package memory

import (
	"sync"

	"git.andreafazzi.eu/andrea/probo/client"
	"git.andreafazzi.eu/andrea/probo/hasher"
	"git.andreafazzi.eu/andrea/probo/models"
	"github.com/google/uuid"
)

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

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

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

	hasher hasher.Hasher
}

func NewMemoryQuizHubCollectorStore(hasher hasher.Hasher) *MemoryQuizHubCollectorStore {
	s := new(MemoryQuizHubCollectorStore)

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

	return s
}

func (s *MemoryQuizHubCollectorStore) readQuiz(id string) *models.Quiz {
	s.lock.RLock()
	defer s.lock.RUnlock()

	quiz, ok := s.quizzes[id]
	if ok {
		return quiz
	}

	return nil
}

func (s *MemoryQuizHubCollectorStore) readQuestion(id string) *models.Question {
	s.lock.RLock()
	defer s.lock.RUnlock()

	question, ok := s.questions[id]
	if ok {
		return question
	}

	return nil
}

func (s *MemoryQuizHubCollectorStore) readAnswer(id string) *models.Answer {
	s.lock.RLock()
	defer s.lock.RUnlock()

	answer, ok := s.answers[id]
	if ok {
		return answer
	}

	return nil
}

func (s *MemoryQuizHubCollectorStore) createQuiz(id string, hash string, quiz *models.Quiz) *models.Quiz {
	s.lock.Lock()
	defer s.lock.Unlock()

	quiz.ID = id
	s.quizzes[hash] = quiz

	return quiz
}

func (s *MemoryQuizHubCollectorStore) createQuestion(id string, question *models.Question) *models.Question {
	s.lock.Lock()
	defer s.lock.Unlock()

	s.questions[id] = question

	return question
}

func (s *MemoryQuizHubCollectorStore) createAnswer(id string, answer *models.Answer) *models.Answer {
	s.lock.Lock()
	defer s.lock.Unlock()

	s.answers[id] = answer

	return answer
}

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

func (s *MemoryQuizHubCollectorStore) CreateQuiz(r *client.CreateQuizRequest) (*models.Quiz, error) {
	hashes := s.hasher.QuizHashes(r.Quiz)

	quizID := uuid.New().String()
	quizHash := hashes[len(hashes)-1]

	quiz := s.readQuiz(quizHash)
	if quiz != nil { // Quiz is already present in the store
		return quiz, nil
	}

	quiz = new(models.Quiz)

	questionHash := hashes[0]
	q := s.readQuestion(questionHash)
	if q == nil { // if the question is not in the store then we should add it
		q = s.createQuestion(questionHash, &models.Question{
			ID:   uuid.New().String(),
			Text: r.Question.Text,
		})
	}

	// Populate Question field
	quiz.Question = q
	for i, answer := range r.Answers {
		answerHash := hashes[i+1]
		a := s.readAnswer(answerHash)
		if a == nil { // if the answer is not in the store add it
			a = s.createAnswer(answerHash, &models.Answer{
				ID:   uuid.New().String(),
				Text: answer.Text,
			})
			if answer.Correct {
				quiz.Correct = a // s.readAnswer(answerID)
			}
		}
		quiz.Answers = append(quiz.Answers, a)
	}

	return s.createQuiz(quizID, quizHash, quiz), nil
}

func (s *MemoryQuizHubCollectorStore) UpdateQuiz(r *client.UpdateQuizRequest) (*models.Quiz, error) {
	hashes := s.hasher.QuizHashes(r.Quiz)

	quizID := uuid.New().String()
	quizHash := hashes[len(hashes)-1]

	quiz := s.readQuiz(quizHash)
	if quiz != nil { // Quiz is already present in the store
		return quiz, nil
	}

	quiz = new(models.Quiz)

	questionHash := hashes[0]
	q := s.readQuestion(questionHash)
	if q == nil { // if the question is not in the store then we should add it
		q = s.createQuestion(questionHash, &models.Question{
			ID:   uuid.New().String(),
			Text: r.Question.Text,
		})
	}

	// Populate Question field
	quiz.Question = q
	for i, answer := range r.Answers {
		answerHash := hashes[i+1]
		a := s.readAnswer(answerHash)
		if a == nil { // if the answer is not in the store add it
			a = s.createAnswer(answerHash, &models.Answer{
				ID:   uuid.New().String(),
				Text: answer.Text,
			})
			if answer.Correct {
				quiz.Correct = a // s.readAnswer(answerID)
			}
		}
		quiz.Answers = append(quiz.Answers, a)
	}

	return s.createQuiz(quizID, quizHash, quiz), nil
}