
                    .with_description("The ID of the resource".to_string()),
                ),
            );
        }

        // Add SPARQL query field
        query_type = query_type.with_field(
            "sparql".to_string(),
            FieldType::new(
                "sparql".to_string(),
                GraphQLType::Scalar(BuiltinScalars::string()),
            )
            .with_description("Execute a raw SPARQL query".to_string())
            .with_argument(
                "query".to_string(),
                ArgumentType::new(
                    "query".to_string(),
                    GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::string()))),
                )
                .with_description("The SPARQL query to execute".to_string()),
            ),
        );

        Ok(query_type)
    }

    fn generate_mutation_type(&self, vocabulary: &RdfVocabulary) -> Result<ObjectType> {
        let mut mutation_type = ObjectType::new("Mutation".to_string())
            .with_description("The root mutation type for modifying RDF data".to_string());

        // Add CRUD operations for each class
        for (class_uri, rdf_class) in &vocabulary.classes {
            if self.config.exclude_classes.contains(class_uri) {
                continue;
            }

            let type_name = self.uri_to_graphql_name(&rdf_class.uri);
            let input_type_name = format!("{type_name}Input");
            let update_input_type_name = format!("{type_name}UpdateInput");

            // Create mutation for adding new instances
            mutation_type = mutation_type.with_field(
                format!("create{type_name}"),
                FieldType::new(
                    format!("create{type_name}"),
                    GraphQLType::Object(ObjectType::new(type_name.clone())),
                )
                .with_description(format!("Create a new {type_name}"))
                .with_argument(
                    "input".to_string(),
                    ArgumentType::new(
                        "input".to_string(),
                        GraphQLType::NonNull(Box::new(GraphQLType::InputObject(
                            InputObjectType::new(input_type_name.clone()),
                        ))),
                    )
                    .with_description(format!("Input data for creating a new {type_name}")),
                ),
            );

            // Update mutation
            mutation_type = mutation_type.with_field(
                format!("update{type_name}"),
                FieldType::new(
                    format!("update{type_name}"),
                    GraphQLType::Object(ObjectType::new(type_name.clone())),
                )
                .with_description(format!("Update an existing {type_name}"))
                .with_argument(
                    "id".to_string(),
                    ArgumentType::new(
                        "id".to_string(),
                        GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::id()))),
                    )
                    .with_description("The ID of the resource to update".to_string()),
                )
                .with_argument(
                    "input".to_string(),
                    ArgumentType::new(
                        "input".to_string(),
                        GraphQLType::NonNull(Box::new(GraphQLType::InputObject(
                            InputObjectType::new(update_input_type_name),
                        ))),
                    )
                    .with_description(format!("Input data for updating the {type_name}")),
                ),
            );

            // Delete mutation
            mutation_type = mutation_type.with_field(
                format!("delete{type_name}"),
                FieldType::new(
                    format!("delete{type_name}"),
                    GraphQLType::Scalar(BuiltinScalars::boolean()),
                )
                .with_description(format!("Delete a {type_name}"))
                .with_argument(
                    "id".to_string(),
                    ArgumentType::new(
                        "id".to_string(),
                        GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::id()))),
                    )
                    .with_description("The ID of the resource to delete".to_string()),
                ),
            );
        }

        // Add bulk operations
        mutation_type = mutation_type.with_field(
            "executeSparqlUpdate".to_string(),
            FieldType::new(
                "executeSparqlUpdate".to_string(),
                GraphQLType::Scalar(BuiltinScalars::boolean()),
            )
            .with_description("Execute a raw SPARQL UPDATE query".to_string())
            .with_argument(
                "update".to_string(),
                ArgumentType::new(
                    "update".to_string(),
                    GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::string()))),
                )
                .with_description("The SPARQL UPDATE query to execute".to_string()),
            ),
        );

        // Add transaction support
        mutation_type = mutation_type.with_field(
            "executeTransaction".to_string(),
            FieldType::new(
                "executeTransaction".to_string(),
                GraphQLType::Scalar(BuiltinScalars::boolean()),
            )
            .with_description("Execute multiple SPARQL UPDATE queries in a transaction".to_string())
            .with_argument(
                "updates".to_string(),
                ArgumentType::new(
                    "updates".to_string(),
                    GraphQLType::NonNull(Box::new(GraphQLType::List(Box::new(
                        GraphQLType::Scalar(BuiltinScalars::string()),
                    )))),
                )
                .with_description("List of SPARQL UPDATE queries to execute".to_string()),
            ),
        );

