/**
 * Intelligent Type Mapper
 * Maps generic/invalid type names to specific semantic types based on data analysis
 * Prevents semantic degradation from overuse of generic types
 */

import { NounType, VerbType } from '../types/graphTypes.js'

/**
 * Common aliases that users might use
 */
const GENERIC_ALIASES = new Set([
  'entity',
  'item',
  'object',
  'node',
  'record',
  'entry',
  'data',
  'resource'
])

/**
 * Field signatures for type inference
 */
const TYPE_SIGNATURES = {
  // Person indicators
  person: {
    required: [],
    indicators: ['email', 'firstName', 'lastName', 'name', 'phone', 'username', 'userId'],
    patterns: [/@/, /^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$/i],
    weight: 10
  },
  
  // User account indicators  
  user: {
    required: [],
    indicators: ['username', 'password', 'accountId', 'loginTime', 'permissions', 'role'],
    patterns: [],
    weight: 9
  },
  
  // Organization indicators
  organization: {
    required: [],
    indicators: ['companyName', 'orgName', 'ein', 'vatNumber', 'employees', 'headquarters'],
    patterns: [],
    weight: 8
  },
  
  // Product indicators
  product: {
    required: [],
    indicators: ['price', 'sku', 'barcode', 'inventory', 'cost', 'productId', 'inStock'],
    patterns: [/^\$?\d+\.?\d*$/, /^[A-Z0-9-]+$/],
    weight: 8
  },
  
  // Document indicators
  document: {
    required: [],
    indicators: ['content', 'text', 'body', 'title', 'author', 'markdown', 'html'],
    patterns: [],
    weight: 7
  },
  
  // Message indicators
  message: {
    required: [],
    indicators: ['from', 'to', 'subject', 'body', 'sentAt', 'messageId', 'threadId'],
    patterns: [],
    weight: 7
  },
  
  // Task indicators
  task: {
    required: [],
    indicators: ['dueDate', 'assignee', 'status', 'priority', 'completed', 'taskId'],
    patterns: [],
    weight: 7
  },
  
  // Event indicators
  event: {
    required: [],
    indicators: ['startTime', 'endTime', 'date', 'location', 'attendees', 'eventType'],
    patterns: [],
    weight: 6
  },
  
  // Location indicators
  location: {
    required: [],
    indicators: ['latitude', 'longitude', 'address', 'city', 'country', 'zipCode', 'coordinates'],
    patterns: [/^-?\d+\.\d+$/, /^\d{5}(-\d{4})?$/],
    weight: 6
  },
  
  // File indicators
  file: {
    required: [],
    indicators: ['filename', 'filepath', 'extension', 'mimeType', 'fileSize', 'checksum'],
    patterns: [/\.[a-z0-9]+$/i],
    weight: 5
  },
  
  // Dataset indicators
  dataset: {
    required: [],
    indicators: ['schema', 'rows', 'columns', 'records', 'dataType', 'format'],
    patterns: [],
    weight: 5
  },
  
  // Media indicators
  media: {
    required: [],
    indicators: ['url', 'thumbnail', 'duration', 'resolution', 'codec', 'bitrate'],
    patterns: [/\.(jpg|jpeg|png|gif|mp4|mp3|wav|avi)$/i],
    weight: 5
  },
  
  // Project indicators
  project: {
    required: [],
    indicators: ['deadline', 'budget', 'team', 'milestones', 'deliverables', 'projectId'],
    patterns: [],
    weight: 5
  },
  
  // Service indicators
  service: {
    required: [],
    indicators: ['endpoint', 'apiKey', 'serviceUrl', 'port', 'protocol', 'healthCheck'],
    patterns: [/^https?:\/\//, /:\d+$/],
    weight: 4
  }
}

/**
 * Intelligent Type Mapper
 */
export class IntelligentTypeMapper {
  private typeCache: Map<string, string> = new Map()
  private inferenceStats = {
    total: 0,
    inferred: 0,
    defaulted: 0,
    cached: 0
  }

  /**
   * Map a noun type, with intelligent inference for generic types
   */
  mapNounType(inputType: string, data?: any): string {
    // Check if it's already a valid type
    if (this.isValidNounType(inputType)) {
      return inputType
    }
    
    // Check cache for this exact input
    const cacheKey = `${inputType}-${JSON.stringify(data || {}).substring(0, 100)}`
    if (this.typeCache.has(cacheKey)) {
      this.inferenceStats.cached++
      return this.typeCache.get(cacheKey)!
    }
    
    this.inferenceStats.total++
    
    // If it's a generic alias and we have data, try to infer
    if (GENERIC_ALIASES.has(inputType.toLowerCase()) && data) {
      const inferred = this.inferTypeFromData(data)
      if (inferred) {
        this.inferenceStats.inferred++
        this.typeCache.set(cacheKey, inferred)
        return inferred
      }
    }
    
    // Handle specific common mappings
    const directMapping = this.getDirectMapping(inputType)
    if (directMapping) {
      this.typeCache.set(cacheKey, directMapping)
      return directMapping
    }
    
    // Default to 'thing' for truly unknown types
    this.inferenceStats.defaulted++
    const defaultType = NounType.Thing
    this.typeCache.set(cacheKey, defaultType)
    return defaultType
  }

