const addon = require('./build/Release/similarity_search_addon');

/**
 * A string similarity search index
 */
class SimilaritySearch {
  /**
   * Create a new SimilaritySearch instance
   * 
   * @param {number} [capacity=500] - Initial capacity of the index
   */
  constructor(capacity = 500) {
    this.index = new addon.SearchIndex(capacity);
  }

  /**
   * Add a string to the search index
   * 
   * @param {string} str - The string to add
   * @returns {boolean} - True if successful, false otherwise
   */
  addString(str) {
    return this.index.addString(str) === 0;
  }

  /**
   * Add multiple strings to the search index
   * 
   * @param {string[]} strings - Array of strings to add
   * @returns {boolean} - True if all adds were successful, false otherwise
   */
  addStrings(strings) {
    let success = true;
    for (const str of strings) {
      if (this.index.addString(str) !== 0) {
        success = false;
      }
    }
    return success;
  }

  /**
   * Search the index for strings similar to the query
   * 
   * @param {string} query - The search query
   * @param {number} [cutoff=0.2] - Similarity threshold (0.0 to 1.0)
   * @returns {Array<{string: string, similarity: number}>} - Array of matching results
   */
  search(query, cutoff = 0.2) {
    return this.index.search(query, cutoff);
  }

  /**
   * Get the number of strings in the index
   * 
   * @returns {number} - Number of strings in the index
   */
  size() {
    return this.index.size();
  }
}

// Add some functions for convenience
/**
 * Generate an index with random test data
 * 
 * @param {number} [size=500] - Number of strings to generate
 * @returns {SimilaritySearch} - A new SimilaritySearch instance with random data
 */
SimilaritySearch.createTestIndex = function(size = 500) {
  const index = new SimilaritySearch(size);
  
  // Add some specific test strings
  index.addString("bio bizz");
  index.addString("lightmix bizz btio substrate");
  index.addString("bizz bio mix light");
  index.addString("plant growth bio formula");
  index.addString("garden soil substrate");
  
  // Generate random strings
  function randomWord(len) {
    const chars = 'abcdefghijklmnopqrstuvwxyz';
    let word = '';
    for (let i = 0; i < len; i++) {
      word += chars.charAt(Math.floor(Math.random() * chars.length));
    }
    return word;
  }
  
  function randomString() {
    const numWords = 2 + Math.floor(Math.random() * 5); // 2-6 words
    let str = '';
    for (let i = 0; i < numWords; i++) {
      if (i > 0) str += ' ';
      str += randomWord(3 + Math.floor(Math.random() * 8)); // 3-10 chars
    }
    return str;
  }
  
  // Generate the rest of the strings
  for (let i = 5; i < size; i++) {
    index.addString(randomString());
  }
  
  return index;
};

/**
 * Benchmark the search performance
 * 
 * @param {SimilaritySearch} index - The index to benchmark
 * @param {string[]} queries - Array of search queries
 * @param {number} [cutoff=0.2] - Similarity threshold to use
 * @returns {Object} - Benchmark results
 */
SimilaritySearch.benchmark = function(index, queries, cutoff = 0.2) {
  const results = [];
  
  for (const query of queries) {
    const start = process.hrtime.bigint();
    const matches = index.search(query, cutoff);
    const end = process.hrtime.bigint();
    
    const timeMs = Number(end - start) / 1000000;
    
    results.push({
      query,
      matches: matches.length,
      timeMs,
      topResults: matches.slice(0, 5)
    });
  }
  
  return results;
};

module.exports = SimilaritySearch;