Redid the layout; improved code readability

OBM.go

@@ -12,21 +12,19 @@ import (
 	"github.com/Unbewohnte/OBM/util"
 )
 
-var (
-	WG sync.WaitGroup
-)
+type result struct {
+	beatmapName   string
+	numberOfDiffs uint
+	successful    uint64
+	failed        uint64
+}
 
 type job struct {
-	beatmapFolderPath    string
+	beatmap              manager.Beatmap
 	replacementImagePath string
 	retrievementPath     string
 }
 
-type result struct {
-	successful uint64
-	failed     uint64
-}
-
 func init() {
 	exists, err := settings.DoesExist()
 	if err != nil {
@@ -44,6 +42,8 @@ func init() {
 }
 
 func main() {
+	var WG sync.WaitGroup
+
 	startingTime := time.Now()
 
 	SETTINGS := settings.Get()
@@ -58,23 +58,24 @@ func main() {
 		}
 	}
 
-	beatmaps, err := manager.GetBeatmapFolderPaths(SETTINGS.OsuDir)
+	beatmaps, err := manager.GetBeatmaps(SETTINGS.OsuDir)
 	if err != nil {
-		logger.LogError(true, "Error getting beatmap folders: ", err)
+		logger.LogError(true, "Error getting beatmaps: ", err)
 	}
-	logger.LogInfo(fmt.Sprintf("Found %d beatmap folders", len(beatmaps)))
+	logger.LogInfo(fmt.Sprintf("Found %d beatmaps", len(beatmaps)))
 
 	// creating jobs for workers
 	jobs := make(chan job, len(beatmaps))
 	for _, beatmap := range beatmaps {
 		jobs <- job{
-			beatmapFolderPath:    beatmap,
+			beatmap:              beatmap,
 			replacementImagePath: SETTINGS.BackgroundReplacement.ReplacementImagePath,
 			retrievementPath:     SETTINGS.BackgroundRetrievement.RetrievementPath,
 		}
 	}
 	close(jobs)
 
+	// perform the magic
 	results := make(chan result, len(jobs))
 	workerPool(jobs, results, SETTINGS.Workers, &WG)
 	WG.Wait()
@@ -85,6 +86,9 @@ func main() {
 	for result := range results {
 		successful += result.successful
 		failed += result.failed
+
+		logger.LogInfo(fmt.Sprintf("Beatmap: %s; Number of diffs: %d;\n Successful: %d; Failed: %d",
+			result.beatmapName, result.numberOfDiffs, result.successful, result.failed))
 	}
 	total := successful + failed
 

