testhub/store/memory.go

package store

import (
	"crypto/sha256"
	"fmt"
	"sync"

	"git.andreafazzi.eu/andrea/testhub/models"
)

type MemoryQuizHubCollectorStore struct {
	questions  map[string]*models.Question
	answers    map[string]*models.Answer
	tests      map[uint]*models.Quiz
	lastQuizID uint

	questionAnswer map[string][]string
	testQuestion   map[string]uint

	// A mutex is used to synchronize read/write access to the map
	lock sync.RWMutex
}

func NewMemoryQuizHubCollectorStore() *MemoryQuizHubCollectorStore {
	s := new(MemoryQuizHubCollectorStore)

	s.questions = make(map[string]*models.Question)
	s.answers = make(map[string]*models.Answer)
	s.tests = make(map[uint]*models.Quiz)

	return s
}

func (s *MemoryQuizHubCollectorStore) ReadAllQuizzes() ([]*models.Quiz, error) {
	result := make([]*models.Quiz, 0)
	for _, t := range s.tests {
		result = append(result, t)
	}
	return result, nil
}

func (s *MemoryQuizHubCollectorStore) CreateQuiz(r *CreateQuizRequest) *models.Quiz {
	questionID := hash(r.Question.Text)
	test := new(models.Quiz)
	q, ok := s.questions[questionID]
	if !ok { // if the question is not in the store add it
		s.questions[questionID] = &models.Question{
			ID:   questionID,
			Text: r.Question.Text,
		}
		q = s.questions[questionID]
	}
	// Populate Question field
	test.Question = q
	for _, answer := range r.Answers {
		// Calculate the hash from text
		answerID := hash(answer.Text)
		_, ok := s.answers[answerID]
		if !ok { // if the answer is not in the store add it
			s.answers[answerID] = &models.Answer{
				ID:   answerID,
				Text: answer.Text,
			}
		}
		if answer.Correct {
			test.Correct = s.answers[answerID]
		}
		test.Answers = append(test.Answers, s.answers[answerID])
	}

	s.lastQuizID++
	test.ID = s.lastQuizID
	s.tests[s.lastQuizID] = test

	return test
}

func hash(text string) string {
	return fmt.Sprintf("%x", sha256.Sum256([]byte(text)))
}