#!/bin/bash
#
# usage: new-theory [--alternate existing-theory] new-theory-dir-name
#

cd "`dirname "$0"`/.."

if ! perl -v &>/dev/null; then
  echo "ERROR: perl is required to run this script." >&2
  exit 1
fi

if [ ! -e src/theory/theory_engine.h ]; then
  echo "ERROR: This script doesn't appear to be the contrib/ subdirectory" >&2
  echo "ERROR: of the CVC4 source tree." >&2
  exit 1
fi

# Trailing whitespaces in src/Makefile.am mess with the regexps (and are
# generally undesirable, so we throw an error instead of ignoring them).
if grep -q '[[:blank:]]$' src/Makefile.am; then
	echo "ERROR: trailing whitespaces in src/Makefile.am" >&2
	exit 1
fi

if [ $# -ge 1 -a "$1" = --alternate ]; then
  shift
  alternate=true
  alttheory="$1"
  shift
else
  alternate=false
fi

if [ $# -ne 1 ]; then
  echo "usage: new-theory [--alternate existing-theory] new-theory-dir-name" >&2
  echo "e.g.:  new-theory arrays" >&2
  echo "e.g.:  new-theory sets" >&2
  echo "e.g.:  new-theory rewrite_rules" >&2
  echo "e.g.:  new-theory --alternate arith difference-logic" >&2
  echo >&2
  echo "This tool will create a new src/theory/<new-theory-dir-name>" >&2
  echo "directory and fill in some infrastructural files in that directory." >&2
  echo "It also will incorporate that directory into the build process." >&2
  echo "Please refer to the file README.WHATS-NEXT file created in that" >&2
  echo "directory for tips on what to do next." >&2
  echo >&2
  echo "Theories with multiple words (e.g. \"rewrite_rules\") should have" >&2
  echo "directories and namespaces separated by an underscore (_).  The" >&2
  echo "resulting class names created by this script will be in CamelCase" >&2
  echo "(e.g. RewriteRules) if that convention is followed." >&2
  echo >&2
  echo "With --alternate, create a new theory directory that is declared as" >&2
  echo "an alternate implementation of an existing host theory.  Such" >&2
  echo "\"alternates\" share preprocessing, typechecking, rewriting (i.e.," >&2
  echo "normal form), and expression kinds with their host theories, but" >&2
  echo "differ in decision procedure implementation.  They are selectable" >&2
  echo "at runtime with --use-theory." >&2
  exit 1
fi

dir="$1"

if [ -e "src/theory/$dir" ]; then
  echo "ERROR: Theory \"$dir\" already exists." >&2
  echo "ERROR: Please choose a new directory name (or move that one aside)." >&2
  echo "ERROR: Or, if you'd like to create an alternate implementation of" >&2
  echo "ERROR: $dir, use this program this way:" >&2
  echo "ERROR:     new-theory --alternate $dir new-implementation-name" >&2
  exit 1
fi

if ! expr "$dir" : '[a-zA-Z][a-zA-Z0-9_]*$' &>/dev/null ||
   expr "$dir" : '_$' &>/dev/null; then
  echo "ERROR: \"$dir\" is not a valid theory name." >&2
  echo "ERROR:" >&2
  echo "ERROR: Theory names must start with a letter and be composed of" >&2
  echo "ERROR: letters, numbers, and the underscore (_) character; an" >&2
  echo "ERROR: underscore cannot be the final character." >&2
  exit 1
fi

if $alternate; then
  if ! [ -d "src/theory/$alttheory" -a -f "src/theory/$alttheory/kinds" ]; then
    echo "ERROR: Theory \"$alttheory\" doesn't exist, or cannot read its kinds file." >&2
    exit 1
  fi
  alt_id="$(
    function theory() { echo $1 | sed 's,^THEORY_,,'; exit; }
    source "src/theory/$alttheory/kinds"
  )"
fi

id="`echo "$dir" | tr a-z A-Z`"
# convoluted, but should be relatively portable and give a CamelCase
# representation for a string.  (e.g. "foo_bar" becomes "FooBar")
camel="`echo "$dir" | awk 'BEGIN { RS="_";ORS="";OFS="" } // {print toupper(substr($1,1,1)),substr($1,2,length($1))} END {print "\n"}'`"

if ! mkdir "src/theory/$dir"; then
  echo "ERROR: encountered an error creating directory src/theory/$dir" >&2
  exit 1
fi

echo "Theory of $dir"
echo "Theory directory: src/theory/$dir"
echo "Theory id: THEORY_$id"
$alternate && echo "Alternate for theory id: THEORY_$alt_id"
echo "Theory class: CVC4::theory::$dir::Theory$camel"
echo