manager/beatmap.go

@@ -0,0 +1,116 @@
+package manager
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/Unbewohnte/OBM/logger"
+	"github.com/Unbewohnte/OBM/util"
+)
+
+// the main beatmap struct, contains necessary data for functions
+type Beatmap struct {
+	Name  string
+	Path  string
+	Diffs []string
+}
+
+// parses given .osu file and returns the filename of its background
+// NOTE: Osu! beatmap (as whole) can have multiple backgrounds for each .osu file
+// the perfect example : https://osu.ppy.sh/beatmapsets/43701#osu/137122
+// this is why this functions asks for a certain difficulty (.osu filename) to be sure
+// to return the correct background name
+func (BEATMAP *Beatmap) GetBackgroundName(mapName string) (string, error) {
+	beatmapBytes, err := os.ReadFile(filepath.Join(BEATMAP.Path, mapName))
+	if err != nil {
+		return "", err
+	}
+	beatmapContents := string(beatmapBytes)
+
+	// get index of "[Events]" (this is where BG filename is stored)
+	eventsIndex := strings.Index(beatmapContents, "[Events]")
+	if eventsIndex == -1 {
+		return "", errors.New("Could not retrieve index of \"[Events]\"")
+	}
+	// get index of [TimingPoints] (this tag is right after the previous "[Events]" tag,
+	// so we can grab the whole "[Events]" tag contents)
+	timingPointsIndex := strings.Index(beatmapContents, "[TimingPoints]")
+	if timingPointsIndex == -1 {
+		return "", errors.New("Could not retrieve index of \"[TimingPoints]\"")
+	}
+	contentBetween := strings.Split(beatmapContents[eventsIndex:timingPointsIndex], ",")
+
+	for _, chunk := range contentBetween {
+		if util.IsImage(chunk) {
+			return strings.Split(chunk, "\"")[1], nil
+		}
+	}
+	return "", nil
+}
+
+// parses each beatmap`s .osu file for background info;
+// removes original background and replaces it with copied version of given image
+func (BEATMAP *Beatmap) ReplaceBackgrounds(replacementPicPath string) (successful, failed uint64) {
+	// looping through each .osu file of a beatmap
+	for _, diff := range BEATMAP.Diffs {
+		background, err := BEATMAP.GetBackgroundName(diff)
+		if err != nil || background == "" {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Error gettings background filename: %s", diff, err))
+			failed++
+			continue
+		}
+		// remove old bg
+		err = os.Remove(filepath.Join(BEATMAP.Path, background))
+		if err != nil {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Could not remove the old bg: %s", diff, err))
+			failed++
+			continue
+		}
+
+		// copy given picture, thus replacing background
+		err = util.CopyFile(replacementPicPath, filepath.Join(BEATMAP.Path, background))
+		if err != nil {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Could not copy: %s", diff, err))
+			failed++
+			continue
+		}
+		successful++
+	}
+	return successful, failed
+}
+
+// retrieves backgrounds from given beatmap folder (same as in `ReplaceBackgrounds`) and copies them to the retrievement path
+func (BEATMAP *Beatmap) RetrieveBackgrounds(retrievementPath string) (successful, failed uint64) {
+	// looping through each .osu file of a beatmap
+	for _, diff := range BEATMAP.Diffs {
+		background, err := BEATMAP.GetBackgroundName(diff)
+		if err != nil || background == "" {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Error gettings background filename: %s", diff, err))
+			failed++
+			continue
+		}
+
+		// creating directory that represents current beatmap
+		dstPath := filepath.Join(retrievementPath, BEATMAP.Name)
+
+		err = os.MkdirAll(dstPath, os.ModePerm)
+		if err != nil {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Error creating a directory: %s", diff, err))
+			failed++
+			continue
+		}
+
+		// copy background to the `retrievementPath`
+		err = util.CopyFile(filepath.Join(BEATMAP.Path, background), filepath.Join(dstPath, background))
+		if err != nil {
+			logger.LogError(false, fmt.Sprintf("BEATMAP: %s: Could not copy: %s", diff, err))
+			failed++
+			continue
+		}
+		successful++
+	}
+	return successful, failed
+}

manager/paths.go

@@ -0,0 +1,82 @@
+package manager
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/Unbewohnte/OBM/util"
+)
+
+// filepath.Joins the main osu directory with its songs folder
+func getSongsDir(baseOsuDir string) (string, error) {
+	songsDir := filepath.Join(baseOsuDir, "Songs")
+
+	stat, err := os.Stat(songsDir)
+	if err != nil {
+		return "", errors.New(fmt.Sprintf("Could not process the given path : %s", err))
+	}
+	if !stat.IsDir() {
+		return "", errors.New("Given Osu! directory is not a directory !")
+	}
+
+	return songsDir, nil
+}
+
+// checks for .osu files in given path and returns all found instances
+func getDiffs(path string) ([]string, error) {
+	files, err := os.ReadDir(path)
+	if err != nil {
+		return nil, errors.New(fmt.Sprintf("Could not read a directory : %s", err))
+	}
+
+	var diffs []string
+	for _, file := range files {
+		filename := file.Name()
+		if util.IsBeatmap(filename) {
+			diffs = append(diffs, filename)
+		}
+	}
+	return diffs, nil
+}
+
+// constructs a `Beatmap` struct and returns it
+func newBeatmap(name, path string, diffs []string) Beatmap {
+	return Beatmap{
+		Name:  name,
+		Path:  path,
+		Diffs: diffs,
+	}
+}
+
+// returns an array of beatmaps from given base Osu! directory
+func GetBeatmaps(baseOsuDir string) ([]Beatmap, error) {
+	songsDir, err := getSongsDir(baseOsuDir)
+	if err != nil {
+		return nil, err
+	}
+	contents, err := os.ReadDir(songsDir)
+	if err != nil {
+		return nil, errors.New(fmt.Sprintf("Could not read a directory : %s", err))
+	}
+
+	var beatmaps []Beatmap
+	// looping through all folders in yourOsuDir/Songs/ directory
+	for _, file := range contents {
+		if file.IsDir() {
+			// retrieving all necessary data for creating a new instance of a beatmap
+			beatmapName := file.Name()
+			pathToBeatmap := filepath.Join(songsDir, beatmapName)
+			diffs, err := getDiffs(pathToBeatmap)
+			if err != nil {
+				continue
+			}
+			newBeatmap := newBeatmap(beatmapName, pathToBeatmap, diffs)
+
+			beatmaps = append(beatmaps, newBeatmap)
+		}
+	}
+
+	return beatmaps, nil
+}

