/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2014-2015 - Timo Strunk
 *  Copyright (C) 2011-2015 - Daniel De Matteis
 * 
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */



#include <stdio.h>
#include <stdint.h>
#include <sys/types.h>

#include <string.h>
#include <retro_miscellaneous.h>
#include <file/file_path.h>
#include <string/string_list.h>
#include "7zip_support.h"

#include "../deps/7zip/7z.h"
#include "../deps/7zip/7zAlloc.h"
#include "../deps/7zip/7zCrc.h"
#include "../deps/7zip/7zFile.h"
#include "../deps/7zip/7zVersion.h"

/* Undefined at the end of the file
 * Don't use outside of this file
 */
#define RARCH_ZIP_SUPPORT_BUFFER_SIZE_MAX 16384

static ISzAlloc g_Alloc = { SzAlloc, SzFree };

static int Buf_EnsureSize(CBuf *dest, size_t size)
{
   if (dest->size >= size)
      return 1;
   Buf_Free(dest, &g_Alloc);
   return Buf_Create(dest, size, &g_Alloc);
}

#ifndef _WIN32

static uint8_t kUtf8Limits[5] = { 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };

static Bool Utf16_To_Utf8(uint8_t *dest, size_t *destLen,
      const uint16_t *src, size_t srcLen)
{
   size_t destPos = 0;
   size_t srcPos  = 0;

   for (;;)
   {
      unsigned numAdds;
      uint32_t value;

      if (srcPos == srcLen)
      {
         *destLen = destPos;
         return True;
      }
      value = src[srcPos++];
      if (value < 0x80)
      {
         if (dest)
            dest[destPos] = (char)value;
         destPos++;
         continue;
      }
      if (value >= 0xD800 && value < 0xE000)
      {
         uint32_t c2;

         if (value >= 0xDC00 || srcPos == srcLen)
            break;
         c2 = src[srcPos++];
         if (c2 < 0xDC00 || c2 >= 0xE000)
            break;
         value = (((value - 0xD800) << 10) | (c2 - 0xDC00)) + 0x10000;
      }
      for (numAdds = 1; numAdds < 5; numAdds++)
         if (value < (((uint32_t)1) << (numAdds * 5 + 6)))
            break;
      if (dest)
         dest[destPos] = (char)(kUtf8Limits[numAdds - 1] 
               + (value >> (6 * numAdds)));
      destPos++;
      do
      {
         numAdds--;
         if (dest)
            dest[destPos] = (char)(0x80 
                  + ((value >> (6 * numAdds)) & 0x3F));
         destPos++;
      }while (numAdds != 0);
   }
   *destLen = destPos;
   return False;
}

static SRes Utf16_To_Utf8Buf(CBuf *dest,
      const uint16_t *src, size_t srcLen)
{
   Bool res;
   size_t destLen = 0;

   Utf16_To_Utf8(NULL, &destLen, src, srcLen);
   destLen += 1;

   if (!Buf_EnsureSize(dest, destLen))
      return SZ_ERROR_MEM;

   res = Utf16_To_Utf8(dest->data, &destLen, src, srcLen);
   dest->data[destLen] = 0;

   return res ? SZ_OK : SZ_ERROR_FAIL;
}
#endif

static SRes Utf16_To_Char(CBuf *buf, const uint16_t *s, int fileMode)
{
   int len = 0;

   for (len = 0; s[len] != '\0'; len++);

#ifdef _WIN32
   {
      int size = len * 3 + 100;
      if (!Buf_EnsureSize(buf, size))
         return SZ_ERROR_MEM;
      {
         char defaultChar = '_';
         BOOL defUsed;
         int numChars = WideCharToMultiByte(fileMode ?
               (
#ifdef UNDER_CE
                     CP_ACP
#else
                     AreFileApisANSI() ? CP_ACP : CP_OEMCP
#endif
               ) : CP_OEMCP,
               0, (LPCWSTR)s, len, (char *)buf->data,
               size, &defaultChar, &defUsed);
         if (numChars == 0 || numChars >= size)
            return SZ_ERROR_FAIL;
         buf->data[numChars] = 0;
         return SZ_OK;
      }
   }
#else
   (void)fileMode;
   return Utf16_To_Utf8Buf(buf, s, len);
#endif
}


static SRes ConvertUtf16toCharString(const uint16_t *s, char *outstring)
{
   CBuf buf;
   SRes res;

   Buf_Init(&buf);
   res = Utf16_To_Char(&buf, s, 0);

   if (res == SZ_OK)
      strncpy(outstring, (const char*)buf.data, PATH_MAX_LENGTH);

