#include <hex/helpers/paths.hpp>
#include <hex/helpers/paths_mac.h>

#include <xdg.hpp>

#if defined(OS_WINDOWS)
    #include <windows.h>
    #include <shlobj.h>
#elif defined(OS_LINUX)
    #include <xdg.hpp>
    #include <linux/limits.h>
#endif

#include <algorithm>
#include <filesystem>
#include <string>
#include <vector>

namespace hex {

    std::string getExecutablePath() {
        #if defined(OS_WINDOWS)
            std::string exePath(MAX_PATH, '\0');
            GetModuleFileName(nullptr, exePath.data(), exePath.length());

            return exePath;
        #elif defined(OS_LINUX)
            std::string exePath(PATH_MAX, '\0');
            readlink("/proc/self/exe", exePath.data(), PATH_MAX);

            return exePath;
        #elif defined(OS_MACOS)
            return getMacExecutableDirectoryPath();
        #else
            return "";
        #endif
    }

    std::vector<std::string> getPath(ImHexPath path, bool listNonExisting) {
        std::vector<std::string> result;

        #if defined(OS_WINDOWS)
            const auto exePath = getExecutablePath();
            const auto parentDir = std::filesystem::path(exePath).parent_path();

            std::filesystem::path appDataDir;
            {
                LPWSTR wAppDataPath = nullptr;
                if (!SUCCEEDED(SHGetKnownFolderPath(FOLDERID_LocalAppData, KF_FLAG_CREATE, nullptr, &wAppDataPath)))
                    throw std::runtime_error("Failed to get APPDATA folder path");

                appDataDir = wAppDataPath;
                CoTaskMemFree(wAppDataPath);
            }

            std::vector<std::filesystem::path> paths = { parentDir, appDataDir / "imhex" };

            switch (path) {
                case ImHexPath::Patterns:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "patterns").string();
                    });
                    break;
                case ImHexPath::PatternsInclude:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "includes").string();
                    });
                    break;
                case ImHexPath::Magic:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "magic").string();
                    });
                    break;
                case ImHexPath::Python:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "python").string();
                    });
                    break;
                case ImHexPath::Plugins:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "plugins").string();
                    });
                    break;
                case ImHexPath::Yara:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "yara").string();
                    });
                    break;
                case ImHexPath::Config:
                    return { (appDataDir / "imhex" / "config").string() };
                case ImHexPath::Resources:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "resources").string();
                    });
                    break;
                case ImHexPath::Constants:
                    std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                        return (path / "constants").string();
                    });
                    break;
                default: __builtin_unreachable();
            }
        #elif defined(OS_MACOS)
            // Get path to special directories
            const auto exePath = getExecutablePath();
            const std::filesystem::path applicationSupportDir(getMacApplicationSupportDirectoryPath());

            std::vector<std::filesystem::path> paths = { exePath, applicationSupportDir };

            switch (path) {
            case ImHexPath::Patterns:
                result.push_back((applicationSupportDir / "patterns").string());
                break;
            case ImHexPath::PatternsInclude:
                result.push_back((applicationSupportDir / "includes").string());
                break;
            case ImHexPath::Magic:
                result.push_back((applicationSupportDir / "magic").string());
                break;
            case ImHexPath::Python:
                result.push_back((applicationSupportDir / "python").string());
                break;
            case ImHexPath::Plugins:
                std::transform(paths.begin(), paths.end(), std::back_inserter(result), [](auto &path){
                    return (path / "plugins").string();
                });
                break;
            case ImHexPath::Yara:
                result.push_back((applicationSupportDir / "yara").string());
                break;
            case ImHexPath::Config:
                result.push_back((applicationSupportDir / "config").string());
                break;
            case ImHexPath::Resources:
                result.push_back((applicationSupportDir / "resources").string());
                break;
            case ImHexPath::Constants:
                result.push_back((applicationSupportDir / "constants").string());
                break;
            default: __builtin_unreachable();
            }
        #else
            std::vector<std::filesystem::path> configDirs = xdg::ConfigDirs();
            std::vector<std::filesystem::path> dataDirs = xdg::DataDirs();

            configDirs.insert(configDirs.begin(), xdg::ConfigHomeDir());
            dataDirs.insert(dataDirs.begin(), xdg::DataHomeDir());

            for (auto &dir : dataDirs)
                dir = dir / "imhex";

            const auto exePath = getExecutablePath();

            if (!exePath.empty())
                dataDirs.emplace(dataDirs.begin(), std::filesystem::path(exePath.data()).parent_path());

            switch (path) {
                case ImHexPath::Patterns:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "patterns").string(); });
                    break;
                case ImHexPath::PatternsInclude:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "includes").string(); });
                    break;
                case ImHexPath::Magic:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "magic").string(); });
                    break;
                case ImHexPath::Python:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p).string(); });
                    break;
                case ImHexPath::Plugins:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "plugins").string(); });
                    break;
                case ImHexPath::Yara:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "yara").string(); });
                    break;
                case ImHexPath::Config:
                    std::transform(configDirs.begin(), configDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "imhex").string(); });
                    break;
                case ImHexPath::Resources:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "resources").string(); });
                    break;
                case ImHexPath::Constants:
                    std::transform(dataDirs.begin(), dataDirs.end(), std::back_inserter(result),
                        [](auto p) { return (p / "constants").string(); });
                    break;
                default: __builtin_unreachable();
            }
        #endif

        if (!listNonExisting) {
            result.erase(std::remove_if(result.begin(), result.end(), [](const auto& path){
                return !std::filesystem::is_directory(path);
            }), result.end());
        }

        return result;
    }

}