From 4eaeeedf15bdabb1a73280c68574356191ca67f9 Mon Sep 17 00:00:00 2001
From: Sandu Liviu Catalin <slc.universe@gmail.com>
Date: Sun, 6 Aug 2023 21:34:57 +0300
Subject: [PATCH] Initial rest server commands implementation.

---
 module/Library/Discord/Cluster.cpp | 27 ++++++++++++++
 module/Library/Discord/Cluster.hpp | 58 ++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/module/Library/Discord/Cluster.cpp b/module/Library/Discord/Cluster.cpp
index 5d82b5b5..20f38131 100644
--- a/module/Library/Discord/Cluster.cpp
+++ b/module/Library/Discord/Cluster.cpp
@@ -15,6 +15,7 @@ DpCluster::DpCluster(DpClusterOptions & o)
     : Base(), mQueue(4096)
     , mC(std::make_unique< dpp::cluster >(o.mToken, o.mIntents, o.mShards, o.mClusterID, o.mMaxClusters, o.mCompressed, o.mPolicy, o.mRequestThreads, o.mRequestThreadsRaw))
     , mSqEvents(), mEvents(), mEventsHandle()
+    , mCCList(), mCCResults(std::make_shared< CCResultQueue >(4096))
 {
     // Make sure all event handles are not valid
     mEventsHandle.fill(0);
@@ -83,6 +84,31 @@ void DpCluster::Process(bool force)
             p->Cleanup();
         }
     }
+    CCResultItem cc_item;
+    // Retrieve each command completion result individually and process it
+    for (size_t count = mCCResults->size_approx(), n = 0; n <= count; ++n)
+    {
+        // Try to get a result from the queue
+        if (mCCResults->try_dequeue(cc_item))
+        {
+            CCResult & r = *cc_item;
+            // Get the script callback
+            Function & cb = *(r.first);
+            // Is there still a valid callback to invoke?
+            if (!cb.IsNull())
+            {
+                // Don't abort everything down the line for an error caused by a script callback
+                try {
+                    cb.Execute(LightObj(SqTypeIdentity< DpCommandConfirmation >{}, cb.GetVM(), std::move(r.second)));
+                } catch (const std::exception & e) {
+                    LogErr("Squirrel exception caught in discord command completion event");
+                    LogSInf("Message: %s", e.what());
+                }
+            }
+            // Release the callback from the list
+            mCCList.erase(r.first);
+        }
+    }
 }
 
 // ------------------------------------------------------------------------------------------------
@@ -122,6 +148,7 @@ void Register_Discord_Cluster(HSQUIRRELVM vm, Table & ns)
         .Func(_SC("Stop"), &DpCluster::Stop)
         .Func(_SC("EnableEvent"), &DpCluster::EnableEvent)
         .Func(_SC("DisableEvent"), &DpCluster::DisableEvent)
+        .CbFunc(_SC("CurrentUserGetGuilds"), &DpCluster::CurrentUserGetGuilds)
     );
 }
 
diff --git a/module/Library/Discord/Cluster.hpp b/module/Library/Discord/Cluster.hpp
index ba49104d..44b81fa1 100644
--- a/module/Library/Discord/Cluster.hpp
+++ b/module/Library/Discord/Cluster.hpp
@@ -333,6 +333,64 @@ private:
     void OnStageInstanceCreate(const dpp::stage_instance_create_t & ev);
     void OnStageInstanceUpdate(const dpp::stage_instance_update_t & ev);
     void OnStageInstanceDelete(const dpp::stage_instance_delete_t & ev);
+
+public:
+
+    // List type for command completion callbacks.
+    using CCList = std::list< Function >;
+    /* --------------------------------------------------------------------------------------------
+     * List of command completion callbacks.
+    */
+    CCList mCCList{};
+
+    /* --------------------------------------------------------------------------------------------
+     * Queue of iterators pointing to results of completed commands and their associated result.
+    */
+    using CCResult = std::pair< CCList::iterator, DpCommandConfirmation::Ptr >;
+    using CCResultItem = std::unique_ptr< CCResult >;
+    using CCResultQueue = moodycamel::ConcurrentQueue< CCResultItem >;
+
+    /* --------------------------------------------------------------------------------------------
+     * Command completion links queue.
+    */
+    std::shared_ptr< CCResultQueue > mCCResults{};
+
+    /* --------------------------------------------------------------------------------------------
+     * Maintains an iterator to the script callback associated with a completed command result.
+    */
+    struct CCLink
+    {
+        // Iterator to the element where the state can be found.
+        CCList::iterator    mItr{};
+        // Reference to the queue of iterators pointing to completed commands.
+        std::shared_ptr< CCResultQueue > mQueue{};
+        /* ----------------------------------------------------------------------------------------
+         * Base constructor.
+        */
+        CCLink(CCList::iterator && itr, std::shared_ptr< CCResultQueue > & q)
+            : mItr(std::forward< CCList::iterator >(itr)), mQueue(q)
+        { }
+        // Copy/Move constructors.
+        CCLink(const CCLink &) = default;
+        CCLink(CCLink &&) noexcept = default;
+        // Copy/Move assignment operators.
+        CCLink & operator = (const CCLink &) = default;
+        CCLink & operator = (CCLink &&) noexcept = default;
+        // Function call operator. Marks the linked callback as ready to invoke with obtained result.
+        void operator () (const dpp::confirmation_callback_t & cc) const
+        {
+            mQueue->enqueue(std::make_unique< CCResult >(std::move(mItr), std::make_unique< dpp::confirmation_callback_t >(cc.http_info)));
+        }
+    };
+
+    /* --------------------------------------------------------------------------------------------
+     * Get current (bot) user guilds.
+     * https://discord.com/developers/docs/resources/user#get-current-user-guilds
+    */
+    void CurrentUserGetGuilds(Function & cb)
+    {
+        Valid("get message").current_user_get_guilds(CCLink(mCCList.emplace(mCCList.cend(), std::move(cb)), mCCResults));
+    }
 };
 
 } // Namespace:: SqMod