Paragon: spell unlearn queue + AE/TE reconciliation

Two related additions to mod-paragon:

  * HandleCommit gains a third payload section, " u:<id>,...", carrying
    spell IDs the player wants to refund + unlearn in the same commit
    that learns / talents through. The protocol stays backward-compat
    (older clients omit the section). PanelUnlearnSpellPurchase mirrors
    the per-spell branch of HandleParagonResetAbilities: tracked passive
    children are removed first, then the chain head, then panel_spells /
    panel_spell_children / panel_spell_revoked rows for that purchase
    are dropped, then LookupSpellAECost(head) is refunded into the
    cache. Unlearns are applied before learns inside the commit so the
    refund covers the same-commit spends. Allow-list for the silence
    window now includes chain ranks + panel_spell_children for the
    intentional unlearns so "You have unlearned X" toasts stay visible
    for the targeted spell while cascade dependents stay silenced.

  * ReconcileEssenceForPlayer reads panel_spells + panel_talents and
    sets the cache to ComputeStartingAE/TE(level) - sum-of-spends.
    Self-heals drift in either direction: clamps the cache down when
    the player has more essence than their level + spends allow
    (cheese clamp), and tops up when they have less (admin-tweak /
    crash recovery). Wired into OnPlayerLogin (after LoadCurrencyFromDb,
    before PushCurrency so the first balance the client sees is the
    reconciled one) and OnPlayerLevelChanged (replaces the old
    GrantLevelUpEssence delta -- Reconcile sets the absolute correct
    balance from level + spend, so it subsumes the per-level grant and
    the cheese clamp in one call). Costs come from the same
    paragon_spell_ae_cost / config keys HandleCommit uses so the math
    stays in lockstep across any future cost rebalance.

Both features ship in patch-enUS-6.MPQ v0.9.16: right-click a learned
spell row to queue an unlearn (header shows +N AE refund preview) and
hit Learn All to apply. The icon picker also got two fixes -- the
leading INV_Misc_QuestionMark is no longer duplicated, and the
selection ring is now a tooltip-border Frame anchored to the cell
bounds (the prior UI-ActionButton-Border texture rendered nearly
invisible at non-native sizes).

Co-authored-by: Cursor <cursoragent@cursor.com>

modules/mod-paragon/src/Paragon_Essence.cpp

@@ -257,6 +257,87 @@ uint32 GetParagonPanelSpellRequiredLevel(SpellInfo const* info)
     return std::max(1u, lv);
 }
 
