Core/ChatCommands: C++17 cleanup (again) (PR #25323)

(cherry picked from commit 2f7d2ef3e979ecd0536f3a3713e56c8e59652a47)

5 files changed, 281 insertions, 323 deletions

diff --git a/src/server/game/Chat/ChatCommands/ChatCommand.h b/src/server/game/Chat/ChatCommands/ChatCommand.h
index c54f7f52cb5..dac914485d0 100644
--- a/src/server/game/Chat/ChatCommands/ChatCommand.h
+++ b/src/server/game/Chat/ChatCommands/ChatCommand.h
@@ -33,199 +33,106 @@
 class ChatHandler;
 class CommandArgs;
 
-template <typename T>
-struct CommandArgsConsumerSingle
+namespace Trinity::Impl::ChatCommands
 {
-    using arginfo = Trinity::ChatCommands::ArgInfo<T>;
-    static char const* TryConsumeTo(T& val, char const* args)
+    template <typename T>
+    struct SingleConsumer
     {
-        return arginfo::TryConsume(val, args);
-    }
-};
-
-struct CommandArgsVariantConsumer
-{
-    template <typename V, typename T1, typename... Ts>
-    static char const* TryConsumeTo(V& val, char const* args)
-    {
-        T1 v;
-        if (char const* next = CommandArgsConsumerSingle<T1>::TryConsumeTo(v, args))
+        static Optional<std::string_view> TryConsumeTo(T& val, std::string_view args)
         {
-            val = std::move(v);
-            return next;
+            return ArgInfo<T>::TryConsume(val, args);
         }
-        else if constexpr (sizeof...(Ts) > 0)
-            return TryConsumeTo<V, Ts...>(val, args);
-        else
-            return nullptr;
-    }
-};
-
-template <typename... Ts>
-struct CommandArgsConsumerSingle<Trinity::ChatCommands::Variant<Ts...>>
-{
-    static char const* TryConsumeTo(Trinity::ChatCommands::Variant<Ts...>& val, char const* args)
-    {
-        return CommandArgsVariantConsumer::TryConsumeTo<Trinity::ChatCommands::Variant<Ts...>, Ts...>(val, args);
-    }
-};
+    };
 
-template <typename T>
-struct CommandArgsConsumerSingle<std::vector<T>>
-{
-    static char const* TryConsumeTo(std::vector<T>& val, char const* args)
+    template <typename... Ts>
+    struct SingleConsumer<Trinity::ChatCommands::Variant<Ts...>>
     {
-        char const* last;
-        val.clear();
-
-        do val.emplace_back();
-        while ((args = CommandArgsConsumerSingle<T>::TryConsumeTo(val.back(), (last = args))));
-
-        val.pop_back();
-        return last;
-    }
-};
+        using V = std::variant<Ts...>;
+        static constexpr size_t N = std::variant_size_v<V>;
 
-template <typename T, std::size_t C>
-struct CommandArgsConsumerSingle<std::array<T, C>>
-{
-    static char const* TryConsumeTo(std::array<T, C>& val, char const* args)
-    {
-        for (T& t : val)
+        template <size_t I>
+        static Optional<std::string_view> TryAtIndex(Trinity::ChatCommands::Variant<Ts...>& val, [[maybe_unused]] std::string_view args)
         {
-            args = CommandArgsConsumerSingle<T>::TryConsumeTo(t, args);
-
-            if (!args)
-                return nullptr;
+            if constexpr (I < N)
+            {
+                if (Optional<std::string_view> next = ArgInfo<std::variant_alternative_t<I, V>>::TryConsume(val.template emplace<I>(), args))
+                    return next;
+                else
+                    return TryAtIndex<I+1>(val, args);
+            }
+            else
+                return std::nullopt;
         }
 
