/**
 * Context Node Matching Utilities
 * 
 * Provides functions for matching RAG context nodes (from Qdrant, SPARQL, TypeDB)
 * against knowledge graph nodes (from Oxigraph).
 * 
 * The core challenge: Context nodes have IDs like "qdrant:123" while graph nodes
 * have URIs like "http://example.org/entity/123". Matching is done via:
 * - Normalized name matching
 * - GHCID matching
 * - ISIL code matching  
 * - Wikidata ID matching
 */

import type { GraphNode, GraphData } from '../components/database/KnowledgeGraphProjector';

/**
 * Source database colors for multi-source visualization
 */
export const SOURCE_COLORS = {
  qdrant: '#6366f1',   // Indigo for vector search
  sparql: '#10b981',   // Emerald for SPARQL/Oxigraph
  typedb: '#f59e0b',   // Amber for TypeDB
} as const;

export type SourceType = keyof typeof SOURCE_COLORS;

/**
 * Context info returned for matched nodes
 */
export interface ContextNodeInfo {
  source?: string;
  sources?: string[];
  sourceColor?: string;
  score?: number;
}

/**
 * Options for building context node IDs
 */
export interface ContextNodeMatchingOptions {
  /** Enable debug logging */
  debug?: boolean;
}

/**
 * Normalizes a name for matching by lowercasing and trimming
 */
export function normalizeName(name: unknown): string {
  if (name === null || name === undefined) return '';
  return String(name).toLowerCase().trim();
}

/**
 * Pattern to extract GHCID from heritage custodian URIs
 * Matches: https://w3id.org/heritage/ghcid/{GHCID}
 */
const GHCID_URI_PATTERN = /^https?:\/\/w3id\.org\/heritage\/ghcid\/([A-Z]{2}-[A-Z0-9-]+)$/i;

/**
 * Extracts GHCID from a node URI if it matches the heritage custodian pattern.
 * Returns null if the URI doesn't contain a GHCID.
 */
export function extractGhcidFromUri(uri: string): string | null {
  const match = uri.match(GHCID_URI_PATTERN);
  return match ? match[1].toUpperCase() : null;
}

/**
 * Extracts potential matching keys from a node's attributes.
 * Returns a set of normalized keys in format "type:value"
 * 
 * Handles both:
 * - Qdrant nodes: Have attributes like { ghcid, name, city }
 * - Oxigraph nodes: Have URIs like https://w3id.org/heritage/ghcid/{GHCID} and label
 */
export function extractMatchingKeys(node: GraphNode): Set<string> {
  const keys = new Set<string>();
  const attrs = node.attributes || {};
  
  // Add direct ID
  keys.add(node.id);
  
  // Extract GHCID from URI (for Oxigraph nodes)
  // URIs like: https://w3id.org/heritage/ghcid/NL-FR-WOL-M-K
  const ghcidFromUri = extractGhcidFromUri(node.id);
  if (ghcidFromUri) {
    keys.add(`ghcid:${ghcidFromUri}`);
  }
  
  // Match by name (normalized) - check multiple attribute names
  const name = normalizeName(attrs.name);
  if (name) {
    keys.add(`name:${name}`);
  }
  
  const custodianName = normalizeName(attrs.custodian_name);
  if (custodianName) {
    keys.add(`name:${custodianName}`);
  }
  
  // Also try the label (primary match for Oxigraph nodes)
  const label = normalizeName(node.label);
  if (label) {
    keys.add(`name:${label}`);
  }
  
  // Match by GHCID from attributes (for Qdrant nodes)
  if (attrs.ghcid) {
    keys.add(`ghcid:${String(attrs.ghcid).toUpperCase()}`);
  }
  
  // Match by ISIL
  if (attrs.isil_code) {
    keys.add(`isil:${String(attrs.isil_code)}`);
  }
  
  // Match by Wikidata ID
  if (attrs.wikidata_id) {
    keys.add(`wikidata:${String(attrs.wikidata_id)}`);
  }
  
  return keys;
}

/**
 * Builds a set of context node IDs for efficient matching.
 * The set contains normalized keys that can be used to check if
 * a graph node matches any context result.
 * 
 * @param contextNodes - Array of nodes from RAG context (Qdrant, SPARQL, TypeDB)
 * @param options - Optional configuration
 * @returns Set of normalized matching keys
 */
export function buildContextNodeIds(
  contextNodes: GraphNode[],
  options: ContextNodeMatchingOptions = {}
): Set<string> {
  const ids = new Set<string>();
  
  if (!contextNodes || contextNodes.length === 0) {
    return ids;
  }
  
  contextNodes.forEach(node => {
    const nodeKeys = extractMatchingKeys(node);
    nodeKeys.forEach(key => ids.add(key));
  });
  
