manager: Render graphviz tree and push it to git

techtree-manager/.gitignore

@@ -1 +1,2 @@
 /target/
+/render-git/

techtree-manager/src/main.rs

@@ -4,6 +4,7 @@ use forgejo_api::Forgejo;
 mod collect;
 mod event_meta;
 mod issue;
+mod render;
 mod tree;
 mod wiki;
 
@@ -21,7 +22,7 @@ async fn run() -> anyhow::Result<()> {
         meta.issue.number
     );
 
-    let timestamp = chrono::Local::now().format("%Y-%m-%d %H:%M:%S");
+    let timestamp = chrono::Local::now().format("%Y-%m-%d %H:%M:%S").to_string();
     log::info!("Timestamp of this run is {timestamp}");
 
     let token =
@@ -33,6 +34,10 @@ async fn run() -> anyhow::Result<()> {
     )
     .context("Failed parsing GITHUB_SERVER_URL as a url")?;
 
+    let mut repo_auth_url = server_url.join(&format!("{}/{}", meta.issue.repository.owner, meta.issue.repository.name)).unwrap();
+    repo_auth_url.set_username("forgejo-actions").unwrap();
+    repo_auth_url.set_password(Some(&token)).unwrap();
+
     let forgejo = Forgejo::new(auth, server_url).context("Could not create API access object")?;
 
     let new_comment_id = if meta.action == event_meta::IssueAction::Opened {
@@ -56,6 +61,11 @@ async fn run() -> anyhow::Result<()> {
         .await
         .context("Failed to collect the techtree from issue metadata")?;
 
+    log::info!("Rendering and publishing techtree to git repository...");
+    render::render_and_publish(&tree, &timestamp, &repo_auth_url)
+        .await
+        .context("Failed to render and publish the techtree to git")?;
+
     let mermaid = tree.to_mermaid();
     let wiki_text = format!(
         r##"This page is automatically updated to show the latest and greatest FAFO techtree:

techtree-manager/src/render.rs

@@ -0,0 +1,69 @@
+use std::process::Command;
+
+use anyhow::Context as _;
+
+pub async fn render_and_publish(
+    tree: &crate::tree::Tree,
+    timestamp: &str,
+    repo_auth_url: &url::Url,
+) -> anyhow::Result<()> {
+    let render_repo = std::path::PathBuf::from("render-git");
+
+    if render_repo.is_dir() {
+        log::info!("Found old {render_repo:?} repository, removing...");
+        std::fs::remove_dir_all(&render_repo).context("Failed to remove stale render repository")?;
+    }
+
+    std::fs::create_dir(&render_repo).context("Failed creating directory for rendered graph")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("init")
+        .status()
+        .context("Failed to initialize render repository")?;
+
+    let dot_file = render_repo.join("techtree.dot");
+    let svg_file = render_repo.join("techtree.svg");
+
+    let dot_source = tree.to_dot();
+    std::fs::write(&dot_file, dot_source.as_bytes())
+        .context("Failed to write `dot` source file")?;
+
+    Command::new("dot")
+        .args(["-T", "svg"])
+        .arg("-o")
+        .arg(&svg_file)
+        .arg(&dot_file)
+        .status()
+        .context("Failed to generate svg graph from dot source")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("add")
+        .arg(dot_file.file_name().unwrap())
+        .arg(svg_file.file_name().unwrap())
+        .status()
+        .context("Failed to add generated graph files to git index")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("commit")
+        .args(["-m", &format!("Updated techtree at {timestamp}")])
+        .status()
+        .context("Failed to add generated graph files to git index")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("push")
+        .arg("--force")
+        .arg(repo_auth_url.to_string())
+        .arg("HEAD:refs/heads/render")
+        .status()
+        .context("Failed to push rendered graph to forgejo repository")?;
+
+    Ok(())
+}