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529090e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | import neo4j, { Driver, Session } from 'neo4j-driver';
export interface GraphNode {
id: string;
labels: string[];
properties: Record<string, any>;
}
export interface GraphRelationship {
id: string;
type: string;
startNodeId: string;
endNodeId: string;
properties: Record<string, any>;
}
export class Neo4jService {
private driver: Driver | null = null;
private uri: string;
private username: string;
private password: string;
constructor() {
this.uri = process.env.NEO4J_URI || 'bolt://localhost:7687';
// Support both NEO4J_USER and NEO4J_USERNAME for compatibility
this.username = process.env.NEO4J_USER || process.env.NEO4J_USERNAME || 'neo4j';
this.password = process.env.NEO4J_PASSWORD || 'password';
}
async connect(): Promise<void> {
try {
this.driver = neo4j.driver(
this.uri,
neo4j.auth.basic(this.username, this.password),
{
maxConnectionPoolSize: 50,
connectionAcquisitionTimeout: 60000,
}
);
await this.driver.verifyConnectivity();
console.log('✅ Neo4j connected successfully', this.uri);
} catch (error) {
console.error('❌ Failed to connect to Neo4j', error);
throw error;
}
}
async disconnect(): Promise<void> {
if (this.driver) {
await this.driver.close();
this.driver = null;
console.log('Neo4j disconnected');
}
}
async close(): Promise<void> {
await this.disconnect();
}
private getSession(): Session {
if (!this.driver) {
throw new Error('Neo4j driver not initialized. Call connect() first.');
}
return this.driver.session();
}
async createNode(labels: string[], properties: Record<string, any>): Promise<GraphNode> {
const session = this.getSession();
try {
const labelsStr = labels.map(l => `:${l}`).join('');
const result = await session.run(
`CREATE (n${labelsStr} $properties) RETURN n`,
{ properties }
);
const node = result.records[0].get('n');
return {
id: node.elementId,
labels: node.labels,
properties: node.properties,
};
} finally {
await session.close();
}
}
async createRelationship(
startNodeId: string,
endNodeId: string,
type: string,
properties: Record<string, any> = {}
): Promise<GraphRelationship> {
const session = this.getSession();
try {
// Use elementId lookup instead of id()
const result = await session.run(
`MATCH (a), (b)
WHERE elementId(a) = $startId AND elementId(b) = $endId
CREATE (a)-[r:${type} $properties]->(b)
RETURN r`,
{ startId: startNodeId, endId: endNodeId, properties }
);
const rel = result.records[0].get('r');
return {
id: rel.elementId,
type: rel.type,
startNodeId: rel.startNodeElementId,
endNodeId: rel.endNodeElementId,
properties: rel.properties,
};
} finally {
await session.close();
}
}
async findNodes(label: string, properties: Record<string, any> = {}): Promise<GraphNode[]> {
const session = this.getSession();
try {
const whereClause = Object.keys(properties).length > 0
? 'WHERE ' + Object.keys(properties).map(k => `n.${k} = $${k}`).join(' AND ')
: '';
const result = await session.run(
`MATCH (n:${label}) ${whereClause} RETURN n`,
properties
);
return result.records.map(record => {
const node = record.get('n');
return {
id: node.elementId,
labels: node.labels,
properties: node.properties,
};
});
} finally {
await session.close();
}
}
async runQuery(query: string, parameters: Record<string, any> = {}): Promise<any[]> {
const session = this.getSession();
try {
const result = await session.run(query, parameters);
return result.records.map(record => record.toObject());
} finally {
await session.close();
}
}
async getNodeById(nodeId: string): Promise<GraphNode | null> {
const session = this.getSession();
try {
const result = await session.run(
'MATCH (n) WHERE elementId(n) = $id RETURN n',
{ id: nodeId }
);
if (result.records.length === 0) return null;
const node = result.records[0].get('n');
return {
id: node.elementId,
labels: node.labels,
properties: node.properties,
};
} finally {
await session.close();
}
}
async deleteNode(nodeId: string): Promise<void> {
const session = this.getSession();
try {
await session.run(
'MATCH (n) WHERE elementId(n) = $id DETACH DELETE n',
{ id: nodeId }
);
} finally {
await session.close();
}
}
async getNodeRelationships(nodeId: string): Promise<GraphRelationship[]> {
const session = this.getSession();
try {
const result = await session.run(
`MATCH (n)-[r]-(m)
WHERE elementId(n) = $id
RETURN r`,
{ id: nodeId }
);
return result.records.map(record => {
const rel = record.get('r');
return {
id: rel.elementId,
type: rel.type,
startNodeId: rel.startNodeElementId,
endNodeId: rel.endNodeElementId,
properties: rel.properties,
};
});
} finally {
await session.close();
}
}
async healthCheck(): Promise<boolean> {
try {
if (!this.driver) return false;
await this.driver.verifyConnectivity();
return true;
} catch (error) {
console.error('Neo4j health check failed', error);
return false;
}
}
}
export const neo4jService = new Neo4jService();
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