#include "init/tasks.hpp"

#include <imgui.h>
#include <imgui_freetype.h>

#include <romfs/romfs.hpp>

#include <hex/helpers/http_requests.hpp>
#include <hex/helpers/fs.hpp>
#include <hex/helpers/logger.hpp>

#include <hex/api_urls.hpp>
#include <hex/api/content_registry.hpp>
#include <hex/api/project_file_manager.hpp>
#include <hex/api/theme_manager.hpp>
#include <hex/api/plugin_manager.hpp>
#include <hex/api/layout_manager.hpp>
#include <hex/api/achievement_manager.hpp>

#include <hex/ui/view.hpp>
#include <hex/ui/popup.hpp>

#include <fonts/fontawesome_font.h>
#include <fonts/codicons_font.h>
#include <fonts/unifont_font.h>

#include <nlohmann/json.hpp>

#include <wolv/io/fs.hpp>
#include <wolv/io/file.hpp>
#include <wolv/hash/uuid.hpp>

namespace hex::init {

    using namespace std::literals::string_literals;

    static bool checkForUpdatesSync() {
        int checkForUpdates = ContentRegistry::Settings::read("hex.builtin.setting.general", "hex.builtin.setting.general.server_contact", 2);

        // Check if we should check for updates
        if (checkForUpdates == 1){
            HttpRequest request("GET", GitHubApiURL + "/releases/latest"s);

            // Query the GitHub API for the latest release version
            auto response = request.execute().get();
            if (response.getStatusCode() != 200)
                return false;

            nlohmann::json releases;
            try {
                releases = nlohmann::json::parse(response.getData());
            } catch (const std::exception &) {
                return false;
            }

            // Check if the response is valid
            if (!releases.contains("tag_name") || !releases["tag_name"].is_string())
                return false;

            // Convert the current version string to a format that can be compared to the latest release
            auto versionString = ImHexApi::System::getImHexVersion();
            size_t versionLength = std::min(versionString.find_first_of('-'), versionString.length());
            auto currVersion   = "v" + versionString.substr(0, versionLength);

            // Get the latest release version string
            auto latestVersion = releases["tag_name"].get<std::string_view>();

            // Check if the latest release is different from the current version
            if (latestVersion != currVersion)
                ImHexApi::System::impl::addInitArgument("update-available", latestVersion.data());

            // Check if there is a telemetry uuid
            std::string uuid = ContentRegistry::Settings::read("hex.builtin.setting.general", "hex.builtin.setting.general.uuid", "").get<std::string>();
            if (uuid.empty()) {
                // Generate a new uuid
                uuid = wolv::hash::generateUUID();
                // Save
                ContentRegistry::Settings::write("hex.builtin.setting.general", "hex.builtin.setting.general.uuid", uuid);
            }

            TaskManager::createBackgroundTask("Sending statistics...", [uuid, versionString](auto&) {
                // To avoid potentially flooding our database with lots of dead users
                // from people just visiting the website, don't send telemetry data from
                // the web version
                #if defined(OS_WEB)
                    return;
                #endif

                // Make telemetry request
                nlohmann::json telemetry = {
                        { "uuid", uuid },
                        { "format_version", "1" },
                        { "imhex_version", versionString },
                        { "imhex_commit", fmt::format("{}@{}", ImHexApi::System::getCommitHash(true), ImHexApi::System::getCommitBranch()) },
                        { "install_type", ImHexApi::System::isPortableVersion() ? "Portable" : "Installed" },
                        { "os", ImHexApi::System::getOSName() },
                        { "os_version", ImHexApi::System::getOSVersion() },
                        { "arch", ImHexApi::System::getArchitecture() },
                        { "gpu_vendor", ImHexApi::System::getGPUVendor() }
                };

                HttpRequest telemetryRequest("POST", ImHexApiURL + "/telemetry"s);
                telemetryRequest.setTimeout(500);

                telemetryRequest.setBody(telemetry.dump());
                telemetryRequest.addHeader("Content-Type", "application/json");

