add dc_msg_set_html() api (#2153)

* draft dc_msg_set_html() api

* implement setting 'html to be send'

* test sending html-parts

* more flexible html-partbuilder

* write html-parts to database and also send them

* add 'sendhtml' command to repl tool

src/html.rs

@@ -17,6 +17,7 @@ use crate::context::Context;
 use crate::headerdef::{HeaderDef, HeaderDefMap};
 use crate::message::{Message, MsgId};
 use crate::mimeparser::parse_message_id;
+use crate::param::Param::SendHtml;
 use crate::plaintext::PlainText;
 use lettre_email::PartBuilder;
 use mailparse::ParsedContentType;
@@ -31,6 +32,24 @@ impl Message {
     pub fn has_html(&self) -> bool {
         self.mime_modified
     }
+
+    /// Set HTML-part part of a message that is about to be sent.
+    /// The HTML-part is written to the database before sending and
+    /// used as the `text/html` part in the MIME-structure.
+    ///
+    /// Received HTML parts are handled differently,
+    /// they are saved together with the whole MIME-structure
+    /// in `mime_headers` and the HTML-part is extracted using `MsgId::get_html()`.
+    /// (To underline this asynchronicity, we are using the wording "SendHtml")
+    pub fn set_html(&mut self, html: Option<String>) {
+        if let Some(html) = html {
+            self.param.set(SendHtml, html);
+            self.mime_modified = true;
+        } else {
+            self.param.remove(SendHtml);
+            self.mime_modified = false;
+        }
+    }
 }
 
 /// Type defining a rough mime-type.
@@ -250,33 +269,25 @@ impl MsgId {
             None
         }
     }
+}
 
-    /// Wraps HTML generated by [`MsgId::get_html`] into a text/html mimepart structure.
-    ///
-    /// Used on forwarding messages to avoid leaking the original mime structure
-    /// and also to avoid sending too much, maybe large data.
-    pub async fn get_html_as_mimepart(self, context: &Context) -> Option<PartBuilder> {
-        self.get_html(context).await.map(|s| {
-            PartBuilder::new()
-                .content_type(&"text/html; charset=utf-8".parse::<mime::Mime>().unwrap())
-                .body(s)
-        })
-    }
-
-    // As [`MsgId::get_html_as_mimepart`] but wraps [`MsgId::get_html`] into text/html mime raw string.
-    pub async fn get_html_as_rawmime(self, context: &Context) -> Option<String> {
-        self.get_html_as_mimepart(context)
-            .await
-            .map(|p| p.build().as_string())
-    }
+/// Wraps HTML text into a new text/html mimepart structure.
+///
+/// Used on forwarding messages to avoid leaking the original mime structure
+/// and also to avoid sending too much, maybe large data.
+pub async fn new_html_mimepart(html: String) -> PartBuilder {
+    PartBuilder::new()
+        .content_type(&"text/html; charset=utf-8".parse::<mime::Mime>().unwrap())
+        .body(html)
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::chat;
     use crate::chat::forward_msgs;
     use crate::config::Config;
-    use crate::constants::DC_CONTACT_ID_SELF;
+    use crate::constants::{Viewtype, DC_CONTACT_ID_SELF};
     use crate::dc_receive_imf::dc_receive_imf;
     use crate::message::MessengerMessage;
     use crate::test_utils::TestContext;
@@ -519,4 +530,36 @@ test some special html-characters as &lt; &gt; and &amp; but also &quot; and &#x
         let html = msg.get_id().get_html(&alice).await.unwrap();
         assert!(html.find("this is <b>html</b>").is_some());
     }
+
+    #[async_std::test]
+    async fn test_set_html() {
+        let alice = TestContext::new_alice().await;
+        let bob = TestContext::new_bob().await;
+
+        // alice sends a message with html-part to bob
+        let chat_id = alice.create_chat(&bob).await.id;
+        let mut msg = Message::new(Viewtype::Text);
+        msg.set_text(Some("plain text".to_string()));
+        msg.set_html(Some("<b>html</b> text".to_string()));
+        assert!(msg.mime_modified);
+        chat::send_msg(&alice, chat_id, &mut msg).await.unwrap();
+
+        // check the message is written correctly to alice's db
+        let msg = alice.get_last_msg_in(chat_id).await;
+        assert_eq!(msg.get_text(), Some("plain text".to_string()));
+        assert!(!msg.is_forwarded());
+        assert!(msg.mime_modified);
+        let html = msg.get_id().get_html(&alice).await.unwrap();
+        assert!(html.find("<b>html</b> text").is_some());
+
+        // let bob receive the message
+        let chat_id = bob.create_chat(&alice).await.id;
+        bob.recv_msg(&alice.pop_sent_msg().await).await;
+        let msg = bob.get_last_msg_in(chat_id).await;
+        assert_eq!(msg.get_text(), Some("plain text".to_string()));
+        assert!(!msg.is_forwarded());
+        assert!(msg.mime_modified);
+        let html = msg.get_id().get_html(&bob).await.unwrap();
+        assert!(html.find("<b>html</b> text").is_some());
+    }
 }