feat: Donation request device message (#6913)

If there are at least {10,30,70...} outgoing delivered encrypted messages, add a donation request
device messaage, but not more than once every two weeks.

Author: iequidoo

src/chat.rs

@@ -2983,6 +2983,9 @@ async fn prepare_send_msg(
     let row_ids = create_send_msg_jobs(context, msg)
         .await
         .context("Failed to create send jobs")?;
+    if !row_ids.is_empty() {
+        donation_request_maybe(context).await.log_err(context).ok();
+    }
     Ok(row_ids)
 }
 
@@ -3227,6 +3230,43 @@ pub async fn send_videochat_invitation(context: &Context, chat_id: ChatId) -> Re
     send_msg(context, chat_id, &mut msg).await
 }
 
+async fn donation_request_maybe(context: &Context) -> Result<()> {
+    let request_ts = context.get_config_i64(Config::DonationRequestTs).await?;
+    let now = time();
+    let update_config = if request_ts.saturating_add(14 * 24 * 60 * 60) <= now {
+        let msg_cnt_prev = context
+            .get_config_parsed(Config::DonationRequestMsgCnt)
+            .await?
+            .unwrap_or(0);
+        let msg_cnt = context
+            .sql
+            .count(
+                "
+                SELECT COUNT(*) FROM msgs
+                WHERE state>=? AND hidden=0 AND chat_id!=? AND param GLOB \"*c=*\"",
+                (MessageState::OutDelivered, DC_CHAT_ID_TRASH),
+            )
+            .await?;
+        // 10, 30, 70...
+        if msg_cnt_prev < msg_cnt.saturating_sub(8) / 2 {
+            context
+                .set_config_internal(Config::DonationRequestMsgCnt, Some(&msg_cnt.to_string()))
+                .await?;
+            let mut msg = Message::new_text(stock_str::donation_request(context).await);
+            add_device_msg(context, None, Some(&mut msg)).await?;
+        }
+        true
+    } else {
+        request_ts > now
+    };
+    if update_config {
+        context
+            .set_config_internal(Config::DonationRequestTs, Some(&now.to_string()))
+            .await?;
+    }
+    Ok(())
+}
+
 /// Chat message list request options.
 #[derive(Debug)]
 pub struct MessageListOptions {

src/config.rs

@@ -369,6 +369,12 @@ pub enum Config {
     #[strum(props(default = "0"))]
     DisableIdle,
 
+    /// Timestamp of the last check for donation request need.
+    DonationRequestTs,
+
+    /// Number of outgoing encrypted messages at the time of the last donation request.
+    DonationRequestMsgCnt,
+
     /// Defines the max. size (in bytes) of messages downloaded automatically.
     /// 0 = no limit.
     #[strum(props(default = "0"))]

src/context.rs

@@ -1032,6 +1032,18 @@ impl Context {
                 .await?
                 .to_string(),
         );
+        res.insert(
+            "donation_request_ts",
+            self.get_config_i64(Config::DonationRequestTs)
+                .await?
+                .to_string(),
+        );
+        res.insert(
+            "donation_request_msg_cnt",
+            self.get_config_u64(Config::DonationRequestMsgCnt)
+                .await?
+                .to_string(),
+        );
 
         let elapsed = time_elapsed(&self.creation_time);
         res.insert("uptime", duration_to_str(elapsed));

src/stock_str.rs

@@ -433,6 +433,16 @@ pub enum StockMessage {
         fallback = "The contact must be online to proceed.\n\nThis process will continue automatically in background."
     ))]
     SecurejoinTakesLonger = 192,
+
+    #[strum(props(fallback = "❤️ Seems you're using Delta Chat!
+
+Please consider donating to help that Delta Chat stays free for everyone.
+
+While Delta Chat is free to use and open source, development costs time and developers need money.
+Help keeping us to keep Delta Chat independent and make it more awesome in the future.
+
+https://delta.chat/donate"))]
+    DonationRequest = 193,
 }
 
 impl StockMessage {
@@ -829,6 +839,11 @@ pub(crate) async fn securejoin_takes_longer(context: &Context) -> String {
     translated(context, StockMessage::SecurejoinTakesLonger).await
 }
 
+/// Stock string: `❤️ Seems you're using Delta Chat!`…
+pub(crate) async fn donation_request(context: &Context) -> String {
+    translated(context, StockMessage::DonationRequest).await
+}
+
 /// Stock string: `Scan to chat with %1$s`.
 pub(crate) async fn setup_contact_qr_description(
     context: &Context,