                // Execute request
                telemetryRequest.execute();
            });
        }
        return true;
    }
    
    static bool checkForUpdates() {
        TaskManager::createBackgroundTask("Checking for updates", [](auto&) { checkForUpdatesSync(); });
        return true;
    }

    bool setupEnvironment() {
        hex::log::debug("Using romfs: '{}'", romfs::name());

        return true;
    }

    bool createDirectories() {
        bool result = true;

        using enum fs::ImHexPath;

        // Try to create all default directories
        for (u32 path = 0; path < u32(fs::ImHexPath::END); path++) {
            for (auto &folder : fs::getDefaultPaths(static_cast<fs::ImHexPath>(path), true)) {
                try {
                    wolv::io::fs::createDirectories(folder);
                } catch (...) {
                    log::error("Failed to create folder {}!", wolv::util::toUTF8String(folder));
                    result = false;
                }
            }
        }

        if (!result)
            ImHexApi::System::impl::addInitArgument("folder-creation-error");

        return result;
    }

    bool migrateConfig(){

        // Check if there is a new config in folder
        auto configPaths = hex::fs::getDefaultPaths(hex::fs::ImHexPath::Config, false);

        // There should always be exactly one config path on Linux
        std::fs::path newConfigPath = configPaths[0];
        wolv::io::File newConfigFile(newConfigPath / "settings.json", wolv::io::File::Mode::Read);
        if (!newConfigFile.isValid()) {

            // Find an old config
            std::fs::path oldConfigPath;
            for (const auto &dir : hex::fs::appendPath(hex::fs::getDataPaths(), "config")) {
                wolv::io::File oldConfigFile(dir / "settings.json", wolv::io::File::Mode::Read);
                if (oldConfigFile.isValid()) {
                    oldConfigPath = dir;
                    break;
                }
            }

            if (!oldConfigPath.empty()) {
                log::info("Found config file in {}! Migrating to {}", oldConfigPath.string(), newConfigPath.string());

                std::fs::rename(oldConfigPath / "settings.json", newConfigPath / "settings.json");
                wolv::io::File oldIniFile(oldConfigPath / "interface.ini", wolv::io::File::Mode::Read);
                if (oldIniFile.isValid()) {
                    std::fs::rename(oldConfigPath / "interface.ini", newConfigPath / "interface.ini");
                }

                std::fs::remove(oldConfigPath);
            }
        }
        return true;
    }

    static bool loadFontsImpl(bool loadUnicode) {
        const float defaultFontSize = ImHexApi::System::DefaultFontSize * std::round(ImHexApi::System::getGlobalScale());

        // Load custom font related settings
        if (ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.custom_font_enable", false).get<bool>()) {
            std::fs::path fontFile = ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.font_path", "").get<std::string>();
            if (!fontFile.empty()) {
                if (!wolv::io::fs::exists(fontFile) || !wolv::io::fs::isRegularFile(fontFile)) {
                    log::warn("Custom font file {} not found! Falling back to default font.", wolv::util::toUTF8String(fontFile));
                    fontFile.clear();
                }

                log::info("Loading custom font from {}", wolv::util::toUTF8String(fontFile));
            }

            // If no custom font has been specified, search for a file called "font.ttf" in one of the resource folders
            if (fontFile.empty()) {
                for (const auto &dir : fs::getDefaultPaths(fs::ImHexPath::Resources)) {
                    auto path = dir / "font.ttf";
                    if (wolv::io::fs::exists(path)) {
                        log::info("Loading custom font from {}", wolv::util::toUTF8String(path));

                        fontFile = path;
                        break;
                    }
                }
            }

            ImHexApi::System::impl::setCustomFontPath(fontFile);

            // If a custom font has been loaded now, also load the font size
            float fontSize = defaultFontSize;
            if (!fontFile.empty()) {
                fontSize = ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.font_size", 13).get<int>() * ImHexApi::System::getGlobalScale();
            }

