Add human-readable identifiers in temp draft files

Draft files that are created in temp directories to be opened and edited
by the user's editor get UUID filenames with the `.eml` extension. Give
them filenames with the draft subject, recipient and date to make it
easier to discern a file's identity on the filesystem.

Closes #466

Resolves: <https://git.meli-email.org/meli/meli/issues/466>
Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

meli/src/mail/compose.rs

@@ -41,6 +41,7 @@ use crate::{
     accounts::JobRequest,
     jobs::{IsAsync, JoinHandle},
     terminal::embedded::Terminal,
+    types::{sanitize_filename, File},
 };
 
 #[cfg(feature = "gpgme")]
@@ -1867,10 +1868,25 @@ impl Component for Composer {
                     account_settings!(context[self.account_hash].composing.wrap_header_preamble)
                         .clone(),
                 );
+                let filename = format!(
+                    "{date}_{subject}_{to}_{in_reply_to}",
+                    date = self.draft.headers.get(HeaderName::DATE).unwrap_or_default(),
+                    subject = self
+                        .draft
+                        .headers
+                        .get(HeaderName::SUBJECT)
+                        .unwrap_or_default(),
+                    to = self.draft.headers.get(HeaderName::TO).unwrap_or_default(),
+                    in_reply_to = self
+                        .draft
+                        .headers
+                        .get(HeaderName::IN_REPLY_TO)
+                        .unwrap_or_default()
+                );
 
                 let f = match File::create_temp_file(
                     self.draft.to_edit_string().as_bytes(),
-                    None,
+                    sanitize_filename(filename).as_deref(),
                     None,
                     Some("eml"),
                     true,

meli/src/types.rs

@@ -33,12 +33,8 @@
 //! [`UIEvent`] is the type passed around
 //! [`Component`]'s when something happens.
 
-#[macro_use]
-mod helpers;
-
 use std::{borrow::Cow, sync::Arc};
 
-pub use helpers::*;
 use indexmap::IndexMap;
 use melib::{
     backends::{AccountHash, BackendEvent, MailboxHash},
@@ -54,6 +50,10 @@ use super::{
 };
 use crate::components::{Component, ComponentId, ScrollUpdate};
 
+#[macro_use]
+mod helpers;
+pub use helpers::*;
+
 pub type UIMessage = Box<dyn 'static + std::any::Any + Send + Sync>;
 
 #[derive(Debug)]

meli/src/types/helpers.rs

@@ -91,7 +91,11 @@ impl File {
             dir.push("meli");
             std::fs::DirBuilder::new().recursive(true).create(&dir)?;
             if let Some(filename) = filename {
-                dir.push(filename)
+                dir.push(filename);
+                while dir.try_exists().unwrap_or_default() {
+                    dir.pop();
+                    dir.push(format!("{filename}_{}", Uuid::new_v4().as_simple()));
+                }
             } else {
                 let u = Uuid::new_v4();
                 dir.push(u.as_simple().to_string());
@@ -136,6 +140,25 @@ pub fn pipe() -> Result<(OwnedFd, OwnedFd)> {
     })
 }
 
+/// Create a shell-friendly filename by removing control characters and
+/// replacing characters that need escaping.
+pub fn sanitize_filename(og: String) -> Option<String> {
+    use regex::Regex;
+
+    let regex = Regex::new(r"(?m)[[:space:]]+").ok()?; // _
+    let mut ret = regex.replace_all(&og, "_").to_string();
+    let regex = Regex::new(r"(?m)[[:punct:]]").ok()?; // -
+    ret = regex.replace_all(&ret, "-").to_string();
+    let regex = Regex::new(r"(?m)[[:cntrl:]]*").ok()?; //
+    ret = regex.replace_all(&ret, "").to_string();
+    let regex = Regex::new(r"(?m)[[:blank:]]*").ok()?; //
+    ret = regex.replace_all(&ret, "").to_string();
+    let regex = Regex::new(r"^[[:punct:]]*").ok()?; //
+    ret = regex.replace_all(&ret, "").to_string();
+    let regex = Regex::new(r"[[:punct:]]*$").ok()?; //
+    Some(regex.replace_all(&ret, "").to_string())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -180,4 +203,12 @@ mod tests {
 
         _ = tempdir.close();
     }
+
+    #[test]
+    fn test_file_sanitize_filename() {
+        assert_eq!(
+            sanitize_filename("Re: Some long subject - \"User Dot. Name\" <user1@example.com> Sent from my bPad 2024-09-07, on   a sunny Saturday".to_string()),
+            Some("Re--Some-long-subject----User-Dot--Name---user1-example-com--Sent-from-my-bPad-2024-09-07--on-a-sunny-Saturday".to_string())
+        );
+    }
 }