Add command for removing libraries or releases

Once a library submission is accepted, the registration and releases is stored in the library database. This means that
a library release or library will remain in Library Manager even after the removal of a tag or repository by the library
maintainer, or the removal of the library's registration from the registry.

A library release or library removal requires direct action by a maintainer. This procedure will be facilitated by adding
the capability to the engine tool's command line interface in the form of the new `remove` subcommand.

It can be used to remove specific releases:

```
libraries-repository-engine remove LIBRARY_NAME@VERSION...
```

or libraries entirely:

```
libraries-repository-engine remove LIBRARY_NAME...
```

Author: per1234

internal/cli/remove.go

@@ -0,0 +1,46 @@
+// This file is part of libraries-repository-engine.
+//
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+package cli
+
+import (
+	"github.com/arduino/libraries-repository-engine/internal/command/remove"
+	"github.com/spf13/cobra"
+)
+
+// removeCmd defines the `remove` CLI subcommand.
+var removeCmd = &cobra.Command{
+	Short:                 "Remove libraries or releases",
+	Long:                  "Remove libraries or library releases from Library Manager",
+	DisableFlagsInUseLine: true,
+	Use: `remove [FLAG]... LIBRARY_NAME[@RELEASE]...
+
+Remove library name LIBRARY_NAME Library Manager content entirely.
+-or-
+Remove release RELEASE of library name LIBRARY_NAME from the Library Manager content.`,
+	Run: remove.Run,
+}
+
+func init() {
+	rootCmd.AddCommand(removeCmd)
+}

