/**
 * Interfaces and constants used by the lexical model compiler. These target
 * the LMLayer's internal worker code, so we provide those definitions too.
 */

interface LexicalModelDeclaration {
  readonly format: 'trie-1.0'|'fst-foma-1.0'|'custom-1.0',
  //... metadata ...
}

/**
 * Keyman 14.0+ word breaker specification:
 *
 * Can support all old word breaking specification,
 * but can also be extended with options.
 */
interface WordBreakerSpec {
  readonly use: SimpleWordBreakerSpec;
  /**
   * If present, joins words that were split by the word breaker
   * together at the given strings. e.g.,
   *
   *    joinWordsAt: ['-'] // to keep hyphenated items together
   */
  readonly joinWordsAt?: string[];
}

/**
 * Keyman 11.0+ word breaker specification:
 */
type SimpleWordBreakerSpec = 'default' | 'ascii' | WordBreakingFunction;

interface LexicalModelSource extends LexicalModelDeclaration {
  readonly sources: Array<string>;
  /**
   * The name of the type to instantiate (without parameters) as the base object for a custom predictive model.
   */
  readonly rootClass?: string

  /**
   * Which word breaker to use. Choose from:
   *
   *  - 'default' -- breaks according to Unicode UAX #29 §4.1 Default Word
   *    Boundary Specification, which works well for *most* languages.
   *  - 'ascii' -- a very simple word breaker, for demonstration purposes only.
   *  - word breaking function -- provide your own function that breaks words.
   *  - class-based word-breaker - may be supported in the future.
   */
  readonly wordBreaker?: WordBreakerSpec | SimpleWordBreakerSpec;

  /**
   * How to simplify words, to convert them into simplifired search keys
   * This often involves removing accents, lowercasing, etc.
   */
  readonly searchTermToKey?: (term: string) => string;

  /**
   * Punctuation and spacing suggested by the model.
   *
   * @see LexicalModelPunctuation
   */
  readonly punctuation?: LexicalModelPunctuation;
}

interface LexicalModelCompiled extends LexicalModelDeclaration {
  readonly id: string;
}