package question

import (
	"math/rand"

	"github.com/hhhapz/codequest/models"
)

var bank Bank

// Bank is a map of different questions registered.
// The key of the map is the ID of the question.
//
// A custom type was created for convenience for picking random questions based
// on difficulties, and for registration.
type Bank [][]*Question

func Register(q *Question) {
	bank[q.Level] = append(bank[q.Level], q)
}

func Questions(user *models.User, level Level) []*Question {
	qs := make([]*Question, len(bank))
	r := rand.New(rand.NewSource(user.CreatedAt.Time().Unix()))
	for level := range bank {
		idx := r.Intn(len(bank[level]))
		qs[level] = bank[level][idx]
	}

	return qs
}

type Question struct {
	ID    string
	Text  string
	Level Level

	Generate func(user *models.User) string
	Validate func(user *models.User, solution string) bool
}

// Level represents the difficulty of each question.
// As the level gets higher, the difficulty also gets higher.
type Level int

// Allowed difficulty levels.
const (
	Level1 Level = iota
	Level2
	Level3
)