Support for new TTT entity ttt_filter_role (#1789)

closes #1786

new ttt_filter_role entity is from
Facepunch/garrysmod#2225

Author: wgetJane

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable changes to TTT2 will be documented here. Inspired by [keep a changel
 ### Added
 
 - Added option to select preferred unit of length for distance displays (by @wgetJane)
+- Port new TTT entity ttt_filter_role to TTT2 (Facepunch/garrysmod/pull/2225 by @figardo, ported by @wgetJane)
 
 ### Changed
 - Updated Russian and English localization files (by @Satton2)

gamemodes/terrortown/entities/entities/ttt_filter_role.lua

@@ -0,0 +1,65 @@
+---
+-- @class ENT
+-- @section ttt_filter_role
+
+ENT.Type = "filter"
+ENT.Base = "base_filter"
+
+ROLE_NONE = ROLE_NONE or 3
+
+ENT.checkingRole = ROLE_NONE
+
+if CLIENT then
+    return
+end
+
+---
+-- @param string key
+-- @param string|number value
+-- @realm server
+function ENT:KeyValue(key, value)
+    if key == "Role" then
+        if isstring(value) then
+            value = _G[value] or value
+        end
+
+        self.checkingRole = tonumber(value)
+
+        if not self.checkingRole then
+            ErrorNoHalt("ttt_filter_role: bad value for Role key, not a number\n")
+
+            self.checkingRole = ROLE_NONE
+        end
+    end
+end
+
+---
+-- @param Entity caller
+-- @param Entity activator
+-- @realm server
+function ENT:PassesFilter(caller, activator)
+    if not IsValid(activator) or not activator:IsPlayer() then
+        return
+    end
+
+    ---
+    -- @realm server
+    local role, team = hook.Run("TTT2ModifyLogicRoleCheck", activator, self, activator, caller, "")
+    local activatorRole = roles.GetByIndex(role, roles.INNOCENT):GetBaseRole()
+    local activatorTeam = (gameloop.GetRoundState() == ROUND_PREP) and TEAM_INNOCENT or team
+
+    if
+        self.checkingRole == ROLE_TRAITOR and util.IsEvilTeam(activatorTeam)
+        or self.checkingRole == ROLE_INNOCENT and not util.IsEvilTeam(activatorTeam)
+        or self.checkingRole == activatorRole and not (self.checkingRole == ROLE_TRAITOR or self.checkingRole == ROLE_INNOCENT)
+        or self.checkingRole == ROLE_NONE
+    then
+        Dev(2, activator, "passed filter_role test of", self:GetName())
+
+        return true
+    end
+
+    Dev(2, activator, "failed filter_role test of", self:GetName())
+
+    return false
+end