        Ok(mutation_type)
    }

    fn generate_subscription_type(&self, vocabulary: &RdfVocabulary) -> Result<ObjectType> {
        let mut subscription_type = ObjectType::new("Subscription".to_string()).with_description(
            "The root subscription type for real-time RDF data updates".to_string(),
        );

        // Add change subscriptions for each class
        for (class_uri, rdf_class) in &vocabulary.classes {
            if self.config.exclude_classes.contains(class_uri) {
                continue;
            }

            let type_name = self.uri_to_graphql_name(&rdf_class.uri);
            let field_name = format!("{}Changed", self.to_camel_case(&type_name));

            // Resource change subscription
            subscription_type = subscription_type.with_field(
                field_name.clone(),
                FieldType::new(
                    field_name.clone(),
                    GraphQLType::Object(ObjectType::new(format!("{type_name}ChangeEvent"))),
                )
                .with_description(format!("Subscribe to changes for {type_name} instances"))
                .with_argument(
                    "id".to_string(),
                    ArgumentType::new("id".to_string(), GraphQLType::Scalar(BuiltinScalars::id()))
                        .with_description(
                            "Subscribe to changes for a specific resource ID".to_string(),
                        ),
                )
                .with_argument(
                    "changeType".to_string(),
                    ArgumentType::new(
                        "changeType".to_string(),
                        GraphQLType::Enum(EnumType::new("ChangeType".to_string())),
                    )
                    .with_description(
                        "Filter by change type (CREATED, UPDATED, DELETED)".to_string(),
                    ),
                ),
            );

            // Collection changes subscription
            let collection_field = format!("{}CollectionChanged", self.to_camel_case(&type_name));
            subscription_type = subscription_type.with_field(
                collection_field.clone(),
                FieldType::new(
                    collection_field.clone(),
                    GraphQLType::Object(ObjectType::new("CollectionChangeEvent".to_string())),
                )
                .with_description(format!("Subscribe to collection changes for {type_name}"))
                .with_argument(
                    "filter".to_string(),
                    ArgumentType::new(
                        "filter".to_string(),
                        GraphQLType::Scalar(BuiltinScalars::string()),
                    )
                    .with_description("SPARQL filter condition for subscription".to_string()),
                ),
            );
        }

        // Add property-specific change subscriptions
        for (property_uri, property) in &vocabulary.properties {
            if self.config.exclude_properties.contains(property_uri) {
                continue;
            }

            let property_name = self.uri_to_graphql_name(&property.uri);
            let field_name = format!("{}PropertyChanged", self.to_camel_case(&property_name));

            subscription_type = subscription_type.with_field(
                field_name.clone(),
                FieldType::new(
                    field_name.clone(),
                    GraphQLType::Object(ObjectType::new("PropertyChangeEvent".to_string())),
                )
                .with_description(format!(
                    "Subscribe to changes for the {property_name} property"
                ))
                .with_argument(
                    "subject".to_string(),
                    ArgumentType::new(
                        "subject".to_string(),
                        GraphQLType::Scalar(RdfScalars::iri()),
                    )
                    .with_description("The subject resource to monitor".to_string()),
                ),
            );
        }

        // Add query-based subscription
        subscription_type = subscription_type.with_field(
            "queryResultChanged".to_string(),
            FieldType::new(
                "queryResultChanged".to_string(),
                GraphQLType::Object(ObjectType::new("QueryResultChangeEvent".to_string())),
            )
            .with_description("Subscribe to changes in SPARQL query results".to_string())
            .with_argument(
                "query".to_string(),
                ArgumentType::new(
                    "query".to_string(),
                    GraphQLType::NonNull(Box::new(GraphQLType::Scalar(BuiltinScalars::string()))),
                )
                .with_description("The SPARQL query to monitor".to_string()),
            )
            .with_argument(
                "pollInterval".to_string(),
                ArgumentType::new(
                    "pollInterval".to_string(),
                    GraphQLType::Scalar(BuiltinScalars::int()),
                )
                .with_default_value(crate::ast::Value::IntValue(5000))
                .with_description("Polling interval in milliseconds".to_string()),
            ),
        );