            ImHexApi::System::impl::setFontSize(fontSize);
        }

        float fontSize = ImHexApi::System::getFontSize();

        const auto &fontFile = ImHexApi::System::getCustomFontPath();

        // Setup basic font configuration
        auto fonts       = IM_NEW(ImFontAtlas)();
        ImFontConfig cfg = {};
        cfg.OversampleH = cfg.OversampleV = 1, cfg.PixelSnapH = true;
        cfg.SizePixels = fontSize;

        fonts->Flags |= ImFontAtlasFlags_NoPowerOfTwoHeight;
        fonts->TexDesiredWidth = 4096;

        // Configure font glyph ranges that should be loaded from the default font and unifont
        static ImVector<ImWchar> ranges;
        {
            ImFontGlyphRangesBuilder glyphRangesBuilder;

            {
                constexpr static std::array<ImWchar, 3> controlCodeRange   = { 0x0001, 0x001F, 0 };
                constexpr static std::array<ImWchar, 3> extendedAsciiRange = { 0x007F, 0x00FF, 0 };

                glyphRangesBuilder.AddRanges(controlCodeRange.data());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesDefault());
                glyphRangesBuilder.AddRanges(extendedAsciiRange.data());
            }

            if (loadUnicode) {
                constexpr static std::array<ImWchar, 3> fullRange = { 0x0100, 0xFFEF, 0 };

                glyphRangesBuilder.AddRanges(fullRange.data());
            } else {
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesJapanese());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesChineseFull());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesCyrillic());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesKorean());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesThai());
                glyphRangesBuilder.AddRanges(fonts->GetGlyphRangesVietnamese());
            }

            glyphRangesBuilder.BuildRanges(&ranges);
        }

        // Glyph range for font awesome icons
        constexpr static std::array<ImWchar, 3> fontAwesomeRange = {
                ICON_MIN_FA, ICON_MAX_FA, 0
        };

        // Glyph range for codicons icons
        constexpr static std::array<ImWchar, 3> codiconsRange = {
                ICON_MIN_VS, ICON_MAX_VS, 0
        };

        // Load main font
        // If a custom font has been specified, load it, otherwise load the default ImGui font
        if (fontFile.empty()) {
            fonts->Clear();
            fonts->AddFontDefault(&cfg);
        } else {
            if (ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.font_bold", false))
                cfg.FontBuilderFlags |= ImGuiFreeTypeBuilderFlags_Bold;
            if (ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.font_italic", false))
                cfg.FontBuilderFlags |= ImGuiFreeTypeBuilderFlags_Oblique;
            if (!ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.font_antialias", false))
                cfg.FontBuilderFlags |= ImGuiFreeTypeBuilderFlags_Monochrome | ImGuiFreeTypeBuilderFlags_MonoHinting;

            auto font = fonts->AddFontFromFileTTF(wolv::util::toUTF8String(fontFile).c_str(), 0, &cfg, ranges.Data);

            cfg.FontBuilderFlags = 0;

            if (font == nullptr) {
                log::warn("Failed to load custom font! Falling back to default font.");

                ImHexApi::System::impl::setFontSize(defaultFontSize);
                cfg.SizePixels = defaultFontSize;
                fonts->Clear();
                fonts->AddFontDefault(&cfg);
            }
        }

        // Merge all fonts into one big font atlas
        cfg.MergeMode = true;

        // Add font awesome and codicons icons to font atlas
        cfg.GlyphOffset = ImVec2(0, 3_scaled);
        fonts->AddFontFromMemoryCompressedTTF(font_awesome_compressed_data, font_awesome_compressed_size, 0, &cfg, fontAwesomeRange.data());
        fonts->AddFontFromMemoryCompressedTTF(codicons_compressed_data, codicons_compressed_size, 0, &cfg, codiconsRange.data());

        cfg.GlyphOffset = ImVec2(0, 0);
        // Add unifont if unicode support is enabled
        fonts->AddFontFromMemoryCompressedTTF(unifont_compressed_data, unifont_compressed_size, 0, &cfg, ranges.Data);

