/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2022 Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "filelister.h"

#include "config.h"
#include "path.h"
#include "pathmatch.h"
#include "utils.h"

#include <cstddef>
#include <cstring>
// fix NAME_MAX not found on macOS GCC8.1
#include <climits>

#ifdef _WIN32

///////////////////////////////////////////////////////////////////////////////
////// This code is WIN32 systems /////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

#include <windows.h>
#include <shlwapi.h>

// Here is the catch: cppcheck core is Ansi code (using char type).
// When compiling Unicode targets WinAPI automatically uses *W Unicode versions
// of called functions. Thus, we explicitly call *A versions of the functions.

static BOOL myIsDirectory(const std::string& path)
{
// See http://msdn.microsoft.com/en-us/library/bb773621(VS.85).aspx
    return PathIsDirectoryA(path.c_str());
}

static HANDLE myFindFirstFile(const std::string& path, LPWIN32_FIND_DATAA findData)
{
    HANDLE hFind = FindFirstFileA(path.c_str(), findData);
    return hFind;
}

static BOOL myFileExists(const std::string& path)
{
    return PathFileExistsA(path.c_str()) && !PathIsDirectoryA(path.c_str());
}

std::string FileLister::recursiveAddFiles(std::map<std::string, std::size_t> &files, const std::string &path, const std::set<std::string> &extra, const PathMatch& ignored)
{
    return addFiles(files, path, extra, true, ignored);
}

std::string FileLister::addFiles(std::map<std::string, std::size_t> &files, const std::string &path, const std::set<std::string> &extra, bool recursive, const PathMatch& ignored)
{
    const std::string cleanedPath = Path::toNativeSeparators(path);

    // basedir is the base directory which is used to form pathnames.
    // It always has a trailing backslash available for concatenation.
    std::string basedir;

    // searchPattern is the search string passed into FindFirst and FindNext.
    std::string searchPattern = cleanedPath;

    // The user wants to check all files in a dir
    const bool checkAllFilesInDir = (myIsDirectory(cleanedPath) != FALSE);

    if (checkAllFilesInDir) {
        const char c = cleanedPath.back();
        switch (c) {
        case '\\':
            searchPattern += '*';
            basedir = cleanedPath;
            break;
        case '*':
            basedir = cleanedPath.substr(0, cleanedPath.length() - 1);
            break;
        default:
            searchPattern += "\\*";
            if (cleanedPath != ".")
                basedir = cleanedPath + '\\';
        }
    } else {
        const std::string::size_type pos = cleanedPath.find_last_of('\\');
        if (std::string::npos != pos) {
            basedir = cleanedPath.substr(0, pos + 1);
        }
    }

    WIN32_FIND_DATAA ffd;
    HANDLE hFind = myFindFirstFile(searchPattern, &ffd);
    if (INVALID_HANDLE_VALUE == hFind)
        return "";

    do {
        if (ffd.cFileName[0] == '.' || ffd.cFileName[0] == '\0')
            continue;

        const char* ansiFfd = ffd.cFileName;
        if (std::strchr(ansiFfd,'?')) {
            ansiFfd = ffd.cAlternateFileName;
        }

        const std::string fname(basedir + ansiFfd);

        if ((ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0) {
            // File
            if ((!checkAllFilesInDir || Path::acceptFile(fname, extra)) && !ignored.match(fname)) {
                const std::string nativename = Path::fromNativeSeparators(fname);

                // Limitation: file sizes are assumed to fit in a 'size_t'
#ifdef _WIN64
                files[nativename] = (static_cast<std::size_t>(ffd.nFileSizeHigh) << 32) | ffd.nFileSizeLow;
#else
                files[nativename] = ffd.nFileSizeLow;
#endif
            }
        } else {
            // Directory
            if (recursive) {
                if (!ignored.match(fname)) {
                    std::string err = FileLister::recursiveAddFiles(files, fname, extra, ignored);
                    if (!err.empty())
                        return err;
                }
            }
        }
    } while (FindNextFileA(hFind, &ffd) != FALSE);

    FindClose(hFind);
    return "";
}

bool FileLister::isDirectory(const std::string &path)
{
    return (myIsDirectory(path) != FALSE);
}

bool FileLister::fileExists(const std::string &path)
{
    return (myFileExists(path) != FALSE);
}


#else

///////////////////////////////////////////////////////////////////////////////
////// This code is POSIX-style systems ///////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

