Generate sieve script from hashmap

.gitignore

@@ -29,3 +29,10 @@ testdata/virt_aliases
 
 # Added by cargo
 /target
+
+
+
+# Nix
+/result
+# Direnv
+/.direnv

main.rs

@@ -1,27 +1,42 @@
-use std::fs::File;
+use std::io::{self};
-use std::io::{self, BufRead};
-use std::path::Path;
-use std::env;
 use std::collections::HashMap;
 
 fn main() {
-    let args: Vec<String> = env::args().collect();
+    let redirects = parse_alias_to_hashmap();
+    let sieve_script = generate_sieve_script(redirects);
+    println!("{}", sieve_script);
+}
 
-    let file_path = &args[1];
+fn generate_sieve_script(redirects: HashMap<String, Vec<String>>) -> String {
+    let mut script : String = "require [\"envelope\", \"copy\"];\n".to_string();
+    for (redirect, destinations) in redirects {
+        script +=  format!("if envelope :is \"to\" \"{}\" {{\n{}}}\n", redirect,
+            (|| {
+                let mut subscript : String = "".to_string();
+                for destination in destinations.iter().rev().skip(1).rev() {
+                    subscript += format!("  redirect :copy \"{}\";\n", destination).as_str();
+                }
+                subscript += format!("  redirect \"{}\";\n", destinations.iter().rev().next().unwrap()).as_str();
+                return subscript;
+            })()
+            ).as_str();
+    }
+    return  script;
+}
 
+fn parse_alias_to_hashmap() -> HashMap<String, Vec<String>> {
     // File must exist in the current path
-    if let Ok(lines) = read_lines(file_path) {
-        // Consumes the iterator, returns an (Optional) String
     let mut redirect_map : HashMap<String, Vec<String>> = HashMap::new();
     let mut destinations : Vec<String> = Vec::new();
-        for line in lines.flatten() {
+    for line in io::stdin().lines() {
+        let line = line.unwrap();
         let line = String::from(line.split_at(line.find("#").unwrap_or(line.len())).0);
         let destination = line.split_at(line.find(char::is_whitespace).unwrap_or(0)).0;
         if destination == "" {
             continue;
         }
-            let redirects: Vec<String> = line.split_at(line.find(char::is_whitespace).unwrap_or(0)).1.split(", ")
+        let redirects: Vec<String> = line.split_at(line.find(char::is_whitespace).unwrap_or(0)).1.split(" ")
-              .map(|address| to_mailaddress(address)).collect();
+            .filter(|address| address.trim().to_string().replace(",","") != "").map(|address| to_mailaddress(address)).collect();
         if redirects.len() == 0 {
             continue;
         }
@@ -41,29 +56,19 @@ fn main() {
                     all_new_redirects.entry(destination.clone()).and_modify(|d| d.extend(new_redirects.iter().map(|x| x.clone())));
                 }
             }
-                
         }
-            
         for (destination, new_redirect) in all_new_redirects {
             *redirect_map.get_mut(&destination).unwrap() = new_redirect;
         }
     }
-        println!("{:#?}", redirect_map);
+    return redirect_map;
-    }
 }
 
 fn to_mailaddress(local_part: &str) -> String {
-    let local_part = local_part.trim();
+    let mut addr = local_part.trim().to_string();
-    if local_part.contains("@") {
+    addr = addr.replace(",", "");
-        return String::from(local_part);
+    if addr.contains("@") {
+        return addr;
     }
-    return local_part.to_string() + "@mathebau.de";
+    return addr + "@mathebau.de";
-}
-
-// The output is wrapped in a Result to allow matching on errors.
-// Returns an Iterator to the Reader of the lines of the file.
-fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
-where P: AsRef<Path>, {
-    let file = File::open(filename)?;
-    Ok(io::BufReader::new(file).lines())
 }