cat: Add tree subcommand

src/commands/cat.rs

@@ -1,56 +1,119 @@
-use anyhow::{anyhow, bail, Result};
-use clap::Parser;
+use std::path::PathBuf;
+
+use anyhow::{anyhow, Result};
+use clap::{Parser, Subcommand};
 
 use crate::backend::{DecryptReadBackend, FileType, ReadBackend};
+use crate::blob::Tree;
 use crate::id::Id;
 use crate::index::{IndexBackend, ReadIndex};
+use crate::repo::SnapshotFile;
 
 #[derive(Parser)]
 pub(super) struct Opts {
-    /// file type to list
-    tpe: String,
+    #[clap(subcommand)]
+    command: Command,
+}
 
-    /// file type to list
+#[derive(Subcommand)]
+enum Command {
+    Blob(IdOpt),
+    Config(IdOpt),
+    Index(IdOpt),
+    Snapshot(IdOpt),
+    Key(IdOpt),
+    /// display a tree within a snapshot
+    Tree(TreeOpts),
+}
+
+#[derive(Parser)]
+struct IdOpt {
+    /// id to cat
     id: String,
 }
 
+#[derive(Parser)]
+struct TreeOpts {
+    /// snapshot id
+    id: String,
+
+    /// path within snapshot
+    path: PathBuf,
+}
+
 pub(super) fn execute(
     be: &impl ReadBackend,
     dbe: &impl DecryptReadBackend,
     opts: Opts,
 ) -> Result<()> {
-    let tpe = match opts.tpe.as_str() {
+    match opts.command {
+        Command::Config(opt) => cat_file(dbe, FileType::Config, opt),
+        Command::Index(opt) => cat_file(dbe, FileType::Index, opt),
+        Command::Snapshot(opt) => cat_file(dbe, FileType::Snapshot, opt),
+        // special treatment for catting key files: those need no decryption
+        Command::Key(opt) => cat_file(be, FileType::Key, opt),
         // special treatment for catingg blobs: read the index and use it to locate the blob
-        "blob" => {
-            let id = Id::from_hex(&opts.id)?;
-            println!("reading index files..");
-            let index = IndexBackend::new(dbe)?;
-            let dec = index
-                .get_id(&id)
-                .ok_or(anyhow!("blob not found in index"))?
-                .read_data(dbe)?;
-            print!("{}", String::from_utf8_lossy(&dec));
-            return Ok(());
-        }
-        "config" => FileType::Config,
-        "index" => FileType::Index,
-        "snapshot" => FileType::Snapshot,
-        "key" => FileType::Key,
-        t => bail!("invalid type: {}", t),
-    };
+        Command::Blob(opt) => cat_blob(dbe, opt),
+        // special treatment for cating a tree within a snapshot
+        Command::Tree(opts) => cat_tree(dbe, opts),
+    }
+}
 
-    let id = Id::from_hex(&opts.id).or_else(|_| {
+fn cat_file(be: &impl ReadBackend, tpe: FileType, opt: IdOpt) -> Result<()> {
+    let id = Id::from_hex(&opt.id).or_else(|_| {
         // if the given id param is not a full Id, search for a suitable one
-        be.find_starts_with(tpe, &[&opts.id])?.remove(0)
+        be.find_starts_with(tpe, &[&opt.id])?.remove(0)
     })?;
 
-    let dec = match tpe {
-        // special treatment for catting key files: those need no decryption
-        FileType::Key => be.read_full(tpe, &id)?,
-        _ => dbe.read_full(tpe, &id)?,
-    };
+    let dec = be.read_full(tpe, &id)?;
 
     print!("{}", String::from_utf8_lossy(&dec));
 
     Ok(())
 }
+
+fn cat_blob(be: &impl DecryptReadBackend, opt: IdOpt) -> Result<()> {
+    let id = Id::from_hex(&opt.id)?;
+    eprintln!("reading index files..");
+    let index = IndexBackend::new(be)?;
+    let dec = index
+        .get_id(&id)
+        .ok_or(anyhow!("blob not found in index"))?
+        .read_data(be)?;
+    print!("{}", String::from_utf8_lossy(&dec));
+    return Ok(());
+}
+
+fn cat_tree(be: &impl DecryptReadBackend, opts: TreeOpts) -> Result<()> {
+    let snap = SnapshotFile::from_str(be, &opts.id, |_| true)?;
+
+    eprintln!("reading index files..");
+    let index = IndexBackend::new(be)?;
+
+    let mut id = snap.tree;
+
+    for p in opts.path.iter() {
+        let p = p.to_str().unwrap();
+        // TODO: check for root instead
+        if p == "/" {
+            continue;
+        }
+        let tree = Tree::from_backend(&index, &id)?;
+
+        id = tree
+            .nodes()
+            .iter()
+            .find(|node| node.name() == p)
+            .unwrap()
+            .subtree()
+            .unwrap();
+    }
+
+    let dec = index
+        .get_id(&id)
+        .ok_or(anyhow!("blob not found in index"))?
+        .read_data(be)?;
+    print!("{}", String::from_utf8_lossy(&dec));
+
+    return Ok(());
+}