// Author: Vitaliy Pavlyuk

#include <qpdf/QPDF.hh>
#include <qpdf/QPDFWriter.hh>
#include <qpdf/QPDFObjectHandle.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/QTC.hh>
#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

static char const* version = "1.1";
static char const* whoami = 0;

void usage()
{
    std::cerr
	<< "Usage: " << whoami
	<< " -in in_file [-out out_file] [-key key [-val val]?]+\n"
	<< "Modifies/Adds/Removes PDF /Info entries in the in_file\n"
	<< "and stores the result in out_file\n"
	<< "Special mode: " << whoami << " --dump file\n"
	<< "dumps all /Info entries to stdout\n";
    exit(2);
}

void dumpInfoDict(QPDF& pdf,
		  std::ostream& os = std::cout,
		  std::string const& sep = ":\t")
{
    QPDFObjectHandle trailer = pdf.getTrailer();
    if (trailer.hasKey("/Info"))
    {
	for (auto& it: trailer.getKey("/Info").ditems())
	{
	    std::string val;
	    if (it.second.isString())
	    {
		val = it.second.getStringValue();
	    }
	    else if (it.second.isName())
	    {
		val = it.second.getName();
	    }
	    else // according to PDF Spec 1.5, shouldn't happen
	    {
		val = it.second.unparseResolved();
	    }
	    os << it.first.substr(1) << sep << val << std::endl; // skip '/'
	}
    }
}

void pdfDumpInfoDict(char const* fname)
{
    try
    {
	QPDF pdf;
	pdf.processFile(fname);
	dumpInfoDict(pdf);
    }
    catch (std::exception& e)
    {
	std::cerr << e.what() << std::endl;
	exit(2);
    }
}

int main(int argc, char* argv[])
{

    bool static_id = false;
    std::map<std::string, std::string> Keys;

    whoami = QUtil::getWhoami(argv[0]);

    // For libtool's sake....
    if (strncmp(whoami, "lt-", 3) == 0)
    {
	whoami += 3;
    }

    if ((argc == 2) && (! strcmp(argv[1], "--version")) )
    {
	std::cout << whoami << " version " << version << std::endl;
	exit(0);
    }
    if ((argc == 4) && (! strcmp(argv[1], "--dump")) &&
	(strcmp(argv[2], "-in") == 0) )
    {
	QTC::TC("examples", "pdf-mod-info --dump");
	pdfDumpInfoDict(argv[3]);
	exit(0);
    }

    char* fl_in = 0;
    char* fl_out = 0;
    std::string cur_key;

    for (int i = 1; i < argc; ++i)
    {
	if ((! strcmp(argv[i], "-in")) && (++i < argc))
	{
	    fl_in = argv[i];
	}
	else if ((! strcmp(argv[i], "-out")) && (++i < argc))
	{
	    fl_out = argv[i];
	}
	else if (! strcmp(argv[i], "--static-id")) // don't document
	{
	    static_id = true; // this should be used in test suites only
	}
	else if ((! strcmp(argv[i], "-key")) && (++i < argc))
	{
	    QTC::TC("examples", "pdf-mod-info -key");
	    cur_key = argv[i];
	    if (! ((cur_key.length() > 0) && (cur_key.at(0) == '/')))
	    {
		cur_key = "/" + cur_key;
	    }
	    Keys[cur_key] = "";
	}
	else if ((! strcmp(argv[i], "-val")) && (++i < argc))
	{
	    if (cur_key.empty())
	    {
		QTC::TC("examples", "pdf-mod-info usage wrong val");
		usage();
	    }
	    QTC::TC("examples", "pdf-mod-info -val");
	    Keys[cur_key] = argv[i];
	    cur_key.clear();
	}
	else
	{
	    QTC::TC("examples", "pdf-mod-info usage junk");
	    usage();
	}
    }
    if (! fl_in)
    {
	QTC::TC("examples", "pdf-mod-info no in file");
	usage();
    }
    if (! fl_out)
    {
	QTC::TC("examples", "pdf-mod-info in-place");
	fl_out = fl_in;
    }
    if (Keys.size() == 0)
    {
	QTC::TC("examples", "pdf-mod-info no keys");
	usage();
    }

    std::string fl_tmp = fl_out;
    fl_tmp += ".tmp";

    try
    {
	QPDF file;
	file.processFile(fl_in);

	QPDFObjectHandle filetrailer = file.getTrailer();
	QPDFObjectHandle fileinfo;

	for (std::map<std::string, std::string>::const_iterator it =
		 Keys.begin(); Keys.end() != it; ++it)
	{
	    if (! fileinfo.isInitialized())
	    {
		if (filetrailer.hasKey("/Info"))
		{
		    QTC::TC("examples", "pdf-mod-info has info");
		    fileinfo = filetrailer.getKey("/Info");
		}
		else
		{
		    QTC::TC("examples", "pdf-mod-info file no info");
		    fileinfo = QPDFObjectHandle::newDictionary();
		    filetrailer.replaceKey("/Info", fileinfo);
		}
	    }
	    if (it->second == "")
	    {
		fileinfo.removeKey(it->first);
	    }
	    else
	    {
		QPDFObjectHandle elt = fileinfo.newString(it->second);
		elt.makeDirect();
		fileinfo.replaceKey(it->first, elt);
	    }
	}
	QPDFWriter w(file, fl_tmp.c_str());
	w.setStreamDataMode(qpdf_s_preserve);
	w.setLinearization(true);
	w.setStaticID(static_id); // for testing only
	w.write();
    }
    catch (std::exception& e)
    {
	std::cerr << e.what() << std::endl;
	exit(2);
    }

    try
    {
	(void) remove(fl_out);
	QUtil::os_wrapper("rename " + fl_tmp + " " + std::string(fl_out),
			  rename(fl_tmp.c_str(), fl_out));
    }
    catch (std::exception& e)
    {
	std::cerr << e.what() << std::endl;
	exit(2);
    }

    return 0;
}