+// Reconciles the player's AE/TE cache against what they SHOULD have
+// based on level (ComputeStartingAE/TE) minus what they've spent through
+// Character Advancement (sum over character_paragon_panel_spells +
+// character_paragon_panel_talents). Updates the cache + DB if either
+// direction drifts:
+//   * actual < expected: top up (handles per-level grants automatically;
+//     also self-heals from admin commands / crashes that lost essence).
+//   * actual > expected: clamp down (prevents .modify-style cheese, ghost
+//     panel rows that were rolled back, or any path that left more
+//     essence than the level allowed).
+// Logs at INFO when drift is corrected so we can spot abuse patterns.
+//
+// Cheap (two SELECTs of small per-character tables) and safe to call from
+// OnPlayerLogin and OnPlayerLevelChanged. SAFE TO CALL ANY TIME the panel
+// DB is in a steady state (i.e. NOT mid-HandleCommit).
+void ReconcileEssenceForPlayer(Player* pl)
+{
+    if (!pl || pl->getClass() != CLASS_PARAGON)
+        return;
+    if (!sConfigMgr->GetOption<bool>("Paragon.Currency.Enabled", true))
+        return;
+
+    uint32 const lowGuid = pl->GetGUID().GetCounter();
+    uint8 const  level   = pl->GetLevel();
+
+    // Sum AE / TE spent through panel purchases. Mirrors the cost lookups
+    // used by HandleCommit so reconciliation matches the spend math byte-
+    // for-byte (no off-by-one if config keys are tweaked at runtime).
+    uint32 spentAE = 0;
+    uint32 spentTE = 0;
+
+    if (QueryResult r = CharacterDatabase.Query(
+            "SELECT spell_id FROM character_paragon_panel_spells WHERE guid = {}", lowGuid))
+    {
+        do
+        {
+            spentAE += LookupSpellAECost(r->Fetch()[0].Get<uint32>());
+        } while (r->NextRow());
+    }
+
+    uint32 const tePerRank = sConfigMgr->GetOption<uint32>("Paragon.Currency.TE.TalentLearnCost", 1);
+    uint32 const aePerRank = sConfigMgr->GetOption<uint32>("Paragon.Currency.AE.TalentLearnCost", 1);
+    if (QueryResult r = CharacterDatabase.Query(
+            "SELECT talent_id, `rank` FROM character_paragon_panel_talents WHERE guid = {}", lowGuid))
+    {
+        do
+        {
+            Field const* f = r->Fetch();
+            uint32 const tid  = f[0].Get<uint32>();
+            uint32 const rank = f[1].Get<uint32>();
+            TalentEntry const* te = sTalentStore.LookupEntry(tid);
+            if (!te || !rank)
+                continue;
+            spentTE += rank * tePerRank;
+            if (te->addToSpellBook)
+                spentAE += rank * aePerRank;
+        } while (r->NextRow());
+    }
+
+    uint32 const expectedTotalAE = ComputeStartingAE(level);
+    uint32 const expectedTotalTE = ComputeStartingTE(level);
+    uint32 const expectedBalAE   = expectedTotalAE > spentAE ? expectedTotalAE - spentAE : 0;
+    uint32 const expectedBalTE   = expectedTotalTE > spentTE ? expectedTotalTE - spentTE : 0;
+
+    ParagonCurrencyData& d = GetOrCreateCacheEntry(lowGuid);
+    if (d.abilityEssence == expectedBalAE && d.talentEssence == expectedBalTE)
+        return;
+
+    LOG_INFO("module",
+        "Paragon essence reconciled for {} (lvl {}): AE {}->{} TE {}->{} (spent AE={} TE={}, expected total AE={} TE={})",
+        pl->GetName(), uint32(level),
+        d.abilityEssence, expectedBalAE,
+        d.talentEssence,  expectedBalTE,
+        spentAE, spentTE,
+        expectedTotalAE, expectedTotalTE);
+
+    d.abilityEssence = expectedBalAE;
+    d.talentEssence  = expectedBalTE;
+    SaveCurrencyToDb(pl);
+}
+
 // Forward declaration: reset handlers below need PushSnapshot, which itself
 // is defined later (after PushSpellSnapshot / PushTalentSnapshot).
 void PushSnapshot(Player* pl);
@@ -989,10 +1070,12 @@ uint32 ComputeTalentRankAnySpec(Player* pl, uint32 talentId)
 // ---- Commit handler --------------------------------------------------------
 //
 // Wire format from Net.lua Net:Commit:
-//   "C COMMIT s:<id1>,<id2>,...<empty allowed> t:<talentId>:<delta>,..."
+//   "C COMMIT s:<id1>,<id2>,...<empty allowed> t:<talentId>:<delta>,... u:<id>,..."
-// Both sub-lists are optional but the leading tags are not. Examples:
+// The " u:" spell-unlearn section is optional (omitted by older clients).
+// Both s: and t: leading tags are required. Examples:
 //   "C COMMIT s:5176,8921 t:"
 //   "C COMMIT s: t:1234:1,5678:2"
+//   "C COMMIT s: t: u:45477"
 // We parse leniently and abort on any structural error.
 //
 // On success we push:
@@ -1035,12 +1118,15 @@ std::vector<uint32> ParseCsvUInt(std::string_view csv)
 //   * full chain ids for every spell the player explicitly purchased (so
 //     the player still sees "Plague Strike (Rank 1..N) learned" toasts);
 //   * every talent rank id the player explicitly purchased (so addToSpellBook
-//     talents like Bladestorm/Starfall still toast normally).
+//     talents like Bladestorm/Starfall still toast normally);
+//   * chain ids + tracked passive children for spells intentionally unlearned
+//     in this commit (so "You have unlearned …" for those stays visible).
 // Anything else learned/unlearned during the window -- the SkillLineAbility
 // cascade and our diff-revoke cleanup -- is silenced.
 void SendSilenceOpenForCommit(Player* pl,
                               std::vector<std::pair<uint32, uint32>> const& spellsAndCosts,
-                              std::vector<std::pair<uint32, uint32>> const& talentDeltas)
+                              std::vector<std::pair<uint32, uint32>> const& talentDeltas,
+                              std::vector<uint32> const& unlearnTrackIds = {})
 {
     if (!pl)
         return;
@@ -1049,6 +1135,26 @@ void SendSilenceOpenForCommit(Player* pl,
     for (auto const& kv : spellsAndCosts)
         CollectSpellChainIds(kv.first, allow);
 