  // Debug logging
  if (options.debug && contextNodes.length > 0) {
    const sampleNode = contextNodes[0];
    console.log('[Context Matching] Context nodes sample:', {
      totalContextNodes: contextNodes.length,
      sampleId: sampleNode.id,
      sampleLabel: sampleNode.label,
      sampleAttrs: sampleNode.attributes,
      matchingKeysGenerated: Array.from(ids).slice(0, 10),
    });
  }
  
  return ids;
}

/**
 * Checks if a graph node matches any context result.
 * 
 * Handles both:
 * - Qdrant nodes: Have attributes like { ghcid, name, city }
 * - Oxigraph nodes: Have URIs like https://w3id.org/heritage/ghcid/{GHCID} and label
 * 
 * @param node - A graph node from the full knowledge graph
 * @param contextNodeIds - Set of matching keys from buildContextNodeIds
 * @returns true if the node matches any context result
 */
export function isNodeInContext(
  node: GraphNode,
  contextNodeIds: Set<string>
): boolean {
  if (contextNodeIds.size === 0) return false;
  
  // Direct ID match
  if (contextNodeIds.has(node.id)) return true;
  
  const attrs = node.attributes || {};
  
  // Match by GHCID extracted from URI (for Oxigraph nodes)
  // URIs like: https://w3id.org/heritage/ghcid/NL-FR-WOL-M-K
  const ghcidFromUri = extractGhcidFromUri(node.id);
  if (ghcidFromUri && contextNodeIds.has(`ghcid:${ghcidFromUri}`)) return true;
  
  // Match by normalized name (try multiple attributes)
  const name = normalizeName(attrs.name || attrs.custodian_name || node.label);
  if (name && contextNodeIds.has(`name:${name}`)) return true;
  
  // Match by GHCID from attributes (for Qdrant nodes)
  if (attrs.ghcid && contextNodeIds.has(`ghcid:${String(attrs.ghcid).toUpperCase()}`)) return true;
  
  // Match by ISIL
  if (attrs.isil_code && contextNodeIds.has(`isil:${String(attrs.isil_code)}`)) return true;
  
  // Match by Wikidata ID
  if (attrs.wikidata_id && contextNodeIds.has(`wikidata:${String(attrs.wikidata_id)}`)) return true;
  
  return false;
}

/**
 * Finds the matching context node for a graph node and returns its info.
 * 
 * Handles both:
 * - Qdrant nodes: Have attributes like { ghcid, name, city }
 * - Oxigraph nodes: Have URIs like https://w3id.org/heritage/ghcid/{GHCID} and label
 * 
 * @param node - A graph node from the full knowledge graph
 * @param contextNodes - Array of nodes from RAG context
 * @returns Context info (source, score) or null if no match
 */
export function getContextNodeInfo(
  node: GraphNode,
  contextNodes: GraphNode[]
): ContextNodeInfo | null {
  if (!contextNodes || contextNodes.length === 0) return null;
  
  const attrs = node.attributes || {};
  const nodeName = normalizeName(attrs.name || attrs.custodian_name || node.label);
  
  // Extract GHCID from URI (for Oxigraph nodes)
  const ghcidFromUri = extractGhcidFromUri(node.id);
  const nodeGhcid = ghcidFromUri || (attrs.ghcid ? String(attrs.ghcid).toUpperCase() : null);
  
  // Find matching context node
  const contextNode = contextNodes.find(cn => {
    // Direct ID match
    if (cn.id === node.id) return true;
    
    const cnAttrs = cn.attributes || {};
    const cnName = normalizeName(cnAttrs.name || cnAttrs.custodian_name || cn.label);
    
    // Name match
    if (nodeName && cnName && nodeName === cnName) return true;
    
    // GHCID match (handle both URI-extracted and attribute-based)
    const cnGhcid = cnAttrs.ghcid ? String(cnAttrs.ghcid).toUpperCase() : null;
    if (nodeGhcid && cnGhcid && nodeGhcid === cnGhcid) return true;
    
    // ISIL match
    if (attrs.isil_code && cnAttrs.isil_code && attrs.isil_code === cnAttrs.isil_code) return true;
    
