/*
** Copyright (c) 2007 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License version 2 as published by the Free Software Foundation.
**
** This program 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 this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains code used to generate ZIP archives.
*/
#include <assert.h>
#include <zlib.h>
#include "config.h"
#include "zip.h"

/*
** Write a 16- or 32-bit integer as little-endian into the given buffer.
*/
static void put16(char *z, int v){
  z[0] = v & 0xff;
  z[1] = (v>>8) & 0xff;
}
static void put32(char *z, int v){
  z[0] = v & 0xff;
  z[1] = (v>>8) & 0xff;
  z[2] = (v>>16) & 0xff;
  z[3] = (v>>24) & 0xff;
}

/*
** Variables in which to accumulate a growing ZIP archive.
*/
static Blob body;    /* The body of the ZIP archive */
static Blob toc;     /* The table of contents */
static int nEntry;   /* Number of files */
static int dosTime;  /* DOS-format time */
static int dosDate;  /* DOS-format date */

/*
** Initialize a new ZIP archive.
*/
void zip_open(void){
  blob_zero(&body);
  blob_zero(&toc);
  nEntry = 0;
  dosTime = 0;
  dosDate = 0;
}

/*
** Set the date and time values from an ISO8601 date string.
*/
void zip_set_timedate_from_str(const char *zDate){
  int y, m, d;
  int H, M, S;

  y = atoi(zDate);
  m = atoi(&zDate[5]);
  d = atoi(&zDate[8]);
  H = atoi(&zDate[11]);
  M = atoi(&zDate[14]);
  S = atoi(&zDate[17]);
  dosTime = (H<<11) + (M<<5) + S;
  dosDate = ((y-1980)<<9) + (m<<5) + d;
}

/*
** Set the date and time from a julian day number.
*/
void zip_set_timedate(double rDate){
  char *zDate = db_text(0, "SELECT datetime(%.17g)", rDate);
  zip_set_timedate_from_str(zDate);
  free(zDate);
}

/*
** Append a single file to a growing ZIP archive.
**
** pFile is the file to be appended.  zName is the name
** that the file should be saved as.
*/
void zip_add_file(const char *zName, const Blob *pFile){
  z_stream stream;
  int nameLen;
  int skip;
  int toOut;
  int iStart;
  int iCRC;
  int nByte;
  int nByteCompr;
  char *z;
  char zHdr[30];
  char zBuf[100];
  char zOutBuf[100000];

  /* Fill in as much of the header as we know.
  */
  nameLen = strlen(zName);
  put32(&zHdr[0], 0x04034b50);
  put16(&zHdr[4], 0x0014);
  put16(&zHdr[6], 0);
  put16(&zHdr[8], 8);
  put16(&zHdr[10], dosTime);
  put16(&zHdr[12], dosDate);
  put16(&zHdr[26], nameLen);
  put16(&zHdr[28], 0);

  /* Write the header and filename.
  */
  iStart = blob_size(&body);
  blob_append(&body, zHdr, 30);
  blob_append(&body, zName, nameLen);

  /* The first two bytes that come out of the deflate compressor are
  ** some kind of header that ZIP does not use.  So skip the first two
  ** output bytes.
  */
  skip = 2;

  /* Write the compressed file.  Compute the CRC as we progress.
  */
  stream.zalloc = (alloc_func)0;
  stream.zfree = (free_func)0;
  stream.opaque = 0;
  stream.avail_in = blob_size(pFile);
  stream.next_in = (unsigned char*)blob_buffer(pFile);
  stream.avail_out = sizeof(zOutBuf);
  stream.next_out = (unsigned char*)zOutBuf;
  deflateInit(&stream, 9);
  iCRC = crc32(0, stream.next_in, stream.avail_in);
  while( stream.avail_in>0 ){
    deflate(&stream, 0);
    toOut = sizeof(zOutBuf) - stream.avail_out;
    if( toOut>skip ){
      blob_append(&body, &zOutBuf[skip], toOut - skip);
      skip = 0;
    }else{
      skip -= toOut;
    }
    stream.avail_out = sizeof(zOutBuf);
    stream.next_out = (unsigned char*)zOutBuf;
  }
  do{
    stream.avail_out = sizeof(zOutBuf);
    stream.next_out = (unsigned char*)zOutBuf;
    deflate(&stream, Z_FINISH);
    toOut = sizeof(zOutBuf) - stream.avail_out;
    if( toOut>skip ){
      blob_append(&body, &zOutBuf[skip], toOut - skip);
      skip = 0;
    }else{
      skip -= toOut;
    }
  }while( stream.avail_out==0 );
  nByte = stream.total_in;
  nByteCompr = stream.total_out - 2;
  deflateEnd(&stream);

  /* Go back and write the header, now that we know the compressed file size.
  */
  z = &blob_buffer(&body)[iStart];
  put32(&z[14], iCRC);
  put32(&z[18], nByteCompr);
  put32(&z[22], nByte);

  /* Make an entry in the tables of contents
  */
  memset(zBuf, 0, sizeof(zBuf));
  put32(&zBuf[0], 0x02014b50);
  put16(&zBuf[4], 0x0317);
  put16(&zBuf[6], 0x0014);
  put16(&zBuf[8], 0);
  put16(&zBuf[10], 0x0008);
  put16(&zBuf[12], dosTime);
  put16(&zBuf[14], dosDate);
  put32(&zBuf[16], iCRC);
  put32(&zBuf[20], nByteCompr);
  put32(&zBuf[24], nByte);
  put16(&zBuf[28], nameLen);
  put16(&zBuf[30], 0);
  put16(&zBuf[32], 0);
  put16(&zBuf[34], 1);
  put16(&zBuf[36], 0);
  put32(&zBuf[38], (0100000 | 0644)<<16);
  put32(&zBuf[42], iStart);
  blob_append(&toc, zBuf, 46);
  blob_append(&toc, zName, nameLen);
  nEntry++;
}


