package gallery

import (
	"context"
	"fmt"
	"path/filepath"
	"strings"
	"time"

	"github.com/stashapp/stash/pkg/file"
	"github.com/stashapp/stash/pkg/logger"
	"github.com/stashapp/stash/pkg/models"
	"github.com/stashapp/stash/pkg/plugin"
)

// const mutexType = "gallery"

type FinderCreatorUpdater interface {
	Finder
	Create(ctx context.Context, newGallery *models.Gallery, fileIDs []file.ID) error
	AddFileID(ctx context.Context, id int, fileID file.ID) error
}

type SceneFinderUpdater interface {
	FindByPath(ctx context.Context, p string) ([]*models.Scene, error)
	Update(ctx context.Context, updatedScene *models.Scene) error
	AddGalleryIDs(ctx context.Context, sceneID int, galleryIDs []int) error
}

type ScanHandler struct {
	CreatorUpdater     FullCreatorUpdater
	SceneFinderUpdater SceneFinderUpdater

	PluginCache *plugin.Cache
}

func (h *ScanHandler) Handle(ctx context.Context, f file.File) error {
	baseFile := f.Base()

	// try to match the file to a gallery
	existing, err := h.CreatorUpdater.FindByFileID(ctx, f.Base().ID)
	if err != nil {
		return fmt.Errorf("finding existing gallery: %w", err)
	}

	if len(existing) == 0 {
		// try also to match file by fingerprints
		existing, err = h.CreatorUpdater.FindByFingerprints(ctx, baseFile.Fingerprints)
		if err != nil {
			return fmt.Errorf("finding existing gallery by fingerprints: %w", err)
		}
	}

	if len(existing) > 0 {
		if err := h.associateExisting(ctx, existing, f); err != nil {
			return err
		}
	} else {
		// create a new gallery
		now := time.Now()
		newGallery := &models.Gallery{
			CreatedAt: now,
			UpdatedAt: now,
		}

		logger.Infof("%s doesn't exist. Creating new gallery...", f.Base().Path)

		if err := h.CreatorUpdater.Create(ctx, newGallery, []file.ID{baseFile.ID}); err != nil {
			return fmt.Errorf("creating new gallery: %w", err)
		}

		h.PluginCache.ExecutePostHooks(ctx, newGallery.ID, plugin.GalleryCreatePost, nil, nil)

		existing = []*models.Gallery{newGallery}
	}

	if err := h.associateScene(ctx, existing, f); err != nil {
		return err
	}

	return nil
}

func (h *ScanHandler) associateExisting(ctx context.Context, existing []*models.Gallery, f file.File) error {
	for _, i := range existing {
		found := false
		for _, sf := range i.Files {
			if sf.Base().ID == f.Base().ID {
				found = true
				break
			}
		}

		if !found {
			logger.Infof("Adding %s to gallery %s", f.Base().Path, i.GetTitle())
			i.Files = append(i.Files, f)
		}

		if err := h.CreatorUpdater.AddFileID(ctx, i.ID, f.Base().ID); err != nil {
			return fmt.Errorf("adding file to gallery: %w", err)
		}
	}

	return nil
}

func (h *ScanHandler) associateScene(ctx context.Context, existing []*models.Gallery, f file.File) error {
	galleryIDs := make([]int, len(existing))
	for i, g := range existing {
		galleryIDs[i] = g.ID
	}

	path := f.Base().Path
	withoutExt := strings.TrimSuffix(path, filepath.Ext(path))

	// find scenes with a file that matches
	scenes, err := h.SceneFinderUpdater.FindByPath(ctx, withoutExt)
	if err != nil {
		return err
	}

	for _, scene := range scenes {
		// found related Scene
		if err := h.SceneFinderUpdater.AddGalleryIDs(ctx, scene.ID, galleryIDs); err != nil {
			return err
		}
	}

	return nil
}

// type Scanner struct {
// 	file.Scanner

// 	ImageExtensions    []string
// 	StripFileExtension bool
// 	CaseSensitiveFs    bool
// 	TxnManager         txn.Manager
// 	CreatorUpdater     FinderCreatorUpdater
// 	Paths              *paths.Paths
// 	PluginCache        *plugin.Cache
// 	MutexManager       *utils.MutexManager
// }

// func FileScanner(hasher file.Hasher) file.Scanner {
// 	return file.Scanner{
// 		Hasher:       hasher,
// 		CalculateMD5: true,
// 	}
// }

// func (scanner *Scanner) ScanExisting(ctx context.Context, existing file.FileBased, file file.SourceFile) (retGallery *models.Gallery, scanImages bool, err error) {
// 	scanned, err := scanner.Scanner.ScanExisting(existing, file)
// 	if err != nil {
// 		return nil, false, err
// 	}

// 	// we don't currently store sizes for gallery files
// 	// clear the file size so that we don't incorrectly detect a
// 	// change
// 	scanned.New.Size = ""

// 	retGallery = existing.(*models.Gallery)

// 	path := scanned.New.Path

// 	changed := false

// 	if scanned.ContentsChanged() {
// 		retGallery.SetFile(*scanned.New)
// 		changed = true
// 	} else if scanned.FileUpdated() {
// 		logger.Infof("Updated gallery file %s", path)

// 		retGallery.SetFile(*scanned.New)
// 		changed = true
// 	}

// 	if changed {
// 		scanImages = true
// 		logger.Infof("%s has been updated: rescanning", path)

// 		retGallery.UpdatedAt = time.Now()

