/*

  Additional tools for Minizip

  Code: Xavier Roche '2004

  License: Same as ZLIB (www.gzip.org)

*/

/* Code */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "zlib.h"

#include "unzip.h"

#define READ_8(adr)  ((unsigned char)*(adr))

#define READ_16(adr) ( READ_8(adr) | (READ_8(adr+1) << 8) )

#define READ_32(adr) ( READ_16(adr) | (READ_16((adr)+2) << 16) )

#define WRITE_8(buff, n) do { \

  *((unsigned char*)(buff)) = (unsigned char) ((n) & 0xff); \

} while(0)

#define WRITE_16(buff, n) do { \

  WRITE_8((unsigned char*)(buff), n); \

  WRITE_8(((unsigned char*)(buff)) + 1, (n) >> 8); \

} while(0)

#define WRITE_32(buff, n) do { \

  WRITE_16((unsigned char*)(buff), (n) & 0xffff); \

  WRITE_16((unsigned char*)(buff) + 2, (n) >> 16); \

} while(0)

extern int ZEXPORT unzRepair(file, fileOut, fileOutTmp, nRecovered, bytesRecovered)

const char* file;

const char* fileOut;

const char* fileOutTmp;

uLong* nRecovered;

uLong* bytesRecovered;

{

  int err = Z_OK;

  FILE* fpZip = fopen(file, "rb");

  FILE* fpOut = fopen(fileOut, "wb");

  FILE* fpOutCD = fopen(fileOutTmp, "wb");

  if (fpZip != NULL &&  fpOut != NULL) {

    int entries = 0;

    uLong totalBytes = 0;

    char header[30];

    char filename[256];

    char extra[1024];

    int offset = 0;

    int offsetCD = 0;

    while ( fread(header, 1, 30, fpZip) == 30 ) {

      int currentOffset = offset;

      /* File entry */

      if (READ_32(header) == 0x04034b50) {

        unsigned int version = READ_16(header + 4);

        unsigned int gpflag = READ_16(header + 6);

        unsigned int method = READ_16(header + 8);

        unsigned int filetime = READ_16(header + 10);

        unsigned int filedate = READ_16(header + 12);

        unsigned int crc = READ_32(header + 14); /* crc */

        unsigned int cpsize = READ_32(header + 18); /* compressed size */

        unsigned int uncpsize = READ_32(header + 22); /* uncompressed sz */

        unsigned int fnsize = READ_16(header + 26); /* file name length */

        unsigned int extsize = READ_16(header + 28); /* extra field length */

        filename[0] = extra[0] = '\0';

        /* Header */

        if (fwrite(header, 1, 30, fpOut) == 30) {

          offset += 30;

        } else {

          err = Z_ERRNO;

          break;

        }

        /* Filename */

        if (fnsize > 0) {

          if (fread(filename, 1, fnsize, fpZip) == fnsize) {

            if (fwrite(filename, 1, fnsize, fpOut) == fnsize) {

              offset += fnsize;

            } else {

              err = Z_ERRNO;

              break;

            }

          } else {

            err = Z_ERRNO;

            break;

          }

        } else {

          err = Z_STREAM_ERROR;

          break;

        }

        /* Extra field */

        if (extsize > 0) {

          if (fread(extra, 1, extsize, fpZip) == extsize) {

            if (fwrite(extra, 1, extsize, fpOut) == extsize) {

              offset += extsize;

            } else {

              err = Z_ERRNO;

              break;

            }

          } else {

            err = Z_ERRNO;

            break;

          }

        }

        /* Data */

        {

          int dataSize = cpsize;

          if (dataSize == 0) {

            dataSize = uncpsize;

          }

          if (dataSize > 0) {

            char* data = malloc(dataSize);

            if (data != NULL) {

              if ((int)fread(data, 1, dataSize, fpZip) == dataSize) {

                if ((int)fwrite(data, 1, dataSize, fpOut) == dataSize) {

                  offset += dataSize;

                  totalBytes += dataSize;

                } else {

                  err = Z_ERRNO;

                }

              } else {

                err = Z_ERRNO;

              }

              free(data);

              if (err != Z_OK) {

                break;

              }

            } else {

              err = Z_MEM_ERROR;

              break;

