#include "StdAfx.h"
#include "MasterEncoder.h"
#include <fstream>
#include <string>
#include <iostream>

namespace SimplePluginsFile {

MasterEncoder::MasterEncoder()
{
    _codeKey = 100;
    _sign = nullptr;
    _signLen = 0;
}

MasterEncoder::~MasterEncoder()
{
    SAFE_DELETE_AR(_sign);
}

void MasterEncoder::setSignAndKey(char* sign, int signLen, unsigned char key)
{
    if (sign && signLen) {
        _signLen = signLen;
        SAFE_DELETE_AR(_sign);
        _sign = new char[signLen];
        if (_sign) {
            memcpy(_sign, sign, signLen);
        } else {
            Mprintf("setSignAndKey Failed!\n");
        }
    }
    _codeKey = key;
}

void MasterEncoder::encode(unsigned char* data, long size)
{
    for (long i = 0; i < size; i++) {
        data[i] ^= _codeKey;
    }
}

void MasterEncoder::decode(unsigned char* data, long size)
{
    for (long i = 0; i < size; i++) {
        data[i] ^= _codeKey;
    }
}

unsigned char* MasterEncoder::readPDF(const std::string& filepath, long& size)
{
    std::ifstream ifs;
    ifs.open(filepath, std::ios::in | std::ios::binary);

    if (!ifs.is_open()) {
        Mprintf("文件打开失败: %s\n", filepath.c_str());
        return nullptr;
    }

    ifs.seekg(0, std::ios_base::end);
    size =(long) ifs.tellg();
    ifs.seekg(0, std::ios_base::beg);
    unsigned char* data = new unsigned char[size];
    long count = 0;
    while (count < size) {
        ifs.read((char*)&data[count], sizeof(unsigned char));
        count++;
    }

    Mprintf("read PDF size = %d\n", size);

    ifs.close();

    return data;
}

void MasterEncoder::writePDF(const std::string& filePath, unsigned char* data, long size)
{
    std::ofstream ofs;
    ofs.open(filePath, std::ios::out | std::ios::trunc | std::ios::binary);

    if (!ofs.is_open()) {
        Mprintf("文件打开失败: %s\n", filePath.c_str());
        return;
    }

    long count = 0;
    while (count < size) {
        ofs.write((char*)&data[count], sizeof(unsigned char));
        count++;
    }
    Mprintf("save PDF size = %d\n", size);
    ofs.close();
}

void MasterEncoder::encodePDF(const std::string& pdfPath, const std::string& savePath)
{
    long size = 0;
    unsigned char* data = readPDF(pdfPath, size);

    //判断是否已经加密过
    if (memcmp(data, _sign, _signLen) == 0) {
        Mprintf("加密过了, 直接保存: %s\n", pdfPath.c_str());
        writePDF(savePath, data, size);
    } else {
        encode(data, size);

        if (_signLen > 0) {
            unsigned char* p = new unsigned char[size + _signLen];
            memcpy(p, _sign, _signLen);
            memcpy(p + _signLen, data, size);

            writePDF(savePath, p, size + _signLen);

            delete[] p;
        } else {
            writePDF(savePath, data, size);
        }
    }

    delete[] data;
}

void MasterEncoder::decodePDF(const std::string& pdfPath, const std::string& savePath)
{
    long size = 0;
    unsigned char* data = readPDF(pdfPath, size);

    if (_signLen == 0) {
        decode(data, size);
        writePDF(savePath, data, size);
    } else if (memcmp(data, _sign, _signLen) == 0) {
        unsigned char* p = (data + _signLen);
        decode(p, size - _signLen);
        writePDF(savePath, p, size - _signLen);
    } else {
        Mprintf("解密失败: %s\n", pdfPath.c_str());
    }

    delete[] data;
}

unsigned char* MasterEncoder::decode(const std::string& pdfPath, long& size)
{
    unsigned char* data = readPDF(pdfPath, size);

    if (_signLen == 0) {
        decode(data, size);
        return data;
    } else if (memcmp(data, _sign, _signLen) == 0) {
        size -= _signLen;
        unsigned char* p = new unsigned char[size];
        memcpy(p, data + _signLen, size);
        decode(p, size);
        delete[] data;
        return p;
    } else {
        return data;
    }
}

}