#include "components/misc/osgpluginchecker.hpp"

#include <components/debug/debuglog.hpp>
#include <components/misc/strings/conversion.hpp>

#include <osg/Config>
#include <osgDB/PluginQuery>

#include <algorithm>
#include <filesystem>
#include <string_view>

namespace Misc
{
#ifdef OSG_LIBRARY_STATIC

    bool checkRequiredOSGPluginsArePresent()
    {
        // assume they were linked in at build time and CMake would have failed if they were missing
        return true;
    }

#else

    namespace
    {
        std::string_view USED_OSG_PLUGIN_FILENAMES = "${USED_OSG_PLUGIN_FILENAMES}";

        constexpr auto getRequiredOSGPlugins()
        {
            // TODO: this is only constexpr due to an MSVC extension, so doesn't work on GCC and Clang
            // I tried replacing it with std::views::split_range, but we support compilers without that bit of C++20, and it wasn't obvious how to use the result as a string_view without C++23
            std::vector<std::string_view> requiredOSGPlugins;
            auto currentStart = USED_OSG_PLUGIN_FILENAMES.begin();
            while (currentStart != USED_OSG_PLUGIN_FILENAMES.end())
            {
                auto currentEnd = std::find(currentStart, USED_OSG_PLUGIN_FILENAMES.end(), ';');
                requiredOSGPlugins.emplace_back(currentStart, currentEnd);
                if (currentEnd == USED_OSG_PLUGIN_FILENAMES.end())
                    break;
                currentStart = currentEnd + 1;
            }
            return requiredOSGPlugins;
        }
    }

    bool checkRequiredOSGPluginsArePresent()
    {
        auto availableOSGPlugins = osgDB::listAllAvailablePlugins();
        auto requiredOSGPlugins = getRequiredOSGPlugins();
        bool haveAllPlugins = true;
        for (std::string_view plugin : requiredOSGPlugins)
        {
            if (std::find_if(availableOSGPlugins.begin(), availableOSGPlugins.end(), [&](std::string_view availablePlugin) {
#ifdef OSG_USE_UTF8_FILENAME
                std::filesystem::path pluginPath {stringToU8String(availablePlugin)};
#else
                std::filesystem::path pluginPath {availablePlugin};
#endif
                return pluginPath.filename() == plugin;
            }) == availableOSGPlugins.end())
            {
                Log(Debug::Error) << "Missing OSG plugin: " << plugin;
                haveAllPlugins = false;
            }
        }
        return haveAllPlugins;
    }

#endif
}