/*
  Copyright (c) 2021, Grégory Soutadé

  All rights reserved.
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:
  
  * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
  * Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.
  * Neither the name of the copyright holder nor the
    names of its contributors may be used to endorse or promote products
    derived from this software without specific prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <getopt.h>

#include <iostream>

#include <libgourou.h>
#include <libgourou_common.h>

#include "drmprocessorclientimpl.h"
#include "utils_common.h"

static const char* deviceFile     = "device.xml";
static const char* activationFile = "activation.xml";
static const char* devicekeyFile  = "devicesalt";
static const char* inputFile      = 0;
static const char* outputFile     = 0;
static const char* outputDir      = 0;

static char*          encryptionKeyUser  = 0;
static unsigned char* encryptionKey      = 0;
static unsigned       encryptionKeySize  = 0;

static inline unsigned char htoi(unsigned char c)
{
    if (c >= '0' && c <= '9')
	c -= '0';
    else if (c >= 'a' && c <= 'f')
	c -= 'a' - 10;
    else if (c >= 'A' && c <= 'F')
	c -= 'A' - 10;
    else
	EXCEPTION(gourou::USER_INVALID_INPUT, "Invalid character " << c << " in encryption key");

    return c;
}

static inline bool endsWith(const std::string& s, const std::string& suffix)
{
    return s.rfind(suffix) == std::abs((int)(s.size()-suffix.size()));
}

class ADEPTRemove
{
public:
   
    int run()
    {
	int ret = 0;
	try
	{
	    gourou::DRMProcessor::ITEM_TYPE type;
	    DRMProcessorClientImpl client;
	    gourou::DRMProcessor processor(&client, deviceFile, activationFile, devicekeyFile);
	    
	    std::string filename;
	    if (!outputFile)
		filename = std::string(inputFile);
	    else
		filename = outputFile;
	    
	    if (outputDir)
	    {
		if (!fileExists(outputDir))
		    mkpath(outputDir);

		filename = std::string(outputDir) + "/" + filename;
	    }

	    if (endsWith(filename, ".epub"))
		type = gourou::DRMProcessor::ITEM_TYPE::EPUB;
	    else if (endsWith(filename, ".pdf"))
		type = gourou::DRMProcessor::ITEM_TYPE::PDF;
	    else
	    {
		EXCEPTION(gourou::DRM_FORMAT_NOT_SUPPORTED, "Unsupported file format of " << filename);
	    }
	    
	    if (inputFile != filename)
	    {
		unlink(filename.c_str());
		fileCopy(inputFile, filename.c_str());
		processor.removeDRM(inputFile, filename, type, encryptionKey, encryptionKeySize);
		std::cout << "DRM removed into new file " << filename << std::endl;
	    }
	    else
	    {
		// Use temp file for PDF
		if (type == gourou::DRMProcessor::ITEM_TYPE::PDF)
		{
		    std::string tempFile = filename + ".tmp";
		    /* Be sure there is not already a temp file */
		    unlink(tempFile.c_str());
		    processor.removeDRM(filename, tempFile, type, encryptionKey, encryptionKeySize);
		    /* Original file must be removed before doing a copy... */
		    unlink(filename.c_str());
		    if (rename(tempFile.c_str(), filename.c_str()))
		    {
			EXCEPTION(gourou::DRM_FILE_ERROR, "Unable to copy " << tempFile << " into " << filename);
		    }
		}
		else
		    processor.removeDRM(inputFile, filename, type, encryptionKey, encryptionKeySize);
		std::cout << "DRM removed from " << filename << std::endl;
	    }
	} catch(std::exception& e)
	{
	    std::cout << e.what() << std::endl;
	    ret = 1;
	}

	return ret;
    }
};	      

static void usage(const char* cmd)
{
    std::cout << "Remove ADEPT DRM (from Adobe) of EPUB/PDF file" << std::endl;
    
    std::cout << "Usage: " << basename((char*)cmd) << " [(-D|--adept-directory) dir] [(-d|--device-file) device.xml] [(-a|--activation-file) activation.xml] [(-k|--device-key-file) devicesalt] [(-O|--output-dir) dir] [(-o|--output-file) output(.epub|.pdf|.der)] [(-v|--verbose)] [(-h|--help)] (-f|--input-file) file(.epub|pdf)" << std::endl << std::endl;
    
    std::cout << "  " << "-D|--adept-directory" << "\t"   << ".adept directory that must contains device.xml, activation.xml and devicesalt" << std::endl;
    std::cout << "  " << "-d|--device-file"     << "\t"   << "device.xml file from eReader" << std::endl;
    std::cout << "  " << "-a|--activation-file" << "\t"   << "activation.xml file from eReader" << std::endl;
    std::cout << "  " << "-k|--device-key-file" << "\t"   << "private device key file (eg devicesalt/devkey.bin) from eReader" << std::endl;
    std::cout << "  " << "-O|--output-dir"      << "\t"   << "Optional output directory were to put result (default ./)" << std::endl;
    std::cout << "  " << "-o|--output-file"     << "\t"   << "Optional output filename (default inplace DRM removal>)" << std::endl;
    std::cout << "  " << "-f|--input-file"      << "\t"   << "EPUB/PDF file to process" << std::endl;
    std::cout << "  " << "-v|--verbose"         << "\t\t" << "Increase verbosity, can be set multiple times" << std::endl;
    std::cout << "  " << "-V|--version"         << "\t\t" << "Display libgourou version" << std::endl;
    std::cout << "  " << "-h|--help"            << "\t\t" << "This help" << std::endl;

