/*
 * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
 *
 * Use of this source code is governed by MIT license that can be found in the
 * LICENSE file in the root of the source tree. All contributing project authors
 * may be found in the AUTHORS file in the root of the source tree.
 */

#include <string.h>
#include "strCoding.h"

#if defined(_WIN32)
#include <windows.h> 
#endif//defined(_WIN32)

namespace mediakit {

//////////////////////////通用///////////////////////
void UTF8ToUnicode(wchar_t* pOut, const char *pText)
{
    char* uchar = (char *)pOut;
    uchar[1] = ((pText[0] & 0x0F) << 4) + ((pText[1] >> 2) & 0x0F);
    uchar[0] = ((pText[1] & 0x03) << 6) + (pText[2] & 0x3F);
    return;
}
void UnicodeToUTF8(char* pOut, const wchar_t* pText)
{
    // 注意 WCHAR高低字的顺序,低字节在前，高字节在后 
    const char* pchar = (const char *)pText;
    pOut[0] = (0xE0 | ((pchar[1] & 0xF0) >> 4));
    pOut[1] = (0x80 | ((pchar[1] & 0x0F) << 2)) + ((pchar[0] & 0xC0) >> 6);
    pOut[2] = (0x80 | (pchar[0] & 0x3F));
    return;
}

char CharToInt(char ch) 
{
    if (ch >= '0' && ch <= '9')return (char)(ch - '0');
    if (ch >= 'a' && ch <= 'f')return (char)(ch - 'a' + 10);
    if (ch >= 'A' && ch <= 'F')return (char)(ch - 'A' + 10);
    return -1;
}
char StrToBin(const char *str) 
{
    char tempWord[2];
    char chn;
    tempWord[0] = CharToInt(str[0]); //make the B to 11 -- 00001011 
    tempWord[1] = CharToInt(str[1]); //make the 0 to 0 -- 00000000 
    chn = (tempWord[0] << 4) | tempWord[1]; //to change the BO to 10110000 
    return chn;
}

string strCoding::UrlEncode(const string &str) {
    string out;
    size_t len = str.size();
    for (size_t i = 0; i < len; ++i) {
        char ch = str[i];
        if (isalnum((uint8_t)ch)) {
            out.push_back(ch);
        }else {
            char buf[4];
            sprintf(buf, "%%%X%X", (uint8_t)ch >> 4,(uint8_t)ch & 0x0F);
            out.append(buf);
        }
    }
    return out;
}
string strCoding::UrlDecode(const string &str) {
    string output = "";
    char tmp[2];
    size_t i = 0, len = str.length();
    while (i < len) {
        if (str[i] == '%') {
            if(i > len - 3){
                //防止内存溢出
                break;
            }
            tmp[0] = str[i + 1];
            tmp[1] = str[i + 2];
            output += StrToBin(tmp);
            i = i + 3;
        } else if (str[i] == '+') {
            output += ' ';
            i++;
        } else {
            output += str[i];
            i++;
        }
    }
    return output;
}


///////////////////////////////windows专用///////////////////////////////////
#if defined(_WIN32)
void UnicodeToGB2312(char* pOut, wchar_t uData)
{
    WideCharToMultiByte(CP_ACP, NULL, &uData, 1, pOut, sizeof(wchar_t), NULL, NULL);
}
void Gb2312ToUnicode(wchar_t* pOut, const char *gbBuffer)
{
    MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, gbBuffer, 2, pOut, 1);
}

string strCoding::UTF8ToGB2312(const string &str) {
    auto len = str.size();
    auto pText = str.data();
    char Ctemp[4] = {0};
    char *pOut = new char[len + 1];
    memset(pOut, 0, len + 1);

    int i = 0, j = 0;
    while (i < len)
    {
        if (pText[i] >= 0)
        {
            pOut[j++] = pText[i++];
        }
        else
        {
            wchar_t Wtemp;
            UTF8ToUnicode(&Wtemp, pText + i);
            UnicodeToGB2312(Ctemp, Wtemp);
            pOut[j] = Ctemp[0];
            pOut[j + 1] = Ctemp[1];
            i += 3;
            j += 2;
        }
    }
    string ret = pOut;
    delete[] pOut;
    return ret;
}

string strCoding::GB2312ToUTF8(const string &str) {
    auto len = str.size();
    auto pText = str.data();
    char buf[4] = { 0 };
    auto nLength = len * 3;
    char* pOut = new char[nLength];
    memset(pOut, 0, nLength);
    size_t i = 0, j = 0;
    while (i < len)
    {
        //如果是英文直接复制就可以   
        if (*(pText + i) >= 0)
        {
            pOut[j++] = pText[i++];
        }
        else
        {
            wchar_t pbuffer;
            Gb2312ToUnicode(&pbuffer, pText + i);
            UnicodeToUTF8(buf, &pbuffer);
            pOut[j] = buf[0];
            pOut[j + 1] = buf[1];
            pOut[j + 2] = buf[2];
            j += 3;
            i += 2;
        }
    }   
    string ret = pOut;
    delete[] pOut;
    return ret;
}
#endif//defined(_WIN32)




} /* namespace mediakit */
