generator.go

package uniquenamegenerator

import (
	"math/rand"
	"strings"
	"time"

	"github.com/dillonstreator/go-unique-name-generator/dictionaries"
)

// UniqueNameGenerator is a unique name generator instance
type UniqueNameGenerator struct {
	separator    string
	dictionaries [][]string
	transformer  Transformer

	rnd *rand.Rand
}

// NewUniqueNameGenerator creates a new instance of UniqueNameGenerator
func NewUniqueNameGenerator(opts ...option) *UniqueNameGenerator {
	ung := &UniqueNameGenerator{
		separator: "_",
		dictionaries: [][]string{
			dictionaries.Adjectives,
			dictionaries.Colors,
			dictionaries.Names,
		},
		rnd: rand.New(rand.NewSource(time.Now().UTC().UnixNano())),
	}

	for _, opt := range opts {
		opt(ung)
	}

	return ung
}

// Generate generates a new unique name with the configuration
func (ung *UniqueNameGenerator) Generate() string {
	words := make([]string, len(ung.dictionaries))

	for i, dict := range ung.dictionaries {
		randomIndex := ung.rnd.Intn(len(dict))
		word := dict[randomIndex]

		if ung.transformer != nil {
			word = ung.transformer(dict[randomIndex])
		}

		words[i] = word
	}

	return strings.Join(words, ung.separator)
}

// UniquenessCount returns the number of unique combinations
func (ung *UniqueNameGenerator) UniquenessCount() uint64 {
	if len(ung.dictionaries) == 0 {
		return 0
	}

	var count uint64 = 1

	for _, set := range ung.dictionaries {
		count *= uint64(len(set))
	}

	return count
}