/*
** 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 cross link manifests
*/
#include "config.h"
#include "manifest.h"
#include <assert.h>

#if INTERFACE
/*
** A parsed manifest
*/
struct Manifest {
  Blob content;         /* The original content blob */
  char *zComment;       /* Decoded comment */
  double rDate;         /* Time in the "D" line */
  char *zUser;          /* Name of the user */
  char *zRepoCksum;     /* MD5 checksum of the baseline content */
  int nFile;            /* Number of F lines */
  int nFileAlloc;       /* Slots allocated in aFile[] */
  struct { 
    char *zName;           /* Name of a file */
    char *zUuid;           /* UUID of the file */
  } *aFile;
  int nParent;          /* Number of parents */
  int nParentAlloc;     /* Slots allocated in azParent[] */
  char **azParent;      /* UUIDs of parents */
};
#endif


/*
** Clear the memory allocated in a manifest object
*/
void manifest_clear(Manifest *p){
  blob_reset(&p->content);
  free(p->aFile);
  free(p->azParent);
  memset(p, 0, sizeof(*p));
}

/*
** Parse a manifest blob into a Manifest object.  The Manifest
** object takes over the input blob and will free it when the
** Manifest object is freed.  Zeros are inserted into the blob
** as string terminators so that blob should not be used again.
**
** Return TRUE if the content really is a manifest.  Return FALSE
** if there are syntax errors.
**
** The pContent is reset.  If TRUE is returned, then pContent will
** be reset when the Manifest object is cleared.  If FALSE is
** returned then the Manifest object is cleared automatically
** and pContent is reset before the return.
*/
int manifest_parse(Manifest *p, Blob *pContent){
  int seenHeader = 0;
  int i;
  Blob line, token, a1, a2, a3;

  memset(p, 0, sizeof(*p));
  memcpy(&p->content, pContent, sizeof(p->content));
  blob_zero(pContent);
  pContent = &p->content;

  blob_zero(&a1);
  blob_zero(&a2);
  md5sum_init();
  while( blob_line(pContent, &line) ){
    char *z = blob_buffer(&line);
    if( z[0]=='-' ){
      if( strncmp(z, "-----BEGIN PGP ", 15)!=0 ){
        goto manifest_syntax_error;
      }
      if( seenHeader ){
        break;
      }
      while( blob_line(pContent, &line)>1 ){}
      if( blob_line(pContent, &line)==0 ) break;
      z = blob_buffer(&line);
    }
    seenHeader = 1;
    if( blob_token(&line, &token)!=1 ) goto manifest_syntax_error;
    if( z[0]=='F' ){
      char *zName, *zUuid;
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a3)!=0 ) goto manifest_syntax_error;
      zName = blob_terminate(&a1);
      zUuid = blob_terminate(&a2);
      if( blob_size(&a2)!=UUID_SIZE ) goto manifest_syntax_error;
      if( !validate16(zUuid, UUID_SIZE) ) goto manifest_syntax_error;
      defossilize(zName);
      if( !file_is_simple_pathname(zName) ){
        goto manifest_syntax_error;
      }
      if( p->nFile>=p->nFileAlloc ){
        p->nFileAlloc = p->nFileAlloc*2 + 10;
        p->aFile = realloc(p->aFile, p->nFileAlloc*sizeof(p->aFile[0]) );
        if( p->aFile==0 ) fossil_panic("out of memory");
      }
      i = p->nFile++;
      p->aFile[i].zName = zName;
      p->aFile[i].zUuid = zUuid;
      if( i>0 && strcmp(p->aFile[i-1].zName, zName)>=0 ){
        goto manifest_syntax_error;
      }
    }else if( z[0]=='C' ){
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      if( p->zComment!=0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)!=0 ) goto manifest_syntax_error;
      p->zComment = blob_terminate(&a1);
      defossilize(p->zComment);
    }else if( z[0]=='D' ){
      char *zDate;
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      if( p->rDate!=0.0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)!=0 ) goto manifest_syntax_error;
      zDate = blob_terminate(&a1);
      p->rDate = db_double(0.0, "SELECT julianday(%Q)", zDate);
    }else if( z[0]=='U' ){
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      if( p->zUser!=0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)!=0 ) goto manifest_syntax_error;
      p->zUser = blob_terminate(&a1);
      defossilize(p->zUser);
    }else if( z[0]=='R' ){
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      if( p->zRepoCksum!=0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)!=0 ) goto manifest_syntax_error;
      if( blob_size(&a1)!=32 ) goto manifest_syntax_error;
      p->zRepoCksum = blob_terminate(&a1);
      if( !validate16(p->zRepoCksum, 32) ) goto manifest_syntax_error;
    }else if( z[0]=='P' ){
      md5sum_step_text(blob_buffer(&line), blob_size(&line)+1);
      while( blob_token(&line, &a1) ){
        char *zUuid;
        if( blob_size(&a1)!=UUID_SIZE ) goto manifest_syntax_error;
        zUuid = blob_terminate(&a1);
        if( !validate16(zUuid, UUID_SIZE) ) goto manifest_syntax_error;
        if( p->nParent>=p->nParentAlloc ){
          p->nParentAlloc = p->nParentAlloc*2 + 5;
          p->azParent = realloc(p->azParent, p->nParentAlloc*sizeof(char*));
          if( p->azParent==0 ) fossil_panic("out of memory");
        }
        i = p->nParent++;
        p->azParent[i] = zUuid;
      }
    }else if( z[0]=='Z' ){
      int rc;
      Blob hash;
      if( blob_token(&line, &a1)==0 ) goto manifest_syntax_error;
      if( blob_token(&line, &a2)!=0 ) goto manifest_syntax_error;
      if( blob_size(&a1)!=32 ) goto manifest_syntax_error;
      if( !validate16(blob_buffer(&a1), 32) ) goto manifest_syntax_error;
      md5sum_finish(&hash);
      rc = blob_compare(&hash, &a1);
      blob_reset(&hash);
      if( rc!=0 ) goto manifest_syntax_error;
    }else{
      goto manifest_syntax_error;
    }
  }
  if( !seenHeader ) goto manifest_syntax_error;
  md5sum_init();
  return 1;