-        return args;
-    }
-};
-
-template <>
-struct CommandArgsConsumerSingle<CommandArgs*>
-{
-    static char const* TryConsumeTo(CommandArgs*&, char const* args) { return args; }
-};
-
-template <>
-struct CommandArgsConsumerSingle<char const*>
-{
-    static char const* TryConsumeTo(char const*&, char const* args) { return args; }
-};
-
-template <typename T, size_t offset>
-struct CommandArgsConsumerNext;
-
-template <typename Tuple, typename NextType, size_t offset>
-struct CommandArgsConsumerMulti
-{
-    static char const* TryConsumeTo(Tuple& tuple, char const* args)
-    {
-        if (char const* next = CommandArgsConsumerSingle<NextType>::TryConsumeTo(std::get<offset>(tuple), args))
-            return CommandArgsConsumerNext<Tuple, offset+1>::GoNext(tuple, next);
-        else
-            return nullptr;
-    }
-};
-
-template <typename Tuple, typename NestedNextType, size_t offset>
-struct CommandArgsConsumerMulti<Tuple, Optional<NestedNextType>, offset>
-{
-    static char const* TryConsumeTo(Tuple& tuple, char const* args)
+        static Optional<std::string_view> TryConsumeTo(Trinity::ChatCommands::Variant<Ts...>& val, std::string_view args)
+        {
+            return TryAtIndex<0>(val, args);
+        }
+    };
+
+    /*
+      for backwards compatibility, consumes the rest of the string
+      new code should use the Tail/WTail tags defined in ChatCommandTags
+    */
+    template <>
+    struct SingleConsumer<char const*>
     {
-        // try with the argument
-        auto& myArg = std::get<offset>(tuple);
-        myArg.emplace();
-        if (char const* next = CommandArgsConsumerSingle<NestedNextType>::TryConsumeTo(myArg.value(), args))
-            if ((next = CommandArgsConsumerNext<Tuple, offset+1>::GoNext(tuple, next)))
-                return next;
-        // try again omitting the argument
-        myArg = std::nullopt;
-        if (char const* next = CommandArgsConsumerNext<Tuple, offset+1>::GoNext(tuple, args))
-            return next;
-        return nullptr;
-    }
-};
+        static Optional<std::string_view> TryConsumeTo(char const*& arg, std::string_view args) { arg = args.data(); return std::string_view(); }
+    };
 
-template <size_t offset, typename... Ts>
-struct CommandArgsConsumerNext<std::tuple<Ts...>, offset>
-{
-    using tuple_type = std::tuple<Ts...>;
 
-    template <bool C = (offset < sizeof...(Ts))>
-    static std::enable_if_t<C, char const*> GoNext(tuple_type& tuple, char const* args)
-    {
-        return CommandArgsConsumerMulti<tuple_type, std::tuple_element_t<offset, tuple_type>, offset>::TryConsumeTo(tuple, args);
-    }
+    // forward declaration
+    // ConsumeFromOffset contains the bounds check for offset, then hands off to MultiConsumer
+    // the call stack is MultiConsumer -> ConsumeFromOffset -> MultiConsumer -> ConsumeFromOffset etc
+    // MultiConsumer calls SingleConsumer in each iteration
+    template <typename Tuple, size_t offset>
+    Optional<std::string_view> ConsumeFromOffset(Tuple&, std::string_view args);
 
-    template <bool C = (offset < sizeof...(Ts))>
-    static std::enable_if_t<!C, char const*> GoNext(tuple_type&, char const* args)
+    template <typename Tuple, typename NextType, size_t offset>
+    struct MultiConsumer
     {
-        return args;
-    }
-};
-
-class TC_GAME_API CommandArgs
-{
-    public:
-        CommandArgs(char const* args) : _original(args), _args(args) {}
-
-        template <typename T1, typename T2, typename... Ts>
-        auto TryConsume()
+        static Optional<std::string_view> TryConsumeTo(Tuple& tuple, std::string_view args)
         {
-            Optional<std::tuple<advstd::remove_cvref_t<T1>, advstd::remove_cvref_t<T2>, advstd::remove_cvref_t<Ts>...>> rv;
-            rv.emplace();
-            if (!TryConsumeToTuple<0>(rv.value()))
-                rv = std::nullopt;
-            return rv;
-        }
-
-        template <typename T1>
-        auto TryConsume()
-        {
-            using T = advstd::remove_cvref_t<T1>;
-            Optional<T> rv;
-            rv.emplace();
-            if (char const* next = CommandArgsConsumerSingle<T>::TryConsumeTo(rv.value(), _args))
-                _args = next;
+            if (Optional<std::string_view> next = SingleConsumer<NextType>::TryConsumeTo(std::get<offset>(tuple), args))
+                return ConsumeFromOffset<Tuple, offset + 1>(tuple, *next);
             else
-                rv = std::nullopt;
-            return rv;
+                return std::nullopt;
         }
+    };
 
-        template <size_t offset = 0, typename T>
-        bool TryConsumeToTuple(T& tuple)
+    template <typename Tuple, typename NestedNextType, size_t offset>
+    struct MultiConsumer<Tuple, Optional<NestedNextType>, offset>
+    {
+        static Optional<std::string_view> TryConsumeTo(Tuple& tuple, std::string_view args)
         {
-            if (char const* next = CommandArgsConsumerNext<T, offset>::GoNext(tuple, _args))
-            {
-                _args = next;
-                return true;
-            }
-            else
-                return false;
+            // try with the argument
+            auto& myArg = std::get<offset>(tuple);
+            myArg.emplace();
+            if (Optional<std::string_view> next = SingleConsumer<NestedNextType>::TryConsumeTo(myArg.value(), args))
+                if ((next = ConsumeFromOffset<Tuple, offset + 1>(tuple, *next)))
+                    return next;
+            // try again omitting the argument
+            myArg = std::nullopt;
+            return ConsumeFromOffset<Tuple, offset + 1>(tuple, args);
         }
+    };
 