+    uint32 const lowGuid = pl->GetGUID().GetCounter();
+    for (uint32 trackId : unlearnTrackIds)
+    {
+        if (!trackId)
+            continue;
+        CollectSpellChainIds(trackId, allow);
+        if (QueryResult cr = CharacterDatabase.Query(
+                "SELECT child_spell_id FROM character_paragon_panel_spell_children "
+                "WHERE guid = {} AND parent_spell_id = {}",
+                lowGuid, trackId))
+        {
+            do
+            {
+                uint32 const cid = cr->Fetch()[0].Get<uint32>();
+                if (cid)
+                    allow.insert(cid);
+            } while (cr->NextRow());
+        }
+    }
+
     for (auto const& [tid, delta] : talentDeltas)
     {
         (void)delta;
@@ -1094,6 +1200,71 @@ void SendSilenceClose(Player* pl)
         SendAddonMessage(pl, "R SILENCE CLOSE");
 }
 
+// Removes one Character Advancement spell purchase (chain head in
+// character_paragon_panel_spells). Refunds that row's AE cost, unlearns
+// tracked passive children then the parent chain, and clears matching
+// panel_* DB rows (mirrors the per-spell portion of HandleParagonResetAbilities).
+// `spellId` may be any rank id from the bake; normalized to GetFirstSpellInChain.
+bool PanelUnlearnSpellPurchase(Player* pl, uint32 spellId, std::string* err)
+{
+    if (!pl || !spellId)
+    {
+        if (err)
+            *err = "bad player or spell";
+        return false;
+    }
+
+    uint32 const lowGuid = pl->GetGUID().GetCounter();
+    uint32 const head    = sSpellMgr->GetFirstSpellInChain(spellId);
+    uint32 const sid      = head ? head : spellId;
+
+    if (!CharacterDatabase.Query(
+            "SELECT 1 FROM character_paragon_panel_spells WHERE guid = {} AND spell_id = {} LIMIT 1",
+            lowGuid, sid))
+    {
+        if (err)
+            *err = fmt::format("spell {} is not a panel purchase", sid);
+        return false;
+    }
+
+    uint32 const refund = LookupSpellAECost(sid);
+
+    if (QueryResult cr = CharacterDatabase.Query(
+            "SELECT child_spell_id FROM character_paragon_panel_spell_children "
+            "WHERE guid = {} AND parent_spell_id = {}",
+            lowGuid, sid))
+    {
+        do
+        {
+            uint32 const cid = cr->Fetch()[0].Get<uint32>();
+            if (pl->HasSpell(cid))
+                pl->removeSpell(cid, SPEC_MASK_ALL, false);
+        } while (cr->NextRow());
+    }
+
+    if (pl->HasSpell(sid))
+        pl->removeSpell(sid, SPEC_MASK_ALL, false);
+
+    CharacterDatabase.DirectExecute(
+        "DELETE FROM character_paragon_panel_spell_children WHERE guid = {} AND parent_spell_id = {}",
+        lowGuid, sid);
+    CharacterDatabase.DirectExecute(
+        "DELETE FROM character_paragon_panel_spell_revoked WHERE guid = {} AND parent_spell_id = {}",
+        lowGuid, sid);
+
+    std::unordered_set<uint32> chainIds;
+    CollectSpellChainIds(sid, chainIds);
+    DbDeletePanelSpellRevokedForChain(lowGuid, chainIds);
+
+    CharacterDatabase.DirectExecute(
+        "DELETE FROM character_paragon_panel_spells WHERE guid = {} AND spell_id = {}",
+        lowGuid, sid);
+
+    ParagonCurrencyData& d = GetOrCreateCacheEntry(lowGuid);
+    d.abilityEssence += refund;
+    return true;
+}
+
 bool HandleCommit(Player* pl, std::string const& body, std::string* err)
 {
     // Strip leading "C COMMIT " (already stripped by caller, but be defensive)
@@ -1111,10 +1282,20 @@ bool HandleCommit(Player* pl, std::string const& body, std::string* err)
         return false;
     }
 
