package store

import (
	"fmt"
	"strings"

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

type ErrQuizAlreadyPresent struct {
	hash string
}

func (e *ErrQuizAlreadyPresent) Error() string {
	return fmt.Sprintf("Quiz with hash %v is already present in the store.", e.hash)
}

type QuizStore struct {
	// Memory store for quizzes. It satisfies FilterStorer
	// interface.
	*FilterStore[*models.Quiz]

	questions *Store[*models.Question]
	answers   *Store[*models.Answer]
}

func NewQuizStore() *QuizStore {
	store := new(QuizStore)

	store.questions = NewStore[*models.Question]()
	store.answers = NewStore[*models.Answer]()
	store.FilterStore = NewFilterStore[*models.Quiz]()

	return store

}

func (s *QuizStore) Create(quiz *models.Quiz) (*models.Quiz, error) {
	if hash := quiz.GetHash(); hash != "" {
		q, ok := s.hashes[hash]
		if ok {
			return q, &ErrQuizAlreadyPresent{hash}
		}
	}

	question, err := s.questions.Create(quiz.Question)
	if err != nil {
		return nil, err
	}

	answers := make([]*models.Answer, 0)

	for _, a := range quiz.Answers {
		storedAnswer, err := s.answers.Create(a)
		if err != nil {
			return nil, err
		}
		answers = append(answers, storedAnswer)
	}

	tags := make([]*models.Tag, 0)

	q, err := s.Store.Create(&models.Quiz{
		Meta:       quiz.Meta,
		Question:   parseTags[*models.Question](&tags, question)[0],
		Answers:    parseTags[*models.Answer](&tags, answers...),
		Correct:    answers[quiz.CorrectPos],
		CorrectPos: quiz.CorrectPos,
		Tags:       tags,
	})
	if err != nil {
		return nil, err
	}

	return q, nil
}

func (s *QuizStore) Update(quiz *models.Quiz, id string) (*models.Quiz, error) {
	_, err := s.Read(id)
	if err != nil {
		return quiz, err
	}

	question, err := s.questions.Create(quiz.Question)
	if err != nil {
		return nil, err
	}

	answers := make([]*models.Answer, 0)

	for _, a := range quiz.Answers {
		storedAnswer, err := s.answers.Create(a)
		if err != nil {
			return nil, err
		}
		answers = append(answers, storedAnswer)
	}

	tags := make([]*models.Tag, 0)

	q, err := s.Store.Update(&models.Quiz{
		Question:   parseTags[*models.Question](&tags, question)[0],
		Answers:    parseTags[*models.Answer](&tags, answers...),
		Correct:    answers[quiz.CorrectPos],
		CorrectPos: quiz.CorrectPos,
		Tags:       tags,
	}, id)
	if err != nil {
		return nil, err
	}

	return q, nil
}

func (s *QuizStore) FilterInCollection(collection *models.Collection, filter *models.Filter) []*models.Quiz {
	quizzes := s.ReadAll()
	filteredQuizzes := s.Filter(quizzes, func(q *models.Quiz) bool {
		count := 0
		for _, qTag := range q.Tags {
			if s.isTagInFilter(qTag, filter) {
				count++
			}
		}
		if count == len(filter.Tags) {
			return true
		}
		return false
	})

	collection.Quizzes = filteredQuizzes

	return collection.Quizzes
}

func (s *QuizStore) isTagInFilter(tag *models.Tag, filter *models.Filter) bool {
	for _, fTag := range filter.Tags {
		if tag.Name == fTag.Name {
			return true
		}
	}
	return false
}

func parseTags[T fmt.Stringer](tags *[]*models.Tag, entities ...T) []T {
	for _, entity := range entities {
		// Trim the following chars
		trimChars := "*:.,/\\@()[]{}<>"

		// Split the text into words
		words := strings.Fields(entity.String())

		for _, word := range words {
			// If the word starts with '#', it is considered as a tag
			if strings.HasPrefix(word, "#") {
				// Check if the tag already exists in the tags slice
				exists := false
				for _, tag := range *tags {
					if tag.Name == word {
						exists = true
						break
					}
				}

				// If the tag does not exist in the tags slice, add it
				if !exists {
					*tags = append(*tags, &models.Tag{Name: strings.TrimRight(word, trimChars)})
				}
			}
		}
	}

	return entities
}