        // Add graph-level subscription
        subscription_type = subscription_type.with_field(
            "graphChanged".to_string(),
            FieldType::new(
                "graphChanged".to_string(),
                GraphQLType::Object(ObjectType::new("GraphChangeEvent".to_string())),
            )
            .with_description("Subscribe to any changes in the RDF graph".to_string())
            .with_argument(
                "graph".to_string(),
                ArgumentType::new("graph".to_string(), GraphQLType::Scalar(RdfScalars::iri()))
                    .with_description(
                        "The named graph to monitor (default graph if not specified)".to_string(),
                    ),
            ),
        );

        // Add transaction subscription
        subscription_type = subscription_type.with_field(
            "transactionCompleted".to_string(),
            FieldType::new(
                "transactionCompleted".to_string(),
                GraphQLType::Object(ObjectType::new("TransactionEvent".to_string())),
            )
            .with_description("Subscribe to transaction completion events".to_string()),
        );

        Ok(subscription_type)
    }

    fn uri_to_graphql_name(&self, uri: &str) -> String {
        if let Some(fragment) = uri.split('#').next_back() {
            self.to_pascal_case(fragment)
        } else if let Some(segment) = uri.split('/').next_back() {
            self.to_pascal_case(segment)
        } else {
            "Resource".to_string()
        }
    }

    fn to_pascal_case(&self, input: &str) -> String {
        let mut result = String::new();
        let mut capitalize_next = true;

        for ch in input.chars() {
            if ch.is_alphanumeric() {
                if capitalize_next {
                    result.push(ch.to_uppercase().next().unwrap_or(ch));
                    capitalize_next = false;
                } else {
                    result.push(ch);
                }
            } else {
                capitalize_next = true;
            }
        }

        result
    }

    fn to_camel_case(&self, input: &str) -> String {
        let pascal = self.to_pascal_case(input);
        if let Some(first_char) = pascal.chars().next() {
            first_char.to_lowercase().collect::<String>() + &pascal[first_char.len_utf8()..]
        } else {
            pascal
        }
    }

    fn pluralize(&self, word: &str) -> String {
        if word.ends_with('s') || word.ends_with("sh") || word.ends_with("ch") {
            format!("{word}es")
        } else if let Some(stripped) = word.strip_suffix('y') {
            format!("{stripped}ies")
        } else {
            format!("{word}s")
        }
    }

    fn schema_to_sdl(&self, schema: &Schema) -> String {
        let mut sdl = String::new();

        // Write schema definition
        writeln!(sdl, "schema {{").expect("writing to String should not fail");
        if let Some(ref query) = schema.query_type {
            writeln!(sdl, "  query: {query}").expect("writing to String should not fail");
        }
        if let Some(ref mutation) = schema.mutation_type {
            writeln!(sdl, "  mutation: {mutation}").expect("writing to String should not fail");
        }
        if let Some(ref subscription) = schema.subscription_type {
            writeln!(sdl, "  subscription: {subscription}")
                .expect("writing to String should not fail");
        }
        writeln!(sdl, "}}").expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");

        // Write type definitions
        for graphql_type in schema.types.values() {
            match graphql_type {
                GraphQLType::Object(obj) => {
                    self.write_object_type_sdl(&mut sdl, obj);
                }
                GraphQLType::Scalar(scalar)
                    if !["String", "Int", "Float", "Boolean", "ID"]
                        .contains(&scalar.name.as_str()) =>
                {
                    self.write_scalar_type_sdl(&mut sdl, scalar);
                }
                GraphQLType::Enum(enum_type) => {
                    self.write_enum_type_sdl(&mut sdl, enum_type);
                }
                GraphQLType::Interface(interface) => {
                    self.write_interface_type_sdl(&mut sdl, interface);
                }
                GraphQLType::Union(union_type) => {
                    self.write_union_type_sdl(&mut sdl, union_type);
                }
                _ => {} // Skip other types
            }
        }

        sdl
    }

    fn write_object_type_sdl(&self, sdl: &mut String, obj: &ObjectType) {
        if let Some(ref description) = obj.description {
            writeln!(sdl, "\"\"\"\n{description}\n\"\"\"")
                .expect("writing to String should not fail");
        }

        write!(sdl, "type {}", obj.name).expect("writing to String should not fail");

        if !obj.interfaces.is_empty() {
            write!(sdl, " implements {}", obj.interfaces.join(" & "))
                .expect("writing to String should not fail");
        }