        // Try to build the font atlas
        if (!fonts->Build()) {
            // The main reason the font atlas failed to build is that the font is too big for the GPU to handle
            // If unicode support is enabled, therefor try to load the font atlas without unicode support
            // If that still didn't work, there's probably something else going on with the graphics drivers
            // Especially Intel GPU drivers are known to have various bugs

            if (loadUnicode) {
                log::error("Failed to build font atlas! Disabling Unicode support.");
                IM_DELETE(fonts);

                // Disable unicode support in settings
                ContentRegistry::Settings::write("hex.builtin.setting.font", "hex.builtin.setting.font.load_all_unicode_chars", false);

                // Try to load the font atlas again
                return loadFontsImpl(false);
            } else {
                log::error("Failed to build font atlas! Check your Graphics driver!");
                return false;
            }
        }

        // Configure ImGui to use the font atlas
        ImHexApi::System::impl::setFontAtlas(fonts);

        return true;
    }

    bool loadFonts() {
        // Check if unicode support is enabled in the settings and that the user doesn't use the No GPU version on Windows
        // The Mesa3D software renderer on Windows identifies itself as "VMware, Inc."
        bool shouldLoadUnicode =
                ContentRegistry::Settings::read("hex.builtin.setting.font", "hex.builtin.setting.font.load_all_unicode_chars", false) &&
                ImHexApi::System::getGPUVendor() != "VMware, Inc.";

        return loadFontsImpl(shouldLoadUnicode);
    }

    bool deleteSharedData() {
        // This function is called when ImHex is closed. It deletes all shared data that was created by plugins
        // This is a bit of a hack but necessary because when ImHex gets closed, all plugins are unloaded in order for
        // destructors to be called correctly. To prevent crashes when ImHex exits, we need to delete all shared data

        EventManager::post<EventImHexClosing>();

        EventManager::clear();

        while (ImHexApi::Provider::isValid())
            ImHexApi::Provider::remove(ImHexApi::Provider::get());
        ContentRegistry::Provider::impl::getEntries().clear();

        ImHexApi::System::getInitArguments().clear();
        ImHexApi::HexEditor::impl::getBackgroundHighlights().clear();
        ImHexApi::HexEditor::impl::getForegroundHighlights().clear();
        ImHexApi::HexEditor::impl::getBackgroundHighlightingFunctions().clear();
        ImHexApi::HexEditor::impl::getForegroundHighlightingFunctions().clear();
        ImHexApi::HexEditor::impl::getTooltips().clear();
        ImHexApi::HexEditor::impl::getTooltipFunctions().clear();
        ImHexApi::System::getAdditionalFolderPaths().clear();
        ImHexApi::System::getCustomFontPath().clear();
        ImHexApi::Messaging::impl::getHandlers().clear();

        ContentRegistry::Settings::impl::getSettings().clear();
        ContentRegistry::Settings::impl::getSettingsData().clear();

        ContentRegistry::CommandPaletteCommands::impl::getEntries().clear();
        ContentRegistry::CommandPaletteCommands::impl::getHandlers().clear();

        ContentRegistry::PatternLanguage::impl::getFunctions().clear();
        ContentRegistry::PatternLanguage::impl::getPragmas().clear();
        ContentRegistry::PatternLanguage::impl::getVisualizers().clear();
        ContentRegistry::PatternLanguage::impl::getInlineVisualizers().clear();

        ContentRegistry::Views::impl::getEntries().clear();
        impl::PopupBase::getOpenPopups().clear();


        ContentRegistry::Tools::impl::getEntries().clear();
        ContentRegistry::DataInspector::impl::getEntries().clear();

        ContentRegistry::Language::impl::getLanguages().clear();
        ContentRegistry::Language::impl::getLanguageDefinitions().clear();
        LocalizationManager::impl::resetLanguageStrings();

