package question

import (
	"math/rand"
	"strconv"

	"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 = append(bank, q)
}

func QuestionByID(id string) *Question {
	for _, q := range bank {
		if q.ID == id {
			return q
		}
	}
	return nil
}

func Questions(user *models.User, level Level) []*Question {
	// TODO: player skill level should be used to determine which problems to return
	return bank
}

type Question struct {
	ID    string
	Name  string
	Text  string
	Level Level

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

type Level int

const (
	Level1 Level = iota
	Level2
)

type Part int

const (
	Part1 Part = iota
	Part2
)

// TODO: Internal autoincrement id
func UserRandom(u *models.User) *rand.Rand {
	id := u.ID
	if len(id) > 17 {
		id = id[:17]
	}
	seed, _ := strconv.ParseInt(id, 10, 64)
	return rand.New(rand.NewSource(seed))
}