package store

import (
	"log"
	"sync"
	"time"

	"github.com/google/uuid"
)

// StoredImage represents an image with its data and expiration time
type Image struct {
	Data        []byte
	ContentType string
}

// ImageStore holds uploaded images in memory
type Store struct {
	mu     sync.RWMutex
	images map[string]*Image
}

// NewStore creates a new image store
func newStore() *Store {
	s := &Store{
		images: make(map[string]*Image),
	}
	// Start cleanup goroutine
	return s
}

var store *Store

// Get retrieves an image by ID
func (s *Store) Get(id string) (*Image, bool) {
	s.mu.RLock()
	defer s.mu.RUnlock()

	image, exists := s.images[id]
	if !exists {
		return nil, false
	} else {

		// drop this guy 30 seconds after the first access
		go func(id string) {
			log.Println("delete", id, "in ~30s (after access)")
			time.Sleep(time.Second * 30)

			log.Println("lock map...")
			s.mu.Lock()
			defer s.mu.Unlock()
			log.Println("delete", id)
			delete(s.images, id)
		}(id)
	}

	return image, true
}

// Save stores an image and returns its ID
func (s *Store) Save(data []byte, contentType string) string {
	s.mu.Lock()
	defer s.mu.Unlock()

	id := uuid.New().String()
	s.images[id] = &Image{
		Data:        data,
		ContentType: contentType,
	}

	// start a goroutine to drop this guy in 1 hour
	go func(id string) {
		log.Println("delete", id, "in ~1h (after creation)")
		time.Sleep(time.Hour * 1)

		log.Println("lock map...")
		s.mu.Lock()
		defer s.mu.Unlock()
		log.Println("delete", id)
		delete(s.images, id)
	}(id)

	return id
}

func Get(id string) (*Image, bool) {
	if store == nil {
		store = newStore()
	}

	return store.Get(id)
}

func Save(data []byte, contentType string) string {
	if store == nil {
		store = newStore()
	}
	return store.Save(data, contentType)
}