-    std::string_view spellsCsv  = rest.substr(2, tPos - 2);
+    std::string_view spellsCsv = rest.substr(2, tPos - 2);
-    std::string_view talentsCsv = rest.substr(tPos + 3);
+    std::string_view talentsCsv;
+    std::string_view unlearnCsv;
+    size_t const uPos = rest.find(" u:", tPos);
+    if (uPos != std::string_view::npos)
+    {
+        talentsCsv = rest.substr(tPos + 3, uPos - (tPos + 3));
+        unlearnCsv = rest.substr(uPos + 3);
+    }
+    else
+        talentsCsv = rest.substr(tPos + 3);
 
     std::vector<uint32> spellIds = ParseCsvUInt(spellsCsv);
+    std::vector<uint32> unlearnRaw = ParseCsvUInt(unlearnCsv);
 
     // Talents are "id:delta,id:delta,...". Parse into vector of pairs.
     std::vector<std::pair<uint32, uint32>> talentDeltas;
@@ -1152,12 +1333,37 @@ bool HandleCommit(Player* pl, std::string const& body, std::string* err)
         }
     }
 
-    if (spellIds.size() + talentDeltas.size() > kCommitMaxItems)
+    std::unordered_set<uint32> unlearnTrackSet;
+    std::vector<uint32> unlearnTracks;
+    for (uint32 raw : unlearnRaw)
+    {
+        if (!raw)
+            continue;
+        uint32 const head = sSpellMgr->GetFirstSpellInChain(raw);
+        uint32 const tid  = head ? head : raw;
+        if (unlearnTrackSet.insert(tid).second)
+            unlearnTracks.push_back(tid);
+    }
+
+    if (spellIds.size() + talentDeltas.size() + unlearnTracks.size() > kCommitMaxItems)
     {
         *err = "commit exceeds size cap";
         return false;
     }
 
+    uint32 unlearnRefundAE = 0;
+    for (uint32 tid : unlearnTracks)
+    {
+        if (!CharacterDatabase.Query(
+                "SELECT 1 FROM character_paragon_panel_spells WHERE guid = {} AND spell_id = {} LIMIT 1",
+                pl->GetGUID().GetCounter(), tid))
+        {
+            *err = fmt::format("cannot unlearn {} (not a panel purchase)", tid);
+            return false;
+        }
+        unlearnRefundAE += LookupSpellAECost(tid);
+    }
+
     // Pre-validate spells: must be valid SpellInfo, not already learned,
     // and afford their combined AE cost.
     uint32 totalAE = 0;
@@ -1181,6 +1387,13 @@ bool HandleCommit(Player* pl, std::string const& body, std::string* err)
             *err = fmt::format("requires level {} for spell {}", reqLv, id);
             return false;
         }
+        uint32 const learnHead = sSpellMgr->GetFirstSpellInChain(id);
+        uint32 const learnTrack = learnHead ? learnHead : id;
+        if (unlearnTrackSet.count(learnTrack))
+        {
+            *err = "cannot learn and unlearn the same spell in one commit";
+            return false;
+        }
         uint32 cost = LookupSpellAECost(id);
         spellsAndCosts.emplace_back(id, cost);
         totalAE += cost;
@@ -1222,9 +1435,10 @@ bool HandleCommit(Player* pl, std::string const& body, std::string* err)
         *err = fmt::format("not enough TE (need {} have {})", talentsTE, GetTE(pl));
         return false;
     }
-    if (GetAE(pl) < (totalAE + talentsAE))
+    if (GetAE(pl) + unlearnRefundAE < (totalAE + talentsAE))
     {
-        *err = fmt::format("not enough AE (need {} have {})", totalAE + talentsAE, GetAE(pl));
+        *err = fmt::format("not enough AE (need {} total; you have {} plus {} from unlearns in this commit)",
+                          totalAE + talentsAE, GetAE(pl), unlearnRefundAE);
         return false;
     }
 
