// Graph API Implementation (Neo4j-like operations)
import { CBDAdapter } from '../cbd-adapter.js';
import { GraphQuery, GraphNode, GraphRelationship, CNDError } from '../types.js';

export class GraphAPI implements GraphQuery {
  private matchPattern: string = '';
  private whereConditions: Record<string, any> = {};

  constructor(private adapter: CBDAdapter) { }

  match(pattern: string): GraphQuery {
    this.matchPattern = pattern;
    return this;
  }

  where(conditions: Record<string, any>): GraphQuery {
    this.whereConditions = { ...this.whereConditions, ...conditions };
    return this;
  }

  async return(fields: string[]): Promise<any[]> {
    try {
      return await this.adapter.queryGraph(this.matchPattern, {
        where: this.whereConditions,
        return: fields
      });
    } catch (error) {
      throw new CNDError(
        `Graph query failed: ${error}`,
        'GRAPH_QUERY_ERROR',
        { pattern: this.matchPattern, conditions: this.whereConditions, fields }
      );
    }
  }

  async create(node: Partial<GraphNode>): Promise<GraphNode> {
    try {
      return await this.adapter.createNode(
        node.labels || [],
        node.properties || {}
      );
    } catch (error) {
      throw new CNDError(
        `Graph node creation failed: ${error}`,
        'GRAPH_CREATE_NODE_ERROR',
        { node }
      );
    }
  }

  async relate(
    from: string,
    to: string,
    type: string,
    properties?: Record<string, any>
  ): Promise<GraphRelationship> {
    try {
      return await this.adapter.createRelationship(from, to, type, properties || {});
    } catch (error) {
      throw new CNDError(
        `Graph relationship creation failed: ${error}`,
        'GRAPH_CREATE_RELATIONSHIP_ERROR',
        { from, to, type, properties }
      );
    }
  }

  // Additional graph operations
  async createNode(labels: string[], properties: Record<string, any>): Promise<GraphNode> {
    return this.create({ labels, properties });
  }

  async findNodes(label: string, properties?: Record<string, any>): Promise<GraphNode[]> {
    const pattern = `(n:${label})`;
    const query = new GraphAPI(this.adapter).match(pattern);

    if (properties) {
      query.where(properties);
    }

    return query.return(['n']);
  }

  async findNodeById(id: string): Promise<GraphNode | null> {
    const results = await this.match('(n)').where({ 'n.id': id }).return(['n']);
    return results.length > 0 ? results[0] : null;
  }

  async findRelationships(
    type?: string,
    properties?: Record<string, any>
  ): Promise<GraphRelationship[]> {
    const pattern = type ? `()-[r:${type}]->()` : '()-[r]->()';
    const query = new GraphAPI(this.adapter).match(pattern);

    if (properties) {
      query.where(properties);
    }

    return query.return(['r']);
  }

  async findPath(
    startNodeId: string,
    endNodeId: string,
    relationshipType?: string,
    maxDepth: number = 5
  ): Promise<any[]> {
    const relPattern = relationshipType ? `[:${relationshipType}*1..${maxDepth}]` : `[*1..${maxDepth}]`;
    const pattern = `(start)-${relPattern}-(end)`;

    return this.match(pattern)
      .where({ 'start.id': startNodeId, 'end.id': endNodeId })
      .return(['start', 'end']);
  }

  async deleteNode(id: string): Promise<boolean> {
    try {
      // In real implementation, this would delete the node from CBD Engine
      console.log(`Graph API: Deleting node ${id}`);
      return true;
    } catch (error) {
      throw new CNDError(
        `Graph node deletion failed: ${error}`,
        'GRAPH_DELETE_NODE_ERROR',
        { id }
      );
    }
  }

  async deleteRelationship(id: string): Promise<boolean> {
    try {
      // In real implementation, this would delete the relationship from CBD Engine
      console.log(`Graph API: Deleting relationship ${id}`);
      return true;
    } catch (error) {
      throw new CNDError(
        `Graph relationship deletion failed: ${error}`,
        'GRAPH_DELETE_RELATIONSHIP_ERROR',
        { id }
      );
    }
  }

  async updateNode(id: string, properties: Record<string, any>): Promise<GraphNode> {
    try {
      // In real implementation, this would update the node in CBD Engine
      console.log(`Graph API: Updating node ${id}`, properties);

      // Return updated node (simulated)
      return {
        id,
        labels: [],
        properties: { ...properties, updatedAt: new Date() }
      };
    } catch (error) {
      throw new CNDError(
        `Graph node update failed: ${error}`,
        'GRAPH_UPDATE_NODE_ERROR',
        { id, properties }
      );
    }
  }

  async updateRelationship(
    id: string,
    properties: Record<string, any>
  ): Promise<GraphRelationship> {
    try {
      // In real implementation, this would update the relationship in CBD Engine
      console.log(`Graph API: Updating relationship ${id}`, properties);

      // Return updated relationship (simulated)
      return {
        id,
        type: '',
        startNode: '',
        endNode: '',
        properties: { ...properties, updatedAt: new Date() }
      };
    } catch (error) {
      throw new CNDError(
        `Graph relationship update failed: ${error}`,
        'GRAPH_UPDATE_RELATIONSHIP_ERROR',
        { id, properties }
      );
    }
  }

  // Cypher-like query methods
  async cypher(query: string, parameters?: Record<string, any>): Promise<any[]> {
    try {
      // In real implementation, this would execute Cypher queries in CBD Engine
      console.log('Graph API: Executing Cypher query:', query, parameters);
      return [];
    } catch (error) {
      throw new CNDError(
        `Cypher query failed: ${error}`,
        'GRAPH_CYPHER_ERROR',
        { query, parameters }
      );
    }
  }

  // Graph algorithms
  async shortestPath(
    startNodeId: string,
    endNodeId: string,
    relationshipType?: string
  ): Promise<any[]> {
    const relPattern = relationshipType ? `[:${relationshipType}*]` : '[*]';
    const pattern = `(start)-${relPattern}-(end)`;

    return this.match(`shortestPath(${pattern})`)
      .where({ 'start.id': startNodeId, 'end.id': endNodeId })
      .return(['start', 'end']);
  }

  async pageRank(iterations: number = 20, dampingFactor: number = 0.85): Promise<any[]> {
    try {
      // In real implementation, this would run PageRank algorithm in CBD Engine
      console.log(`Graph API: Running PageRank (iterations: ${iterations}, damping: ${dampingFactor})`);
      return [];
    } catch (error) {
      throw new CNDError(
        `PageRank algorithm failed: ${error}`,
        'GRAPH_PAGERANK_ERROR',
        { iterations, dampingFactor }
      );
    }
  }

  async communityDetection(algorithm: 'louvain' | 'labelPropagation' = 'louvain'): Promise<any[]> {
    try {
      // In real implementation, this would run community detection in CBD Engine
      console.log(`Graph API: Running community detection (${algorithm})`);
      return [];
    } catch (error) {
      throw new CNDError(
        `Community detection failed: ${error}`,
        'GRAPH_COMMUNITY_DETECTION_ERROR',
        { algorithm }
      );
    }
  }
}