#pragma once

#include <hex.hpp>
#include <hex/helpers/concepts.hpp>
#include <hex/pattern_language/token.hpp>
#include <hex/api/imhex_api.hpp>
#include <hex/api/event.hpp>

#include <functional>
#include <map>
#include <string>
#include <string_view>
#include <vector>

#include <nlohmann/json_fwd.hpp>

namespace hex {

    class View;
    class LanguageDefinition;
    namespace pl { class Evaluator; }
    namespace dp { class Node; }
    namespace prv { class Provider; }

    /*
        The Content Registry is the heart of all features in ImHex that are in some way extendable by Plugins.
        It allows you to add/register new content that will be picked up and used by the ImHex core or by other
        plugins when needed.
    */
    namespace ContentRegistry {

        /* Settings Registry. Allows adding of new entries into the ImHex preferences window. */
        namespace Settings {
            using Callback = std::function<bool(const std::string&, nlohmann::json&)>;

            struct Entry {
                std::string name;
                Callback callback;
            };

            void load();
            void store();

            void add(const std::string &unlocalizedCategory, const std::string &unlocalizedName, s64 defaultValue, const Callback &callback);
            void add(const std::string &unlocalizedCategory, const std::string &unlocalizedName, const std::string &defaultValue, const Callback &callback);

            void write(const std::string &unlocalizedCategory, const std::string &unlocalizedName, s64 value);
            void write(const std::string &unlocalizedCategory, const std::string &unlocalizedName, const std::string &value);
            void write(const std::string &unlocalizedCategory, const std::string &unlocalizedName, const std::vector<std::string>& value);

            s64 read(const std::string &unlocalizedCategory, const std::string &unlocalizedName, s64 defaultValue);
            std::string read(const std::string &unlocalizedCategory, const std::string &unlocalizedName, const std::string &defaultValue);
            std::vector<std::string> read(const std::string &unlocalizedCategory, const std::string &unlocalizedName, const std::vector<std::string>& defaultValue = { });

            std::map<std::string, std::vector<Entry>>& getEntries();
            nlohmann::json getSetting(const std::string &unlocalizedCategory, const std::string &unlocalizedName);
            nlohmann::json& getSettingsData();
        }

        /* Command Palette Command Registry. Allows adding of new commands to the command palette */
        namespace CommandPaletteCommands {

            enum class Type : u32 {
                SymbolCommand,
                KeywordCommand
            };

            using DisplayCallback = std::function<std::string(std::string)>;
            using ExecuteCallback = std::function<void(std::string)>;

            struct Entry {
                Type type;
                std::string command;
                std::string unlocalizedDescription;
                DisplayCallback displayCallback;
                ExecuteCallback executeCallback;
            };

            void add(Type type, const std::string &command, const std::string &unlocalizedDescription, const DisplayCallback &displayCallback, const ExecuteCallback &executeCallback = [](auto){});
            std::vector<Entry>& getEntries();
        }

        /* Pattern Language Function Registry. Allows adding of new functions that may be used inside the pattern language */
        namespace PatternLanguage {

            constexpr static u32 UnlimitedParameters   = 0xFFFF'FFFF;
            constexpr static u32 MoreParametersThan    = 0x8000'0000;
            constexpr static u32 LessParametersThan    = 0x4000'0000;
            constexpr static u32 NoParameters          = 0x0000'0000;

            using Namespace = std::vector<std::string>;
            using Callback = std::function<std::optional<hex::pl::Token::Literal>(hex::pl::Evaluator*, const std::vector<hex::pl::Token::Literal>&)>;

            struct Function {
                u32 parameterCount;
                Callback func;
                bool dangerous;
            };

            void addFunction(const Namespace &ns, const std::string &name, u32 parameterCount, const Callback &func);
            void addDangerousFunction(const Namespace &ns, const std::string &name, u32 parameterCount, const Callback &func);
            std::map<std::string, ContentRegistry::PatternLanguage::Function>& getFunctions();
        }

