#!/usr/bin/mawk -We
# *********************************************************************
#  Written by and copyright Carlo Strozzi <carlos@linux.it>.
#
#  istable: checks that a file is a valid NoSQL table.
#  Copyright (C) 1998-2001 Carlo Strozzi <carlos@linux.it>
#
#  This program 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 Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  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 program; if not, write to the Free Software
#  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#  2001-01-03 Ported to NoSQL v3
#  2001-01-15 Fixed a typo in an error message
#  2001-03-09 Added option '-E'
#  2001-04-17 Added inline help
#  2001-08-17 Added stdio portability
#
#  $Id$
# *********************************************************************

BEGIN {
  NULL = ""; FS = OFS = "\t"

  while (ARGV[++i] != NULL) {
    if (ARGV[i] == "-v" || ARGV[i] == "--verbose") verbose = 1
    else if (ARGV[i] == "-n" || ARGV[i] == "--skip-header") skip_hdr = 1
    else if (ARGV[i] == "-e" || ARGV[i] == "--echo") gEcho = 1
    else if (ARGV[i] == "-E" || ARGV[i] == "--edit") edit = 1
    else if (ARGV[i] == "-N" || ARGV[i] == "--no-header") gMinRec = 2
    else if (ARGV[i] == "-i" || ARGV[i] == "--input") sIfile = ARGV[++i]
    else if (ARGV[i] == "-h" || ARGV[i] == "--help") {
       system("grep -v '^#' @NOSQLPATH@/nosql/help/istable.txt")
       rc = 1
       exit(rc)
    }
  }

  ARGC = 1						# Fix argv[]

  if (sIfile != NULL) { ARGV[1] = sIfile; ARGC = 2 }
}

#
# Main loop
#

gEcho && NR > gMinRec { print }

# Column names.
NR == 1 {
  num_cols = NF

  # Check the column name line.
  if (!/^[A-Za-z0-9\t_ ]+$/) {
    if (verbose)
       print "istable: invalid characters in column names" > "@STDERR@"
    errors = 1
    exit 1
  }

  # Check individual column names.
  for (i = 1; i <= NF; i++) {
    if ($i !~ /^[A-Za-z]/) {
      if (verbose)
         print "istable: invalid column name '" $i "'" > "@STDERR@"
      errors = 1
      exit 1
    }
  }
}

# Dashline.
NR == 2 {
  if (NF != num_cols) {
    if (verbose)
      print "istable: dashes do not match column names" > "@STDERR@"
    errors = 1
    exit 1
  }
  if (!/^[-\t]+$/) {
    if (verbose)
      print "istable: dashline is missing" > "@STDERR@"
    errors = 1
    exit 1
  }
}

NR > 2 {
  # Empty rows in a one-column table are ok.
  if (/^$/ && num_cols == 1) next

  if (NF != num_cols) {
    if (verbose) {
      if (skip_hdr) nr = NR - 2
      else nr = NR
      print "istable: bad No. of fields at line " nr > "@STDERR@"
    }
    errors = 1
    exit 1
  }
}

END {
  if (rc) exit(rc)
  if (NR < 2) { errors = 1; badrow = NR }
  if (verbose) {
    if (errors) {
       print "istable: table not ok" > "@STDERR@"
       if (edit) print "istable: " NR
    }  else print "istable: table ok" > "@STDERR@"
  }
  if (errors) exit 1
}

#
# End of program.
#