function copyskel {
  src="$1"
  dest="`echo "$src" | sed "s/DIR/$dir/g"`"
  echo "Creating src/theory/$dir/$dest..."
  sed "s/\$dir/$dir/g;s/\$camel/$camel/g;s/\$id/$id/g" \
    contrib/theoryskel/$src \
    > "src/theory/$dir/$dest"
}

function copyaltskel {
  src="$1"
  dest="`echo "$src" | sed "s/DIR/$dir/g"`"
  echo "Creating src/theory/$dir/$dest..."
  sed "s/\$dir/$dir/g;s/\$camel/$camel/g;s/\$id/$id/g;s/\$alt_id/$alt_id/g" \
    contrib/alttheoryskel/$src \
    > "src/theory/$dir/$dest"
}

function copyoptions {
  src="$1"
  dest="`echo "$src" | sed "s/DIR/$dir/g"`"
  echo "Creating src/options/$dest..."
  sed "s/\$dir/$dir/g;s/\$camel/$camel/g;s/\$id/$id/g;s/\$alt_id/$alt_id/g" \
    contrib/optionsskel/$src \
    > "src/options/$dest"
}

# copy files from the skeleton, with proper replacements
if $alternate; then
  alternate01=1
  for file in `ls contrib/alttheoryskel`; do
    copyaltskel "$file"
  done
else
  alternate01=0
  for file in `ls contrib/theoryskel`; do
    copyskel "$file"
  done
fi
# Copy the options file independently
for file in `ls contrib/optionsskel`; do
  copyoptions "$file"
done


echo
echo "Adding $dir to THEORIES to src/Makefile.theories..."
if grep -q '^THEORIES = .*[^a-zA-Z0-9_]'"$dir"'\([^a-zA-Z0-9_]\|$\)' src/Makefile.theories &>/dev/null; then
  echo "NOTE: src/Makefile.theories already lists theory $dir"
else
  awk '/^THEORIES = / {print $0,"'"$dir"'"} !/^THEORIES = / {print$0}' src/Makefile.theories > src/Makefile.theories.new-theory
  if ! cp -f src/Makefile.theories src/Makefile.theories~; then
    echo "ERROR: cannot copy src/Makefile.theories !" >&2
    exit 1
  fi
  if ! mv -f src/Makefile.theories.new-theory src/Makefile.theories; then
    echo "ERROR: cannot replace src/Makefile.theories !" >&2
    exit 1
  fi
fi

echo "Adding sources to src/Makefile.am..."

perl -e '
  while(<>) { print; last if /^libcvc4_la_SOURCES = /; }
  if('$alternate01') {
    while(<>) { if(!/\\$/) { chomp; print "$_ \\\n\ttheory/'"$dir"'/theory_'"$dir"'.h \\\n\ttheory/'"$dir"'/theory_'"$dir"'.cpp\n"; last; } else { print; } }
  } else {
    while(<>) { if(!/\\$/) { chomp; print "$_ \\\n\ttheory/'"$dir"'/theory_'"$dir"'.h \\\n\ttheory/'"$dir"'/theory_'"$dir"'.cpp \\\n\ttheory/'"$dir"'/theory_'"$dir"'_rewriter.h \\\n\ttheory/'"$dir"'/theory_'"$dir"'_type_rules.h\n"; last; } else { print; } }
  }
  while(<>) { print; last if /^EXTRA_DIST = /; }
  while(<>) { if(!/\\$/) { chomp; print "$_ \\\n\ttheory/'"$dir"'/kinds\n"; last; } else { print; } }
  while(<>) { print; }' src/Makefile.am > src/Makefile.am.new-theory
if ! mv -f src/Makefile.am.new-theory src/Makefile.am; then
  echo "ERROR: cannot replace src/Makefile.am !" >&2
  exit 1
fi

echo "Adding ${dir}_options.toml to src/options/Makefile.am..."
if grep -q '^	${dir}_options.toml' src/options/Makefile.am &>/dev/null; then
  echo "NOTE: src/options/Makefile.am already seems to link to $dir option files"
else
  awk -v name="$dir" -f contrib/new-theory.awk src/options/Makefile.am > src/options/Makefile.am.new-theory
  if ! cp -f src/options/Makefile.am src/options/Makefile.am~; then
    echo "ERROR: cannot copy src/options/Makefile.am !" >&2
    exit 1
  fi
  if ! mv -f src/options/Makefile.am.new-theory src/options/Makefile.am; then
    echo "ERROR: cannot replace src/options/Makefile.am !" >&2
    exit 1
  fi
fi

echo
echo "Rerunning autogen.sh..."
./autogen.sh