Implementation of an uninstall command. Not completed yet.

cmd/mccl/commands/uninstall_command.go

@@ -0,0 +1,167 @@
+package commands
+
+import (
+	"errors"
+	"fmt"
+	"mccl/internal/assets"
+	"mccl/internal/manifest"
+	"mccl/pkg/util"
+	"os"
+	"path"
+)
+
+type UninstallCommand struct {
+	Id      string
+	GameDir string
+}
+
+func NewUninstallCommand(id, gameDir string) *UninstallCommand {
+	return &UninstallCommand{Id: id, GameDir: gameDir}
+}
+
+func (uc *UninstallCommand) Run() error {
+	if uc.Id == "" {
+		return errors.New("an empty Minecraft version was provided")
+	}
+	if uc.GameDir == "" {
+		return errors.New("an empty path was provided")
+	}
+	return uc.uninstall_client()
+}
+
+func (uc *UninstallCommand) uninstall_client() error {
+	var err error
+
+	if uc.GameDir == "." {
+		execPath, _ := os.Executable()
+		uc.GameDir = path.Dir(execPath)
+	}
+
+	if _, err := os.Stat(uc.GameDir); err != nil {
+		return os.ErrNotExist
+	}
+
+	manifests := make(map[string]*manifest.Manifest)
+
+	entries, err := os.ReadDir(path.Join(uc.GameDir, "versions"))
+	if err != nil {
+		return err
+	}
+	for _, entry := range entries {
+		if entry.IsDir() {
+			data, err := util.ReadFile(path.Join(uc.GameDir, "versions", entry.Name(), entry.Name()+".json"))
+			if err != nil {
+				return err
+			}
+			manifests[entry.Name()], err = manifest.New(data)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	for id, manifest := range manifests {
+		if id == uc.Id {
+			continue
+		}
+
+		if manifest.InheritsFrom == uc.Id {
+			return fmt.Errorf("%s inherits %s. Uninstall %s first", id, uc.Id, id)
+		}
+	}
+
+	assetIndexInUse := manifests[uc.Id].InheritsFrom != ""
+	logConfigInUse := manifests[uc.Id].InheritsFrom != ""
+	libsToDelete := make(map[string]string)
+
+	for _, lib := range manifests[uc.Id].Libraries {
+		libsToDelete[lib.Name] = lib.Path()
+	}
+
+	for id, manifest := range manifests {
+		if id == uc.Id {
+			continue
+		}
+
+		if !assetIndexInUse && manifests[uc.Id].Assets == manifest.Assets {
+			assetIndexInUse = true
+		}
+
+		if !logConfigInUse && manifests[uc.Id].Logging.Client.File.Id == manifest.Logging.Client.File.Id {
+			logConfigInUse = true
+		}
+
+		for _, lib := range manifest.Libraries {
+			if name, ok := libsToDelete[lib.Name]; ok {
+				delete(libsToDelete, name)
+			}
+		}
+	}
+
+	if !logConfigInUse {
+		dir := path.Join(uc.GameDir, "assets", "log_configs")
+		if err := os.Remove(path.Join(dir, manifests[uc.Id].Logging.Client.File.Id)); err != nil {
+			return fmt.Errorf("failed to remove assets/log_configs/%s: %s", manifests[uc.Id].Logging.Client.File.Id, err)
+		}
+		if d, err := os.ReadDir(dir); err == nil && len(d) == 0 {
+			if err := os.Remove(path.Join(dir, manifests[uc.Id].Logging.Client.File.Id)); err != nil {
+				return fmt.Errorf("failed to remove assets/log_configs directory: %s", err)
+			}
+		}
+	}
+
+	if !assetIndexInUse {
+		dir := path.Join(uc.GameDir, "assets")
+
+		assetFiles := make(map[string]*assets.Assets)
+
+		for _, manifest := range manifests {
+			if _, ok := assetFiles[manifest.Assets]; !ok {
+				data, err := os.ReadFile(path.Join(dir, "indexes", manifest.Assets+".json"))
+				if err != nil {
+					return fmt.Errorf("failed to read an index %s file: %s", manifest.Assets, err)
+				}
+				assetFiles[manifest.Assets], err = assets.New(data)
+				if err != nil {
+					return fmt.Errorf("failed to load asset index %s: %s", manifest.Assets, err)
+				}
+			}
+		}
+
+		toRemove := []string{}
+
+		for name, obj := range assetFiles[manifests[uc.Id].Assets].Objects {
+			inUse := false
+			for id, idx := range assetFiles {
+				if id == manifests[uc.Id].Assets {
+					continue
+				}
+				if iobj, ok := idx.Objects[name]; ok && iobj.Hash == obj.Hash {
+					inUse = true
+				}
+			}
+
+			if !inUse {
+				toRemove = append(toRemove, obj.Hash)
+			}
+		}
+
+		for _, hash := range toRemove {
+			if err := os.Remove(path.Join(dir, "objects", hash[:2], hash)); err != nil {
+				return fmt.Errorf("failed to remove an object %s/%s: %s", hash[:2], hash, err)
+			}
+		}
+
+		if err := os.Remove(path.Join(dir, "indexes", manifests[uc.Id].Assets+".json")); err != nil {
+			return fmt.Errorf("failed to remove %s: %s", path.Join("assets", "indexes", manifests[uc.Id].Assets+".json"), err)
+		}
+	}
+
+	for _, path := range libsToDelete {
+		if err := os.Remove(path); err != nil {
+			return fmt.Errorf("failed to remove %s: %s", path, err)
+		}
+	}
+
+	return nil
+}