internal/command/remove/remove.go

@@ -0,0 +1,219 @@
+// This file is part of libraries-repository-engine.
+//
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+// Package remove implements the `remove` CLI subcommand used by the maintainer for removals of libraries or releases.
+package remove
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/arduino/go-paths-helper"
+	"github.com/arduino/libraries-repository-engine/internal/backup"
+	"github.com/arduino/libraries-repository-engine/internal/configuration"
+	"github.com/arduino/libraries-repository-engine/internal/feedback"
+	"github.com/arduino/libraries-repository-engine/internal/libraries"
+	"github.com/arduino/libraries-repository-engine/internal/libraries/archive"
+	"github.com/arduino/libraries-repository-engine/internal/libraries/db"
+	"github.com/arduino/libraries-repository-engine/internal/libraries/metadata"
+
+	"github.com/spf13/cobra"
+)
+
+var config *configuration.Config
+var librariesDb *db.DB
+var libraryData *db.Library
+
+// Run executes the command.
+func Run(command *cobra.Command, cliArguments []string) {
+	config = configuration.ReadConf(command.Flags())
+
+	if len(cliArguments) == 0 {
+		feedback.Error("LIBRARY_NAME argument is required")
+		os.Exit(1)
+	}
+
+	librariesDBPath := paths.New(config.LibrariesDB)
+	exist, err := librariesDBPath.ExistCheck()
+	if err != nil {
+		feedback.Errorf("While checking existence of database file: %s", err)
+		os.Exit(1)
+	}
+	if !exist {
+		feedback.Errorf("Database file not found at %s. Check the LibrariesDB configuration value.", librariesDBPath)
+		os.Exit(1)
+	}
+
+	if err := backup.Backup(librariesDBPath); err != nil {
+		feedback.Errorf("While backing up database: %s", err)
+		os.Exit(1)
+	}
+
+	librariesDb = db.Init(config.LibrariesDB)
+
+	restore, err := removals(cliArguments)
+	if err != nil {
+		feedback.Error(err)
+		if restore {
+			if err := backup.Restore(); err != nil {
+				feedback.Errorf("While restoring the content from backup: %s", err)
+			}
+			fmt.Println("Original files were restored.")
+		} else {
+			if err := backup.Clean(); err != nil {
+				feedback.Errorf("While cleaning up the backup content: %s", err)
+			}
+		}
+		os.Exit(1)
+	}
+
+	if err := librariesDb.Commit(); err != nil {
+		feedback.Errorf("While saving changes to database: %s", err)
+		if err := backup.Restore(); err != nil {
+			feedback.Errorf("While restoring the content from backup: %s", err)
+		}
+		fmt.Println("Original files were restored.")
+		os.Exit(1)
+	}
+
+	if err := backup.Clean(); err != nil {
+		feedback.Errorf("While cleaning up the backup files: %s", err)
+		os.Exit(1)
+	}
+
+	fmt.Println("Success!")
+}
+
+func removals(libraryReferences []string) (bool, error) {
+	for _, libraryReference := range libraryReferences {
+		referenceComponents := strings.SplitN(libraryReference, "@", 2)
+		libraryName := referenceComponents[0]
+		var libraryVersion string
+		if len(referenceComponents) > 1 {
+			if referenceComponents[1] == "" {
+				return false, fmt.Errorf("Missing version for library name %s. For full removal, omit the '@'", libraryName)
+			}
+			libraryVersion = referenceComponents[1]
+		}
+
+		if !librariesDb.HasLibrary(libraryName) {
+			return false, fmt.Errorf("Library name %s not found", libraryName)
+		}
+
+		var err error
+		libraryData, err = librariesDb.FindLibrary(libraryName)
+		if err != nil {
+			return true, err
+		}
+
+		if libraryVersion == "" {
+			// Remove the library entirely.
+			if err := removeLibrary(libraryName); err != nil {
+				return true, err
+			}
+		} else {
+			// Remove only a specific release of the library.
+			if err := removeRelease(libraryName, libraryVersion); err != nil {
+				return true, err
+			}
+		}
+	}
+
+	return false, nil
+}
+
+func removeLibrary(libraryName string) error {
+	fmt.Printf("Removing %s\n", libraryName)
+
+	// Remove the library's release archive files.
+	releasesData := librariesDb.FindReleasesOfLibrary(libraryData)
+	for _, releaseData := range releasesData {
+		if err := removeReleaseArchive(releaseData.Version.String()); err != nil {
+			return err
+		}
+	}
+
+	// Remove the library and its releases from database.
+	if err := librariesDb.RemoveLibrary(libraryName); err != nil {
+		return err
+	}
+
+	// Remove the library Git clone folder.
+	libraryRegistration := libraries.Repo{URL: libraryData.Repository}
+	gitCloneSubfolder, err := libraryRegistration.AsFolder()
+	if err != nil {
+		return err
+	}
+	gitClonePath := paths.New(config.GitClonesFolder, gitCloneSubfolder)
+	if err := backup.Backup(gitClonePath); err != nil {
+		return fmt.Errorf("While backing up library's Git clone: %w", err)
+	}
+	if err := gitClonePath.RemoveAll(); err != nil {
+		return fmt.Errorf("While removing library Git clone: %s", err)
+	}
+
+	return nil
+}
+
+func removeRelease(libraryName string, version string) error {
+	fmt.Printf("Removing %s@%s\n", libraryName, version)
+
+	if !librariesDb.HasReleaseByNameVersion(libraryName, version) {
+		return fmt.Errorf("Library release %s@%s not found", libraryName, version)
+	}
+
+	// Remove the release archive file.
+	if err := removeReleaseArchive(version); err != nil {
+		return err
+	}
+
+	// Remove the release from the database.
+	if err := librariesDb.RemoveReleaseByNameVersion(libraryName, version); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func removeReleaseArchive(version string) error {
+	repositoryObject := libraries.Repository{URL: libraryData.Repository}
+	libraryMetadata := metadata.LibraryMetadata{
+		Name:    libraryData.Name,
+		Version: version,
+	}
+	archiveObject, err := archive.New(&repositoryObject, &libraryMetadata, config)
+	if err != nil {
+		panic(err)
+	}
+
+	archivePath := paths.New(archiveObject.Path)
+	if err := backup.Backup(archivePath); err != nil {
+		return fmt.Errorf("While backing up library release archive: %w", err)
+	}
+	if err := archivePath.RemoveAll(); err != nil {
+		return fmt.Errorf("While removing library release archive: %s", err)
+	}
+
+	return nil
+}