feat(faction): add C_Reputation.GetFactionDataByID

Keys the modern FactionData table by faction ID instead of by
displayed-list position. Reuses the shared ReadFactionData chain and
table builder, so it needs no new engine work.

Unlike GetFactionInfoByID this is not limited to the player's
reputation list: an unencountered faction fills cleanly with
currentStanding 0 and atWarWith false, so any real faction's name,
description and thresholds are readable.

Author: brues-code

README.md

@@ -66,7 +66,7 @@ reference in **[docs/API.md](docs/API.md)**.
 | [EquipmentSet](docs/API.md#equipmentset) | `C_EquipmentSet.CanUseEquipmentSets`, `C_EquipmentSet.ClearIgnoredSlotsForSave`, `C_EquipmentSet.CreateEquipmentSet`, `C_EquipmentSet.DeleteEquipmentSet`, `C_EquipmentSet.EquipmentSetContainsLockedItems`, `C_EquipmentSet.GetEquipmentSetID`, `C_EquipmentSet.GetEquipmentSetIDs`, `C_EquipmentSet.GetEquipmentSetInfo`, `C_EquipmentSet.GetIgnoredSlots`, `C_EquipmentSet.GetItemIDs`, `C_EquipmentSet.GetItemLocations`, `C_EquipmentSet.GetNumEquipmentSets`, `C_EquipmentSet.IgnoreSlotForSave`, `C_EquipmentSet.IsSlotIgnoredForSave`, `C_EquipmentSet.ModifyEquipmentSet`, `C_EquipmentSet.SaveEquipmentSet`, `C_EquipmentSet.UnignoreSlotForSave`, `C_EquipmentSet.UseEquipmentSet` |
 | [Events](docs/API.md#events) | `C_EventUtils.IsEventValid`, `GetFramesRegisteredForEvent` |
 | [Expansion](docs/API.md#expansion) | `ClassicExpansionAtLeast`, `ClassicExpansionAtMost`, `GetClassicExpansionLevel` |
-| [Faction](docs/API.md#faction) | `C_Reputation.GetFactionDataByIndex`, `C_Reputation.GetFactionStandings`, `C_Reputation.GetLastStandingChange`, `C_Reputation.GetWatchedFactionData`, `C_Reputation.SetWatchedFactionByID`, `GetFactionIDByIndex`, `GetFactionInfoByID`, `GetFactionParentID` |
+| [Faction](docs/API.md#faction) | `C_Reputation.GetFactionDataByID`, `C_Reputation.GetFactionDataByIndex`, `C_Reputation.GetFactionStandings`, `C_Reputation.GetLastStandingChange`, `C_Reputation.GetWatchedFactionData`, `C_Reputation.SetWatchedFactionByID`, `GetFactionIDByIndex`, `GetFactionInfoByID`, `GetFactionParentID` |
 | [Focus](docs/API.md#focus) | `ClearFocus`, `FocusUnit` |
 | [Frame](docs/API.md#frame) | `region:SetPoint("point")` (one-arg form), `region:SetSize`, `region:GetSize`, `region:IsMouseOver`, `region:GetRect`, `region:IsDragging`, `GetMouseFoci`, `frame:SetShown`, `fontstring:GetStringHeight`, `fontstring:GetUnboundedStringWidth`, `fontstring:GetWrappedWidth`, `fontstring:GetNumLines`, `fontstring:GetLineHeight`, `fontstring:IsTruncated`, `fontstring:SetMaxLines`, `fontstring:GetMaxLines`, `fontstring:SetFormattedText`, `texture:SetRotation`, `texture:GetRotation`, `texture:SetVertexOffset`, `texture:GetVertexOffset`, `texture:SetColorTexture`, `texture:SetMask`, `frame:CreateMaskTexture`, `texture:AddMaskTexture`, `texture:RemoveMaskTexture`, `texture:GetNumMaskTextures`, `texture:GetMaskTexture`, `fontstring:SetRotation`, `fontstring:GetRotation`, `editBox:SetCursorPosition`, `editBox:GetCursorPosition`, `editBox:GetUTF8CursorPosition`, `editBox:ClearHighlightText`, `editBox:HasFocus`, `editBox:HasText`, `editBox:SetHighlightColor`, `editBox:GetHighlightColor`, `editBox:ClearHistory`, `frame:SetResizeBounds`, `frame:HookScript`, `frame:IsEventRegistered`, `frame:GetEffectiveAlpha`, `frame:SetAttribute`, `frame:SetAttributeNoHandler`, `frame:ClearAttribute`, `frame:GetAttribute`, `OnAttributeChanged` (script), `SetModernScriptArgs`, `GetModernScriptArgs`, `PreClick` (script), `PostClick` (script), `GetClickFrame` |
 | [FriendList](docs/API.md#friendlist) | `C_FriendList.GetFriendInfo`, `C_FriendList.GetFriendInfoByIndex`, `C_FriendList.GetNumFriends`, `C_FriendList.GetNumOnlineFriends`, `C_FriendList.GetNumWhoResults`, `C_FriendList.GetWhoInfo`, `C_FriendList.IsFriend`, `C_FriendList.IsIgnored`, `C_FriendList.IsIgnoredByGuid`, `C_FriendList.IsWhoQueryPending`, `C_FriendList.SendWhoQueryByName`, `C_FriendList.SetFriendNotes`, `C_FriendList.SetFriendNotesByIndex` |

