#!/bin/bash
#
# Configure script (front-end to cmake).
##

# Default settings.
BUILD0=build
PREFIX0=/local
#
CXX0=c++
CXXFLAGS0='-g -O2 -Wall -Wextra'

if [[ "$1" =~ ^-+[hH](elp$|$) ]]; then
  cat <<EOT
This helper script configures the CMake build system (any arguments to this
script are passed directly to 'cmake'). The following variables may be set in
the environment to control configuration, with defaults as indicated:

Build settings
--------------
BUILD     Build directory     [$BUILD0]
PREFIX    Install prefix      [$PREFIX0]

Compiler settings
-----------------
CXX       C++ compiler        [$CXX0]
CXXFLAGS  C++ compile flags   [$CXXFLAGS0]


CMake options (append -Dname=value to set)
-------------
cppref    C++ reference location
ldextra   Extra linker flags
mathjax   MathJax location
program   Program executable name
reldate   Program release date
version   Program version string

To build the project, just type 'make' after running this script.
To see the compiler command lines, run 'make VERBOSE=1' instead.
EOT
  exit 0
fi

# Configure variables.
for v in BUILD PREFIX CXX CXXFLAGS; do
  test "${!v}" || eval $v='$(eval echo $'$v'0)'
done
#
export CXX CXXFLAGS
export -n LDFLAGS
SRC=$(cd -P "$(dirname "$0")" && echo $PWD)

# Translate (optional) environment variables.
unset EXTRA
for v in CPPREF LDEXTRA MATHJAX PROGRAM RELDATE VERSION; do
  vlc=$(tr '[[:upper:]]' '[[:lower:]]' <<<"$v")  # MacOS BASH workaround.
  EXTRA="$EXTRA $(test "${!v}" && echo "-D$vlc='${!v}'")"
done

# Generate build system.
test -f Makefile && make confclean
rm -rf   $BUILD
mkdir -p $BUILD || exit 1
${CMAKE:-cmake} -B$BUILD -H$SRC -DCMAKE_INSTALL_PREFIX="$PREFIX" $EXTRA "$@"