separate out activation logic

1 files changed, 108 insertions, 0 deletions

diff --git a/src/utils/activate.rs b/src/utils/activate.rs
new file mode 100644
index 0000000..33774fd
--- /dev/null
+++ b/src/utils/activate.rs
@@ -0,0 +1,108 @@
+use std::process::Stdio;
+use tokio::process::Command;
+
+use std::path::Path;
+
+pub async fn activate(
+    profile_path: String,
+    closure: String,
+    activate_cmd: Option<String>,
+    bootstrap_cmd: Option<String>,
+    auto_rollback: bool,
+) -> Result<(), Box<dyn std::error::Error>> {
+    info!("Activating profile");
+
+    Command::new("nix-env")
+        .arg("-p")
+        .arg(&profile_path)
+        .arg("--set")
+        .arg(&closure)
+        .stdout(Stdio::null())
+        .spawn()?
+        .await?;
+
+    if let (Some(bootstrap_cmd), false) = (bootstrap_cmd, !Path::new(&profile_path).exists()) {
+        let bootstrap_status = Command::new("bash")
+            .arg("-c")
+            .arg(&bootstrap_cmd)
+            .env("PROFILE", &profile_path)
+            .stdout(Stdio::null())
+            .stderr(Stdio::null())
+            .status()
+            .await;
+
+        match bootstrap_status {
+            Ok(s) if s.success() => (),
+            _ => {
+                tokio::fs::remove_file(&profile_path).await?;
+                good_panic!("Failed to execute bootstrap command");
+            }
+        }
+    }
+
+    if let Some(activate_cmd) = activate_cmd {
+        let activate_status = Command::new("bash")
+            .arg("-c")
+            .arg(&activate_cmd)
+            .env("PROFILE", &profile_path)
+            .status()
+            .await;
+
+        match activate_status {
+            Ok(s) if s.success() => (),
+            _ if auto_rollback => {
+                Command::new("nix-env")
+                    .arg("-p")
+                    .arg(&profile_path)
+                    .arg("--rollback")
+                    .stdout(Stdio::null())
+                    .stderr(Stdio::null())
+                    .spawn()?
+                    .await?;
+
+                let c = Command::new("nix-env")
+                    .arg("-p")
+                    .arg(&profile_path)
+                    .arg("--list-generations")
+                    .output()
+                    .await?;
+                let generations_list = String::from_utf8(c.stdout)?;
+
+                let last_generation_line = generations_list
+                    .lines()
+                    .last()
+                    .expect("Expected to find a generation in list");
+
+                let last_generation_id = last_generation_line
+                    .split_whitespace()
+                    .next()
+                    .expect("Expected to get ID from generation entry");
+
+                debug!("Removing generation entry {}", last_generation_line);
+                warn!("Removing generation by ID {}", last_generation_id);
+
+                Command::new("nix-env")
+                    .arg("-p")
+                    .arg(&profile_path)
+                    .arg("--delete-generations")
+                    .arg(last_generation_id)
+                    .stdout(Stdio::null())
+                    .stderr(Stdio::null())
+                    .spawn()?
+                    .await?;
+
+                // TODO: Find some way to make sure this command never changes, otherwise this will not work
+                Command::new("bash")
+                    .arg("-c")
+                    .arg(&activate_cmd)
+                    .spawn()?
+                    .await?;
+
+                good_panic!("Failed to execute activation command");
+            }
+            _ => {}
+        }
+    }
+
+    Ok(())
+}