// 		// we are operating on a checksum now, so grab a mutex on the checksum
// 		done := make(chan struct{})
// 		scanner.MutexManager.Claim(mutexType, scanned.New.Checksum, done)

// 		if err := txn.WithTxn(ctx, scanner.TxnManager, func(ctx context.Context) error {
// 			// free the mutex once transaction is complete
// 			defer close(done)

// 			// ensure no clashes of hashes
// 			if scanned.New.Checksum != "" && scanned.Old.Checksum != scanned.New.Checksum {
// 				dupe, _ := scanner.CreatorUpdater.FindByChecksum(ctx, retGallery.Checksum)
// 				if dupe != nil {
// 					return fmt.Errorf("MD5 for file %s is the same as that of %s", path, *dupe.Path)
// 				}
// 			}

// 			return scanner.CreatorUpdater.Update(ctx, retGallery)
// 		}); err != nil {
// 			return nil, false, err
// 		}

// 		scanner.PluginCache.ExecutePostHooks(ctx, retGallery.ID, plugin.GalleryUpdatePost, nil, nil)
// 	}

// 	return
// }

// func (scanner *Scanner) ScanNew(ctx context.Context, file file.SourceFile) (retGallery *models.Gallery, scanImages bool, err error) {
// 	scanned, err := scanner.Scanner.ScanNew(file)
// 	if err != nil {
// 		return nil, false, err
// 	}

// 	path := file.Path()
// 	checksum := scanned.Checksum
// 	isNewGallery := false
// 	isUpdatedGallery := false
// 	var g *models.Gallery

// 	// grab a mutex on the checksum
// 	done := make(chan struct{})
// 	scanner.MutexManager.Claim(mutexType, checksum, done)
// 	defer close(done)

// 	if err := txn.WithTxn(ctx, scanner.TxnManager, func(ctx context.Context) error {
// 		qb := scanner.CreatorUpdater

// 		g, _ = qb.FindByChecksum(ctx, checksum)
// 		if g != nil {
// 			exists, _ := fsutil.FileExists(*g.Path)
// 			if !scanner.CaseSensitiveFs {
// 				// #1426 - if file exists but is a case-insensitive match for the
// 				// original filename, then treat it as a move
// 				if exists && strings.EqualFold(path, *g.Path) {
// 					exists = false
// 				}
// 			}

// 			if exists {
// 				logger.Infof("%s already exists.  Duplicate of %s ", path, *g.Path)
// 			} else {
// 				logger.Infof("%s already exists.  Updating path...", path)
// 				g.Path = &path
// 				err = qb.Update(ctx, g)
// 				if err != nil {
// 					return err
// 				}

// 				isUpdatedGallery = true
// 			}
// 		} else if scanner.hasImages(path) { // don't create gallery if it has no images
// 			currentTime := time.Now()

// 			title := fsutil.GetNameFromPath(path, scanner.StripFileExtension)
// 			g = &models.Gallery{
// 				Zip:       true,
// 				Title:     title,
// 				CreatedAt: currentTime,
// 				UpdatedAt: currentTime,
// 			}

// 			g.SetFile(*scanned)

// 			// only warn when creating the gallery
// 			ok, err := isZipFileUncompressed(path)
// 			if err == nil && !ok {
// 				logger.Warnf("%s is using above store (0) level compression.", path)
// 			}

// 			logger.Infof("%s doesn't exist.  Creating new item...", path)
// 			err = qb.Create(ctx, g)
// 			if err != nil {
// 				return err
// 			}

// 			scanImages = true
// 			isNewGallery = true
// 		}

// 		return nil
// 	}); err != nil {
// 		return nil, false, err
// 	}

// 	if isNewGallery {
// 		scanner.PluginCache.ExecutePostHooks(ctx, g.ID, plugin.GalleryCreatePost, nil, nil)
// 	} else if isUpdatedGallery {
// 		scanner.PluginCache.ExecutePostHooks(ctx, g.ID, plugin.GalleryUpdatePost, nil, nil)
// 	}

// 	// Also scan images if zip file has been moved (ie updated) as the image paths are no longer valid
// 	scanImages = isNewGallery || isUpdatedGallery
// 	retGallery = g

// 	return
// }

// // IsZipFileUnmcompressed returns true if zip file in path is using 0 compression level
// func isZipFileUncompressed(path string) (bool, error) {
// 	r, err := zip.OpenReader(path)
// 	if err != nil {
// 		fmt.Printf("Error reading zip file %s: %s\n", path, err)
// 		return false, err
// 	} else {
// 		defer r.Close()
// 		for _, f := range r.File {
// 			if f.FileInfo().IsDir() { // skip dirs, they always get store level compression
// 				continue
// 			}
// 			return f.Method == 0, nil // check compression level of first actual  file
// 		}
// 	}
// 	return false, nil
// }

// func (scanner *Scanner) isImage(pathname string) bool {
// 	return fsutil.MatchExtension(pathname, scanner.ImageExtensions)
// }

// func (scanner *Scanner) hasImages(path string) bool {
// 	readCloser, err := zip.OpenReader(path)
// 	if err != nil {
// 		logger.Warnf("Error while walking gallery zip: %v", err)
// 		return false
// 	}
// 	defer readCloser.Close()

// 	for _, file := range readCloser.File {
// 		if file.FileInfo().IsDir() {
// 			continue
// 		}

// 		if strings.Contains(file.Name, "__MACOSX") {
// 			continue
// 		}

// 		if !scanner.isImage(file.Name) {
// 			continue
// 		}

// 		return true
// 	}

// 	return false
// }