feat: merge attached pdfs to the invoice

src/mailgun/invoices.rs

@@ -1,21 +1,40 @@
 use super::MailgunClient;
 use crate::api::invoices::Invoice;
 use crate::error::Error;
+use crate::merge::merge_pdf;
 use typst::model::Document;
 
 impl MailgunClient {
-    #[allow(dead_code)]
     pub async fn send_mail(self, invoice: Invoice) -> Result<(), Error> {
         let document: Document = invoice.to_owned().try_into()?;
         let pdf = typst_pdf::pdf(&document, typst::foundations::Smart::Auto, None);
 
+        let mut pdfs = vec![pdf];
+        pdfs.extend_from_slice(
+            invoice
+                .attachments
+                .clone()
+                .into_iter()
+                .map(|a| a.bytes)
+                .collect::<Vec<_>>()
+                .as_slice(),
+        );
+
+        let pdf = merge_pdf(pdfs)?;
+
         let invoice_recipient = format!("{} <{}>", invoice.recipient_name, invoice.recipient_email);
         let form = reqwest::multipart::Form::new()
             .text("from", self.from)
             .text("to", self.default_to)
             .text("cc", invoice_recipient)
-            .text("subject", format!("Uusi lasku {}", invoice.recipient_name))
-            .text("html", format!("Uusi lasku {}", invoice.recipient_name))
+            .text(
+                "subject",
+                format!("Uusi lasku, lähettäjä {}", invoice.recipient_name),
+            )
+            .text(
+                "html",
+                format!("Uusi lasku, lähettäjä {}", invoice.recipient_name),
+            )
             .part(
                 "attachment",
                 reqwest::multipart::Part::bytes(pdf).file_name("invoice.pdf"),

src/merge.rs

@@ -3,7 +3,6 @@ use std::collections::BTreeMap;
 
 use lopdf::{Document, Object, ObjectId};
 
-#[allow(dead_code)]
 // Mostly copied from https://github.com/J-F-Liu/lopdf/blob/master/README.md merge example
 pub fn merge_pdf(documents: Vec<Vec<u8>>) -> Result<Vec<u8>, Error> {
     let documents = documents