From 0a6f88e8ade888fb6d57fa8b687cfd79940168f0 Mon Sep 17 00:00:00 2001
From: Kelsi <kelsihates2fa@gmail.com>
Date: Mon, 9 Mar 2026 21:48:41 -0700
Subject: [PATCH] tbc: fix SMSG_SPELL_START and SMSG_SPELL_GO for TBC 2.4.3

TBC 2.4.3 SMSG_SPELL_START and SMSG_SPELL_GO send full uint64 GUIDs for
casterGuid/casterUnit and hit targets.  WotLK uses packed (variable-length)
GUIDs.  Using readPackedGuid() on a full uint64 reads the first byte as the
bitmask, consuming 1-8 wrong bytes, which shifts all subsequent fields
(spellId, castFlags, castTime) and causes:
  - Cast bar to never show for the player's own spells
  - Sound effects to use the wrong spell ID
  - Hit/miss target tracking to be completely wrong

Additionally, TBC SMSG_SPELL_GO lacks the WotLK timestamp field after
castFlags.

Add TbcPacketParsers::parseSpellStart and ::parseSpellGo using full GUIDs,
add virtual base methods, and route both handlers through virtual dispatch.
---
 include/game/packet_parsers.hpp | 14 +++++++
 src/game/game_handler.cpp       |  4 +-
 src/game/packet_parsers_tbc.cpp | 67 +++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+), 2 deletions(-)

diff --git a/include/game/packet_parsers.hpp b/include/game/packet_parsers.hpp
index 8885865e..27e6dfc8 100644
--- a/include/game/packet_parsers.hpp
+++ b/include/game/packet_parsers.hpp
@@ -105,6 +105,16 @@ public:
         return InitialSpellsParser::parse(packet, data);
     }
 
+    /** Parse SMSG_SPELL_START */
+    virtual bool parseSpellStart(network::Packet& packet, SpellStartData& data) {
+        return SpellStartParser::parse(packet, data);
+    }
+
+    /** Parse SMSG_SPELL_GO */
+    virtual bool parseSpellGo(network::Packet& packet, SpellGoData& data) {
+        return SpellGoParser::parse(packet, data);
+    }
+
     /** Parse SMSG_CAST_FAILED */
     virtual bool parseCastFailed(network::Packet& packet, CastFailedData& data) {
         return CastFailedParser::parse(packet, data);
@@ -322,6 +332,10 @@ public:
     bool parseGossipMessage(network::Packet& packet, GossipMessageData& data) override;
     // TBC 2.4.3 SMSG_CAST_RESULT: spellId(u32) + result(u8) — WotLK added castCount(u8) prefix
     bool parseCastResult(network::Packet& packet, uint32_t& spellId, uint8_t& result) override;
+    // TBC 2.4.3 SMSG_SPELL_START: full uint64 GUIDs (WotLK uses packed GUIDs)
+    bool parseSpellStart(network::Packet& packet, SpellStartData& data) override;
+    // TBC 2.4.3 SMSG_SPELL_GO: full uint64 GUIDs, no timestamp field (WotLK added one)
+    bool parseSpellGo(network::Packet& packet, SpellGoData& data) override;
     // TBC 2.4.3 SMSG_MAIL_LIST_RESULT: uint8 count (not uint32+uint8), no body field,
     // attachment uses uint64 itemGuid (not uint32), enchants are 7×u32 id-only (not 7×{id+dur+charges})
     bool parseMailList(network::Packet& packet, std::vector<MailMessage>& inbox) override;
diff --git a/src/game/game_handler.cpp b/src/game/game_handler.cpp
index 86f83351..37c6591f 100644
--- a/src/game/game_handler.cpp
+++ b/src/game/game_handler.cpp
@@ -12410,7 +12410,7 @@ static audio::SpellSoundManager::MagicSchool schoolMaskToMagicSchool(uint32_t ma
 
 void GameHandler::handleSpellStart(network::Packet& packet) {
     SpellStartData data;
-    if (!SpellStartParser::parse(packet, data)) return;
+    if (!packetParsers_->parseSpellStart(packet, data)) return;
 
     // If this is the player's own cast, start cast bar
     if (data.casterUnit == playerGuid && data.castTime > 0) {
@@ -12435,7 +12435,7 @@ void GameHandler::handleSpellStart(network::Packet& packet) {
 
 void GameHandler::handleSpellGo(network::Packet& packet) {
     SpellGoData data;
-    if (!SpellGoParser::parse(packet, data)) return;
+    if (!packetParsers_->parseSpellGo(packet, data)) return;
 
