feat: add extract command

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://git.rustybever.be/Chewing_Bever/alex/src/branch/dev)
 
+### Added
+
+* Extract command for working with the output of export
+
 ### Changed
 
 * Export command no longer reads backups that do not contribute to the final

src/backup/mod.rs

@@ -55,6 +55,45 @@ impl Backup<()> {
         let filename = format!("{}", start_time.format(Self::FILENAME_FORMAT));
         backup_dir.join(filename)
     }
+
+    /// Extract an archive.
+    ///
+    /// # Arguments
+    ///
+    /// * `backup_path` - Path to the archive to extract
+    /// * `dirs` - list of tuples `(path_in_tar, dst_dir)` with `dst_dir` the directory on-disk
+    ///     where the files stored under `path_in_tar` inside the tarball should be extracted to.
+    pub fn extract_archive<P: AsRef<Path>>(
+        archive_path: P,
+        dirs: &Vec<(PathBuf, PathBuf)>,
+    ) -> io::Result<()> {
+        let tar_gz = File::open(archive_path)?;
+        let enc = GzDecoder::new(tar_gz);
+        let mut ar = tar::Archive::new(enc);
+
+        // Unpack each file by matching it with one of the destination directories and extracting
+        // it to the right path
+        for entry in ar.entries()? {
+            let mut entry = entry?;
+            let entry_path_in_tar = entry.path()?.to_path_buf();
+
+            for (path_in_tar, dst_dir) in dirs {
+                if entry_path_in_tar.starts_with(path_in_tar) {
+                    let dst_path =
+                        dst_dir.join(entry_path_in_tar.strip_prefix(path_in_tar).unwrap());
+
+                    // Ensure all parent directories are present
+                    std::fs::create_dir_all(dst_path.parent().unwrap())?;
+
+                    entry.unpack(dst_path)?;
+
+                    break;
+                }
+            }
+        }
+
+        Ok(())
+    }
 }
 
 impl<T: Clone> Backup<T> {
@@ -199,31 +238,8 @@ impl<T: Clone> Backup<T> {
         backup_dir: P,
         dirs: &Vec<(PathBuf, PathBuf)>,
     ) -> io::Result<()> {
-        let path = Backup::path(backup_dir, self.start_time);
-        let tar_gz = File::open(path)?;
-        let enc = GzDecoder::new(tar_gz);
-        let mut ar = tar::Archive::new(enc);
-
-        // Unpack each file by matching it with one of the destination directories and extracting
-        // it to the right path
-        for entry in ar.entries()? {
-            let mut entry = entry?;
-            let entry_path_in_tar = entry.path()?.to_path_buf();
-
-            for (path_in_tar, dst_dir) in dirs {
-                if entry_path_in_tar.starts_with(path_in_tar) {
-                    let dst_path =
-                        dst_dir.join(entry_path_in_tar.strip_prefix(path_in_tar).unwrap());
-
-                    // Ensure all parent directories are present
-                    std::fs::create_dir_all(dst_path.parent().unwrap())?;
-
-                    entry.unpack(dst_path)?;
-
-                    break;
-                }
-            }
-        }
+        let backup_path = Backup::path(backup_dir, self.start_time);
+        Backup::extract_archive(backup_path, dirs)?;
 
         // Remove any files
         for (path_in_tar, dst_dir) in dirs {

src/cli/backup.rs

@@ -12,10 +12,13 @@ pub enum BackupCommands {
     List(BackupListArgs),
     /// Manually create a new backup
     Create(BackupCreateArgs),
-    /// Restore a backup
+    /// Restore a backup including all of its required predecessors
     Restore(BackupRestoreArgs),
     /// Export a backup into a full archive
     Export(BackupExportArgs),
+    /// Extract a single backup; meant as a convenience method for working with the output of
+    /// `export`
+    Extract(BackupExtractArgs),
 }
 
 #[derive(Args)]
@@ -63,6 +66,22 @@ pub struct BackupExportArgs {
     make: bool,
 }
 
+#[derive(Args)]
+pub struct BackupExtractArgs {
+    /// Path to the backup to extract
+    path: PathBuf,
+    /// Directory to store config in
+    output_config: PathBuf,
+    /// Directory to store worlds in
+    output_worlds: PathBuf,
+    /// Whether to overwrite the contents of the output directories
+    #[arg(short, long, default_value_t = false)]
+    force: bool,
+    /// Create output directories if they don't exist
+    #[arg(short, long, default_value_t = false)]
+    make: bool,
+}
+
 impl BackupArgs {
     pub fn run(&self, cli: &Cli) -> io::Result<()> {
         match &self.command {
@@ -70,6 +89,7 @@ impl BackupArgs {
             BackupCommands::List(args) => args.run(cli),
             BackupCommands::Restore(args) => args.run(cli),
             BackupCommands::Export(args) => args.run(cli),
+            BackupCommands::Extract(args) => args.run(cli),
         }
     }
 }
@@ -219,3 +239,44 @@ impl BackupExportArgs {
         }
     }
 }
+
+impl BackupExtractArgs {
+    pub fn run(&self, _cli: &Cli) -> io::Result<()> {
+        // Create directories if needed
+        if self.make {
+            std::fs::create_dir_all(&self.output_config)?;
+            std::fs::create_dir_all(&self.output_worlds)?;
+        }
+
+        let output_config = self.output_config.canonicalize()?;
+        let output_worlds = self.output_worlds.canonicalize()?;
+        let backup_path = self.path.canonicalize()?;
+
+        // Clear previous contents of directories
+        let mut entries = output_config
+            .read_dir()?
+            .chain(output_worlds.read_dir()?)
+            .peekable();
+
+        if entries.peek().is_some() && !self.force {
+            return Err(other("Output directories are not empty. If you wish to overwrite these contents, use the force flag."));
+        }
+
+        for entry in entries {
+            let path = entry?.path();
+
+            if path.is_dir() {
+                std::fs::remove_dir_all(path)?;
+            } else {
+                std::fs::remove_file(path)?;
+            }
+        }
+
+        let dirs = vec![
+            (PathBuf::from("config"), output_config),
+            (PathBuf::from("worlds"), output_worlds),
+        ];
+
+        Backup::extract_archive(backup_path, &dirs)
+    }
+}