-        void Reset() { _args = _original; }
-
-        char const* GetFullArgs() const { return _original; }
-        char const* GetRemainingArgs() const { return _args; }
-
-        bool IsEmpty() const { return !!*_args; }
-        explicit operator bool() const { return IsEmpty(); }
-
-    private:
-        char const* const _original;
-        char const* _args;
-};
+    template <typename Tuple, size_t offset>
+    Optional<std::string_view> ConsumeFromOffset(Tuple& tuple, std::string_view args)
+    {
+        if constexpr (offset < std::tuple_size_v<Tuple>)
+            return MultiConsumer<Tuple, std::tuple_element_t<offset, Tuple>, offset>::TryConsumeTo(tuple, args);
+        else if (!args.empty()) /* the entire string must be consumed */
+            return std::nullopt;
+        else
+            return args;
+    }
 
-template <typename T> struct ChatCommandHandlerToTuple { static_assert(!std::is_same_v<T,T>, "Invalid command handler signature"); };
-template <typename... Ts> struct ChatCommandHandlerToTuple<bool(*)(ChatHandler*, Ts...)> { using type = std::tuple<ChatHandler*, advstd::remove_cvref_t<Ts>...>; };
+    template <typename T> struct HandlerToTuple { static_assert(Trinity::dependant_false_v<T>, "Invalid command handler signature"); };
+    template <typename... Ts> struct HandlerToTuple<bool(*)(ChatHandler*, Ts...)> { using type = std::tuple<ChatHandler*, advstd::remove_cvref_t<Ts>...>; };
+    template <typename T> using TupleType = typename HandlerToTuple<T>::type;
+}
 
-template <typename T> struct ChatCommandStoreLastArg { static void store(T&, CommandArgs&) {} };
-template <> struct ChatCommandStoreLastArg<char const*> { static void store(char const*& arg, CommandArgs& args) { arg = args.GetRemainingArgs(); } };
-template <> struct ChatCommandStoreLastArg<CommandArgs*> { static void store(CommandArgs*& arg, CommandArgs& args) { arg = &args; } };
 
 class TC_GAME_API ChatCommand
 {
@@ -238,18 +145,12 @@ class TC_GAME_API ChatCommand
         {
             _wrapper = [](void* handler, ChatHandler* chatHandler, char const* argsStr)
             {
-                using tuple_type = typename ChatCommandHandlerToTuple<TypedHandler>::type;
+                using Tuple = Trinity::Impl::ChatCommands::TupleType<TypedHandler>;
 
-                tuple_type arguments;
+                Tuple arguments;
                 std::get<0>(arguments) = chatHandler;
-
-                CommandArgs args(argsStr);
-                if (args.TryConsumeToTuple<1>(arguments))
-                {
-                    auto& last = std::get<std::tuple_size_v<tuple_type>-1>(arguments);
-                    ChatCommandStoreLastArg<advstd::remove_cvref_t<decltype(last)>>::store(last, args);
+                if (Trinity::Impl::ChatCommands::ConsumeFromOffset<Tuple, 1>(arguments, argsStr))
                     return std::apply(reinterpret_cast<TypedHandler>(handler), std::move(arguments));
-                }
                 else
                     return false;
             };
@@ -272,7 +173,7 @@ class TC_GAME_API ChatCommand
         bool HasHandler() const { return !!_handler; }
 
         char const* Name;
-        uint32 Permission;                   // function pointer required correct align (use uint32)
+        uint32 Permission;
         bool AllowConsole;
         std::string Help;
         std::vector<ChatCommand> ChildCommands;
diff --git a/src/server/game/Chat/ChatCommands/ChatCommandArgs.cpp b/src/server/game/Chat/ChatCommands/ChatCommandArgs.cpp
index 9f62839d612..df74ac40e26 100644
--- a/src/server/game/Chat/ChatCommands/ChatCommandArgs.cpp
+++ b/src/server/game/Chat/ChatCommands/ChatCommandArgs.cpp
@@ -20,6 +20,7 @@
 #include "DB2Stores.h"
 #include "ObjectMgr.h"
 #include "SpellMgr.h"
+#include "Util.h"
 
 using namespace Trinity::ChatCommands;
 