        writeln!(sdl, " {{").expect("writing to String should not fail");

        for field in obj.fields.values() {
            self.write_field_sdl(sdl, field);
        }

        writeln!(sdl, "}}").expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");
    }

    fn write_field_sdl(&self, sdl: &mut String, field: &FieldType) {
        if let Some(ref description) = field.description {
            writeln!(sdl, "  \"{description}\"").expect("writing to String should not fail");
        }

        write!(sdl, "  {}", field.name).expect("writing to String should not fail");

        if !field.arguments.is_empty() {
            write!(sdl, "(").expect("writing to String should not fail");
            let args: Vec<String> = field
                .arguments
                .values()
                .map(|arg| format!("{}: {}", arg.name, arg.argument_type))
                .collect();
            write!(sdl, "{}", args.join(", ")).expect("writing to String should not fail");
            write!(sdl, ")").expect("writing to String should not fail");
        }

        writeln!(sdl, ": {}", field.field_type).expect("writing to String should not fail");
    }

    fn write_scalar_type_sdl(&self, sdl: &mut String, scalar: &ScalarType) {
        if let Some(ref description) = scalar.description {
            writeln!(sdl, "\"\"\"\n{description}\n\"\"\"")
                .expect("writing to String should not fail");
        }
        writeln!(sdl, "scalar {}", scalar.name).expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");
    }

    fn write_enum_type_sdl(&self, sdl: &mut String, enum_type: &EnumType) {
        if let Some(ref description) = enum_type.description {
            writeln!(sdl, "\"\"\"\n{description}\n\"\"\"")
                .expect("writing to String should not fail");
        }
        writeln!(sdl, "enum {} {{", enum_type.name).expect("writing to String should not fail");

        for value in enum_type.values.values() {
            if let Some(ref description) = value.description {
                writeln!(sdl, "  \"{description}\"").expect("writing to String should not fail");
            }
            writeln!(sdl, "  {}", value.name).expect("writing to String should not fail");
        }

        writeln!(sdl, "}}").expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");
    }

    fn write_interface_type_sdl(&self, sdl: &mut String, interface: &InterfaceType) {
        if let Some(ref description) = interface.description {
            writeln!(sdl, "\"\"\"\n{description}\n\"\"\"")
                .expect("writing to String should not fail");
        }
        writeln!(sdl, "interface {} {{", interface.name)
            .expect("writing to String should not fail");

        for field in interface.fields.values() {
            self.write_field_sdl(sdl, field);
        }

        writeln!(sdl, "}}").expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");
    }

    fn write_union_type_sdl(&self, sdl: &mut String, union_type: &UnionType) {
        if let Some(ref description) = union_type.description {
            writeln!(sdl, "\"\"\"\n{description}\n\"\"\"")
                .expect("writing to String should not fail");
        }
        writeln!(
            sdl,
            "union {} = {}",
            union_type.name,
            union_type.types.join(" | ")
        )
        .expect("writing to String should not fail");
        writeln!(sdl).expect("writing to String should not fail");
    }

    /// Load and parse RDF ontology from URI
    async fn load_ontology_from_uri(&self, ontology_uri: &str) -> Result<RdfVocabulary> {
        // Create a temporary store to load the ontology
        let store = crate::RdfStore::new()?;

        // Determine format based on URI or default to RDF/XML
        let format = self.detect_rdf_format(ontology_uri);

        // Fetch ontology content from URI
        let content = self.fetch_ontology_content(ontology_uri).await?;

        // Parse the RDF content into the store using format-specific parsing
        let parser = RdfParser::new(format);

        // Insert parsed quads into the store
        for quad_result in parser.for_slice(&content) {
            match quad_result {
                Ok(quad) => {
                    store.insert(&quad)?;
                }
                Err(e) => {
                    return Err(anyhow::anyhow!(
                        "Failed to parse quad from {}: {}",
                        ontology_uri,
                        e
                    ));
                }
            }
        }

        // Extract vocabulary from the loaded ontology using existing method
        self.extract_vocabulary_from_store(&store)
    }

