1 files changed, 78 insertions, 0 deletions
diff --git a/server/data/src/book/diagram_layout.rs b/server/data/src/book/diagram_layout.rs
new file mode 100644
index 00000000..0ea26a69
--- /dev/null
+++ b/server/data/src/book/diagram_layout.rs
@@ -0,0 +1,78 @@
+/*
+    Hurry Curry! - a game about cooking
+    Copyright (C) 2025 Hurry Curry! Contributors
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, version 3 of the License only.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+*/
+
+use anyhow::{Result, anyhow};
+use hurrycurry_protocol::{book::Diagram, glam::Vec2};
+use serde::Deserialize;
+use std::{
+    collections::BTreeMap,
+    fmt::Write as W2,
+    io::Write,
+    process::{Command, Stdio},
+};
+
+pub struct Layout {
+    pub nodes: BTreeMap<String, Vec2>,
+    pub edges: Vec<(usize, usize)>,
+}
+
+pub fn diagram_layout(diagram: &mut Diagram) -> Result<()> {
+    let mut child = Command::new("dot")
+        .arg("-Tjson")
+        .arg("-Kdot")
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()?;
+
+    let mut out = String::new();
+    writeln!(out, "digraph {{")?;
+    for (i, _) in diagram.nodes.iter().enumerate() {
+        writeln!(out, "k{i} [width=1, height=1]")?;
+    }
+    for edge in &diagram.edges {
+        writeln!(out, "k{} -> k{}", edge.src, edge.dst)?;
+    }
+    writeln!(out, "}}")?;
+
+    child.stdin.as_mut().unwrap().write_all(out.as_bytes())?;
+    let output = child.wait_with_output()?;
+
+    #[derive(Deserialize)]
+    struct Out {
+        objects: Vec<Object>,
+    }
+    #[derive(Deserialize)]
+    struct Object {
+        name: String,
+        pos: String,
+    }
+    let graph: Out = serde_json::from_slice(&output.stdout)?;
+    for o in graph.objects {
+        let pos = o.pos.split_once(",").ok_or(anyhow!("malformed position"))?;
+        let pos = Vec2::new(pos.0.parse()?, pos.1.parse()?);
+
+        let index = o
+            .name
+            .strip_prefix("k")
+            .ok_or(anyhow!("invalid node name"))?
+            .parse::<usize>()?;
+        diagram.nodes[index].position = pos
+    }
+
+    Ok(())
+}