    // Wikidata match
    if (attrs.wikidata_id && cnAttrs.wikidata_id && attrs.wikidata_id === cnAttrs.wikidata_id) return true;
    
    return false;
  });
  
  if (!contextNode) return null;
  
  return {
    source: contextNode.attributes?.source as string | undefined,
    sources: contextNode.attributes?.sources as string[] | undefined,
    sourceColor: contextNode.attributes?.sourceColor as string | undefined,
    score: contextNode.attributes?.score as number | undefined,
  };
}

/**
 * Enhanced node with context highlighting attributes
 */
export interface EnhancedGraphNode extends GraphNode {
  attributes: GraphNode['attributes'] & {
    isContextResult?: boolean;
    isSourceVisible?: boolean;
    dimmed?: boolean;
    source?: string;
    sources?: string[];
    sourceColor?: string;
    score?: number;
  };
}

/**
 * Merges context highlighting into full graph data.
 * Nodes matching context results are marked as highlighted;
 * non-matching nodes are marked as dimmed.
 * 
 * @param graphData - Full graph data from Oxigraph
 * @param contextData - Context graph data from RAG results
 * @param visibleSources - Set of source types currently visible (for filtering)
 * @param options - Optional configuration
 * @returns Enhanced graph data with highlighting attributes
 */
export function mergeContextHighlighting(
  graphData: GraphData,
  contextData: GraphData,
  visibleSources: Set<string>,
  options: ContextNodeMatchingOptions = {}
): GraphData {
  if (!graphData) {
    return { nodes: [], edges: [] };
  }
  
  const contextNodeIds = buildContextNodeIds(contextData?.nodes || [], options);
  
  let matchedCount = 0;
  const enhancedNodes: EnhancedGraphNode[] = graphData.nodes.map(node => {
    const inContext = isNodeInContext(node, contextNodeIds);
    
    if (inContext) matchedCount++;
    
    if (!inContext) {
      // Not in context - return with dimmed styling
      return {
        ...node,
        attributes: {
          ...node.attributes,
          isContextResult: false,
          dimmed: true,
        },
      };
    }
    
    // Node is in context - add highlighting and source info
    const contextInfo = getContextNodeInfo(node, contextData?.nodes || []);
    
    // Check if this source is currently visible
    const source = contextInfo?.source;
    const sources = contextInfo?.sources;
    let isSourceVisible = true;
    
    if (sources && sources.length > 0) {
      isSourceVisible = sources.some(s => visibleSources.has(s));
    } else if (source) {
      isSourceVisible = visibleSources.has(source);
    }
    
    return {
      ...node,
      attributes: {
        ...node.attributes,
        isContextResult: true,
        isSourceVisible,
        dimmed: !isSourceVisible,
        source: contextInfo?.source,
        sources: contextInfo?.sources,
        sourceColor: contextInfo?.sourceColor,
        score: contextInfo?.score,
      },
    };
  });
  
  // Debug logging
  if (options.debug && graphData.nodes.length > 0) {
    const sampleGraphNode = graphData.nodes[0];
    const sampleContextNode = contextData?.nodes?.[0];
    console.log('[Context Matching] Graph nodes vs context matching:', {
      totalGraphNodes: graphData.nodes.length,
      contextNodeIdsSize: contextNodeIds.size,
      matchedNodes: matchedCount,
      sampleGraphNode: {
        id: sampleGraphNode.id,
        label: sampleGraphNode.label,
        attrs: sampleGraphNode.attributes,
        extractedKeys: Array.from(extractMatchingKeys(sampleGraphNode)),
      },
      sampleContextNode: sampleContextNode ? {
        id: sampleContextNode.id,
        label: sampleContextNode.label,
        attrs: sampleContextNode.attributes,
        extractedKeys: Array.from(extractMatchingKeys(sampleContextNode)),
      } : null,
      contextKeysSample: Array.from(contextNodeIds).slice(0, 15),
    });
  }
  
  return {
    nodes: enhancedNodes,
    edges: graphData.edges,
  };
}

/**
 * Counts how many graph nodes match context results
 * Useful for debugging and UI display
 */
export function countContextMatches(
  graphNodes: GraphNode[],
  contextNodes: GraphNode[]
): { matched: number; total: number; percentage: number } {
  const contextNodeIds = buildContextNodeIds(contextNodes);
  
  let matched = 0;
  graphNodes.forEach(node => {
    if (isNodeInContext(node, contextNodeIds)) {
      matched++;
    }
  });
  
  const total = graphNodes.length;
  const percentage = total > 0 ? Math.round((matched / total) * 100) : 0;
  
  return { matched, total, percentage };
}