import Foundation

/// The short word list handed to the speech engine as context.
public enum VocabularyBuilder {
    /// Terms first (file order), then the unique right-hand sides of correction pairs; at most `maxTerms` words.
    public static func build(from entries: [DictionaryEntry], maxTerms: Int = 24) -> [String] {
        var out: [String] = []
        var seen = Set<String>()
        func add(_ word: String) {
            let key = word.lowercased()
            guard !word.isEmpty, !seen.contains(key) else { return }
            seen.insert(key)
            out.append(word)
        }
        for entry in entries { if case .term(let term) = entry.kind { add(term) } }
        for entry in entries { if case .correction(_, let wrote) = entry.kind { add(wrote) } }
        return Array(out.prefix(maxTerms))
    }
}