@@ -29,12 +30,13 @@ struct AchievementVisitor
     value_type operator()(Hyperlink<achievement> achData) const { return achData->Achievement; }
     value_type operator()(uint32 achId) const { return sAchievementStore.LookupEntry(achId); }
 };
-char const* Trinity::ChatCommands::ArgInfo<AchievementEntry const*>::TryConsume(AchievementEntry const*& data, char const* args)
+Optional<std::string_view> Trinity::Impl::ChatCommands::ArgInfo<AchievementEntry const*>::TryConsume(AchievementEntry const*& data, std::string_view args)
 {
     Variant<Hyperlink<achievement>, uint32> val;
-    if ((args = CommandArgsConsumerSingle<decltype(val)>::TryConsumeTo(val, args)))
+    Optional<std::string_view> next = SingleConsumer<decltype(val)>::TryConsumeTo(val, args);
+    if (next)
         data = val.visit(AchievementVisitor());
-    return args;
+    return next;
 }
 
 struct CurrencyTypesVisitor
@@ -43,10 +45,11 @@ struct CurrencyTypesVisitor
     value_type operator()(Hyperlink<currency> currency) const { return currency->Currency; }
     value_type operator()(uint32 currencyId) const { return sCurrencyTypesStore.LookupEntry(currencyId); }
 };
-char const* Trinity::ChatCommands::ArgInfo<CurrencyTypesEntry const*>::TryConsume(CurrencyTypesEntry const*& data, char const* args)
+Optional<std::string_view> Trinity::Impl::ChatCommands::ArgInfo<CurrencyTypesEntry const*>::TryConsume(CurrencyTypesEntry const*& data, std::string_view args)
 {
     Variant<Hyperlink<currency>, uint32> val;
-    if ((args = CommandArgsConsumerSingle<decltype(val)>::TryConsumeTo(val, args)))
+    Optional<std::string_view> next = SingleConsumer<decltype(val)>::TryConsumeTo(val, args);
+    if (next)
         data = val.visit(CurrencyTypesVisitor());
     return args;
 }
@@ -57,12 +60,13 @@ struct GameTeleVisitor
     value_type operator()(Hyperlink<tele> tele) const { return sObjectMgr->GetGameTele(tele); }
     value_type operator()(std::string const& tele) const { return sObjectMgr->GetGameTele(tele); }
 };
-char const* Trinity::ChatCommands::ArgInfo<GameTele const*>::TryConsume(GameTele const*& data, char const* args)
+Optional<std::string_view> Trinity::Impl::ChatCommands::ArgInfo<GameTele const*>::TryConsume(GameTele const*& data, std::string_view args)
 {
     Variant<Hyperlink<tele>, std::string> val;
-    if ((args = CommandArgsConsumerSingle<decltype(val)>::TryConsumeTo(val, args)))
+    Optional<std::string_view> next = SingleConsumer<decltype(val)>::TryConsumeTo(val, args);
+    if (next)
         data = val.visit(GameTeleVisitor());
-    return args;
+    return next;
 }
 
 struct SpellInfoVisitor
@@ -80,26 +84,11 @@ struct SpellInfoVisitor
 
     value_type operator()(uint32 spellId) const { return sSpellMgr->GetSpellInfo(spellId, DIFFICULTY_NONE); }
 };
-char const* Trinity::ChatCommands::ArgInfo<SpellInfo const*>::TryConsume(SpellInfo const*& data, char const* args)
+Optional<std::string_view> Trinity::Impl::ChatCommands::ArgInfo<SpellInfo const*>::TryConsume(SpellInfo const*& data, std::string_view args)
 {
     Variant<Hyperlink<apower>, Hyperlink<conduit>, Hyperlink<enchant>, Hyperlink<mawpower>, Hyperlink<pvptal>, Hyperlink<spell>, Hyperlink<talent>, Hyperlink<trade>, uint32> val;
-    if ((args = CommandArgsConsumerSingle<decltype(val)>::TryConsumeTo(val, args)))
+    Optional<std::string_view> next = SingleConsumer<decltype(val)>::TryConsumeTo(val, args);
+    if (next)
         data = val.visit(SpellInfoVisitor());
-    return args;
-}
-
-char const* Trinity::ChatCommands::ArgInfo<bool>::TryConsume(bool& data, char const* args)
-{
-    std::string val;
-    if ((args = CommandArgsConsumerSingle<std::string>::TryConsumeTo(val, args)))
-    {
-        strToLower(val);
-        if (val == "on" || val == "yes" || val == "true" || val == "1" || val == "y")
-            data = true;
-        else if (val == "off" || val == "no" || val == "false" || val == "0" || val == "n")
-            data = false;
-        else
-            return nullptr;
-    }
-    return args;
+    return next;
 }
diff --git a/src/server/game/Chat/ChatCommands/ChatCommandArgs.h b/src/server/game/Chat/ChatCommands/ChatCommandArgs.h
index e2270c0259f..22e96b1ccda 100644
--- a/src/server/game/Chat/ChatCommands/ChatCommandArgs.h
+++ b/src/server/game/Chat/ChatCommands/ChatCommandArgs.h
@@ -30,17 +30,15 @@
 
 struct GameTele;
 
