#include "lib.h"
#include <string>

#ifdef USE_BOOST_FILESYSTEM
#include <boost/filesystem.hpp>
namespace fs = boost::filesystem;
#else
#include <filesystem>
namespace fs = std::filesystem;
#endif

/*
    return 语句的值代表着你从 C++ 函数返回的 Lua 堆栈上的元素个数。
*/

static const luaL_Reg lua_fs[] = {{"exists", exists},
                                  {"is_regular_file", is_regular_file},
                                  {"copy_file", copy_file},
                                  {"delete_file", delete_file},
                                  {"get_dir_files", get_dir_files},
                                  {"get_current_directory", get_current_directory},
                                  {"get_parent", get_parent},
                                  {"append_path", append_path},
                                  {"mkdir", mkdir},
                                  {"normalize", normalize},
                                  {NULL, NULL}};

int luaopen_lua_fs(lua_State* L)
{
    luaL_newlib(L, lua_fs);
    return 1;
}

static std::string replace(const std::string& str, const std::string& from, const std::string& to)
{
    if (from.empty()) {
        return str;
    }
    std::string result = str;
    size_t startPos = 0;
    while ((startPos = result.find(from, startPos)) != std::string::npos) {
        result.replace(startPos, from.length(), to);
        startPos += to.length();
    }
    return result;
}

/// @brief 创建文件夹
/// @param path string 路径或者文件夹名称
/// @return boolean
int mkdir(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    try {
        fs::path p(path);
        if (p.is_relative()) {
            p = fs::current_path().append(path);
        }
        fs::create_directories(p);
        lua_pushboolean(L, true);
        return 1;
    } catch (const std::exception& e) {
        lua_pushnil(L);
        lua_pushstring(L, e.what());
        return 2;
    }
}

/// @brief 获取父目录
/// @param path string 路径
/// @return string
int get_parent(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    auto r = fs::path(path).parent_path().string();
    lua_pushstring(L, r.c_str());
    return 1;
}

/// @brief 规范化路径
/// @param path string 路径 
/// @return string
int normalize(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
#ifdef _WIN32
    std::string normalized = replace(path, "/", "\\");
    if (!normalized.empty() && normalized.back() == '\\') {
        normalized.pop_back();
    }
#else
    std::string normalized = replace(path, "\\", "/");
    if (!normalized.empty() && normalized.back() == '/') {
        normalized.pop_back();
    }
#endif
    lua_pushstring(L, normalized.c_str());
    return 1;
}

/// @brief 拼接路径
/// @param path string 基本路径
/// @param append string 添加路径
/// @return string
int append_path(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    const char* append = luaL_checkstring(L, 2);
    auto r = fs::path(path).append(append).string();
    lua_pushstring(L, r.c_str());
    return 1;
}

/// @brief 文件是否存在
/// @param path string 文件路径
/// @return boolean
int exists(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    bool result = fs::exists(path);
    lua_pushboolean(L, result);
    return 1;
}

/// @brief 文件是否是一个常规文件
/// @param path string 文件路径
/// @return boolean
int is_regular_file(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    bool result = fs::is_regular_file(path);
    lua_pushboolean(L, result);
    return 1;
}

/// @brief 复制文件
/// @param source string 源文件
/// @param destination string 目标文件
/// @return boolean
int copy_file(lua_State* L)
{
    const char* source = luaL_checkstring(L, 1);
    const char* destination = luaL_checkstring(L, 2);
    bool result = fs::copy_file(source, destination);
    lua_pushboolean(L, result);
    return 1;
}

/// @brief 删除文件
/// @param path string 文件路径
/// @return boolean
int delete_file(lua_State* L)
{
    const char* path = luaL_checkstring(L, 1);
    bool result = fs::remove(path);
    lua_pushboolean(L, result);
    return 1;
}

/// @brief 获取当前工作目录
/// @return string
int get_current_directory(lua_State* L)
{
    std::string current_dir = fs::current_path().string();
    lua_pushstring(L, current_dir.c_str());
    return 1;
}

/// @brief 获取一个目录下所有文件（不递归）
/// @param dir_path string 目录
/// @return table
int get_dir_files(lua_State* L)
{
    // 获取第一个参数：目录路径
    const char* dir_path = luaL_checkstring(L, 1);

    // 检查目录是否存在
    if (!fs::exists(dir_path) || !fs::is_directory(dir_path)) {
        lua_pushnil(L);
        lua_pushstring(L, "Invalid directory path");
        return 2;   // 返回 nil 和错误信息
    }

    // 创建一个新的 Lua 表用于存放文件列表
    lua_newtable(L);
    int table_index = lua_gettop(L);   // 获取当前 Lua 表的位置

    int index = 1;
    for (const auto& entry : fs::directory_iterator(dir_path)) {
        if (fs::is_regular_file(entry.status())) {
            lua_pushstring(L, entry.path().filename().string().c_str());
            lua_rawseti(L, table_index, index);
            index++;
        }
    }
    return 1;
}