import * as plugins from './smartfuzzy.plugins.js';

/**
 * Result of a fuzzy search on objects
 *
 * @typeParam T - The type of object being searched
 */
export interface IFuzzySearchResult<T> {
  /** The matched object */
  item: T;

  /** The index of the object in the original array */
  refIndex: number;

  /** The match score (lower is better) */
  score?: number;
}

/**
 * Handles fuzzy searching and sorting of objects based on their properties
 *
 * @typeParam T - The type of objects to search through
 *
 * @example
 * ```typescript
 * interface User {
 *   name: string;
 *   email: string;
 * }
 *
 * const users = [
 *   { name: 'John Smith', email: 'john@example.com' },
 *   { name: 'Jane Doe', email: 'jane@example.com' }
 * ];
 *
 * const sorter = new ObjectSorter<User>(users);
 * const results = sorter.sort('john', ['name', 'email']);
 * ```
 */
export class ObjectSorter<T> {
  /**
   * The collection of objects to search through
   */
  public objectDictionary: T[];

  /**
   * Creates a new ObjectSorter instance
   *
   * @param objectDictionaryArg - Array of objects to search through
   */
  constructor(objectDictionaryArg: T[] = []) {
    if (objectDictionaryArg !== undefined && !Array.isArray(objectDictionaryArg)) {
      throw new Error('Object dictionary must be an array');
    }
    this.objectDictionary = objectDictionaryArg;
  }

  /**
   * Searches and sorts objects based on how well they match the search string
   * in the specified object properties
   *
   * @param stringArg - The search query string
   * @param objectKeysArg - Array of object property names to search within
   * @returns Array of results sorted by relevance (best matches first)
   *
   * @example
   * ```typescript
   * // Search for 'john' in both name and email fields
   * const results = sorter.sort('john', ['name', 'email']);
   *
   * // First result is the best match
   * console.log(results[0].item.name); // 'John Smith'
   * ```
   */
  public sort(stringArg: string, objectKeysArg: string[]): Array<IFuzzySearchResult<T>> {
    if (typeof stringArg !== 'string') {
      throw new Error('Search string must be a string');
    }

    if (!Array.isArray(objectKeysArg)) {
      throw new Error('Object keys must be an array');
    }

    if (objectKeysArg.length === 0) {
      throw new Error('At least one object key must be provided for searching');
    }

    // Verify all keys are strings
    for (const key of objectKeysArg) {
      if (typeof key !== 'string') {
        throw new Error('All object keys must be strings');
      }
    }

    // Empty dictionary should return empty results instead of error
    if (this.objectDictionary.length === 0) {
      return [];
    }

    const fuseOptions = {
      shouldSort: true,
      threshold: 0.6,     // Lower values = more strict matching
      location: 0,        // Where to start searching in the string
      distance: 100,      // How far to search in the string
      maxPatternLength: 32,
      minMatchCharLength: 1,
      keys: objectKeysArg,
    };
    const fuse = new plugins.fuseJs<T>(this.objectDictionary, fuseOptions);
    const result = fuse.search(stringArg);
    return result;
  }
}