            }

          }

        }

        /* Central directory entry */

        {

          char header[46];

          char* comment = "";

          int comsize = (int) strlen(comment);

          WRITE_32(header, 0x02014b50);

          WRITE_16(header + 4, version);

          WRITE_16(header + 6, version);

          WRITE_16(header + 8, gpflag);

          WRITE_16(header + 10, method);

          WRITE_16(header + 12, filetime);

          WRITE_16(header + 14, filedate);

          WRITE_32(header + 16, crc);

          WRITE_32(header + 20, cpsize);

          WRITE_32(header + 24, uncpsize);

          WRITE_16(header + 28, fnsize);

          WRITE_16(header + 30, extsize);

          WRITE_16(header + 32, comsize);

          WRITE_16(header + 34, 0);     /* disk # */

          WRITE_16(header + 36, 0);     /* int attrb */

          WRITE_32(header + 38, 0);     /* ext attrb */

          WRITE_32(header + 42, currentOffset);

          /* Header */

          if (fwrite(header, 1, 46, fpOutCD) == 46) {

            offsetCD += 46;

            /* Filename */

            if (fnsize > 0) {

              if (fwrite(filename, 1, fnsize, fpOutCD) == fnsize) {

                offsetCD += fnsize;

              } else {

                err = Z_ERRNO;

                break;

              }

            } else {

              err = Z_STREAM_ERROR;

              break;

            }

            /* Extra field */

            if (extsize > 0) {

              if (fwrite(extra, 1, extsize, fpOutCD) == extsize) {

                offsetCD += extsize;

              } else {

                err = Z_ERRNO;

                break;

              }

            }

            /* Comment field */

            if (comsize > 0) {

              if ((int)fwrite(comment, 1, comsize, fpOutCD) == comsize) {

                offsetCD += comsize;

              } else {

                err = Z_ERRNO;

                break;

              }

            }

          } else {

            err = Z_ERRNO;

            break;

          }

        }

        /* Success */

        entries++;

      } else {

        break;

      }

    }

    /* Final central directory  */

    {

      int entriesZip = entries;

      char header[22];

      char* comment = ""; // "ZIP File recovered by zlib/minizip/mztools";

      int comsize = (int) strlen(comment);

      if (entriesZip > 0xffff) {

        entriesZip = 0xffff;

      }

      WRITE_32(header, 0x06054b50);

      WRITE_16(header + 4, 0);    /* disk # */

      WRITE_16(header + 6, 0);    /* disk # */

      WRITE_16(header + 8, entriesZip);   /* hack */

      WRITE_16(header + 10, entriesZip);  /* hack */

      WRITE_32(header + 12, offsetCD);    /* size of CD */

      WRITE_32(header + 16, offset);      /* offset to CD */

      WRITE_16(header + 20, comsize);     /* comment */

      /* Header */

      if (fwrite(header, 1, 22, fpOutCD) == 22) {

        /* Comment field */

        if (comsize > 0) {

          if ((int)fwrite(comment, 1, comsize, fpOutCD) != comsize) {

            err = Z_ERRNO;

          }

        }

      } else {

        err = Z_ERRNO;

      }

    }

    /* Final merge (file + central directory) */

    fclose(fpOutCD);

    if (err == Z_OK) {

      fpOutCD = fopen(fileOutTmp, "rb");

      if (fpOutCD != NULL) {

        int nRead;

        char buffer[8192];

        while ( (nRead = (int)fread(buffer, 1, sizeof(buffer), fpOutCD)) > 0) {

          if ((int)fwrite(buffer, 1, nRead, fpOut) != nRead) {

            err = Z_ERRNO;

            break;

          }

        }

        fclose(fpOutCD);

      }

    }

    /* Close */

    fclose(fpZip);

    fclose(fpOut);

    /* Wipe temporary file */

    (void)remove(fileOutTmp);

    /* Number of recovered entries */

    if (err == Z_OK) {

      if (nRecovered != NULL) {

        *nRecovered = entries;

      }

      if (bytesRecovered != NULL) {

        *bytesRecovered = totalBytes;

      }

    }

  } else {

    err = Z_STREAM_ERROR;

  }

  return err;

}