//========================================================================
//
// pdfdetach.cc
//
// Copyright 2010 Glyph & Cog, LLC
//
//========================================================================

//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2011 Carlos Garcia Campos <carlosgc@gnome.org>
// Copyright (C) 2013 Yury G. Kudryashov <urkud.urkud@gmail.com>
// Copyright (C) 2014, 2017 Adrian Johnson <ajohnson@redneon.com>
// Copyright (C) 2018, 2020, 2022, 2024-2026 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2018 Adam Reichold <adam.reichold@t-online.de>
// Copyright (C) 2019, 2021, 2024 Oliver Sander <oliver.sander@tu-dresden.de>
// Copyright (C) 2020 <r.coeffier@bee-buzziness.com>
// Copyright (C) 2024, 2025 g10 Code GmbH, Author: Sune Stolborg Vuorela <sune@vuorela.dk>
// Copyright (C) 2026 Stefan Brüns <stefan.bruens@rwth-aachen.de>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================

#include "config.h"
#include <poppler-config.h>
#include <cstdio>
#include "parseargs.h"
#include "Annot.h"
#include "GlobalParams.h"
#include "Page.h"
#include "PDFDoc.h"
#include "PDFDocFactory.h"
#include "FileSpec.h"
#include "CharTypes.h"
#include "Catalog.h"
#include "UnicodeMap.h"
#include "PDFDocEncoding.h"
#include "Error.h"
#include "UTF.h"
#include "Win32Console.h"

#include <filesystem>

static bool doList = false;
static int saveNum = 0;
static char saveFile[128] = "";
static bool saveAll = false;
static char savePath[1024] = "";
static char textEncName[128] = "";
static char ownerPassword[33] = "\001";
static char userPassword[33] = "\001";
static bool printVersion = false;
static bool printHelp = false;

static const ArgDesc argDesc[] = { { .arg = "-list", .kind = argFlag, .val = &doList, .size = 0, .usage = "list all embedded files" },
                                   { .arg = "-save", .kind = argInt, .val = &saveNum, .size = 0, .usage = "save the specified embedded file (file number)" },
                                   { .arg = "-savefile", .kind = argString, .val = &saveFile, .size = sizeof(saveFile), .usage = "save the specified embedded file (file name)" },
                                   { .arg = "-saveall", .kind = argFlag, .val = &saveAll, .size = 0, .usage = "save all embedded files" },
                                   { .arg = "-o", .kind = argString, .val = savePath, .size = sizeof(savePath), .usage = "file name for the saved embedded file" },
                                   { .arg = "-enc", .kind = argString, .val = textEncName, .size = sizeof(textEncName), .usage = "output text encoding name" },
                                   { .arg = "-opw", .kind = argString, .val = ownerPassword, .size = sizeof(ownerPassword), .usage = "owner password (for encrypted files)" },
                                   { .arg = "-upw", .kind = argString, .val = userPassword, .size = sizeof(userPassword), .usage = "user password (for encrypted files)" },
                                   { .arg = "-v", .kind = argFlag, .val = &printVersion, .size = 0, .usage = "print copyright and version info" },
                                   { .arg = "-h", .kind = argFlag, .val = &printHelp, .size = 0, .usage = "print usage information" },
                                   { .arg = "-help", .kind = argFlag, .val = &printHelp, .size = 0, .usage = "print usage information" },
                                   { .arg = "--help", .kind = argFlag, .val = &printHelp, .size = 0, .usage = "print usage information" },
                                   { .arg = "-?", .kind = argFlag, .val = &printHelp, .size = 0, .usage = "print usage information" },
                                   {} };

static std::string getFileName(const std::string &s, const UnicodeMap &uMap)
{
    size_t j;
    Unicode u;
    bool isUnicode;
    char uBuf[8];
    std::string res;
    if (hasUnicodeByteOrderMarkAndLengthIsEven(s)) {
        isUnicode = true;
        j = 2;
    } else {
        isUnicode = false;
        j = 0;
    }
    while (j < s.size()) {
        if (isUnicode) {
            u = ((s[j] & 0xff) << 8) | (s[j + 1] & 0xff);
            j += 2;
        } else {
            u = pdfDocEncoding[s[j] & 0xff];
            ++j;
        }
        const int n = uMap.mapUnicode(u, uBuf, sizeof(uBuf));
        res.append(uBuf, n);
    }
    return res;
}

int main(int argc, char *argv[])
{
    std::unique_ptr<PDFDoc> doc;
    GooString *fileName;
    const UnicodeMap *uMap;
    std::optional<GooString> ownerPW, userPW;
    bool ok;
    bool hasSaveFile;
    std::vector<std::unique_ptr<FileSpec>> embeddedFiles;
    int nFiles, nPages, i;
    Page *page;
    Annots *annots;

    Win32Console win32Console(&argc, &argv);

    // parse args
    ok = parseArgs(argDesc, &argc, argv);
    hasSaveFile = strlen(saveFile) > 0;
    if ((doList ? 1 : 0) + ((saveNum != 0) ? 1 : 0) + ((hasSaveFile != 0) ? 1 : 0) + (saveAll ? 1 : 0) != 1) {
        ok = false;
    }
    if (!ok || argc != 2 || printVersion || printHelp) {
        fprintf(stderr, "pdfdetach version %s\n", PACKAGE_VERSION);
        fprintf(stderr, "%s\n", popplerCopyright);
        fprintf(stderr, "%s\n", xpdfCopyright);
        if (!printVersion) {
            printUsage("pdfdetach", "<PDF-file>", argDesc);
        }
        return 99;
    }
    fileName = new GooString(argv[1]);