    /// Fetch ontology content from URI (HTTP/HTTPS or local file)
    async fn fetch_ontology_content(&self, uri: &str) -> Result<Vec<u8>> {
        if uri.starts_with("http://") || uri.starts_with("https://") {
            // Fetch from HTTP/HTTPS
            self.fetch_http_content(uri).await
        } else if uri.starts_with("file://") || !uri.contains("://") {
            // Load from local file
            let file_path = if let Some(stripped) = uri.strip_prefix("file://") {
                stripped // Remove "file://" prefix
            } else {
                uri
            };

            match std::fs::read(file_path) {
                Ok(content) => Ok(content),
                Err(e) => Err(anyhow::anyhow!(
                    "Failed to read local file {}: {}",
                    file_path,
                    e
                )),
            }
        } else {
            Err(anyhow::anyhow!("Unsupported URI scheme: {}", uri))
        }
    }

    /// Fetch content from HTTP/HTTPS URI
    async fn fetch_http_content(&self, uri: &str) -> Result<Vec<u8>> {
        use reqwest;

        let client = reqwest::Client::builder()
            .timeout(std::time::Duration::from_secs(30))
            .build()?;

        let response = client
            .get(uri)
            .header(
                "Accept",
                "application/rdf+xml, text/turtle, application/n-triples, application/ld+json",
            )
            .send()
            .await?;

        if !response.status().is_success() {
            return Err(anyhow::anyhow!(
                "HTTP error {}: Failed to fetch ontology from {}",
                response.status(),
                uri
            ));
        }

        let content = response.bytes().await?;
        Ok(content.to_vec())
    }

    /// Detect RDF format based on URI or content-type
    fn detect_rdf_format(&self, uri: &str) -> RdfFormat {
        use oxirs_core::format::JsonLdProfileSet;

        let uri_lower = uri.to_lowercase();

        if uri_lower.ends_with(".ttl") || uri_lower.ends_with(".turtle") {
            RdfFormat::Turtle
        } else if uri_lower.ends_with(".nt") || uri_lower.ends_with(".ntriples") {
            RdfFormat::NTriples
        } else if uri_lower.ends_with(".jsonld") || uri_lower.ends_with(".json-ld") {
            RdfFormat::JsonLd {
                profile: JsonLdProfileSet::empty(),
            }
        } else if uri_lower.ends_with(".n3") {
            RdfFormat::N3
        } else {
            // Default to RDF/XML for .rdf, .owl, or unknown extensions
            RdfFormat::RdfXml
        }
    }

    #[allow(dead_code)]
    fn load_mock_vocabulary(&self, _ontology_uri: &str) -> Result<RdfVocabulary> {
        // Enhanced mock vocabulary for demonstration
        let mut classes = HashMap::new();
        let mut properties = HashMap::new();
        let mut namespaces = HashMap::new();

        // Common namespaces
        namespaces.insert("foaf".to_string(), "http://xmlns.com/foaf/0.1/".to_string());
        namespaces.insert("schema".to_string(), "http://schema.org/".to_string());
        namespaces.insert(
            "dbo".to_string(),
            "http://dbpedia.org/ontology/".to_string(),
        );
        namespaces.insert(
            "dc".to_string(),
            "http://purl.org/dc/elements/1.1/".to_string(),
        );

        // FOAF Agent (base class)
        classes.insert(
            "http://xmlns.com/foaf/0.1/Agent".to_string(),
            RdfClass {
                uri: "http://xmlns.com/foaf/0.1/Agent".to_string(),
                label: Some("Agent".to_string()),
                comment: Some(
                    "An agent (eg. person, group, software or physical artifact)".to_string(),
                ),
                super_classes: vec![],
                properties: vec!["http://xmlns.com/foaf/0.1/name".to_string()],
            },
        );

        // FOAF Person class
        classes.insert(
            "http://xmlns.com/foaf/0.1/Person".to_string(),
            RdfClass {
                uri: "http://xmlns.com/foaf/0.1/Person".to_string(),
                label: Some("Person".to_string()),
                comment: Some("A person".to_string()),
                super_classes: vec!["http://xmlns.com/foaf/0.1/Agent".to_string()],
                properties: vec![
                    "http://xmlns.com/foaf/0.1/name".to_string(),
                    "http://xmlns.com/foaf/0.1/email".to_string(),
                    "http://xmlns.com/foaf/0.1/knows".to_string(),
                    "http://xmlns.com/foaf/0.1/age".to_string(),
                    "http://xmlns.com/foaf/0.1/homepage".to_string(),
                ],
            },
        );

