package storage

import (
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"time"

	"luxick/chronological/internal/models"
)

// PhotoStore handles scanning and serving photos from the filesystem.
type PhotoStore struct {
	rootFolder string
}

// NewPhotoStore creates a new photo store with the given root folder.
func NewPhotoStore(rootFolder string) *PhotoStore {
	return &PhotoStore{
		rootFolder: rootFolder,
	}
}

// Supported image extensions
var supportedExtensions = map[string]bool{
	".jpg":  true,
	".jpeg": true,
	".png":  true,
	".gif":  true,
	".webp": true,
}

// Filename pattern: YYYY-MM-DD_description.ext
var filenamePattern = regexp.MustCompile(`^(\d{4})-(\d{2})-(\d{2}) (.+)\.(\w+)$`)

// LoadAllPhotos scans and loads all photos from the configured directory.
func (s *PhotoStore) LoadAllPhotos() ([]*models.Photo, error) {
	if s.rootFolder == "" {
		return nil, nil
	}

	var photos []*models.Photo

	// Walk through year folders
	entries, err := os.ReadDir(s.rootFolder)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, fmt.Errorf("failed to read photo root folder: %w", err)
	}

	for _, entry := range entries {
		if !entry.IsDir() {
			continue
		}

		yearFolder := entry.Name()
		yearPath := filepath.Join(s.rootFolder, yearFolder)

		yearPhotos, err := s.loadPhotosFromYear(yearFolder, yearPath)
		if err != nil {
			continue // Skip problematic folders
		}

		photos = append(photos, yearPhotos...)
	}

	return photos, nil
}

// LoadPhotosForMonth loads photos for a specific month.
func (s *PhotoStore) LoadPhotosForMonth(year int, month time.Month) ([]*models.Photo, error) {
	allPhotos, err := s.LoadAllPhotos()
	if err != nil {
		return nil, err
	}

	var monthPhotos []*models.Photo
	for _, photo := range allPhotos {
		if photo.Date.Year() == year && photo.Date.Month() == month {
			monthPhotos = append(monthPhotos, photo)
		}
	}

	return monthPhotos, nil
}

// LoadPhotosForDate loads photos for a specific date.
func (s *PhotoStore) LoadPhotosForDate(date time.Time) ([]*models.Photo, error) {
	allPhotos, err := s.LoadAllPhotos()
	if err != nil {
		return nil, err
	}

	targetDate := date.Truncate(24 * time.Hour)
	var datePhotos []*models.Photo

	for _, photo := range allPhotos {
		if photo.Date.Truncate(24 * time.Hour).Equal(targetDate) {
			datePhotos = append(datePhotos, photo)
		}
	}

	return datePhotos, nil
}

// GetPhotoPath returns the full filesystem path for a photo.
func (s *PhotoStore) GetPhotoPath(year, filename string) string {
	return filepath.Join(s.rootFolder, year, filename)
}

func (s *PhotoStore) loadPhotosFromYear(yearFolder, yearPath string) ([]*models.Photo, error) {
	var photos []*models.Photo

	entries, err := os.ReadDir(yearPath)
	if err != nil {
		return nil, err
	}

	for _, entry := range entries {
		if entry.IsDir() {
			continue
		}

		filename := entry.Name()
		ext := strings.ToLower(filepath.Ext(filename))

		if !supportedExtensions[ext] {
			continue
		}

		photo := parsePhotoFilename(yearFolder, filename, filepath.Join(yearPath, filename))
		if photo != nil {
			photos = append(photos, photo)
		}
	}

	return photos, nil
}

func parsePhotoFilename(yearFolder, filename, fullPath string) *models.Photo {
	matches := filenamePattern.FindStringSubmatch(filename)
	if matches == nil {
		return nil
	}

	dateStr := fmt.Sprintf("%s-%s-%s", matches[1], matches[2], matches[3])
	date, err := time.Parse("2006-01-02", dateStr)
	if err != nil {
		return nil
	}

	description := matches[4]
	// Convert underscores and camelCase to spaces for display
	description = strings.ReplaceAll(description, "_", " ")

	return &models.Photo{
		Date:        date,
		Year:        yearFolder,
		Filename:    filename,
		Description: description,
		FullPath:    fullPath,
	}
}