-namespace Trinity
-{
-namespace ChatCommands
+namespace Trinity::Impl::ChatCommands
 {
 
 /************************** ARGUMENT HANDLERS *******************************************\
 |* Define how to extract contents of a certain requested type from a string             *|
 |* Must implement the following:                                                        *|
-|* - TryConsume: T&, char const* -> char const*                                         *|
-|*   returns nullptr if no match, otherwise pointer to first character of next token    *|
-|*     - if nullptr is returned, state of T& is indeterminate                           *|
+|* - TryConsume: T&, std::string_view -> Optional<std::string_view>                     *|
+|*   returns nullopt if no match, otherwise tail of argument string                     *|
+|*     - if nullopt is returned, state of T& is indeterminate                           *|
 |*     - otherwise, T& should be initialized to the intended return value               *|
 |*                                                                                      *|
 \****************************************************************************************/
@@ -51,16 +49,17 @@ struct ArgInfo { static_assert(!std::is_same_v<T,T>, "Invalid command parameter
 template <typename T>
 struct ArgInfo<T, std::enable_if_t<std::is_integral_v<T>>>
 {
-    static char const* TryConsume(T& val, char const* args)
+    static Optional<std::string_view> TryConsume(T& val, std::string_view args)
     {
-        char const* next = args;
-        std::string_view token(args, Trinity::Impl::ChatCommands::tokenize(next));
+        auto [token, tail] = tokenize(args);
+        if (token.empty())
+            return std::nullopt;
 
         if (Optional<T> v = StringTo<T>(token, 0))
             val = *v;
         else
-            return nullptr;
-        return next;
+            return std::nullopt;
+        return tail;
     }
 };
 
@@ -68,20 +67,26 @@ struct ArgInfo<T, std::enable_if_t<std::is_integral_v<T>>>
 template <typename T>
 struct ArgInfo<T, std::enable_if_t<std::is_floating_point_v<T>>>
 {
-    static char const* TryConsume(T& val, char const* args)
+    static Optional<std::string_view> TryConsume(T& val, std::string_view args)
     {
-        char const* next = args;
-        std::string token(args, Trinity::Impl::ChatCommands::tokenize(next));
+        auto [token, tail] = tokenize(args);
+        if (token.empty())
+            return std::nullopt;
+
         try
         {
             // @todo replace this once libc++ supports double args to from_chars for required minimum
             size_t processedChars = 0;
-            val = std::stold(token, &processedChars);
+            val = std::stold(std::string(token), &processedChars);
             if (processedChars != token.length())
-                return nullptr;
+                return std::nullopt;
         }
-        catch (...) { return nullptr; }
-        return std::isfinite(val) ? next : nullptr;
+        catch (...) { return std::nullopt; }
+
+        if (std::isfinite(val))
+            return tail;
+        else
+            return std::nullopt;
     }
 };
 
@@ -89,16 +94,13 @@ struct ArgInfo<T, std::enable_if_t<std::is_floating_point_v<T>>>
 template <>
 struct ArgInfo<std::string_view, void>
 {
-    static char const* TryConsume(std::string_view& val, char const* args)
+    static Optional<std::string_view> TryConsume(std::string_view& val, std::string_view args)
     {
-        char const* next = args;
-        if (size_t len = Trinity::Impl::ChatCommands::tokenize(next))
-        {
-            val = std::string_view(args, len);
-            return next;
-        }
-        else
-            return nullptr;
+        auto [token, next] = tokenize(args);
+        if (token.empty())
+            return std::nullopt;
+        val = token;
+        return next;
     }
 };
 
@@ -106,13 +108,13 @@ struct ArgInfo<std::string_view, void>
 template <>
 struct ArgInfo<std::string, void>
 {
-    static char const* TryConsume(std::string& val, char const* args)
+    static Optional<std::string_view> TryConsume(std::string& val, std::string_view args)
     {
         std::string_view view;
-        args = ArgInfo<std::string_view>::TryConsume(view, args);
-        if (args)
+        Optional<std::string_view> next = ArgInfo<std::string_view>::TryConsume(view, args);
+        if (next)
             val.assign(view);
-        return args;
+        return next;
     }
 };
 