        /* View Registry. Allows adding of new windows */
        namespace Views {

            namespace impl {

                void add(View *view);

            }


            template<hex::derived_from<View> T, typename ... Args>
            void add(Args&& ... args) {
                return impl::add(new T(std::forward<Args>(args)...));
            }

            std::vector<View*>& getEntries();

        }

        /* Tools Registry. Allows adding new entries to the tools window */
        namespace Tools {

            namespace impl {

                using Callback = std::function<void()>;

                struct Entry {
                    std::string name;
                    Callback function;
                };

            }

            void add(const std::string &unlocalizedName, const impl::Callback &function);

            std::vector<impl::Entry>& getEntries();
        }

        /* Data Inspector Registry. Allows adding of new types to the data inspector */
        namespace DataInspector {

            enum class NumberDisplayStyle {
                Decimal,
                Hexadecimal,
                Octal
            };

            namespace impl {

                using DisplayFunction = std::function<std::string()>;
                using GeneratorFunction = std::function<DisplayFunction(const std::vector<u8>&, std::endian, NumberDisplayStyle)>;

                struct Entry {
                    std::string unlocalizedName;
                    size_t requiredSize;
                    impl::GeneratorFunction generatorFunction;
                };

            }

            void add(const std::string &unlocalizedName, size_t requiredSize, impl::GeneratorFunction function);

            std::vector<impl::Entry>& getEntries();
        }

        /* Data Processor Node Registry. Allows adding new processor nodes to be used in the data processor */
        namespace DataProcessorNode {

            namespace impl {

                using CreatorFunction = std::function<dp::Node*()>;

                struct Entry {
                    std::string category;
                    std::string name;
                    CreatorFunction creatorFunction;
                };

                void add(const Entry &entry);

            }


            template<hex::derived_from<dp::Node> T, typename ... Args>
            void add(const std::string &unlocalizedCategory, const std::string &unlocalizedName, Args&& ... args) {
                add(impl::Entry{ unlocalizedCategory.c_str(), unlocalizedName.c_str(),
                   [=]{
                        auto node = new T(std::forward<Args>(args)...);
                        node->setUnlocalizedName(unlocalizedName);
                        return node;
                   }
                });
            }

            void addSeparator();

            std::vector<impl::Entry>& getEntries();

        }

        /* Language Registry. Allows together with the LangEntry class and the _lang user defined literal to add new languages */
        namespace Language {
            void registerLanguage(const std::string &name, const std::string &languageCode);
            void addLocalizations(const std::string &languageCode, const LanguageDefinition &definition);

            std::map<std::string, std::string>& getLanguages();
            std::map<std::string, std::vector<LanguageDefinition>>& getLanguageDefinitions();
        }

        /* Interface Registry. Allows adding new items to various interfaces */
        namespace Interface {
            using DrawCallback = std::function<void()>;

            void addWelcomeScreenEntry(const DrawCallback &function);
            void addFooterItem(const DrawCallback &function);
            void addToolbarItem(const DrawCallback &function);

            std::vector<DrawCallback>& getWelcomeScreenEntries();
            std::vector<DrawCallback>& getFooterItems();
            std::vector<DrawCallback>& getToolbarItems();
        }

        /* Provider Registry. Allows adding new data providers to be created from the UI */
        namespace Provider {

            namespace impl {

                void addProviderName(const std::string &unlocalizedName);

            }

            template<hex::derived_from<hex::prv::Provider> T>
            void add(const std::string &unlocalizedName, bool addToList = true) {
                (void) EventManager::subscribe<RequestCreateProvider>([expectedName = unlocalizedName](const std::string &name, hex::prv::Provider **provider){
                    if (name != expectedName) return;

                    auto newProvider = new T();

                    hex::ImHexApi::Provider::add(newProvider);

                    if (provider != nullptr)
                        *provider = newProvider;
                });

                if (addToList)
                    impl::addProviderName(unlocalizedName);
            }

            const std::vector<std::string>& getEntries();

        }
    };

}