From dbdf2565ae474c5d6ee97e60c67bedfd73334ac1 Mon Sep 17 00:00:00 2001
From: Andrea Maria Piana <andrea.maria.piana@gmail.com>
Date: Thu, 3 Jun 2021 16:09:30 +0200
Subject: [PATCH] WIP

---
 protocol/message_handler.go     | 64 +++++++++++++++++++++++++++++----
 protocol/message_persistence.go | 37 +++++++++++++++++++
 protocol/messenger_response.go  |  7 ++++
 3 files changed, 102 insertions(+), 6 deletions(-)

diff --git a/protocol/message_handler.go b/protocol/message_handler.go
index 147261198..23343899e 100644
--- a/protocol/message_handler.go
+++ b/protocol/message_handler.go
@@ -585,6 +585,20 @@ func (m *MessageHandler) HandleChatMessage(state *ReceivedMessageState) error {
 		return err
 	}
 
+	if len(receivedMessage.OriginalMessageId) != 0 {
+		if receivedMessage.ContentType != protobuf.ChatMessage_EDIT {
+			return errors.New("replace can only be used with an edit content type")
+		}
+		shouldContinue, err := m.handleEditedMessage(state, receivedMessage)
+		if err != nil {
+			return err
+		}
+
+		if !shouldContinue {
+			return nil
+		}
+	}
+
 	// If the chat is not active, create a notification in the center
 	if chat.OneToOne() && !chat.Active {
 		m.createMessageNotification(chat, state)
@@ -623,12 +637,6 @@ func (m *MessageHandler) HandleChatMessage(state *ReceivedMessageState) error {
 		state.Response.CommunityChanges = append(state.Response.CommunityChanges, communityResponse.Changes)
 	}
 
-	if len(receivedMessage.OriginalMessageId) != 0 {
-		if receivedMessage.ContentType != protobuf.ChatMessage_EDIT {
-			return errors.New("replace can only be used with an edit content type")
-		}
-	}
-
 	state.Response.AddMessage(receivedMessage)
 
 	return nil
@@ -1116,6 +1124,50 @@ func (m *MessageHandler) HandleChatIdentity(state *ReceivedMessageState, ci prot
 	return nil
 }
 
+func (m *MessageHandler) handleEditedMessage(state *ReceivedMessageState, message *common.Message) (bool, error) {
+	originalMessageID := message.OriginalMessageId
+	// Check if it's already in the response
+	originalMessage := state.Response.GetMessage(originalMessageID)
+	// and pull all the edits + original message
+	messageHistory, err := m.persistence.MessagesByOriginalMessageID(originalMessageID)
+	if err != nil {
+		return false, err
+	}
+
+	// Check if we have the original message
+
+	if originalMessage == nil {
+		for _, m := range messageHistory {
+			if m.ID == originalMessageID {
+				originalMessage = m
+			}
+		}
+	}
+
+	// We don't have the original message, save the edited message hidden and continue
+	if originalMessage == nil {
+		// This could be a single query
+		err := m.persistence.SaveMessages([]*common.Message{message})
+		if err != nil {
+			return false, nil
+		}
+		err = m.persistence.HideMessage(message.ID)
+		if err != nil {
+			return false, nil
+		}
+		// We tell them to ignore this message
+		return false, nil
+	}
+
+	// We have an original message and potentially some edits
+
+	// check that the edit is valid
+
+	// find the most up to date edit
+
+	return true, nil
+}
+
 func (m *MessageHandler) isMessageAllowedFrom(allContacts *contactMap, publicKey string, chat *Chat) (bool, error) {
 	onlyFromContacts, err := m.settings.GetMessagesFromContactsOnly()
 	if err != nil {
diff --git a/protocol/message_persistence.go b/protocol/message_persistence.go
index cf65388e2..b3bf42aba 100644
--- a/protocol/message_persistence.go
+++ b/protocol/message_persistence.go
@@ -1454,3 +1454,40 @@ func (db sqlitePersistence) clearHistory(chat *Chat, currentClockValue uint64, t
 	err = db.saveChat(tx, *chat)
 	return err
 }
+
+func (db sqlitePersistence) MessagesByOriginalMessageID(id string) ([]*common.Message, error) {
+	allFields := db.tableUserMessagesAllFieldsJoin()
+
+	// nolint: gosec
+	rows, err := db.db.Query(fmt.Sprintf(`
+			SELECT
+				%s
+			FROM
+				user_messages m1
+			LEFT JOIN
+				user_messages m2
+			ON
+			m1.response_to = m2.id
+
+			LEFT JOIN
+			      contacts c
+			ON
+
+			m1.source = c.id
+			WHERE m1.id = ? OR m1.original_message_id = ?`, allFields), id, id)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []*common.Message
+	for rows.Next() {
+		var message common.Message
+		if err := db.tableUserMessagesScanAllFields(rows, &message); err != nil {
+			return nil, err
+		}
+		result = append(result, &message)
+	}
+
+	return result, nil
+}
diff --git a/protocol/messenger_response.go b/protocol/messenger_response.go
index 5edcb8f47..d6fa4f42f 100644
--- a/protocol/messenger_response.go
+++ b/protocol/messenger_response.go
@@ -272,3 +272,10 @@ func (r *MessengerResponse) SetMessages(messages []*common.Message) {
 	r.messages = make(map[string]*common.Message)
 	r.AddMessages(messages)
 }
+
+func (r *MessengerResponse) GetMessage(messageID string) *common.Message {
+	if r.messages == nil {
+		return nil
+	}
+	return r.messages[messageID]
+}