  /**
   * Map a verb type
   */
  mapVerbType(inputType: string): string {
    // Check if it's already valid
    if (this.isValidVerbType(inputType)) {
      return inputType
    }
    
    // Common verb mappings
    const verbMappings: Record<string, string> = {
      'related': VerbType.RelatedTo,
      'relates': VerbType.RelatedTo,
      'has': VerbType.Contains,
      'includes': VerbType.Contains,
      'belongsTo': VerbType.PartOf,
      'in': VerbType.LocatedAt,
      'at': VerbType.LocatedAt,
      'references': VerbType.References,
      'cites': VerbType.References,
      'before': VerbType.Precedes,
      'after': VerbType.Precedes,
      'causes': VerbType.Causes,
      'needs': VerbType.Requires,
      'requires': VerbType.Requires,
      'makes': VerbType.Creates,
      'produces': VerbType.Creates,
      'changes': VerbType.Modifies,
      'updates': VerbType.Modifies,
      'owns': VerbType.Owns,
      'ownedBy': VerbType.Owns,  // Use BelongsTo for reverse ownership
      'uses': VerbType.Uses,
      'usedBy': VerbType.Uses  // Same relationship, just interpret direction
    }
    
    const normalized = inputType.toLowerCase()
    return verbMappings[normalized] || VerbType.RelatedTo
  }

  /**
   * Infer type from data structure
   */
  private inferTypeFromData(data: any): string | null {
    if (!data || typeof data !== 'object') return null
    
    const scores: Map<string, number> = new Map()
    const fields = Object.keys(data)
    const values = Object.values(data)
    
    // Calculate scores for each type based on field matches
    for (const [type, signature] of Object.entries(TYPE_SIGNATURES)) {
      let score = 0
      
      // Check required fields
      if (signature.required.length > 0) {
        const hasRequired = signature.required.every(field => fields.includes(field))
        if (!hasRequired) continue
        score += signature.weight * 2
      }
      
      // Check indicator fields
      for (const field of fields) {
        if (signature.indicators.some(indicator => 
          field.toLowerCase().includes(indicator.toLowerCase())
        )) {
          score += signature.weight
        }
      }
      
      // Check value patterns
      for (const value of values) {
        if (typeof value === 'string' && signature.patterns.length > 0) {
          for (const pattern of signature.patterns) {
            if (pattern.test(value)) {
              score += signature.weight / 2
              break
            }
          }
        }
      }
      
      if (score > 0) {
        scores.set(type, score)
      }
    }
    
    // Return the type with highest score
    if (scores.size > 0) {
      const sorted = Array.from(scores.entries()).sort((a, b) => b[1] - a[1])
      return sorted[0][0]
    }
    
    // Fallback inference based on data structure
    if (fields.includes('url') || fields.includes('href')) {
      return NounType.Document
    }
    
    if (Array.isArray(data) || fields.includes('items') || fields.includes('elements')) {
      return NounType.Collection
    }
    
    // Check if it looks like a process/workflow
    if (fields.includes('steps') || fields.includes('stages')) {
      return NounType.Process
    }
    
    return null
  }

  /**
   * Get direct mapping for common aliases
   */
  private getDirectMapping(inputType: string): string | null {
    const mappings: Record<string, string> = {
      // Specific mappings that aren't generic
      'company': NounType.Organization,
      'corp': NounType.Organization,
      'business': NounType.Organization,
      'employee': NounType.Person,
      'staff': NounType.Person,
      'customer': NounType.Person,
      'client': NounType.Person,
      'article': NounType.Document,
      'post': NounType.Document,
      'page': NounType.Document,
      'image': NounType.Media,
      'video': NounType.Media,
      'audio': NounType.Media,
      'photo': NounType.Media,
      'place': NounType.Location,
      'address': NounType.Location,
      'country': NounType.Location,
      'city': NounType.Location,
      'todo': NounType.Task,
      'job': NounType.Task,
      'work': NounType.Task,
      'meeting': NounType.Event,
      'appointment': NounType.Event,
      'conference': NounType.Event,
      'folder': NounType.Collection,
      'group': NounType.Collection,
      'list': NounType.Collection,
      'category': NounType.Collection
    }
    
    const normalized = inputType.toLowerCase()
    return mappings[normalized] || null
  }

  /**
   * Check if a type is valid
   */
  private isValidNounType(type: string): boolean {
    return Object.values(NounType).includes(type as any)
  }

  /**
   * Check if a verb type is valid
   */
  private isValidVerbType(type: string): boolean {
    return Object.values(VerbType).includes(type as any)
  }

  /**
   * Get inference statistics
   */
  getStats() {
    return {
      ...this.inferenceStats,
      cacheSize: this.typeCache.size,
      inferenceRate: this.inferenceStats.total > 0 
        ? (this.inferenceStats.inferred / this.inferenceStats.total) 
        : 0
    }
  }

  /**
   * Clear the type cache
   */
  clearCache(): void {
    this.typeCache.clear()
  }
}

// Singleton instance
export const typeMapper = new IntelligentTypeMapper()

/**
 * Helper function for easy type mapping
 */
export function mapNounType(inputType: string, data?: any): string {
  return typeMapper.mapNounType(inputType, data)
}

/**
 * Helper function for verb mapping
 */
export function mapVerbType(inputType: string): string {
  return typeMapper.mapVerbType(inputType)
}