   Buf_Free(&buf, &g_Alloc);
   return res;
}

/* Extract the relative path relative_path from a 7z archive 
 * archive_path and allocate a buf for it to write it in.
 * If optional_outfile is set, extract to that instead and don't alloc buffer.
 */
int read_7zip_file(
      const char *archive_path,
      const char *relative_path, void **buf,
      const char *optional_outfile)
{
   CFileInStream archiveStream;
   CLookToRead lookStream;
   CSzArEx db;
   SRes res;
   ISzAlloc allocImp;
   ISzAlloc allocTempImp;
   uint16_t *temp  = NULL;
   size_t tempSize = 0;
   long outsize    = -1;
   bool file_found = false;

   /*These are the allocation routines.
    * Currently using the non-standard 7zip choices. */
   allocImp.Alloc     = SzAlloc;
   allocImp.Free      = SzFree;
   allocTempImp.Alloc = SzAllocTemp;
   allocTempImp.Free  = SzFreeTemp;

   if (InFile_Open(&archiveStream.file, archive_path))
   {
      RARCH_ERR("Could not open %s as 7z archive\n.",archive_path);
      return -1;
   }
   else
   {
      RARCH_LOG_OUTPUT("Openend archive %s. Now trying to extract %s\n",
            archive_path,relative_path);
   }

   FileInStream_CreateVTable(&archiveStream);
   LookToRead_CreateVTable(&lookStream, False);
   lookStream.realStream = &archiveStream.s;
   LookToRead_Init(&lookStream);
   CrcGenerateTable();
   SzArEx_Init(&db);
   res = SzArEx_Open(&db, &lookStream.s, &allocImp, &allocTempImp);

   if (res == SZ_OK)
   {
      uint32_t i;
      uint32_t blockIndex  = 0xFFFFFFFF;
      uint8_t *outBuffer   = 0;
      size_t outBufferSize = 0;

      for (i = 0; i < db.db.NumFiles; i++)
      {
         size_t len;
         char infile[PATH_MAX_LENGTH] = {0};
         size_t offset           = 0;
         size_t outSizeProcessed = 0;
         const CSzFileItem    *f = db.db.Files + i;

         if (f->IsDir)
         {
            /* We skip over everything which is not a directory. 
             * FIXME: Why continue then if f->IsDir is true?*/
            continue;
         }

         len = SzArEx_GetFileNameUtf16(&db, i, NULL);
         if (len > tempSize)
         {
            free(temp);
            tempSize = len;
            temp = (uint16_t *)malloc(tempSize * sizeof(temp[0]));
            if (temp == 0)
            {
               res = SZ_ERROR_MEM;
               break;
            }
         }
         SzArEx_GetFileNameUtf16(&db, i, temp);
         res = ConvertUtf16toCharString(temp,infile);

         if (!strcmp(infile, relative_path))
         {
            /* C LZMA SDK does not support chunked extraction - see here:
             * sourceforge.net/p/sevenzip/discussion/45798/thread/6fb59aaf/
             * */
            file_found = true;
            res = SzArEx_Extract(&db, &lookStream.s, i,&blockIndex,
                  &outBuffer, &outBufferSize,&offset, &outSizeProcessed,
                  &allocImp, &allocTempImp);
            if (res != SZ_OK)
            {
               break; /* This goes to the error section. */
            }
            outsize = outSizeProcessed;
            if (optional_outfile != NULL)
            {
               FILE* outsink = fopen(optional_outfile,"wb");
               if (outsink == NULL)
               {
                  RARCH_ERR("Could not open outfilepath %s.\n",
                        optional_outfile);
                  IAlloc_Free(&allocImp, outBuffer);
                  SzArEx_Free(&db, &allocImp);
                  free(temp);
                  File_Close(&archiveStream.file);
                  return -1;
               }
               fwrite(outBuffer+offset,1,outsize,outsink);
               fclose(outsink);
            }
            else
            {
               /*We could either use the 7Zip allocated buffer,
                * or create our own and use it.
                * We would however need to realloc anyways, because RetroArch
                * expects a \0 at the end, therefore we allocate new,
                * copy and free the old one. */
               *buf = malloc(outsize + 1);
               ((char*)(*buf))[outsize] = '\0';
               memcpy(*buf,outBuffer+offset,outsize);
            }
            IAlloc_Free(&allocImp, outBuffer);
            break;
         }
      }
   }
   SzArEx_Free(&db, &allocImp);
   free(temp);

   File_Close(&archiveStream.file);

   if (res == SZ_OK && file_found == true)
      return outsize;

