2 files changed, 176 insertions, 4 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(())
+}
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 764e2e9..935f470 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -1,10 +1,7 @@
 use std::borrow::Cow;
 use std::path::PathBuf;
 
-pub mod data;
-pub mod deploy;
-pub mod push;
-
+#[macro_export]
 macro_rules! good_panic {
     ($($tts:tt)*) => {{
         error!($($tts)*);
@@ -12,6 +9,73 @@ macro_rules! good_panic {
     }}
 }
 
+pub mod activate;
+pub mod data;
+pub mod deploy;
+pub mod push;
+
+#[derive(PartialEq, Debug)]
+pub struct DeployFlake<'a> {
+    pub repo: &'a str,
+    pub node: Option<&'a str>,
+    pub profile: Option<&'a str>,
+}
+
+pub fn parse_flake(flake: &str) -> DeployFlake {
+    let flake_fragment_start = flake.find('#');
+    let (repo, maybe_fragment) = match flake_fragment_start {
+        Some(s) => (&flake[..s], Some(&flake[s + 1..])),
+        None => (flake, None),
+    };
+
+    let (node, profile) = match maybe_fragment {
+        Some(fragment) => {
+            let fragment_profile_start = fragment.find('.');
+            match fragment_profile_start {
+                Some(s) => (Some(&fragment[..s]), Some(&fragment[s + 1..])),
+                None => (Some(fragment), None),
+            }
+        }
+        None => (None, None),
+    };
+
+    DeployFlake {
+        repo,
+        node,
+        profile,
+    }
+}
+
+#[test]
+fn test_parse_flake() {
+    assert_eq!(
+        parse_flake("../deploy/examples/system#example"),
+        DeployFlake {
+            repo: "../deploy/examples/system",
+            node: Some("example"),
+            profile: None
+        }
+    );
+
+    assert_eq!(
+        parse_flake("../deploy/examples/system#example.system"),
+        DeployFlake {
+            repo: "../deploy/examples/system",
+            node: Some("example"),
+            profile: Some("system")
+        }
+    );
+
+    assert_eq!(
+        parse_flake("../deploy/examples/system"),
+        DeployFlake {
+            repo: "../deploy/examples/system",
+            node: None,
+            profile: None,
+        }
+    );
+}
+
 pub struct DeployData<'a> {
     pub sudo: Option<String>,
     pub ssh_user: Cow<'a, str>,