From 8975af6cee9cfed40a075a16841cb0e6428ebaa6 Mon Sep 17 00:00:00 2001
From: George Hazan <ghazan@miranda.im>
Date: Sun, 6 Feb 2022 18:11:23 +0300
Subject: duplicate event checking code moved to the core

---
 src/mir_app/src/db_events.cpp | 133 ++++++++++++++++++++++++++++++++++++++++++
 src/mir_app/src/mir_app.def   |   1 +
 src/mir_app/src/mir_app64.def |   1 +
 3 files changed, 135 insertions(+)

(limited to 'src/mir_app')

diff --git a/src/mir_app/src/db_events.cpp b/src/mir_app/src/db_events.cpp
index c42fc6ba67..f30b0af087 100644
--- a/src/mir_app/src/db_events.cpp
+++ b/src/mir_app/src/db_events.cpp
@@ -314,3 +314,136 @@ uint8_t* DB::AUTH_BLOB::makeBlob()
 	return pBlob;
 }
 
+/////////////////////////////////////////////////////////////////////////////////////////
+
+static uint32_t dwPreviousTimeStamp = -1;
+static MCONTACT hPreviousContact = INVALID_CONTACT_ID;
+static MEVENT hPreviousDbEvent = 0;
+
+// Returns TRUE if the event already exist in the database
+MIR_APP_DLL(bool) DB::IsDuplicateEvent(MCONTACT hContact, DBEVENTINFO &dbei)
+{
+	// get last event
+	MEVENT hExistingDbEvent = db_event_last(hContact);
+	if (!hExistingDbEvent)
+		return false;
+
+	DBEVENTINFO dbeiExisting = {};
+	db_event_get(hExistingDbEvent, &dbeiExisting);
+	uint32_t dwEventTimeStamp = dbeiExisting.timestamp;
+
+	// compare with last timestamp
+	if (dbei.timestamp > dwEventTimeStamp) {
+		// remember event
+		hPreviousDbEvent = hExistingDbEvent;
+		dwPreviousTimeStamp = dwEventTimeStamp;
+		return false;
+	}
+
+	if (hContact != hPreviousContact) {
+		hPreviousContact = hContact;
+		// remember event
+		hPreviousDbEvent = hExistingDbEvent;
+		dwPreviousTimeStamp = dwEventTimeStamp;
+
+		// get first event
+		if (!(hExistingDbEvent = db_event_first(hContact)))
+			return false;
+
+		memset(&dbeiExisting, 0, sizeof(dbeiExisting));
+		db_event_get(hExistingDbEvent, &dbeiExisting);
+		dwEventTimeStamp = dbeiExisting.timestamp;
+
+		// compare with first timestamp
+		if (dbei.timestamp <= dwEventTimeStamp) {
+			// remember event
+			dwPreviousTimeStamp = dwEventTimeStamp;
+			hPreviousDbEvent = hExistingDbEvent;
+
+			if (dbei.timestamp != dwEventTimeStamp)
+				return false;
+		}
+	}
+
+	// check for equal timestamps
+	if (dbei.timestamp == dwPreviousTimeStamp) {
+		memset(&dbeiExisting, 0, sizeof(dbeiExisting));
+		db_event_get(hPreviousDbEvent, &dbeiExisting);
+
+		if (dbei == dbeiExisting)
+			return true;
+
+		// find event with another timestamp
+		hExistingDbEvent = db_event_next(hContact, hPreviousDbEvent);
+		while (hExistingDbEvent != 0) {
+			memset(&dbeiExisting, 0, sizeof(dbeiExisting));
+			db_event_get(hExistingDbEvent, &dbeiExisting);
+
+			if (dbeiExisting.timestamp != dwPreviousTimeStamp) {
+				// use found event
+				hPreviousDbEvent = hExistingDbEvent;
+				dwPreviousTimeStamp = dbeiExisting.timestamp;
+				break;
+			}
+
+			hPreviousDbEvent = hExistingDbEvent;
+			hExistingDbEvent = db_event_next(hContact, hExistingDbEvent);
+		}
+	}
+
+	hExistingDbEvent = hPreviousDbEvent;
+
+	if (dbei.timestamp <= dwPreviousTimeStamp) {
+		// look back
+		while (hExistingDbEvent != 0) {
+			memset(&dbeiExisting, 0, sizeof(dbeiExisting));
+			db_event_get(hExistingDbEvent, &dbeiExisting);
+
+			if (dbei.timestamp > dbeiExisting.timestamp) {
+				// remember event
+				hPreviousDbEvent = hExistingDbEvent;
+				dwPreviousTimeStamp = dbeiExisting.timestamp;
+				return false;
+			}
+
+			// Compare event with import candidate
+			if (dbei == dbeiExisting) {
+				// remember event
+				hPreviousDbEvent = hExistingDbEvent;
+				dwPreviousTimeStamp = dbeiExisting.timestamp;
+				return true;
+			}
+
+			// Get previous event in chain
+			hExistingDbEvent = db_event_prev(hContact, hExistingDbEvent);
+		}
+	}
+	else {
+		// look forward
+		while (hExistingDbEvent != 0) {
+			memset(&dbeiExisting, 0, sizeof(dbeiExisting));
+			db_event_get(hExistingDbEvent, &dbeiExisting);
+
+			if (dbei.timestamp < dbeiExisting.timestamp) {
+				// remember event
+				hPreviousDbEvent = hExistingDbEvent;
+				dwPreviousTimeStamp = dbeiExisting.timestamp;
+				return false;
+			}
+
+			// Compare event with import candidate
+			if (dbei == dbeiExisting) {
+				// remember event
+				hPreviousDbEvent = hExistingDbEvent;
+				dwPreviousTimeStamp = dbeiExisting.timestamp;
+				return true;
+			}
+
+			// Get next event in chain
+			hExistingDbEvent = db_event_next(hContact, hExistingDbEvent);
+		}
+	}
+	// reset last event
+	hPreviousContact = INVALID_CONTACT_ID;
+	return false;
+}
diff --git a/src/mir_app/src/mir_app.def b/src/mir_app/src/mir_app.def
index be81fe60de..20befc32d3 100644
--- a/src/mir_app/src/mir_app.def
+++ b/src/mir_app/src/mir_app.def
@@ -791,3 +791,4 @@ _Netlib_SslWrite@12 @877 NONAME
 ?setTyping@CSrmmBaseDialog@@QAEXHPBUUSERINFO@@@Z @879 NONAME
 ?SafeRecycleBin@PU@@YGHPB_W@Z @880 NONAME
 ?IsMirandaFolderWritable@PU@@YG_NXZ @881 NONAME
+?IsDuplicateEvent@DB@@YG_NIAAUDBEVENTINFO@@@Z @882 NONAME
diff --git a/src/mir_app/src/mir_app64.def b/src/mir_app/src/mir_app64.def
index 52a1e3b701..0330b8708a 100644
--- a/src/mir_app/src/mir_app64.def
+++ b/src/mir_app/src/mir_app64.def
@@ -791,3 +791,4 @@ Netlib_SslWrite @877 NONAME
 ?setTyping@CSrmmBaseDialog@@QEAAXHPEBUUSERINFO@@@Z @879 NONAME
 ?SafeRecycleBin@PU@@YAHPEB_W@Z @880 NONAME
 ?IsMirandaFolderWritable@PU@@YA_NXZ @881 NONAME
+?IsDuplicateEvent@DB@@YA_NIAEAUDBEVENTINFO@@@Z @882 NONAME
-- 
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