/*
** Write the ZIP archive into the given BLOB.
*/
void zip_close(Blob *pZip){
  int iTocStart;
  int iTocEnd;
  char zBuf[30];

  iTocStart = blob_size(&body);
  blob_append(&body, blob_buffer(&toc), blob_size(&toc));
  iTocEnd = blob_size(&body);

  memset(zBuf, 0, sizeof(zBuf));
  put32(&zBuf[0], 0x06054b50);
  put16(&zBuf[4], 0);
  put16(&zBuf[6], 0);
  put16(&zBuf[8], nEntry);
  put16(&zBuf[10], nEntry);
  put32(&zBuf[12], iTocEnd - iTocStart);
  put32(&zBuf[16], iTocStart);
  put16(&zBuf[20], 0);
  blob_append(&body, zBuf, 22);
  blob_reset(&toc);
  *pZip = body;
  blob_zero(&body);
  nEntry = 0;
}

/*
** COMMAND: test-filezip
**
** Generate a ZIP archive specified by the first argument that
** contains files given in the second and subsequent arguments.
*/
void filezip_cmd(void){
  int i;
  Blob zip;
  Blob file;
  if( g.argc<3 ){
    usage("ARCHIVE FILE....");
  }
  zip_open();
  for(i=3; i<g.argc; i++){
    blob_zero(&file);
    blob_read_from_file(&file, g.argv[i]);
    zip_add_file(g.argv[i], &file);
    blob_reset(&file);
  }
  zip_close(&zip);
  blob_write_to_file(&zip, g.argv[2]);
}

/*
** Given the RID for a manifest, construct a ZIP archive containing
** all files in the corresponding baseline.
**
** If RID is for an object that is not a real manifest, then the
** resulting ZIP archive contains a single file which is the RID
** object.
**
** If the RID object does not exist in the repository, then
** pZip is zeroed.
**
** zDir is a "synthetic" subdirectory which all zipped files get
** added to as part of the zip file. It may be 0 or an empty string,
** in which case it is ignored. The intention is to create a zip which
** politely expands into a subdir instead of filling your current dir
** with source files. For example, pass a UUID or "ProjectName".
**
*/
void zip_of_baseline(int rid, Blob *pZip, const char *zDir){
  int i;
  Blob mfile, file, hash;
  Manifest m;
  Blob filename;
  int nPrefix;
  
  content_get(rid, &mfile);
  if( blob_size(&mfile)==0 ){
    blob_zero(pZip);
    return;
  }
  blob_zero(&file);
  blob_zero(&hash);
  blob_copy(&file, &mfile);
  blob_zero(&filename);
  zip_open();

  if( zDir && zDir[0] ){
    blob_appendf(&filename, "%s/", zDir);
  }
  nPrefix = blob_size(&filename);

  if( manifest_parse(&m, &mfile) ){
    zip_set_timedate(m.rDate);
    blob_append(&filename, "manifest", -1);
    zip_add_file(blob_str(&filename), &file);
    sha1sum_blob(&file, &hash);
    blob_reset(&file);
    blob_append(&hash, "\n", 1);
    blob_resize(&filename, nPrefix);
    blob_append(&filename, "manifest.uuid", -1);
    zip_add_file(blob_str(&filename), &hash);
    blob_reset(&hash);
    for(i=0; i<m.nFile; i++){
      int fid = uuid_to_rid(m.aFile[i].zUuid, 0);
      if( fid ){
        content_get(fid, &file);
        blob_resize(&filename, nPrefix);
        blob_append(&filename, m.aFile[i].zName, -1);
        zip_add_file(blob_str(&filename), &file);
        blob_reset(&file);
      }
    }
    manifest_clear(&m);
  }else{
    blob_reset(&mfile);
    blob_reset(&file);
  }
  blob_reset(&filename);
  zip_close(pZip);
}

/*
** COMMAND: test-baseline-zip
**
** Generate a ZIP archive for a specified baseline.
*/
void baseline_zip_cmd(void){
  int rid;
  Blob zip;
  if( g.argc!=4 ){
    usage("UUID ZIPFILE");
  }
  db_must_be_within_tree();
  rid = name_to_rid(g.argv[2]);
  zip_of_baseline(rid, &zip, g.argv[2]);
  blob_write_to_file(&zip, g.argv[3]);
}

/*
** WEBPAGE: zip
** URL: /zip/RID.zip
**
** Generate a ZIP archive for the baseline.
** Return that ZIP archive as the HTTP reply content.
*/
void baseline_zip_page(void){
  int rid;
  char *zName, *zRid;
  int nName, nRid;
  Blob zip;

  login_check_credentials();
  if( !g.okZip && (!g.okRead || !g.okHistory) ){ login_needed(); return; }
  zName = mprintf("%s", PD("name",""));
  nName = strlen(zName);
  zRid = mprintf("%s", PD("uuid",""));
  nRid = strlen(zRid);
  for(nName=strlen(zName)-1; nName>5; nName--){
    if( zName[nName]=='.' ){
      zName[nName] = 0;
      break;
    }
  }
  rid = name_to_rid(nRid?zRid:zName);
  if( rid==0 ){
    @ Not found
    return;
  }
  if( nRid==0 && nName>10 ) zName[10] = 0;
  zip_of_baseline(rid, &zip, zName);
  free( zName );
  free( zRid );
  cgi_set_content(&zip);
  cgi_set_content_type("application/zip");
  cgi_reply();
}
