package repositories

import (
	"crypto/md5"
	"errors"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"whimsoc/vindn-backend/models"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

type EventRepository interface {
	Save(event *models.Event) error
	FindAll() ([]models.Event, error)
	SoftDeleteEndedBefore(cutoffDate string) (int64, error)
}

type eventRepository struct {
	db *gorm.DB
}

func NewEventRepository(db *gorm.DB) EventRepository {
	return &eventRepository{db}
}

func (r *eventRepository) Save(event *models.Event) error {
	if event.Geo != nil && event.Geo.Main != nil {
		event.Latitude = event.Geo.Main.Latitude
		event.Longitude = event.Geo.Main.Longitude
	}

	var categories []models.Category
	for _, name := range event.CategoryNames {
		if name == "" {
			continue
		}
		var cat models.Category
		if err := r.db.FirstOrCreate(&cat, models.Category{Name: name}).Error; err != nil {
			return err
		}
		categories = append(categories, cat)
	}

	event.Categories = categories

	var mediaObjects []models.MediaObject
	for _, rawMediaObject := range event.RawMediaObjects {
		if rawMediaObject.Name == "" {
			continue
		}
		var mediaObject models.MediaObject
		h := md5.New()
		io.WriteString(h, rawMediaObject.Rel)
		io.WriteString(h, rawMediaObject.Name)
		io.WriteString(h, rawMediaObject.URL)

		if err := r.db.FirstOrCreate(&mediaObject, models.MediaObject{
			Hash:        fmt.Sprintf("%x", h.Sum(nil)),
			RefID:       rawMediaObject.RefID,
			Name:        rawMediaObject.Name,
			URL:         rawMediaObject.URL,
			Type:        rawMediaObject.Type,
			Rel:         rawMediaObject.Rel,
			Alt:         rawMediaObject.Alt,
			Source:      rawMediaObject.Source,
			Description: rawMediaObject.Description,
			Prio:        rawMediaObject.Prio,
			AiOptimized: rawMediaObject.AiOptimized,
			License:     rawMediaObject.License,
			Ext:         filepath.Ext(rawMediaObject.URL),
		}).Error; err != nil {
			return err
		}

		if mediaObject.Type != "" {
			mediaType, _, mediaTypeFound := strings.Cut(mediaObject.Type, "/")
			if err := r.saveMediaFile(mediaObject.Hash, mediaObject.URL, mediaType, mediaObject.Ext); mediaTypeFound && err != nil {
				log.Fatal(err)
			}
		}
		mediaObjects = append(mediaObjects, mediaObject)
	}

	event.MediaObjects = mediaObjects

	return r.db.Clauses(clause.OnConflict{
		Columns:   []clause.Column{{Name: "external_id"}},
		UpdateAll: true,
	}).Create(event).Error
}

func (r *eventRepository) FindAll() ([]models.Event, error) {
	var events []models.Event
	result := r.db.Find(&events)
	return events, result.Error
}

// SoftDeleteEndedBefore marks events whose end_date is before cutoffDate
// (an exclusive "YYYY-MM-DD" boundary, the same lexicographic string
// comparison the frontend uses for its own date filtering) as deleted.
// .Delete() on a gorm.Model sets deleted_at rather than removing the row,
// consistent with how the frontend already treats soft-deleted events.
// Events with a blank end_date are left alone — there's nothing to
// compare, so leaving them is safer than guessing they're stale.
func (r *eventRepository) SoftDeleteEndedBefore(cutoffDate string) (int64, error) {
	result := r.db.Where("end_date <> '' AND end_date < ?", cutoffDate).Delete(&models.Event{})
	return result.RowsAffected, result.Error
}

func (r *eventRepository) saveMediaFile(filename string, url string, mediaType string, extension string) error {
	mediaFilePath := fmt.Sprintf("./public/storage/%s/%s%s", strings.ToLower(mediaType), filename, extension)

	log.Printf("Get file %s and save it to %s", url, mediaFilePath)

	// Check if the directory exists
	if _, err := os.Stat(filepath.Dir(mediaFilePath)); os.IsNotExist(err) {
		// Create the directory if it doesn't exist
		err := os.MkdirAll(filepath.Dir(mediaFilePath), 0755) // 0755 is a common permission for directories
		if err != nil {
			return fmt.Errorf("failed to create directory: %v", err)
		}
	}

	fileInfo, err := os.Stat(mediaFilePath)

	if errors.Is(err, os.ErrNotExist) || fileInfo.Size() == 0 {
		// Create the file
		out, err := os.Create(mediaFilePath)
		if err != nil {
			return err
		}
		defer out.Close()

		// Get the data
		resp, err := http.Get(url)
		if err != nil {
			return err
		}
		defer resp.Body.Close()

		// Write the body to file
		_, err = io.Copy(out, resp.Body)
		if err != nil {
			return err
		}

	} else {
		log.Printf("File already exists, do not download again. Stats: Name: %s, Size: %d", fileInfo.Name(), fileInfo.Size())
	}

	return nil
}