@@ -120,18 +122,15 @@ struct ArgInfo<std::string, void>
 template <>
 struct ArgInfo<std::wstring, void>
 {
-    static char const* TryConsume(std::wstring& val, char const* args)
+    static Optional<std::string_view> TryConsume(std::wstring& val, std::string_view args)
     {
         std::string_view utf8view;
-        char const* ret = ArgInfo<std::string_view>::TryConsume(utf8view, args);
-
-        if (!ret)
-            return nullptr;
-
-        if (!Utf8toWStr(utf8view, val))
-            return nullptr;
+        Optional<std::string_view> next = ArgInfo<std::string_view>::TryConsume(utf8view, args);
 
-        return ret;
+        if (next && Utf8toWStr(utf8view, val))
+            return next;
+        else
+            return std::nullopt;
     }
 };
 
@@ -189,32 +188,31 @@ struct ArgInfo<T, std::enable_if_t<std::is_enum_v<T>>>
             return nullptr;
     }
 
-    static char const* TryConsume(T& val, char const* args)
+    static Optional<std::string_view> TryConsume(T& val, std::string_view args)
     {
         std::string strVal;
-        char const* ret = ArgInfo<std::string>::TryConsume(strVal, args);
-
-        if (!ret)
-            return nullptr;
+        Optional<std::string_view> next = ArgInfo<std::string>::TryConsume(strVal, args);
 
-        if (T const* tmpVal = Match(strVal))
+        if (next)
         {
-            val = *tmpVal;
-            return ret;
+            if (T const* match = Match(strVal))
+            {
+                val = *match;
+                return next;
+            }
         }
 
         // Value not found. Try to parse arg as underlying type and cast it to enum type
         using U = std::underlying_type_t<T>;
         U uVal = 0;
-        ret = ArgInfo<U>::TryConsume(uVal, args);
-        if (ret)
+        next = ArgInfo<U>::TryConsume(uVal, args);
+        if (next && EnumUtils::IsValid<T>(uVal))
         {
             val = static_cast<T>(uVal);
-            if (!EnumUtils::IsValid(val))
-                return nullptr;
+            return next;
         }
 
-        return ret;
+        return std::nullopt;
     }
 };
 
@@ -222,48 +220,72 @@ struct ArgInfo<T, std::enable_if_t<std::is_enum_v<T>>>
 template <typename T>
 struct ArgInfo<T, std::enable_if_t<std::is_base_of_v<ContainerTag, T>>>
 {
-    static char const* TryConsume(T& tag, char const* args)
+    static Optional<std::string_view> TryConsume(T& tag, std::string_view args)
     {
         return tag.TryConsume(args);
     }
 };
 
+template <typename T>
+struct ArgInfo<std::vector<T>, void>
+{
+    static Optional<std::string_view> TryConsume(std::vector<T>& val, std::string_view args)
+    {
+        val.clear();
+        Optional<std::string_view> next = ArgInfo<T>::TryConsume(val.emplace_back(), args);
+
+        if (!next)
+            return std::nullopt;
+
+        while (Optional<std::string_view> next2 = ArgInfo<T>::TryConsume(val.emplace_back(), *next))
+            next = next2;
+
+        val.pop_back();
+        return next;
+    }
+};
+
+template <typename T, size_t N>
+struct ArgInfo<std::array<T, N>, void>
+{
+    static Optional<std::string_view> TryConsume(std::array<T, N>& val, std::string_view args)
+    {
+        Optional<std::string_view> next = args;
+        for (T& t : val)
+            if (!(next = ArgInfo<T>::TryConsume(t, *next)))
+                return std::nullopt;
+        return next;
+    }
+};
+
 // AchievementEntry* from numeric id or link
 template <>
 struct TC_GAME_API ArgInfo<AchievementEntry const*>
 {
-    static char const* TryConsume(AchievementEntry const*&, char const*);
+    static Optional<std::string_view> TryConsume(AchievementEntry const*&, std::string_view);
 };
 
 // CurrencyTypesEntry* from numeric id or link
 template <>
 struct TC_GAME_API ArgInfo<CurrencyTypesEntry const*>
 {
-    static char const* TryConsume(CurrencyTypesEntry const*&, char const*);
+    static Optional<std::string_view> TryConsume(CurrencyTypesEntry const*&, std::string_view);
 };
 
 // GameTele* from string name or link
 template <>
 struct TC_GAME_API ArgInfo<GameTele const*>
 {
-    static char const* TryConsume(GameTele const*&, char const*);
+    static Optional<std::string_view> TryConsume(GameTele const*&, std::string_view);
 };
 
 // SpellInfo const* from spell id or link
 template <>
 struct TC_GAME_API ArgInfo<SpellInfo const*>
 {
-    static char const* TryConsume(SpellInfo const*&, char const*);
+    static Optional<std::string_view> TryConsume(SpellInfo const*&, std::string_view);
 };
 