    // read config file
    globalParams = std::make_unique<GlobalParams>();
    if (textEncName[0]) {
        globalParams->setTextEncoding(textEncName);
    }

    // get mapping to output encoding
    if (!(uMap = globalParams->getTextEncoding())) {
        error(errConfig, -1, "Couldn't get text encoding");
        delete fileName;
        return 99;
    }

    // open PDF file
    if (ownerPassword[0] != '\001') {
        ownerPW = GooString(ownerPassword);
    }
    if (userPassword[0] != '\001') {
        userPW = GooString(userPassword);
    }

    doc = PDFDocFactory().createPDFDoc(*fileName, ownerPW, userPW);

    if (!doc->isOk()) {
        return 1;
    }

    for (i = 0; i < doc->getCatalog()->numEmbeddedFiles(); ++i) {
        embeddedFiles.push_back(doc->getCatalog()->embeddedFile(i));
    }

    nPages = doc->getCatalog()->getNumPages();
    for (i = 0; i < nPages; ++i) {
        page = doc->getCatalog()->getPage(i + 1);
        if (!page) {
            continue;
        }
        annots = page->getAnnots();
        if (!annots) {
            break;
        }

        for (const std::shared_ptr<Annot> &annot : annots->getAnnots()) {
            if (annot->getType() != Annot::typeFileAttachment) {
                continue;
            }
            embeddedFiles.push_back(std::make_unique<FileSpec>(static_cast<AnnotFileAttachment *>(annot.get())->getFile()));
        }
    }

    nFiles = embeddedFiles.size();

    // list embedded files
    if (doList) {
        printf("%d embedded files\n", nFiles);
        for (i = 0; i < nFiles; ++i) {
            const std::unique_ptr<FileSpec> &fileSpec = embeddedFiles[i];
            printf("%d: ", i + 1);
            const GooString *s1 = fileSpec->getFileName();
            if (!s1) {
                return 3;
            }
            printf("%s\n", getFileName(s1->toStr(), *uMap).c_str());
        }

        // save all embedded files
    } else if (saveAll) {
        std::filesystem::path basePath = savePath;
        if (basePath.empty()) {
            basePath = std::filesystem::current_path();
        }
        basePath = basePath.lexically_normal();

        for (i = 0; i < nFiles; ++i) {
            const std::unique_ptr<FileSpec> &fileSpec = embeddedFiles[i];

            const GooString *s1 = fileSpec->getFileName();
            if (!s1) {
                return 3;
            }
            const std::string currentFileName = getFileName(s1->toStr(), *uMap);
            if (currentFileName.empty()) {
                return 3;
            }
            std::filesystem::path filePath = basePath;
            filePath = filePath.append(currentFileName).lexically_normal();

            if (!filePath.generic_string().starts_with(basePath.generic_string())) {
                error(errIO, -1, "Preventing directory traversal");
                return 3;
            }

            auto *embFile = fileSpec->getEmbeddedFile();
            if (!embFile || !embFile->isOk()) {
                return 3;
            }
            if (!embFile->save(filePath.generic_string())) {
                error(errIO, -1, "Error saving embedded file as '{0:s}'", filePath.c_str());
                return 2;
            }
        }

        // save an embedded file
    } else {
        if (hasSaveFile) {
            for (i = 0; i < nFiles; ++i) {
                const std::unique_ptr<FileSpec> &fileSpec = embeddedFiles[i];
                const GooString *s1 = fileSpec->getFileName();
                if (!s1) {
                    continue;
                }
                const std::string currentFileName = getFileName(s1->toStr(), *uMap);
                if (currentFileName == saveFile) {
                    saveNum = i + 1;
                    break;
                }
            }
        }
        if (saveNum < 1 || saveNum > nFiles) {
            if (hasSaveFile) {
                error(errCommandLine, -1, "Invalid file name");
            } else {
                error(errCommandLine, -1, "Invalid file number");
            }
            return 99;
        }

        const std::unique_ptr<FileSpec> &fileSpec = embeddedFiles[saveNum - 1];
        std::string targetPath = savePath;
        if (targetPath.empty()) {
            // The user hasn't given a path to save, just use the filename specified in the pdf as name
            const GooString *s1 = fileSpec->getFileName();
            if (!s1) {
                return 3;
            }
            const std::string targetFileName = getFileName(s1->toStr(), *uMap);
            targetPath.append(targetFileName);

            const std::filesystem::path basePath = std::filesystem::current_path().lexically_normal();
            std::filesystem::path filePath = basePath;
            filePath = filePath.append(targetPath).lexically_normal();

            if (!filePath.generic_string().starts_with(basePath.generic_string())) {
                error(errIO, -1, "Preventing directory traversal");
                return 3;
            }
            targetPath = filePath.generic_string();
        }

        auto *embFile = fileSpec->getEmbeddedFile();
        if (!embFile || !embFile->isOk()) {
            return 3;
        }
        if (!embFile->save(targetPath)) {
            error(errIO, -1, "Error saving embedded file as '{0:r}'", &targetPath);
            return 2;
        }
    }

    return 0;
}