manifest_syntax_error:
  md5sum_init();
  manifest_clear(p);
  return 0;
}

/*
** Add a single entry to the mlink table.  Also add the filename to
** the filename table if it is not there already.
*/
static void add_one_mlink(
  int mid,                  /* The record ID of the manifest */
  const char *zFromUuid,    /* UUID for the mlink.pid field */
  const char *zToUuid,      /* UUID for the mlink.fid field */
  const char *zFilename     /* Filename */
){
  int fnid, pid, fid;

  fnid = db_int(0, "SELECT fnid FROM filename WHERE name=%Q", zFilename);
  if( fnid==0 ){
    db_multi_exec("INSERT INTO filename(name) VALUES(%Q)", zFilename);
    fnid = db_last_insert_rowid();
  }
  if( zFromUuid==0 ){
    pid = 0;
  }else{
    pid = uuid_to_rid(zFromUuid, 1);
  }
  if( zToUuid==0 ){
    fid = 0;
  }else{
    fid = uuid_to_rid(zToUuid, 1);
  }
  db_multi_exec(
    "INSERT INTO mlink(mid,pid,fid,fnid)"
    "VALUES(%d,%d,%d,%d)", mid, pid, fid, fnid
  );
  if( pid && fid ){
    content_deltify(pid, fid, 0);
  }
}

/*
** Add mlink table entries associated with manifest cid.
** There is an mlink entry for every file that changed going
** from pid to cid.
**
** Deleted files have mlink.fid=0.
** Added files have mlink.pid=0.
** Edited files have both mlink.pid!=0 and mlink.fid!=0
*/
static void add_mlink(int pid, Manifest *pParent, int cid, Manifest *pChild){
  Manifest other;
  Blob otherContent;
  int i, j;

  if( db_exists("SELECT 1 FROM mlink WHERE mid=%d", cid) ){
    return;
  }
  assert( pParent==0 || pChild==0 );
  if( pParent==0 ){
    pParent = &other;
    content_get(pid, &otherContent);
  }else{
    pChild = &other;
    content_get(cid, &otherContent);
  }
  if( blob_size(&otherContent)==0 ) return;
  if( manifest_parse(&other, &otherContent)==0 ) return;
  content_deltify(pid, cid, 0);
  for(i=j=0; i<pParent->nFile && j<pChild->nFile; ){
    int c = strcmp(pParent->aFile[i].zName, pChild->aFile[j].zName);
    if( c<0 ){
      add_one_mlink(cid, pParent->aFile[i].zUuid, 0, pParent->aFile[i].zName);
      i++;
    }else if( c>0 ){
      add_one_mlink(cid, 0, pChild->aFile[j].zUuid, pChild->aFile[j].zName);
      j++;
    }else{
      if( strcmp(pParent->aFile[i].zUuid, pChild->aFile[j].zUuid)!=0 ){
      add_one_mlink(cid, pParent->aFile[i].zUuid, pChild->aFile[j].zUuid, 
                    pChild->aFile[j].zName);
      }
      i++;
      j++;
    }
  }
  while( i<pParent->nFile ){
    add_one_mlink(cid, pParent->aFile[i].zUuid, 0, pParent->aFile[i].zName);
    i++;
  }
  while( j<pChild->nFile ){
    add_one_mlink(cid, 0, pChild->aFile[j].zUuid, pChild->aFile[j].zName);
    j++;
  }
  manifest_clear(&other);
}

/*
** Scan record rid/pContent to see if it is a manifest.  If
** it is a manifest, then populate the mlink, plink,
** filename, and event tables with cross-reference information.
*/
int manifest_crosslink(int rid, Blob *pContent){
  int i;
  Manifest m;
  Stmt q;

  if( manifest_parse(&m, pContent)==0 ){
    return 0;
  }
  db_begin_transaction();
  for(i=0; i<m.nParent; i++){
    int pid = uuid_to_rid(m.azParent[i], 1);
    db_multi_exec("INSERT OR IGNORE INTO plink(pid, cid, isprim, mtime)"
                  "VALUES(%d, %d, %d, %.17g)", pid, rid, i==0, m.rDate);
    if( i==0 ){
      add_mlink(pid, 0, rid, &m);
    }
  }
  db_prepare(&q, "SELECT cid FROM plink WHERE pid=%d AND isprim", rid);
  while( db_step(&q)==SQLITE_ROW ){
    int cid = db_column_int(&q, 0);
    add_mlink(rid, &m, cid, 0);
  }
  db_finalize(&q);
  db_multi_exec(
    "INSERT INTO event(type,mtime,objid,user,comment)"
    "VALUES('ci',%.17g,%d,%Q,%Q)",
    m.rDate, rid, m.zUser, m.zComment
  );
  db_end_transaction(0);
  manifest_clear(&m);
  return 1;
}