-// bool from 1/0 or on/off
-template <>
-struct TC_GAME_API ArgInfo<bool>
-{
-    static char const* TryConsume(bool&, char const*);
-};
-
-}
 }
 
 #endif
diff --git a/src/server/game/Chat/ChatCommands/ChatCommandHelpers.h b/src/server/game/Chat/ChatCommands/ChatCommandHelpers.h
index e22823e5d35..c6cf4f8ad94 100644
--- a/src/server/game/Chat/ChatCommands/ChatCommandHelpers.h
+++ b/src/server/game/Chat/ChatCommands/ChatCommandHelpers.h
@@ -18,10 +18,15 @@
 #ifndef TRINITY_CHATCOMMANDHELPERS_H
 #define TRINITY_CHATCOMMANDHELPERS_H
 
+#include <string_view>
 #include <type_traits>
 
-namespace Trinity::ChatCommands
+namespace Trinity::Impl::ChatCommands
 {
+    /***************** HELPERS *************************\
+    |* These really aren't for outside use...          *|
+    \***************************************************/
+
     static constexpr char COMMAND_DELIMITER = ' ';
 
     template <typename T, typename = void>
@@ -32,19 +37,26 @@ namespace Trinity::ChatCommands
 
     template <typename T>
     using tag_base_t = typename tag_base<T>::type;
-}
 
-namespace Trinity::Impl::ChatCommands
-{
-    /***************** HELPERS *************************\
-    |* These really aren't for outside use...          *|
-    \***************************************************/
-    inline std::size_t tokenize(char const*& end)
+    struct TokenizeResult {
+        explicit operator bool() { return !token.empty(); }
+        std::string_view token;
+        std::string_view tail;
+    };
+
+    inline TokenizeResult tokenize(std::string_view args)
     {
-        std::size_t len = 0;
-        for (; *end && *end != Trinity::ChatCommands::COMMAND_DELIMITER; ++end, ++len);
-        for (; *end && *end == Trinity::ChatCommands::COMMAND_DELIMITER; ++end);
-        return len;
+        TokenizeResult result;
+        if (size_t delimPos = args.find(COMMAND_DELIMITER); delimPos != std::string_view::npos)
+        {
+            result.token = args.substr(0, delimPos);
+            if (size_t tailPos = args.find_first_not_of(COMMAND_DELIMITER, delimPos); tailPos != std::string_view::npos)
+                result.tail = args.substr(tailPos);
+        }
+        else
+            result.token = args;
+
+        return result;
     }
 
     template <typename T, typename... Ts>
diff --git a/src/server/game/Chat/ChatCommands/ChatCommandTags.h b/src/server/game/Chat/ChatCommands/ChatCommandTags.h
index 78f49673794..9255ef18fd3 100644
--- a/src/server/game/Chat/ChatCommands/ChatCommandTags.h
+++ b/src/server/game/Chat/ChatCommands/ChatCommandTags.h
@@ -22,59 +22,95 @@
 #include "ChatCommandHelpers.h"
 #include "Hyperlinks.h"
 #include "Optional.h"
+#include "Util.h"
 #include <cmath>
 #include <cstring>
 #include <iostream>
 #include <string>
+#include <string_view>
 #include <tuple>
 #include <type_traits>
 #include <utility>
 #include <variant>
 
+namespace Trinity::Impl::ChatCommands
+{
+    struct ContainerTag {};
+    template <typename T>
+    struct tag_base<T, std::enable_if_t<std::is_base_of_v<ContainerTag, T>>>
+    {
+        using type = typename T::value_type;
+    };
+}
+
 namespace Trinity::ChatCommands
 {
     /************************** CONTAINER TAGS **********************************************\
     |* Simple holder classes to differentiate between extraction methods                    *|
-    |* Should inherit from ContainerTag for template identification                         *|
+    |* Must inherit from Trinity::Impl::ChatCommands::ContainerTag                          *|
     |* Must implement the following:                                                        *|
-    |* - TryConsume: char const* -> char const*                                             *|
-    |*   returns nullptr if no match, otherwise pointer to first character of next token    *|
+    |* - TryConsume: std::string_view -> Optional<std::string_view>                         *|
+    |*   returns nullopt if no match, otherwise the tail of the provided argument string    *|
     |* - typedef value_type of type that is contained within the tag                        *|
     |* - cast operator to value_type                                                        *|
     |*                                                                                      *|
     \****************************************************************************************/
-    struct ContainerTag {};
-    template <typename T>
-    struct tag_base<T, std::enable_if_t<std::is_base_of_v<ContainerTag, T>>>
-    {
-        using type = typename T::value_type;
-    };
 
     template <char c1, char... chars>
-    struct ExactSequence : public ContainerTag
+    struct ExactSequence : Trinity::Impl::ChatCommands::ContainerTag
     {
         using value_type = void;
 
