Implement immutable DecisionGraph for decision table components

src/main/java/ru/ewc/decisions/core/BasicGraphEdge.java

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+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025 Eugene Terekhov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ru.ewc.decisions.core;
+
+import java.util.Objects;
+
+/**
+ * I am a concrete edge in the DecisionGraph that represents a basic relationship.
+ * I am immutable and connect two nodes with a specific relationship type.
+ *
+ * @since 0.9.2
+ */
+public final class BasicGraphEdge implements GraphEdge {
+    /**
+     * The source node of this edge.
+     */
+    private final GraphNode source;
+
+    /**
+     * The target node of this edge.
+     */
+    private final GraphNode target;
+
+    /**
+     * The type of relationship this edge represents.
+     */
+    private final String relationshipType;
+
+    /**
+     * Constructor.
+     *
+     * @param source The source node of this edge.
+     * @param target The target node of this edge.
+     * @param relationshipType The type of relationship this edge represents.
+     */
+    public BasicGraphEdge(final GraphNode source, final GraphNode target, final String relationshipType) {
+        this.source = Objects.requireNonNull(source, "Source node cannot be null");
+        this.target = Objects.requireNonNull(target, "Target node cannot be null");
+        this.relationshipType = Objects.requireNonNull(relationshipType, "Relationship type cannot be null");
+    }
+
+    @Override
+    public GraphNode source() {
+        return this.source;
+    }
+
+    @Override
+    public GraphNode target() {
+        return this.target;
+    }
+
+    @Override
+    public String relationshipType() {
+        return this.relationshipType;
+    }
+
+    @Override
+    public String id() {
+        return String.format("%s--%s-->%s", this.source.id(), this.relationshipType, this.target.id());
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final BasicGraphEdge that = (BasicGraphEdge) obj;
+        return Objects.equals(this.source, that.source) &&
+            Objects.equals(this.target, that.target) &&
+            Objects.equals(this.relationshipType, that.relationshipType);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.source, this.target, this.relationshipType);
+    }
+
+    @Override
+    public String toString() {
+        return "BasicGraphEdge{" +
+            "source=" + this.source.id() +
+            ", target=" + this.target.id() +
+            ", relationshipType='" + this.relationshipType + '\'' +
+            '}';
+    }
+}

src/main/java/ru/ewc/decisions/core/ConditionNode.java

@@ -0,0 +1,94 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025 Eugene Terekhov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ru.ewc.decisions.core;
+
+import java.util.Objects;
+import ru.ewc.decisions.conditions.Condition;
+
+/**
+ * I am a concrete node in the DecisionGraph that represents a Condition.
+ * I am immutable and provide a unique identifier based on the condition's properties.
+ *
+ * @since 0.9.2
+ */
+public final class ConditionNode implements GraphNode {
+    /**
+     * The condition this node represents.
+     */
+    private final Condition condition;
+
+    /**
+     * The unique identifier for this condition.
+     */
+    private final String identifier;
+
+    /**
+     * Constructor.
+     *
+     * @param condition The condition this node represents.
+     * @param identifier A unique identifier for this condition.
+     */
+    public ConditionNode(final Condition condition, final String identifier) {
+        this.condition = Objects.requireNonNull(condition, "Condition cannot be null");
+        this.identifier = Objects.requireNonNull(identifier, "Identifier cannot be null");
+    }
+
+    @Override
+    public String id() {
+        return "condition:" + this.identifier;
+    }
+
+    @Override
+    public String type() {
+        return "condition";
+    }
+
+    @Override
+    public Object component() {
+        return this.condition;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final ConditionNode that = (ConditionNode) obj;
+        return Objects.equals(this.identifier, that.identifier);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.identifier);
+    }
+
+    @Override
+    public String toString() {
+        return "ConditionNode{" + "identifier='" + this.identifier + '\'' + '}';
+    }
+}

src/main/java/ru/ewc/decisions/core/CoordinateNode.java

@@ -0,0 +1,86 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025 Eugene Terekhov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ru.ewc.decisions.core;
+
+import java.util.Objects;
+
+/**
+ * I am a concrete node in the DecisionGraph that represents a Coordinate.
+ * I am immutable and provide a unique identifier based on the coordinate's string representation.
+ *
+ * @since 0.9.2
+ */
+public final class CoordinateNode implements GraphNode {
+    /**
+     * The coordinate this node represents.
+     */
+    private final Coordinate coordinate;
+
+    /**
+     * Constructor.
+     *
+     * @param coordinate The coordinate this node represents.
+     */
+    public CoordinateNode(final Coordinate coordinate) {
+        this.coordinate = Objects.requireNonNull(coordinate, "Coordinate cannot be null");
+    }
+
+    @Override
+    public String id() {
+        return "coordinate:" + this.coordinate.asString();
+    }
+
+    @Override
+    public String type() {
+        return "coordinate";
+    }
+
+    @Override
+    public Object component() {
+        return this.coordinate;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final CoordinateNode that = (CoordinateNode) obj;
+        return Objects.equals(this.coordinate, that.coordinate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.coordinate);
+    }
+
+    @Override
+    public String toString() {
+        return "CoordinateNode{" + "coordinate=" + this.coordinate.asString() + '}';
+    }
+}

src/main/java/ru/ewc/decisions/core/DecisionGraph.java

@@ -0,0 +1,85 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025 Eugene Terekhov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ru.ewc.decisions.core;
+
+import java.util.Set;
+
+/**
+ * I am an immutable graph representation of decision tables and their components.
+ * My nodes are decision table components like Coordinates, Conditions, Rules, and DecisionTables.
+ * My edges represent relationships like "part_of", "lhs_of", "rhs_of", and "operator_of".
+ * I am thread-safe and built once from source files, then cached for reuse.
+ *
+ * @since 0.9.2
+ */
+public interface DecisionGraph {
+    /**
+     * Returns all nodes in this graph.
+     *
+     * @return An immutable set of all nodes in the graph.
+     */
+    Set<GraphNode> nodes();
+
+    /**
+     * Returns all edges in this graph.
+     *
+     * @return An immutable set of all edges in the graph.
+     */
+    Set<GraphEdge> edges();
+
+    /**
+     * Returns all nodes of a specific type.
+     *
+     * @param nodeType The class of nodes to return.
+     * @param <T> The type of nodes to return.
+     * @return An immutable set of nodes of the specified type.
+     */
+    <T extends GraphNode> Set<T> nodesOfType(Class<T> nodeType);
+
+    /**
+     * Returns all edges of a specific type.
+     *
+     * @param edgeType The class of edges to return.
+     * @param <T> The type of edges to return.
+     * @return An immutable set of edges of the specified type.
+     */
+    <T extends GraphEdge> Set<T> edgesOfType(Class<T> edgeType);
+
+    /**
+     * Returns all edges that have the specified node as their source.
+     *
+     * @param node The source node.
+     * @return An immutable set of edges originating from the specified node.
+     */
+    Set<GraphEdge> edgesFrom(GraphNode node);
+
+    /**
+     * Returns all edges that have the specified node as their target.
+     *
+     * @param node The target node.
+     * @return An immutable set of edges targeting the specified node.
+     */
+    Set<GraphEdge> edgesTo(GraphNode node);
+}