From 0d2a13739a2ddb1da3592c7b1e6a7381af0020ee Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 17 Aug 2023 03:25:12 -0400
Subject: [PATCH] Import the emacs wrapper from organic.

---
 src/main.rs  |  3 +++
 src/parse.rs | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 src/parse.rs

diff --git a/src/main.rs b/src/main.rs
index b3cafd2..b20b551 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,10 @@
+#![feature(exit_status_error)]
 use axum::{http::StatusCode, routing::post, Json, Router};
 use serde::Serialize;
 use tower_http::services::{ServeDir, ServeFile};
 
+mod parse;
+
 #[tokio::main]
 async fn main() {
     let serve_dir = ServeDir::new("static").not_found_service(ServeFile::new("static/index.html"));
diff --git a/src/parse.rs b/src/parse.rs
new file mode 100644
index 0000000..bce786e
--- /dev/null
+++ b/src/parse.rs
@@ -0,0 +1,51 @@
+use std::process::Command;
+
+pub fn emacs_parse_org_document<C>(file_contents: C) -> Result<String, Box<dyn std::error::Error>>
+where
+    C: AsRef<str>,
+{
+    let escaped_file_contents = escape_elisp_string(file_contents);
+    let elisp_script = format!(
+        r#"(progn
+     (erase-buffer)
+     (insert "{escaped_file_contents}")
+     (org-mode)
+     (message "%s" (pp-to-string (org-element-parse-buffer)))
+)"#,
+        escaped_file_contents = escaped_file_contents
+    );
+    let mut cmd = Command::new("emacs");
+    let proc = cmd
+        .arg("-q")
+        .arg("--no-site-file")
+        .arg("--no-splash")
+        .arg("--batch")
+        .arg("--eval")
+        .arg(elisp_script);
+    let out = proc.output()?;
+    out.status.exit_ok()?;
+    let org_sexp = out.stderr;
+    Ok(String::from_utf8(org_sexp)?)
+}
+
+fn escape_elisp_string<C>(file_contents: C) -> String
+where
+    C: AsRef<str>,
+{
+    let source = file_contents.as_ref();
+    let source_len = source.len();
+    // We allocate a string 10% larger than the source to account for escape characters. Without this, we would have more allocations during processing.
+    let mut output = String::with_capacity(source_len + (source_len / 10));
+    for c in source.chars() {
+        match c {
+            '"' | '\\' => {
+                output.push('\\');
+                output.push(c);
+            }
+            _ => {
+                output.push(c);
+            }
+        }
+    }
+    output
+}