-        static char const* _TryConsume(char const* pos)
+        static constexpr size_t N = (sizeof...(chars) + 1);
+
+        static bool Match(char const* pos)
+        {
+            if (*(pos++) != c1)
+                return false;
+            else if constexpr (sizeof...(chars) > 0)
+                return ExactSequence<chars...>::Match(pos);
+            else
+                return true;
+        }
+
+        Optional<std::string_view> TryConsume(std::string_view args) const
         {
-            if (*(pos++) == c1)
+            if ((N <= args.length()) && ExactSequence::Match(args.data()))
             {
-                if constexpr (sizeof...(chars) > 0)
-                    return ExactSequence<chars...>::_TryConsume(pos);
-                else if (Trinity::Impl::ChatCommands::tokenize(pos)) /* we did not consume the entire token */
-                    return nullptr;
-                else
-                    return pos;
+                auto [remainingToken, tail] = Trinity::Impl::ChatCommands::tokenize(args.substr(N));
+                if (remainingToken.empty()) // if this is not empty, then we did not consume the full token
+                    return tail;
             }
-            else
-                return nullptr;
+            return std::nullopt;
+        }
+    };
+
+    struct Tail : std::string_view, Trinity::Impl::ChatCommands::ContainerTag
+    {
+        using value_type = std::string_view;
+
+        Optional<std::string_view> TryConsume(std::string_view args)
+        {
+            std::string_view::operator=(args);
+            return std::string_view();
         }
+    };
 
-        char const* TryConsume(char const* pos) const { return ExactSequence::_TryConsume(pos); }
+    struct WTail : std::wstring, Trinity::Impl::ChatCommands::ContainerTag
+    {
+        using value_type = std::wstring;
+
+        Optional<std::string_view> TryConsume(std::string_view args)
+        {
+            if (Utf8toWStr(args, *this))
+                return std::string_view();
+            else
+                return std::nullopt;
+        }
     };
 
     template <typename linktag>
-    struct Hyperlink : public ContainerTag
+    struct Hyperlink : Trinity::Impl::ChatCommands::ContainerTag
     {
         using value_type = typename linktag::value_type;
         using storage_type = advstd::remove_cvref_t<value_type>;
@@ -84,29 +120,27 @@ namespace Trinity::ChatCommands
             value_type operator*() const { return val; }
             storage_type const* operator->() const { return &val; }
 
-            char const* TryConsume(char const* pos)
+            Optional<std::string_view> TryConsume(std::string_view args)
             {
-                Trinity::Hyperlinks::HyperlinkInfo info = Trinity::Hyperlinks::ParseHyperlink(pos);
+                Trinity::Hyperlinks::HyperlinkInfo info = Trinity::Hyperlinks::ParseSingleHyperlink(args);
                 // invalid hyperlinks cannot be consumed
                 if (!info)
-                    return nullptr;
+                    return std::nullopt;
 
                 // check if we got the right tag
-                if (info.tag.second != strlen(linktag::tag()))
-                    return nullptr;
-                if (strncmp(info.tag.first, linktag::tag(), strlen(linktag::tag())) != 0)
-                    return nullptr;
+                if (info.tag != linktag::tag())
+                    return std::nullopt;
 
                 // store value
-                if (!linktag::StoreTo(val, info.data.first, info.data.second))
-                    return nullptr;
+                if (!linktag::StoreTo(val, info.data))
+                    return std::nullopt;
 
-                // finally, skip to end of token
-                pos = info.next;
-                Trinity::Impl::ChatCommands::tokenize(pos);
-
-                // return final pos
-                return pos;
+                // finally, skip any potential delimiters
+                auto [token, next] = Trinity::Impl::ChatCommands::tokenize(info.tail);
+                if (token.empty()) /* empty token = first character is delimiter, skip past it */
+                    return next;
+                else
+                    return info.tail;
             }
 
         private:
@@ -138,8 +172,8 @@ namespace Trinity::ChatCommands
     {
         using base = std::variant<T1, Ts...>;
 
-        using first_type = tag_base_t<T1>;
-        static constexpr bool have_operators = Trinity::Impl::ChatCommands::are_all_assignable<first_type, tag_base_t<Ts>...>::value;
+        using first_type = Trinity::Impl::ChatCommands::tag_base_t<T1>;
+        static constexpr bool have_operators = Trinity::Impl::ChatCommands::are_all_assignable<first_type, Trinity::Impl::ChatCommands::tag_base_t<Ts>...>::value;
 
         template <bool C = have_operators>
         std::enable_if_t<C, first_type> operator*() const