   /* Error handling */
   if (!file_found)
      RARCH_ERR("File %s not found in %s\n",relative_path,archive_path);
   else if (res == SZ_ERROR_UNSUPPORTED)
      RARCH_ERR("7Zip decoder doesn't support this archive\n");
   else if (res == SZ_ERROR_MEM)
      RARCH_ERR("7Zip decoder could not allocate memory\n");
   else if (res == SZ_ERROR_CRC)
      RARCH_ERR("7Zip decoder encountered a CRC error in the archive\n");
   else
      RARCH_ERR("\nUnspecified error in 7-ZIP archive, error number was: #%d\n", res);
   return -1;
}

struct string_list *compressed_7zip_file_list_new(const char *path,
      const char* ext)
{
   CFileInStream archiveStream;
   CLookToRead lookStream;
   CSzArEx db;
   SRes res;
   ISzAlloc allocImp;
   ISzAlloc allocTempImp;
   uint16_t *temp               = NULL;
   size_t tempSize              = 0;
   long outsize                 = -1;

   struct string_list *ext_list = NULL;
   struct string_list     *list = string_list_new();

   if (!list)
      return NULL;

   if (ext)
      ext_list = string_split(ext, "|");

   (void)outsize;

   /* These are the allocation routines - currently using 
    * the non-standard 7zip choices. */
   allocImp.Alloc     = SzAlloc;
   allocImp.Free      = SzFree;
   allocTempImp.Alloc = SzAllocTemp;
   allocTempImp.Free  = SzFreeTemp;

   if (InFile_Open(&archiveStream.file, path))
   {
      RARCH_ERR("Could not open %s as 7z archive.\n",path);
      goto error;
   }

   FileInStream_CreateVTable(&archiveStream);
   LookToRead_CreateVTable(&lookStream, False);
   lookStream.realStream = &archiveStream.s;
   LookToRead_Init(&lookStream);
   CrcGenerateTable();
   SzArEx_Init(&db);
   res = SzArEx_Open(&db, &lookStream.s, &allocImp, &allocTempImp);

   if (res == SZ_OK)
   {
      uint32_t i;
      uint32_t blockIndex  = 0xFFFFFFFF;
      uint8_t *outBuffer   = 0;
      size_t outBufferSize = 0;

      (void)blockIndex;
      (void)outBufferSize;
      (void)outBuffer;

      for (i = 0; i < db.db.NumFiles; i++)
      {
         union string_list_elem_attr attr;
         const char *file_ext         = NULL;
         char infile[PATH_MAX_LENGTH] = {0};
         size_t offset                = 0;
         size_t outSizeProcessed      = 0;
         size_t                   len = 0;
         bool supported_by_core       = false;
         const CSzFileItem         *f = db.db.Files + i;

         (void)offset;
         (void)outSizeProcessed;

         if (f->IsDir)
         {
            /* we skip over everything, which is a directory. */
            continue;
         }
         len = SzArEx_GetFileNameUtf16(&db, i, NULL);
         if (len > tempSize)
         {
            free(temp);
            tempSize = len;
            temp     = (uint16_t *)malloc(tempSize * sizeof(temp[0]));

            if (temp == 0)
            {
               res = SZ_ERROR_MEM;
               break;
            }
         }
         SzArEx_GetFileNameUtf16(&db, i, temp);
         res      = ConvertUtf16toCharString(temp, infile);
         file_ext = path_get_extension(infile);

         if (string_list_find_elem_prefix(ext_list, ".", file_ext))
            supported_by_core = true;

         /*
          * Currently we only support files without subdirs in the archives.
          * Folders are not supported (differences between win and lin.
          * Archives within archives should imho never be supported.
          */

         if (!supported_by_core)
            continue;

         attr.i = RARCH_COMPRESSED_FILE_IN_ARCHIVE;

         if (!string_list_append(list, infile, attr))
            goto error;

      }
   }
   SzArEx_Free(&db, &allocImp);
   free(temp);
   File_Close(&archiveStream.file);

   if (res != SZ_OK)
   {
      /* Error handling */
      if (res == SZ_ERROR_UNSUPPORTED)
         RARCH_ERR("7Zip decoder doesn't support this archive. \n");
      else if (res == SZ_ERROR_MEM)
         RARCH_ERR("7Zip decoder could not allocate memory. \n");
      else if (res == SZ_ERROR_CRC)
         RARCH_ERR("7Zip decoder encountered a CRC error in the archive. \n");
      else
         RARCH_ERR(
               "\nUnspecified error in 7-ZIP archive, error number was: #%d. \n",
               res);
      goto error;
   }

   string_list_free(ext_list);
   return list;

error:
   RARCH_ERR("Failed to open compressed_file: \"%s\"\n", path);
   SzArEx_Free(&db, &allocImp);
   free(temp);
   File_Close(&archiveStream.file);
   string_list_free(list);
   string_list_free(ext_list);
   return NULL;
}

#undef RARCH_ZIP_SUPPORT_BUFFER_SIZE_MAX