# Avoid hardcoded references to bash for portability
#!/bin/bash

# Script to validate Isabelle certificates.
# This script should be invoked from cert.
# It expects "$PROGRAMATICA", "$certsDir" and "$SERVERDIR" to be set.
# It also expects the name of a certificate on the command line.

type=Isabelle

[ -n "$PROGRAMATICA" ] || { echo >&2 'Bug: $PROGRAMATICA is not set'; exit 1;}
. "$PROGRAMATICA/validation.sh" # defines $module, $conc, $attr, $certpath, etc
hyp=`getattr hyp "$attr"`

proof_dir=isabelle

### Auxiliary functions ########################################################


isabellecheck() {
  isabelle -e "with_path \"$SERVERDIR/lib\" use_thy \"${proof_file%.thy}\";" -q HOLCF Output >"$output"
  grep -q 'val it = () : unit' "$output"
}

validate() {
  pfecmd=isabelle
  echo "pfe $pfecmd $module"
  echo "Translating $module..." >"$output"
  if pfe $pfecmd $module >"$module.thy" 2>>"$output" ; then
    if [ -r "$proof_file" ] ; then
      echo "Proof missing" >"$output"
      if isabellecheck; then 
	markvalid
      else 
	#echo "Proof missing or incomplete."
	tail -1 "$output" # Hmm. Error message can be longer than 1 line!!
	#echo "Put your proof in $proof_file and call it $proof."
	markinvalid
      fi
    else
      abort "Put your proof in $proof_file, then validate again."
    fi
  else
    cat "$output"
    markinvalid
  fi
}

validatenew() {
  validate
}

auxfilechange() {
  while read file ; do
    if [ "$file" -nt "$certpath/valid" ] ; then
      return 0
    fi
  done < <(certauxfiles "$certpath")
  return 1
}

revalidate() {
  tmpdiff="$certsDir/diff$$"
  if [ "$attr" -nt "$certpath/valid" ] ; then
    echo "Certificate attributes have changed."
    validate
  elif auxfilechange ; then
    # This assumes that all relevant files are mentioned in $attrs!!!
    echo "Some auxiliary certificate file has changed."
    validate
  elif ! pfe tadiff "$deps" "$assertion" >"$tmpdiff" || [ -s "$tmpdiff" ] ; then
    #echo "The following changes might affect the validity of"
    echo "There has been changes that might affect the validity of"
    echo "the $type certificate $cert."
    #echo ""
    #cat "$tmpdiff"
    echo ""
    validate
  else
    echo "There has been no changes affecting the validity of"
    echo "the $type certificate $cert. Marking it as still valid."
    datestamp valid $certpath $module
  fi
  status=$?
  rm -f "$tmpdiff"
  return $status
}

### Here we go... ##############################################################

proof_file="`getattr file/proof "$attr"`"
proof="`getattr proof "$attr"`"
#simple="`getattr SimplePatterns "$attr"`"

if [ -z "$proof_file" ] ; then
  # Default file for proofs. The user can change this.
  proof_file="${module}_Proofs.thy"
  setattr file/proof "$proof_file" "$attr"
fi

if [ -z "$proof" ] ; then
  proof="proof$conc"
  setattr proof "$proof" "$attr"
fi


if [ -r "$certpath/valid" ] && [ -r "$deps" ] ; then
  revalidate
else
  validatenew
fi