From ab8d8b032145e054f5ecbb508b8d33e42db6cef2 Mon Sep 17 00:00:00 2001
From: soyouzpanda <soyouzpanda@soyouzpanda.fr>
Date: Fri, 23 Aug 2024 17:57:14 +0200
Subject: [PATCH] feat(generic): Added first generic host

---
 src/nix/host/generic.rs | 182 ++++++++++++++++++++++++++++++++++++++++
 src/nix/host/mod.rs     |   4 +-
 2 files changed, 185 insertions(+), 1 deletion(-)
 create mode 100644 src/nix/host/generic.rs

diff --git a/src/nix/host/generic.rs b/src/nix/host/generic.rs
new file mode 100644
index 0000000..5b1075a
--- /dev/null
+++ b/src/nix/host/generic.rs
@@ -0,0 +1,182 @@
+use std::collections::HashMap;
+use std::process::Stdio;
+
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter};
+use tokio::process::Command;
+
+use super::{CopyDirection, CopyOptions, Host};
+use crate::error::{ColmenaError, ColmenaResult};
+use crate::job::JobHandle;
+use crate::nix::{self, Profile, StorePath};
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct TransportId(String);
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Transport {
+    id: TransportId,
+    name: String,
+    long_name: String,
+    description: String,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct GoalId(String);
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Goal {
+    id: GoalId,
+    name: String,
+    long_name: String,
+    description: String,
+}
+
+/// A request to the activation program
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Request {
+    /// Asks for activation program's capabilities
+    Capabilities,
+
+    /// Copy closure to/from host
+    CopyClosure {
+        transport: TransportId,
+        path: StorePath,
+        to_host: bool,
+        options: HashMap<String, String>,
+    },
+
+    /// Deploys the profile to host
+    Deploy {
+        transport: TransportId,
+        goal: GoalId,
+        toplevel: StorePath,
+        options: HashMap<String, String>,
+    },
+
+    /// Realizes the derivation
+    Realize {
+        transport: TransportId,
+        path: StorePath,
+        options: HashMap<String, String>,
+    },
+
+    /// Uploads keys to host
+    UploadKeys { transport: TransportId },
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum CapabilityResponse {
+    V1 {
+        supported_transports: Vec<Transport>,
+        supported_goals: Vec<Goal>,
+    },
+}
+
+/// A response from the activation program
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Response {
+    Capabilities(CapabilityResponse),
+    Progress { phase: String },
+    NewStorePath { store_path: StorePath },
+}
+
+#[derive(Debug)]
+pub struct GenericHost {
+    activation_program: StorePath,
+    transport: TransportId,
+}
+
+#[async_trait]
+impl Host for GenericHost {
+    async fn copy_closure(
+        &mut self,
+        closure: &StorePath,
+        direction: CopyDirection,
+        options: CopyOptions,
+    ) -> ColmenaResult<()> {
+        self.call(Request::CopyClosure {
+            transport: self.transport.clone(),
+            path: closure.clone(),
+            to_host: direction == CopyDirection::ToRemote,
+            options: HashMap::from([(
+                "include_outputs".to_owned(),
+                if options.include_outputs {
+                    "true".to_owned()
+                } else {
+                    "false".to_owned()
+                },
+            )]),
+        })
+        .await
+    }
+
+    async fn realize_remote(&mut self, derivation: &StorePath) -> ColmenaResult<Vec<StorePath>> {
+        self.call(Request::Realize {
+            transport: self.transport.clone(),
+            path: derivation.clone(),
+            options: HashMap::new(),
+        })
+        .await?;
+
+        Ok(Vec::new())
+    }
+
+    fn set_job(&mut self, bar: Option<JobHandle>) {}
+
+    async fn deploy(
+        &mut self,
+        profile: &Profile,
+        goal: nix::Goal,
+        copy_options: CopyOptions,
+        activation_program: Option<&StorePath>,
+    ) -> ColmenaResult<()> {
+        self.call(Request::Deploy {
+            transport: self.transport.clone(),
+            goal: GoalId(goal.to_string()),
+            toplevel: profile.as_store_path().clone(),
+            options: HashMap::new(),
+        })
+        .await
+    }
+
+    async fn get_current_system_profile(&mut self) -> ColmenaResult<Profile> {
+        Err(ColmenaError::Unsupported)
+    }
+
+    async fn get_main_system_profile(&mut self) -> ColmenaResult<Profile> {
+        Err(ColmenaError::Unsupported)
+    }
+}
+
+impl GenericHost {
+    async fn call(&mut self, request: Request) -> ColmenaResult<()> {
+        let mut command = Command::new(self.activation_program.as_path())
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()?;
+
+        let json = serde_json::to_string(&request).unwrap();
+
+        let mut stdin = BufWriter::new(command.stdin.take().unwrap());
+        let mut stdout = BufReader::new(command.stdout.take().unwrap()).lines();
+
+        stdin.write_all(json.as_bytes()).await?;
+
+        tokio::spawn(async move {
+            let _status = command
+                .wait()
+                .await
+                .expect("child process encountered an error");
+        });
+
+        while let Some(line) = stdout.next_line().await? {
+            let response: Response = serde_json::from_str(line.as_str()).unwrap();
+            println!("{:?}", response);
+        }
+
+        Ok(())
+    }
+}
diff --git a/src/nix/host/mod.rs b/src/nix/host/mod.rs
index 531c26c..69c9b90 100644
--- a/src/nix/host/mod.rs
+++ b/src/nix/host/mod.rs
@@ -14,7 +14,9 @@ pub use local::Local;
 
 mod key_uploader;
 
-#[derive(Copy, Clone, Debug)]
+mod generic;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum CopyDirection {
     ToRemote,
     FromRemote,