    std::cout << std::endl;
    std::cout << "Device file, activation file and device key file are optionals. If not set, they are looked into :" << std::endl;
    std::cout << "  * $ADEPT_DIR environment variable" << std::endl;
    std::cout << "  * /home/<user>/.config/adept" << std::endl;
    std::cout << "  * Current directory" << std::endl;
    std::cout << "  * .adept" << std::endl;
    std::cout << "  * adobe-digital-editions directory" << std::endl;
    std::cout << "  * .adobe-digital-editions directory" << std::endl;
}

int main(int argc, char** argv)
{
    int c, ret = -1;

    const char** files[] = {&devicekeyFile, &deviceFile, &activationFile};
    int verbose = gourou::DRMProcessor::getLogLevel();
    std::string _deviceFile, _activationFile, _devicekeyFile;

    while (1) {
	int option_index = 0;
	static struct option long_options[] = {
	    {"adept-directory",  required_argument, 0,  'D' },
	    {"device-file",      required_argument, 0,  'd' },
	    {"activation-file",  required_argument, 0,  'a' },
	    {"device-key-file",  required_argument, 0,  'k' },
	    {"output-dir",       required_argument, 0,  'O' },
	    {"output-file",      required_argument, 0,  'o' },
	    {"input-file",       required_argument, 0,  'f' },
	    {"encryption-key",   required_argument, 0,  'K' }, // Private option
	    {"verbose",          no_argument,       0,  'v' },
	    {"version",          no_argument,       0,  'V' },
	    {"help",             no_argument,       0,  'h' },
	    {0,                  0,                 0,  0 }
	};

	c = getopt_long(argc, argv, "D:d:a:k:O:o:f:K:vVh",
                        long_options, &option_index);
	if (c == -1)
	    break;

	switch (c) {
	case 'D':
	    _deviceFile = std::string(optarg) + "/device.xml";
	    _activationFile = std::string(optarg) + "/activation.xml";
	    _devicekeyFile = std::string(optarg) + "/devicesalt";
	    deviceFile = _deviceFile.c_str();
	    activationFile = _activationFile.c_str();
	    devicekeyFile = _devicekeyFile.c_str();
	    break;
	case 'd':
	    deviceFile = optarg;
	    break;
	case 'a':
	    activationFile = optarg;
	    break;
	case 'k':
	    devicekeyFile = optarg;
	    break;
	case 'f':
	    inputFile = optarg;
	    break;
	case 'O':
	    outputDir = optarg;
	    break;
	case 'o':
	    outputFile = optarg;
	    break;
	case 'K':
	    encryptionKeyUser = optarg;
	    break;
	case 'v':
	    verbose++;
	    break;
	case 'V':
	    version();
	    return 0;
	case 'h':
	    usage(argv[0]);
	    return 0;
	default:
	    usage(argv[0]);
	    return -1;
	}
    }
   
    gourou::DRMProcessor::setLogLevel(verbose);

    if (!inputFile || (outputDir && !outputDir[0]) ||
	(outputFile && !outputFile[0]))
    {
	usage(argv[0]);
	return -1;
    }

    ADEPTRemove remover;

    int i;
    bool hasErrors = false;
    const char* orig;
    for (i=0; i<(int)ARRAY_SIZE(files); i++)
    {
	orig = *files[i];
	*files[i] = findFile(*files[i]);
	if (!*files[i])
	{
	    std::cout << "Error : " << orig << " doesn't exists, did you activate your device ?" << std::endl;
	    ret = -1;
	    hasErrors = true;
	}
    }

    if (encryptionKeyUser)
    {
	int size = std::string(encryptionKeyUser).size();
	if ((size % 2))
	{
	    std::cout << "Error : Encryption key must be odd length" << std::endl;
	    goto end;
	}

	if (encryptionKeyUser[0] == '0' && encryptionKeyUser[1] == 'x')
	{
	    encryptionKeyUser += 2;
	    size -= 2;
	}

	encryptionKey = new unsigned char[size/2];

	for(i=0; i<size; i+=2)
	{
	    encryptionKey[i/2]  = htoi(encryptionKeyUser[i]) << 4;
	    encryptionKey[i/2] |= htoi(encryptionKeyUser[i+1]);
	}

	encryptionKeySize = size/2;
    }
    
    if (hasErrors)
	goto end;
       
    ret = remover.run();
    
end:
    for (i=0; i<(int)ARRAY_SIZE(files); i++)
    {
	if (*files[i])
	    free((void*)*files[i]);
    }

    if (encryptionKey)
	free(encryptionKey);
    
    return ret;
}