docs/API.md

@@ -158,6 +158,7 @@ build instructions.
   - [`GetFactionParentID(factionID)`](#getfactionparentidfactionid)
   - [`C_Reputation.GetFactionStandings()`](#c_reputationgetfactionstandings)
   - [`C_Reputation.GetWatchedFactionData()`](#c_reputationgetwatchedfactiondata)
+  - [`C_Reputation.GetFactionDataByID(factionID)`](#c_reputationgetfactiondatabyidfactionid)
   - [`C_Reputation.GetFactionDataByIndex(factionSortIndex)`](#c_reputationgetfactiondatabyindexfactionsortindex)
   - [`C_Reputation.SetWatchedFactionByID(factionID)`](#c_reputationsetwatchedfactionbyidfactionid)
   - [`C_Reputation.GetLastStandingChange()`](#c_reputationgetlaststandingchange)
@@ -3861,6 +3862,27 @@ Implementation reads the watched `RepListID` from the player's
 `ReadFactionData` chain (Faction.dbc lookup, reaction band, rep slot
 flags, header/collapsed checks).
 
+### `C_Reputation.GetFactionDataByID(factionID)`
+
+Returns a `FactionData` table for a faction by ID, or `nil` when the ID
+has no `Faction.dbc` record.
+
+The table has the same shape as
+[`C_Reputation.GetFactionDataByIndex`](#c_reputationgetfactiondatabyindexfactionsortindex)
+— see that section for the full field list.
+
+The faction does not have to be in the player's reputation list. One the
+character has never encountered fills cleanly, with `currentStanding` `0`
+and `atWarWith` `false`, so you can read any faction's name, description,
+and standing thresholds without walking the displayed list.
+
+```lua
+local d = C_Reputation.GetFactionDataByID(69)   -- Darnassus
+if d then
+    print(d.name, d.currentStanding, d.nextReactionThreshold)
+end
+```
+
 ### `C_Reputation.GetFactionDataByIndex(factionSortIndex)`
 
 Returns a `FactionData` table for the faction at the given 1-based

src/faction/Info.cpp

@@ -407,6 +407,30 @@ static int __fastcall Script_C_Reputation_GetWatchedFactionData(void *L) {
     return 1;
 }
 
+// `C_Reputation.GetFactionDataByID(factionID)` — modern table-shaped
+// accessor keyed by faction ID rather than by displayed-list position.
+// Returns nil when the ID has no `Faction.dbc` record.
+//
+// Unlike the index form, this doesn't need the faction to be in the
+// player's displayed reputation list: `ReadFactionData` fills an
+// unencountered faction cleanly (currentStanding 0, not at war), so a
+// lookup works for any real faction.
+static int __fastcall Script_C_Reputation_GetFactionDataByID(void *L) {
+    if (!Game::Lua::IsNumber(L, 1)) {
+        Game::Lua::Error(L, "Usage: C_Reputation.GetFactionDataByID(factionID)");
+        return 0;
+    }
+    const int factionID = static_cast<int>(Game::Lua::ToNumber(L, 1));
+
+    FactionData d;
+    if (!ReadFactionData(factionID, &d))
+        return 0; // nil — no such faction
+
+    Game::Lua::SetTop(L, 0);
+    PushFactionDataTable(L, d);
+    return 1;
+}
+
 // `C_Reputation.GetFactionDataByIndex(factionSortIndex)` — modern
 // table-shaped accessor over the displayed reputation list. 1-based
 // index covering the same range as vanilla's `GetFactionInfo(index)`
@@ -479,6 +503,8 @@ static void RegisterLuaFunctions() {
                                      &Script_C_Reputation_GetWatchedFactionData);
     Game::Lua::RegisterTableFunction("C_Reputation", "GetFactionStandings",
                                      &Script_C_Reputation_GetFactionStandings);
+    Game::Lua::RegisterTableFunction("C_Reputation", "GetFactionDataByID",
+                                     &Script_C_Reputation_GetFactionDataByID);
     Game::Lua::RegisterTableFunction("C_Reputation", "GetFactionDataByIndex",
                                      &Script_C_Reputation_GetFactionDataByIndex);
 }