settings/settings.go

@@ -69,7 +69,7 @@ func Create() error {
 	return nil
 }
 
-// unmarshalls settings.json into struct
+// unmarshalls settings.json into struct and processes the edge-cases
 func Get() Settings {
 	settingsFileContents, err := os.ReadFile(settingsFilename)
 	if err != nil {
@@ -82,6 +82,12 @@ func Get() Settings {
 		logger.LogError(true, fmt.Sprintf("Could not unmarshal json file : %s", err))
 	}
 
+	// if all features are disabled
+	if !settings.BackgroundReplacement.Enabled && !settings.BackgroundRetrievement.Enabled {
+		logger.LogInfo("No features enabled. Exiting...")
+		os.Exit(0)
+	}
+
 	// checking for edge cases or mistakes made in the settings file,
 	// enabled and disabled fields
 	if settings.BackgroundReplacement.Enabled {

util/copy.go

@@ -8,14 +8,14 @@ import (
 )
 
 // opens given files, copies one into another
-func CopyFile(src, dst string) error {
-	srcFile, err := os.Open(src)
+func CopyFile(srcPath, dstPath string) error {
+	srcFile, err := os.Open(srcPath)
 	if err != nil {
 		return errors.New(fmt.Sprintf("Could not open src file : %s", err))
 	}
 	defer srcFile.Close()
 
-	dstFile, err := os.OpenFile(dst, os.O_WRONLY, os.ModePerm)
+	dstFile, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE, os.ModePerm)
 	if err != nil {
 		return errors.New(fmt.Sprintf("Could not open dst file : %s", err))
 	}

worker.go

@@ -2,8 +2,6 @@ package main
 
 import (
 	"sync"
-
-	"github.com/Unbewohnte/OBM/manager"
 )
 
 // a basic implementation of a concurrent worker
@@ -13,18 +11,20 @@ func worker(jobs <-chan job, results chan result, WG *sync.WaitGroup) {
 		var successful, failed uint64 = 0, 0
 
 		if job.retrievementPath != "" {
-			s, f := manager.RetrieveBackgrounds(job.beatmapFolderPath, job.retrievementPath)
+			s, f := job.beatmap.RetrieveBackgrounds(job.retrievementPath)
 			successful += s
 			failed += f
 		}
 		if job.replacementImagePath != "" {
-			s, f := manager.ReplaceBackgrounds(job.beatmapFolderPath, job.replacementImagePath)
+			s, f := job.beatmap.ReplaceBackgrounds(job.replacementImagePath)
 			successful += s
 			failed += f
 		}
 		results <- result{
-			successful: successful,
-			failed:     failed,
+			beatmapName:   job.beatmap.Name,
+			numberOfDiffs: uint(len(job.beatmap.Diffs)),
+			successful:    successful,
+			failed:        failed,
 		}
 	}