Consolidate input completion code in preparation for advanced completion strategies (#4639)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/widgets/splits/InputCompletionPopup.hpp

@@ -1,10 +1,13 @@
 #pragma once
 
+#include "controllers/completion/CompletionModel.hpp"
+#include "controllers/completion/sources/Source.hpp"
 #include "widgets/BasePopup.hpp"
-#include "widgets/listview/GenericListModel.hpp"
+#include "widgets/listview/GenericListView.hpp"
 
 #include <functional>
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace chatterino {
@@ -12,35 +15,19 @@ namespace chatterino {
 class Channel;
 using ChannelPtr = std::shared_ptr<Channel>;
 
-struct Emote;
-using EmotePtr = std::shared_ptr<const Emote>;
-
-namespace detail {
-
-    struct CompletionEmote {
-        EmotePtr emote;
-        QString displayName;
-        QString providerName;
-    };
-
-    std::vector<CompletionEmote> buildCompletionEmoteList(const QString &text,
-                                                          ChannelPtr channel);
-
-}  // namespace detail
-
 class GenericListView;
 
 class InputCompletionPopup : public BasePopup
 {
     using ActionCallback = std::function<void(const QString &)>;
 
-    constexpr static int MAX_ENTRY_COUNT = 200;
+    constexpr static size_t MAX_ENTRY_COUNT = 200;
 
 public:
     InputCompletionPopup(QWidget *parent = nullptr);
 
-    void updateEmotes(const QString &text, ChannelPtr channel);
-    void updateUsers(const QString &text, ChannelPtr channel);
+    void updateCompletion(const QString &text, CompletionKind kind,
+                          ChannelPtr channel);
 
     void setInputAction(ActionCallback callback);
 
@@ -54,14 +41,21 @@ protected:
 
 private:
     void initLayout();
+    void beginCompletion(CompletionKind kind, ChannelPtr channel);
+    void endCompletion();
+
+    std::unique_ptr<completion::Source> getSource() const;
 
     struct {
         GenericListView *listView;
     } ui_{};
 
-    GenericListModel model_;
+    CompletionModel model_;
     ActionCallback callback_;
     QTimer redrawTimer_;
+
+    std::optional<CompletionKind> currentKind_{};
+    ChannelPtr currentChannel_{};
 };
 
 }  // namespace chatterino