deb: cross-compilation, ephemeral contexts, local builds

Multiple changes:
- New contexts (schroot, unshare)
- Cross-building quirks, with ephemeral contexts and repositories management
- Contexts with parents, global context manager, better lifetime handling
- Local building of binary packages
- Pull: pulling dsc files by default
- Many small bugfixes and changes

Co-authored-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Co-committed-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>

src/context/mod.rs

@@ -1,16 +1,20 @@
 mod api;
 mod local;
 mod manager;
+mod schroot;
 mod ssh;
+mod unshare;
 
-pub use api::{Context, ContextCommand};
+pub use api::{Context, ContextCommand, ContextConfig};
 pub use manager::ContextManager;
+use std::sync::Arc;
 
-pub fn current_context() -> Context {
-    match ContextManager::new() {
-        Ok(mgr) => mgr.current(),
-        Err(_) => Context::Local,
-    }
+pub fn manager() -> &'static ContextManager {
+    &manager::MANAGER
+}
+
+pub fn current() -> Arc<Context> {
+    manager::MANAGER.current()
 }
 
 #[cfg(test)]
@@ -25,11 +29,16 @@ mod tests {
         let src_file = temp_dir.path().join("src.txt");
         fs::write(&src_file, "local").unwrap();
 
-        let ctx = Context::Local;
+        let ctx = Context::new(ContextConfig::Local);
         let dest = ctx.ensure_available(&src_file, "/tmp").unwrap();
 
-        // Should return canonical path
-        assert_eq!(dest, src_file.canonicalize().unwrap());
+        // Should return a path that exists and has the same content
+        assert!(dest.exists());
+        let content = fs::read_to_string(&dest).unwrap();
+        assert_eq!(content, "local");
+
+        // The dest should be in the /tmp directory
+        assert!(dest.starts_with("/tmp"));
     }
 
     #[test]
@@ -37,18 +46,17 @@ mod tests {
         let temp_file = NamedTempFile::new().unwrap();
         let path = temp_file.path().to_path_buf();
 
-        let mut mgr = ContextManager::with_path(path.clone());
+        let mgr = ContextManager::with_path(path.clone());
 
         // Add
-        let ssh_ctx = Context::Ssh {
+        let ssh_cfg = ContextConfig::Ssh {
             host: "10.0.0.1".into(),
             user: Some("admin".into()),
             port: Some(2222),
         };
-        mgr.add_context("myserver", ssh_ctx.clone()).unwrap();
+        mgr.add_context("myserver", ssh_cfg.clone()).unwrap();
 
-        assert!(mgr.get_context("myserver").is_some());
-        assert_eq!(mgr.get_context("myserver").unwrap(), &ssh_ctx);
+        assert!(mgr.list_contexts().contains(&"myserver".to_string()));
 
         // List
         let list = mgr.list_contexts();
@@ -56,13 +64,11 @@ mod tests {
 
         // Set Current
         mgr.set_current("myserver").unwrap();
-        assert_eq!(mgr.current(), ssh_ctx);
-        assert_eq!(mgr.current_name(), Some("myserver".to_string()));
+        assert_eq!(mgr.current_name(), "myserver".to_string());
 
         // Remove
         mgr.remove_context("myserver").unwrap();
-        assert!(mgr.get_context("myserver").is_none());
-        assert_eq!(mgr.current(), Context::Local);
+        assert!(!mgr.list_contexts().contains(&"myserver".to_string()));
     }
 
     #[test]
@@ -71,18 +77,72 @@ mod tests {
         let config_path = temp_dir.path().join("contexts.json");
 
         {
-            let mut mgr = ContextManager::with_path(config_path.clone());
-            mgr.add_context("persistent", Context::Local).unwrap();
+            let mgr = ContextManager::with_path(config_path.clone());
+            mgr.add_context("persistent", ContextConfig::Local).unwrap();
             mgr.set_current("persistent").unwrap();
         }
 
         let content = fs::read_to_string(&config_path).unwrap();
         let loaded_config: super::manager::Config = serde_json::from_str(&content).unwrap();
 
-        assert_eq!(
-            loaded_config.current_context,
-            Some("persistent".to_string())
-        );
+        assert_eq!(loaded_config.context, "persistent".to_string());
         assert!(loaded_config.contexts.contains_key("persistent"));
     }
+
+    #[test]
+    fn test_context_fallback_on_removal() {
+        let temp_file = NamedTempFile::new().unwrap();
+        let path = temp_file.path().to_path_buf();
+        let mgr = ContextManager::with_path(path);
+
+        // 1. Add and set a context
+        mgr.add_context("temp", ContextConfig::Local).unwrap();
+        mgr.set_current("temp").unwrap();
+        assert_eq!(mgr.current_name(), "temp");
+
+        // 2. Remove it
+        mgr.remove_context("temp").unwrap();
+
+        // 3. Should have fallen back to local
+        assert_eq!(mgr.current_name(), "local");
+        assert!(mgr.list_contexts().contains(&"local".to_string()));
+    }
+
+    #[test]
+    fn test_context_file_ops() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let ctx = Context::new(ContextConfig::Local);
+
+        let file_path = temp_dir.path().join("test.txt");
+        let content = "hello world";
+
+        // 1. Write file
+        ctx.write_file(&file_path, content).unwrap();
+
+        // 2. Read file
+        let read_content = ctx.read_file(&file_path).unwrap();
+        assert_eq!(read_content, content);
+
+        // 3. Copy path
+        let dest_path = temp_dir.path().join("test_copy.txt");
+        ctx.copy_path(&file_path, &dest_path).unwrap();
+        let copied_content = ctx.read_file(&dest_path).unwrap();
+        assert_eq!(copied_content, content);
+
+        // 4. Recursive copy
+        let subdir = temp_dir.path().join("subdir");
+        std::fs::create_dir_all(&subdir).unwrap();
+        let subfile = subdir.join("subfile.txt");
+        ctx.write_file(&subfile, "subcontent").unwrap();
+
+        let subdir_copy = temp_dir.path().join("subdir_copy");
+        ctx.copy_path(&subdir, &subdir_copy).unwrap();
+
+        assert!(subdir_copy.exists());
+        assert!(subdir_copy.join("subfile.txt").exists());
+        assert_eq!(
+            ctx.read_file(&subdir_copy.join("subfile.txt")).unwrap(),
+            "subcontent"
+        );
+    }
 }