Yet another MAM logic rewrite: assume request order by RSM before/after, do not consider RSM limitation themselves as incompleteness

telegram/utils.go

@@ -2478,13 +2478,14 @@ func (c *Client) GetMessagesBetween(chatID, fromMessageId, lastMessageId int64,
 					if firstMessage.Id > fromMessageId {
 						complete = false
 					}
-				} else {
+				} else if fromMessageId == 1 {
 					// try to fetch one more message to check if there are any other before
 					previousMessage, previousMessageErr := c.GetPreviousMessage(chatID, firstMessage.Id)
 					if previousMessageErr == nil && previousMessage != nil {
 						complete = false
 					}
 				}
+				// for 0 one last message is already fetched as there is at least one, right?
 			}
 		} else {
 			for _, message := range fetchedMessages {

xmpp/handlers.go

@@ -2344,18 +2344,10 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 		}
 	}
 
-	if rsmBefore != 0 && rsmAfter == 0 {
-		rsmLastPage = true
-	}
-
 	if rsmLimit == 0 && !justCount {
 		rsmLimit = 100
 	}
 
-	if rsmLastPage {
-		rsmLimit = -rsmLimit // hacky, I know, and? :P
-	}
-
 	// check for mutual parameter compatibility, there's a lot of them, nah?
 	if ((!startTime.IsZero() || !endTime.IsZero()) && (beforeId != 0 || afterId != 0 || ids != nil)) ||
 		((beforeId != 0 || afterId != 0) && (!startTime.IsZero() || !endTime.IsZero() || ids != nil)) ||
@@ -2368,11 +2360,32 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 	// dummy call to circumvent unexported type
 	messages, _, err := session.GetMessagesBetween(toID, 0, 0, 0, false)
 
+	var order bool // false from start, true from end
+	// lower priority
+	if !endTime.IsZero() {
+		order = true
+	}
+	// higher priority
+	if beforeId != 0 {
+		order = false
+	}
+	if afterId != 0 {
+		order = true
+	}
+	if rsmAfter != 0 {
+		order = false
+	}
+	if rsmBefore != 0 || rsmLastPage {
+		order = true
+	}
+	if order {
+		rsmLimit = -rsmLimit // hacky, I know, and? :P
+	}
+
 	quotaTs := time.Now().AddDate(0, 0, -int(gateway.MAMThreshold))
 	var beyond, complete bool
-	canBeComplete := true
+	fromStart := !order
-	fromStart := !rsmLastPage
+	toEnd := order
-	toEnd := rsmLastPage
 	var overallyFirstMessageId, overallyLastMessageId int64
 
 	reverse := query.GetFlipPage() != nil
@@ -2454,7 +2467,6 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 			}
 			if rsmAfter != afterId {
 				fromStart = false
-				canBeComplete = false
 				overallyFirstMessage, overallyFirstMessageErr := session.GetNextMessage(toID, afterId)
 				if overallyFirstMessageErr == nil && overallyFirstMessage != nil {
 					overallyFirstMessageId = overallyFirstMessage.Id
@@ -2471,7 +2483,6 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 			}
 			if rsmBefore < beforeId {
 				toEnd = false
-				canBeComplete = false
 			}
 			beforeId = rsmBefore
 		}
@@ -2486,11 +2497,7 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 		}
 
 		if !beyond {
-			var newComplete bool
+			messages, complete, err = session.GetMessagesBetween(toID, afterId, lastMessageId, rsmLimit, reverse)
-			messages, newComplete, err = session.GetMessagesBetween(toID, afterId, lastMessageId, rsmLimit, reverse)
-			if canBeComplete {
-				complete = newComplete
-			}
 		}
 	} else { // time limit or no limits at all
 		// don't allow to fetch far beyond the quota
@@ -2540,7 +2547,6 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 
 					if rsmAfterMessage.Id > fromMessageId && int64(rsmAfterMessage.Date) >= startTime.Unix() {
 						fromStart = false
-						canBeComplete = false
 						overallyFirstMessage, overallyFirstMessageErr := session.GetNextMessage(toID, fromMessageId)
 						if overallyFirstMessageErr == nil && overallyFirstMessage != nil {
 							overallyFirstMessageId = overallyFirstMessage.Id
@@ -2567,7 +2573,6 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 						newLastMessage, newLastMessageErr := session.GetPreviousMessage(toID, rsmBeforeMessage.Id)
 						if newLastMessageErr == nil && newLastMessage != nil {
 							if lastMessageId == 0 || lastMessageId != newLastMessage.Id {
-								canBeComplete = false
 								toEnd = false
 								lastMessageId = newLastMessage.Id
 							}
@@ -2584,11 +2589,7 @@ func handleSetQueryMAM(s xmpp.Sender, iq *stanza.IQ, query extensions.MAMQuery)
 			}
 
 			if !beyond { // yes🗿, twice
-				var newComplete bool
+				messages, complete, err = session.GetMessagesBetween(toID, fromMessageId, lastMessageId, rsmLimit, reverse)
-				messages, newComplete, err = session.GetMessagesBetween(toID, fromMessageId, lastMessageId, rsmLimit, reverse)
-				if canBeComplete {
-					complete = newComplete
-				}
 			}
 		}
 	}