/*
** Shell-escape the given string.  Append the result to a blob.
*/
static void shell_escape(Blob *pBlob, const char *zIn){
  int n = blob_size(pBlob);
  int k = strlen(zIn);
  int i, c;
  char *z;
  for(i=0; (c = zIn[i])!=0; i++){
    if( isspace(c) || c=='"' || (c=='\\' && zIn[i+1]!=0) ){
      blob_appendf(pBlob, "\"%s\"", zIn);
      z = blob_buffer(pBlob);
      for(i=n+1; i<=n+k; i++){
        if( z[i]=='"' ) z[i] = '_';
      }
      return;
    }
  }
  blob_append(pBlob, zIn, -1);
}

/*
** Run the fossil diff command separately for every file in the current
** checkout that has changed.
*/
static void diff_all(int internalDiff,  const char *zRevision){
  Stmt q;
  Blob cmd;
  int nCmdBase;
  int vid;
  
  vid = db_lget_int("checkout", 0);
  vfile_check_signature(vid);
  blob_zero(&cmd);
  shell_escape(&cmd, g.argv[0]);
  blob_append(&cmd, " diff ", -1);
  if( internalDiff ){
    blob_append(&cmd, "-i ", -1);
  }
  if( zRevision ){
    blob_append(&cmd, "-r ", -1);
    shell_escape(&cmd, zRevision);
    blob_append(&cmd, " ", 1);
  }
  nCmdBase = blob_size(&cmd);
  db_prepare(&q, 
    "SELECT pathname, deleted, chnged, rid FROM vfile "
    "WHERE chnged OR deleted OR rid=0 ORDER BY 1"
  );

  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isChnged = db_column_int(&q,2);
    int isNew = db_column_int(&q,3)==0;
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    cmd.nUsed = nCmdBase;
    if( isDeleted ){
      printf("DELETED  %s\n", zPathname);
    }else if( access(zFullName, 0) ){
      printf("MISSING  %s\n", zPathname);
    }else if( isNew ){
      printf("ADDED    %s\n", zPathname);
    }else if( isDeleted ){
      printf("DELETED  %s\n", zPathname);
    }else if( isChnged==3 ){
      printf("ADDED_BY_MERGE %s\n", zPathname);
    }else{
      shell_escape(&cmd, zFullName);
      printf("%s\n", blob_str(&cmd));
      fflush(stdout);
      system(blob_str(&cmd));
    }
    free(zFullName);
  }
  db_finalize(&q);
}

/*
** COMMAND: diff
** COMMAND: gdiff
**
** Usage: %fossil diff|gdiff ?-i? ?-r REVISION? FILE...

**   %fossil setting gdiff-command eskill22
**   %fossil setting gdiff-command tortoisemerge
**   %fossil setting gdiff-command meld
**   %fossil setting gdiff-command xxdiff
**   %fossil setting gdiff-command kdiff3
*/
void diff_cmd(void){
  int isGDiff = g.argv[1][0]=='g';
  const char *zFile, *zRevision;
  Blob cmd;
  Blob fname;
  Blob vname;
  Blob record;
  int cnt=0,internalDiff;

  internalDiff = find_option("internal","i",0)!=0;
  zRevision = find_option("revision", "r", 1);
  verify_all_options();
  db_must_be_within_tree();

  if( !isGDiff && g.argc==2 ){
    diff_all(internalDiff, zRevision);
    return;
  }
  if( g.argc<3 ){
    usage("?OPTIONS? FILE");
  }


  if( internalDiff==0 ){
    const char *zExternalCommand;
    if( !isGDiff ){
      zExternalCommand = db_get("diff-command", 0);
    }else{
      zExternalCommand = db_get("gdiff-command", 0);
    }
    if( zExternalCommand==0 ){
      internalDiff=1;
    }

  if( zRevision==0 ){
    int rid = db_int(0, "SELECT rid FROM vfile WHERE pathname=%B", &fname);
    if( rid==0 ){
      fossil_panic("no history for file: %b", &fname);
    }
    content_get(rid, &record);
  }else{
    historical_version_of_file(zRevision, blob_str(&fname), &record);
  }
  if( internalDiff ){
    Blob out;
    Blob current;
    blob_zero(&current);
    blob_read_from_file(&current, zFile);
    blob_zero(&out);
    text_diff(&record, &current, &out, 5);
    printf("%s\n", blob_str(&out));