     // Cast completed
     if (data.casterUnit == playerGuid) {
diff --git a/src/game/packet_parsers_tbc.cpp b/src/game/packet_parsers_tbc.cpp
index b13ee058..141f9f96 100644
--- a/src/game/packet_parsers_tbc.cpp
+++ b/src/game/packet_parsers_tbc.cpp
@@ -977,6 +977,73 @@ bool TbcPacketParsers::parseMailList(network::Packet& packet, std::vector<MailMe
     return !inbox.empty();
 }
 
+// ============================================================================
+// TbcPacketParsers::parseSpellStart — TBC 2.4.3 SMSG_SPELL_START
+//
+// TBC uses full uint64 GUIDs for casterGuid and casterUnit.
+// WotLK uses packed (variable-length) GUIDs.
+// TBC also lacks the castCount byte — format:
+//   casterGuid(u64) + casterUnit(u64) + castCount(u8) + spellId(u32) + castFlags(u32) + castTime(u32)
+// Wait: TBC DOES have castCount. But WotLK removed spellId in some paths.
+// Correct TBC format (cmangos-tbc): objectGuid(u64) + casterGuid(u64) + castCount(u8) + spellId(u32) + castFlags(u32) + castTime(u32)
+// ============================================================================
+bool TbcPacketParsers::parseSpellStart(network::Packet& packet, SpellStartData& data) {
+    if (packet.getSize() - packet.getReadPos() < 22) return false;
+
+    data.casterGuid = packet.readUInt64();   // full GUID (object)
+    data.casterUnit = packet.readUInt64();   // full GUID (caster unit)
+    data.castCount  = packet.readUInt8();
+    data.spellId    = packet.readUInt32();
+    data.castFlags  = packet.readUInt32();
+    data.castTime   = packet.readUInt32();
+
+    if (packet.getReadPos() + 4 <= packet.getSize()) {
+        uint32_t targetFlags = packet.readUInt32();
+        if ((targetFlags & 0x02) && packet.getReadPos() + 8 <= packet.getSize()) {
+            data.targetGuid = packet.readUInt64();  // full GUID in TBC
+        }
+    }
+
+    LOG_DEBUG("[TBC] Spell start: spell=", data.spellId, " castTime=", data.castTime, "ms");
+    return true;
+}
+
+// ============================================================================
+// TbcPacketParsers::parseSpellGo — TBC 2.4.3 SMSG_SPELL_GO
+//
+// TBC uses full uint64 GUIDs, no timestamp field after castFlags.
+// WotLK uses packed GUIDs and adds a timestamp (u32) after castFlags.
+// ============================================================================
+bool TbcPacketParsers::parseSpellGo(network::Packet& packet, SpellGoData& data) {
+    if (packet.getSize() - packet.getReadPos() < 19) return false;
+
+    data.casterGuid = packet.readUInt64();   // full GUID in TBC
+    data.casterUnit = packet.readUInt64();   // full GUID in TBC
+    data.castCount  = packet.readUInt8();
+    data.spellId    = packet.readUInt32();
+    data.castFlags  = packet.readUInt32();
+    // NOTE: NO timestamp field here in TBC (WotLK added packet.readUInt32())
+
+    if (packet.getReadPos() >= packet.getSize()) {
+        LOG_DEBUG("[TBC] Spell go: spell=", data.spellId, " (no hit data)");
+        return true;
+    }
+
+    data.hitCount = packet.readUInt8();
+    data.hitTargets.reserve(data.hitCount);
+    for (uint8_t i = 0; i < data.hitCount && packet.getReadPos() + 8 <= packet.getSize(); ++i) {
+        data.hitTargets.push_back(packet.readUInt64());  // full GUID in TBC
+    }
+
+    if (packet.getReadPos() < packet.getSize()) {
+        data.missCount = packet.readUInt8();
+    }
+
+    LOG_DEBUG("[TBC] Spell go: spell=", data.spellId, " hits=", (int)data.hitCount,
+              " misses=", (int)data.missCount);
+    return true;
+}
+
 // ============================================================================
 // TbcPacketParsers::parseCastResult — TBC 2.4.3 SMSG_CAST_RESULT
 //