// Package bip39wordlist provides the BIP39 English wordlist and helpers for
// validating, normalizing, and generating BIP39 mnemonic phrases.
//
// The wordlist is embedded in the binary from english.txt and parsed once
// at package initialization. The mnemonic helpers accept phrases in any
// letter case and with any whitespace between words; NormalizeWordlist
// returns the canonical lowercase, single-space-separated form that BIP39
// seed derivation requires, and refuses anything that is not a valid
// mnemonic.
package bip39wordlist

import (
	_ "embed"
	"slices"
	"strings"
)

// WordlistSize is the number of words in a BIP39 wordlist.
const WordlistSize = 2048

//go:embed english.txt
var englishWordlistData string

// WordlistEnglish is the BIP39 English wordlist, one entry per word, in
// the canonical (sorted) BIP39 order. Callers must not modify it.
//
//nolint:gochecknoglobals // static lookup table parsed once from embedded data
var WordlistEnglish = strings.Fields(englishWordlistData)

// Wordlist is the default wordlist, which is WordlistEnglish. Callers must
// not modify it.
//
//nolint:gochecknoglobals // static lookup table, alias of WordlistEnglish
var Wordlist = WordlistEnglish

// Contains reports whether word is in the English wordlist. The comparison
// is exact, so word must already be lowercase.
func Contains(word string) bool {
	_, found := slices.BinarySearch(WordlistEnglish, word)

	return found
}