Add retrieving limited number of messages

Optional `lastMsg` now works by getting all messages with a newer
timestamp than the reference message.
  Optional `limit` works using SQL ~magic~ keyword `LIMIT`.
  Also `limit` has to be at least 1.

src/graphql.rs

@@ -610,14 +610,46 @@ impl Query {
         Ok(chats)
     }
 
-    async fn getMessages(context: &Context, user: ID, password_hash: String, chat: ID, last_msg: Option<ID>) -> FieldResult<Vec<Message>> {
+    async fn getMessages(context: &Context, user: ID, password_hash: String, chat: ID, last_msg: Option<ID>, limit: Option<i32>) -> FieldResult<Vec<Message>> {
+        let limit = match limit {
+            Some(l) if l < 1 => Err("limit cannot be negative or 0".to_string())?,
+            Some(l) => Some(l as u32),
+            None => None,
+        };
+
         let user = id_to_uuid(&user)?.to_simple();
         user_authentication(&context.db, &user, &password_hash).await?;
 
+        let chat = id_to_uuid(&chat)?.to_simple();
+
+        let last_msg_timestamp = if let Some(last_msg) = last_msg {
+            Some(
+                sqlx::query(format!(
+                    r#"SELECT timestamp FROM msgdata_{} WHERE msg_id = "{}""#,
+                    chat,
+                    id_to_uuid(&last_msg)?.to_simple(),
+                ).as_str())
+                    .fetch_one(&context.db).await?
+                    .try_get::<i64, _>("timestamp")? as u128
+            )
+        } else {
+            None
+        };
+
         let mut messages = Vec::new();
         for message in sqlx::query(format!(
-            r#"SELECT * FROM msgdata_{} ORDER BY timestamp DESC"#,
+            r#"SELECT * FROM msgdata_{} {} ORDER BY timestamp DESC {}"#,
             chat,
+            if let Some(last_msg_timestamp) = last_msg_timestamp {
+                format!("WHERE timestamp > {}", last_msg_timestamp)
+            } else {
+                String::new()
+            },
+            if let Some(limit) = limit {
+                format!("LIMIT {}", limit)
+            } else {
+                String::new()
+            },
         ).as_str()).fetch_all(&context.db).await? {
             messages.push(Message {
                 id: ID::from(message.try_get::<String, _>("msg_id")?),

test-api.sh

@@ -19,8 +19,27 @@ abc=$(echo "$chatIDs" | jq -r .aGroupChats[0].id)
 
 echo
 echo Send a private/group message:
-curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"mutation sendMessages(\$a: ID!, \$pwHash: String!, \$bChat: ID!, \$abc: ID!, \$msg: MessageInput!) {\n  chat: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$bChat, msg: \$msg)\n  group: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$abc, msg: \$msg)\n}\",\"variables\":{\"pwHash\":\"1234567890\",\"a\":\"$a\",\"bChat\":\"$ab\",\"abc\":\"$abc\",\"msg\":{\"msgType\":\"TEXT\",\"content\":\"Test\"}},\"operationName\":\"sendMessages\"}" | jq .
+sentMessageIDs=$(curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"mutation sendMessages(\$a: ID!, \$pwHash: String!, \$bChat: ID!, \$abc: ID!, \$msg: MessageInput!) {\n  chat: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$bChat, msg: \$msg)\n  group: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$abc, msg: \$msg)\n}\",\"variables\":{\"pwHash\":\"1234567890\",\"a\":\"$a\",\"bChat\":\"$ab\",\"abc\":\"$abc\",\"msg\":{\"msgType\":\"TEXT\",\"content\":\"Test\"}},\"operationName\":\"sendMessages\"}" | jq .data)
+echo "$sentMessageIDs" | jq .
+lastChatMsg=$(echo "$sentMessageIDs" | jq -r .chat)
+lastGroupChatMsg=$(echo "$sentMessageIDs" | jq -r .group)
 
 echo
 echo Get private/group messages:
 curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"query getMessages(\$a: ID!, \$pwHash: String!, \$chat: ID!, \$groupChat: ID!) {\n  chat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$chat) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n  groupChat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$groupChat) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n}\",\"variables\":{\"a\":\"$a\",\"pwHash\":\"1234567890\",\"chat\":\"$ab\",\"groupChat\":\"$abc\"},\"operationName\":\"getMessages\"}" | jq .data
+
+echo
+echo Send a new private/group message:
+curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"mutation sendNewMessages(\$a: ID!, \$pwHash: String!, \$chat: ID!, \$groupChat: ID!, \$msg: MessageInput!) {\n  chat: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$chat, msg: \$msg)\n  group: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$groupChat, msg: \$msg)\n}\",\"variables\":{\"a\":\"$a\",\"pwHash\":\"1234567890\",\"chat\":\"$ab\",\"groupChat\":\"$abc\",\"msg\":{\"msgType\":\"TEXT\",\"content\":\"New Message!\"}},\"operationName\":\"sendNewMessages\"}" | jq .data
+
+echo
+echo Send a second new private/group message:
+curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"mutation sendNewMessages(\$a: ID!, \$pwHash: String!, \$chat: ID!, \$groupChat: ID!, \$msg: MessageInput!) {\n  chat: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$chat, msg: \$msg)\n  group: sendMessage(user: \$a, passwordHash: \$pwHash, chat: \$groupChat, msg: \$msg)\n}\",\"variables\":{\"a\":\"$a\",\"pwHash\":\"1234567890\",\"chat\":\"$ab\",\"groupChat\":\"$abc\",\"msg\":{\"msgType\":\"TEXT\",\"content\":\"New Message!\"}},\"operationName\":\"sendNewMessages\"}" | jq .data
+
+echo
+echo Get new private/group messages:
+curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"query getMessages(\$a: ID!, \$pwHash: String!, \$chat: ID!, \$groupChat: ID!, \$lastChatMsg: ID!, \$lastGroupChatMsg: ID!) {\n  chat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$chat, lastMsg: \$lastChatMsg) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n  groupChat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$groupChat, lastMsg: \$lastGroupChatMsg) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n}\",\"variables\":{\"a\":\"$a\",\"pwHash\":\"1234567890\",\"chat\":\"$ab\",\"groupChat\":\"$abc\",\"lastChatMsg\":\"$lastChatMsg\",\"lastGroupChatMsg\":\"$lastGroupChatMsg\"},\"operationName\":\"getMessages\"}" | jq .data
+
+echo
+echo Get new private/group messages with a limit of 1:
+curl "localhost:8080/graphql" -X POST -H "content-type: application/json" --data "{\"query\":\"query getMessages(\$a: ID!, \$pwHash: String!, \$chat: ID!, \$groupChat: ID!, \$lastChatMsg: ID!, \$lastGroupChatMsg: ID!, \$limit: Int) {\n  chat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$chat, lastMsg: \$lastChatMsg, limit: \$limit) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n  groupChat: getMessages(user: \$a, passwordHash: \$pwHash, chat: \$groupChat, lastMsg: \$lastGroupChatMsg, limit: \$limit) {\n    id\n    timestamp\n    sender\n    msgType\n    content\n    hideFor\n    seenBy\n  }\n}\",\"variables\":{\"a\":\"$a\",\"pwHash\":\"1234567890\",\"chat\":\"$ab\",\"groupChat\":\"$abc\",\"lastChatMsg\":\"$lastChatMsg\",\"lastGroupChatMsg\":\"$lastGroupChatMsg\",\"limit\":1},\"operationName\":\"getMessages\"}" | jq .data