        ContentRegistry::Interface::impl::getWelcomeScreenEntries().clear();
        ContentRegistry::Interface::impl::getFooterItems().clear();
        ContentRegistry::Interface::impl::getToolbarItems().clear();
        ContentRegistry::Interface::impl::getMainMenuItems().clear();
        ContentRegistry::Interface::impl::getMenuItems().clear();
        ContentRegistry::Interface::impl::getSidebarItems().clear();
        ContentRegistry::Interface::impl::getTitleBarButtons().clear();

        ShortcutManager::clearShortcuts();

        TaskManager::getRunningTasks().clear();

        ContentRegistry::DataProcessorNode::impl::getEntries().clear();

        ContentRegistry::DataFormatter::impl::getEntries().clear();
        ContentRegistry::FileHandler::impl::getEntries().clear();
        ContentRegistry::Hashes::impl::getHashes().clear();
        ContentRegistry::HexEditor::impl::getVisualizers().clear();

        ContentRegistry::BackgroundServices::impl::stopServices();
        ContentRegistry::BackgroundServices::impl::getServices().clear();

        ContentRegistry::CommunicationInterface::impl::getNetworkEndpoints().clear();

        ContentRegistry::Experiments::impl::getExperiments().clear();
        ContentRegistry::Reports::impl::getGenerators().clear();

        LayoutManager::reset();

        ThemeManager::reset();

        AchievementManager::getAchievements().clear();

        ProjectFile::getHandlers().clear();
        ProjectFile::getProviderHandlers().clear();
        ProjectFile::setProjectFunctions(nullptr, nullptr);

        fs::setFileBrowserErrorCallback(nullptr);

        return true;
    }

    bool loadPlugins() {
        // Load all plugins
        for (const auto &dir : fs::getDefaultPaths(fs::ImHexPath::Plugins)) {
            PluginManager::load(dir);
        }

        // Get loaded plugins
        auto &plugins = PluginManager::getPlugins();

        // If no plugins were loaded, ImHex wasn't installed properly. This will trigger an error popup later on
        if (plugins.empty()) {
            log::error("No plugins found!");

            ImHexApi::System::impl::addInitArgument("no-plugins");
            return false;
        }

        const auto shouldLoadPlugin = [executablePath = wolv::io::fs::getExecutablePath()](const Plugin &plugin) {
            // In debug builds, ignore all plugins that are not part of the executable directory
            #if !defined(DEBUG)
                return true;
            #endif

            if (!executablePath.has_value())
                return true;

            // Check if the plugin is somewhere in the same directory tree as the executable
            return !std::fs::relative(plugin.getPath(), executablePath->parent_path()).string().starts_with("..");
        };

        u32 builtinPlugins = 0;
        u32 loadErrors     = 0;

        // Load the builtin plugin first, so it can initialize everything that's necessary for ImHex to work
        for (const auto &plugin : plugins) {
            if (!plugin.isBuiltinPlugin()) continue;

            if (!shouldLoadPlugin(plugin)) {
                log::debug("Skipping built-in plugin {}", plugin.getPath().string());
                continue;
            }

            // Make sure there's only one built-in plugin
            if (builtinPlugins > 1) continue;

            // Initialize the plugin
            if (!plugin.initializePlugin()) {
                log::error("Failed to initialize plugin {}", wolv::util::toUTF8String(plugin.getPath().filename()));
                loadErrors++;
            } else {
                builtinPlugins++;
            }
        }

        // Load all other plugins
        for (const auto &plugin : plugins) {
            if (plugin.isBuiltinPlugin()) continue;

            if (!shouldLoadPlugin(plugin)) {
                log::debug("Skipping plugin {}", plugin.getPath().string());
                continue;
            }

            // Initialize the plugin
            if (!plugin.initializePlugin()) {
                log::error("Failed to initialize plugin {}", wolv::util::toUTF8String(plugin.getPath().filename()));
                loadErrors++;
            }
        }