        // FOAF Organization class
        classes.insert(
            "http://xmlns.com/foaf/0.1/Organization".to_string(),
            RdfClass {
                uri: "http://xmlns.com/foaf/0.1/Organization".to_string(),
                label: Some("Organization".to_string()),
                comment: Some("An organization".to_string()),
                super_classes: vec!["http://xmlns.com/foaf/0.1/Agent".to_string()],
                properties: vec![
                    "http://xmlns.com/foaf/0.1/name".to_string(),
                    "http://xmlns.com/foaf/0.1/homepage".to_string(),
                ],
            },
        );

        // Schema.org Product class
        classes.insert(
            "http://schema.org/Product".to_string(),
            RdfClass {
                uri: "http://schema.org/Product".to_string(),
                label: Some("Product".to_string()),
                comment: Some("Any offered product or service".to_string()),
                super_classes: vec![],
                properties: vec![
                    "http://schema.org/name".to_string(),
                    "http://schema.org/description".to_string(),
                    "http://schema.org/price".to_string(),
                    "http://schema.org/manufacturer".to_string(),
                ],
            },
        );

        // Properties
        let property_definitions = vec![
            (
                "http://xmlns.com/foaf/0.1/name",
                "name",
                "A name for some thing",
                PropertyType::DataProperty,
                vec!["http://xmlns.com/foaf/0.1/Agent"],
                vec!["http://www.w3.org/2001/XMLSchema#string"],
            ),
            (
                "http://xmlns.com/foaf/0.1/email",
                "email",
                "An email address",
                PropertyType::DataProperty,
                vec!["http://xmlns.com/foaf/0.1/Person"],
                vec!["http://www.w3.org/2001/XMLSchema#string"],
            ),
            (
                "http://xmlns.com/foaf/0.1/age",
                "age",
                "The age in years of some agent",
                PropertyType::DataProperty,
                vec!["http://xmlns.com/foaf/0.1/Person"],
                vec!["http://www.w3.org/2001/XMLSchema#int"],
            ),
            (
                "http://xmlns.com/foaf/0.1/homepage",
                "homepage",
                "A homepage for some thing",
                PropertyType::DataProperty,
                vec!["http://xmlns.com/foaf/0.1/Agent"],
                vec!["http://www.w3.org/2001/XMLSchema#anyURI"],
            ),
            (
                "http://xmlns.com/foaf/0.1/knows",
                "knows",
                "A person known by this person",
                PropertyType::ObjectProperty,
                vec!["http://xmlns.com/foaf/0.1/Person"],
                vec!["http://xmlns.com/foaf/0.1/Person"],
            ),
            (
                "http://schema.org/name",
                "name",
                "The name of the item",
                PropertyType::DataProperty,
                vec!["http://schema.org/Product"],
                vec!["http://www.w3.org/2001/XMLSchema#string"],
            ),
            (
                "http://schema.org/description",
                "description",
                "A description of the item",
                PropertyType::DataProperty,
                vec!["http://schema.org/Product"],
                vec!["http://www.w3.org/2001/XMLSchema#string"],
            ),
            (
                "http://schema.org/price",
                "price",
                "The price of the product",
                PropertyType::DataProperty,
                vec!["http://schema.org/Product"],
                vec!["http://www.w3.org/2001/XMLSchema#decimal"],
            ),
            (
                "http://schema.org/manufacturer",
                "manufacturer",
                "The manufacturer of the product",
                PropertyType::ObjectProperty,
                vec!["http://schema.org/Product"],
                vec!["http://xmlns.com/foaf/0.1/Organization"],
            ),
        ];

        for (uri, label, comment, prop_type, domain, range) in property_definitions {
            properties.insert(
                uri.to_string(),
                RdfProperty {
                    uri: uri.to_string(),
                    label: Some(label.to_string()),
                    comment: Some(comment.to_string()),
                    domain: domain.into_iter().map(|s| s.to_string()).collect(),
                    range: range.into_iter().map(|s| s.to_string()).collect(),
                    property_type: prop_type,
                    functional: matches!(label, "email" | "age" | "homepage"),
                    inverse_functional: label == "email",
                },
            );
        }

        Ok(RdfVocabulary {
            classes,
            properties,
            namespaces,
        })
    }
}

impl Default for SchemaGenerator {
    fn default() -> Self {
        Self::new()
    }
}