#if defined(__CYGWIN__)
#undef __STRICT_ANSI__
#endif

#include <dirent.h>
#include <sys/stat.h>
#include <cerrno>

#ifndef NAME_MAX
#ifdef MAXNAMLEN
#define NAME_MAX MAXNAMLEN
#endif
#endif

#if defined(__amigaos4__) && !defined(__CLIB2__)
static int readdir_r(DIR *dir, struct dirent *buf, struct dirent **result) {
    struct dirent *de;

    de = readdir(dir);
    if (de)
        memcpy(buf, de, de->d_reclen);
    else
        buf = NULL;

    *result = buf;
    return 0;
}
#endif

static std::string addFiles2(std::map<std::string, std::size_t> &files,
                             const std::string &path,
                             const std::set<std::string> &extra,
                             bool recursive,
                             const PathMatch& ignored
                             )
{
    struct stat file_stat;
    if (stat(path.c_str(), &file_stat) != -1) {
        if ((file_stat.st_mode & S_IFMT) == S_IFDIR) {
            DIR * dir = opendir(path.c_str());
            if (!dir)
                return "";

            dirent * dir_result;
            // make sure we reserve enough space for the readdir_r() buffer;
            // according to POSIX:
            //   The storage pointed to by entry shall be large enough for a
            //   dirent with an array of char d_name members containing at
            //   least {NAME_MAX}+1 elements.
            // on some platforms, d_name is not a static sized-array but
            // a pointer to space usually reserved right after the dirent
            // struct; the union here allows to reserve the space and to
            // provide a pointer to the right type that can be passed where
            // needed without casts
            union {
                dirent entry;
                char buf[sizeof(*dir_result) + (sizeof(dir_result->d_name) > 1 ? 0 : NAME_MAX + 1)];
            } dir_result_buffer;
            // TODO: suppress instead?
            (void)dir_result_buffer.buf; // do not trigger cppcheck itself on the "unused buf"
            std::string new_path;
            new_path.reserve(path.length() + 100);// prealloc some memory to avoid constant new/deletes in loop


            while ((SUPPRESS_DEPRECATED_WARNING(readdir_r(dir, &dir_result_buffer.entry, &dir_result)) == 0) && (dir_result != nullptr)) {
                if ((std::strcmp(dir_result->d_name, ".") == 0) ||
                    (std::strcmp(dir_result->d_name, "..") == 0))
                    continue;

                new_path = path + '/' + dir_result->d_name;

#if defined(_DIRENT_HAVE_D_TYPE) || defined(_BSD_SOURCE)
                bool path_is_directory = (dir_result->d_type == DT_DIR || (dir_result->d_type == DT_UNKNOWN && FileLister::isDirectory(new_path)));
#else
                bool path_is_directory = FileLister::isDirectory(new_path);
#endif
                if (path_is_directory) {
                    if (recursive && !ignored.match(new_path)) {
                        std::string err = addFiles2(files, new_path, extra, recursive, ignored);
                        if (!err.empty())
                            return err;
                    }
                } else {
                    if (Path::acceptFile(new_path, extra) && !ignored.match(new_path)) {
                        if (stat(new_path.c_str(), &file_stat) != -1)
                            files[new_path] = file_stat.st_size;
                        else
                            return "Can't stat " + new_path + " errno: " + std::to_string(errno);
                    }
                }
            }
            closedir(dir);
        } else
            files[path] = file_stat.st_size;
    }
    return "";
}

std::string FileLister::recursiveAddFiles(std::map<std::string, std::size_t> &files, const std::string &path, const std::set<std::string> &extra, const PathMatch& ignored)
{
    return addFiles(files, path, extra, true, ignored);
}

std::string FileLister::addFiles(std::map<std::string, std::size_t> &files, const std::string &path, const std::set<std::string> &extra, bool recursive, const PathMatch& ignored)
{
    if (!path.empty()) {
        std::string corrected_path = path;
        if (endsWith(corrected_path, '/'))
            corrected_path.erase(corrected_path.end() - 1);

        return addFiles2(files, corrected_path, extra, recursive, ignored);
    }

    return "";
}

bool FileLister::isDirectory(const std::string &path)
{
    struct stat file_stat;
    return (stat(path.c_str(), &file_stat) != -1 && (file_stat.st_mode & S_IFMT) == S_IFDIR);
}

bool FileLister::fileExists(const std::string &path)
{
    struct stat file_stat;
    return (stat(path.c_str(), &file_stat) != -1 && (file_stat.st_mode & S_IFMT) == S_IFREG);
}

#endif