        // If no plugins were loaded successfully, ImHex wasn't installed properly. This will trigger an error popup later on
        if (loadErrors == plugins.size()) {
            log::error("No plugins loaded successfully!");
            ImHexApi::System::impl::addInitArgument("no-plugins");
            return false;
        }

        // ImHex requires exactly one built-in plugin
        // If no built-in plugin or more than one was found, something's wrong and we can't continue
        #if !defined(EMSCRIPTEN)
            if (builtinPlugins == 0) {
                log::error("Built-in plugin not found!");
                ImHexApi::System::impl::addInitArgument("no-builtin-plugin");
                return false;
            } else if (builtinPlugins > 1) {
                log::error("Found more than one built-in plugin!");
                ImHexApi::System::impl::addInitArgument("multiple-builtin-plugins");
                return false;
            }
        #endif

        return true;
    }

    bool clearOldLogs() {
        for (const auto &path : fs::getDefaultPaths(fs::ImHexPath::Logs)) {
            try {
                std::vector<std::filesystem::directory_entry> files;

                for (const auto& file : std::filesystem::directory_iterator(path))
                    files.push_back(file);

                if (files.size() <= 10)
                    return true;

                std::sort(files.begin(), files.end(), [](const auto& a, const auto& b) {
                    return std::filesystem::last_write_time(a) > std::filesystem::last_write_time(b);
                });

                for (auto it = files.begin() + 10; it != files.end(); it += 1)
                    std::filesystem::remove(it->path());
            } catch (std::filesystem::filesystem_error &e) {
                log::error("Failed to clear old log! {}", e.what());
            }
        }

        return true;
    }

    bool unloadPlugins() {
        PluginManager::unload();

        return true;
    }

    bool loadSettings() {
        try {
            // Try to load settings from file
            ContentRegistry::Settings::impl::load();
        } catch (std::exception &e) {
            // If that fails, create a new settings file

            log::error("Failed to load configuration! {}", e.what());

            ContentRegistry::Settings::impl::clear();
            ContentRegistry::Settings::impl::store();

            return false;
        }

        return true;
    }

    bool configureUIScale() {
        int interfaceScaleSetting = ContentRegistry::Settings::read("hex.builtin.setting.interface", "hex.builtin.setting.interface.scaling", 0.0F).get<float>() * 10;

        float interfaceScaling;
        if (interfaceScaleSetting == 0)
            interfaceScaling = ImHexApi::System::getNativeScale();
        else
            interfaceScaling = interfaceScaleSetting / 10.0F;

        ImHexApi::System::impl::setGlobalScale(interfaceScaling);

        return true;
    }

    bool storeSettings() {
        try {
            ContentRegistry::Settings::impl::store();
        } catch (std::exception &e) {
            log::error("Failed to store configuration! {}", e.what());
            return false;
        }
        return true;
    }

    // Run all exit tasks, and print to console
    void runExitTasks() {
        for (const auto &[name, task, async] : init::getExitTasks()) {
            bool result = task();
            log::info("Exit task '{0}' finished {1}", name, result ? "successfully" : "unsuccessfully");
        }
    }

    std::vector<Task> getInitTasks() {
        return {
            { "Setting up environment",  setupEnvironment,    false },
            { "Creating directories",    createDirectories,   false },
            #if defined(OS_LINUX)
            { "Migrate config to .config", migrateConfig,     false },
            #endif
            { "Loading settings",        loadSettings,        false },
            { "Configuring UI scale",    configureUIScale,    false },
            { "Loading plugins",         loadPlugins,         true  },
            { "Checking for updates",    checkForUpdates,     false },
            { "Loading fonts",           loadFonts,           true  },
        };
    }

    std::vector<Task> getExitTasks() {
        return {
            { "Saving settings",         storeSettings,    false },
            { "Cleaning up shared data", deleteSharedData, false },
            { "Unloading plugins",       unloadPlugins,    false },
            { "Clearing old logs",       clearOldLogs,     false },
        };
    }

}