@@ -1234,8 +1448,18 @@ bool HandleCommit(Player* pl, std::string const& body, std::string* err)
     // learnSpell drags along (Death Coil/Death Grip/Blood Plague/Blood
     // Presence/Forceful Deflection/Runic Focus/...) don't spam learn/
     // unlearn toasts. Allow list = chain ranks of explicitly purchased
-    // spells + talent rank ids. Closed below at the end of the commit.
+    // spells + talent rank ids + chains/children for intentional unlearns.
-    SendSilenceOpenForCommit(pl, spellsAndCosts, talentDeltas);
+    SendSilenceOpenForCommit(pl, spellsAndCosts, talentDeltas, unlearnTracks);
+
+    // Apply spell unlearns first so refunded AE is available for spends.
+    for (uint32 tid : unlearnTracks)
+    {
+        if (!PanelUnlearnSpellPurchase(pl, tid, err))
+        {
+            SendSilenceClose(pl);
+            return false;
+        }
+    }
 
     // Apply spells: each consumes its individual AE cost. PanelLearnSpellChain
     // also grants every higher rank up to the player's current level so the
@@ -2924,6 +3148,13 @@ public:
     void OnPlayerLogin(Player* player) override
     {
         LoadCurrencyFromDb(player);
+        // Verify AE/TE matches what the player's level + panel spend
+        // permit. Self-heals admin / crash drift in either direction
+        // and is a no-op (just two small SELECTs) when the balance is
+        // already correct. Has to run BEFORE PushCurrency so the
+        // client's first balance update of the session is the
+        // reconciled one.
+        ReconcileEssenceForPlayer(player);
         PushCurrency(player);
         PushSnapshot(player);
         PushBuildCatalog(player);
@@ -3003,7 +3234,7 @@ public:
         // Player isn't fully in-world here; OnPlayerLogin will push.
     }
 
-    void OnPlayerLevelChanged(Player* player, uint8 oldLevel) override
+    void OnPlayerLevelChanged(Player* player, uint8 /*oldLevel*/) override
     {
         if (!player || player->getClass() != CLASS_PARAGON)
             return;
@@ -3017,10 +3248,13 @@ public:
         if (gParagonCurrencyCache.find(lowGuid) == gParagonCurrencyCache.end())
             LoadCurrencyFromDb(player);
 
-        GrantLevelUpEssence(player, oldLevel, player->GetLevel());
+        // Single source of truth: ComputeStartingAE/TE(newLevel) - spent.
-
+        // Subsumes the old GrantLevelUpEssence per-level delta AND catches
-        // Persist the grant immediately so a crash before next save doesn't
+        // drift in both directions (cheese clamp + restore-from-loss).
-        // lose freshly-awarded essence. Cheap (single REPLACE).
+        // SaveCurrencyToDb runs inside Reconcile when drift is detected;
+        // call it once more here so a no-drift level-up still flushes any
+        // pending cache changes from this session.
+        ReconcileEssenceForPlayer(player);
         SaveCurrencyToDb(player);
         PushCurrency(player);
     }