#!/bin/bash
function do_help() {
    printf "Options:
  --help (-h)   Display this message
  --prefix      Path to install MOOG
  --bindir      Path to install MOOG binaries (default: PREFIX/bin)
  --datadir     Path to install MOOG data files (default: PREFIX/share/moog)
  --with-x11    Path to X11 library
  --with-sm     Path to SuperMongo libraries\n"
}

FC=${FC:-gfortran}
if [[ ! -f "$(which $FC 2>/dev/null)" ]]; then
    echo "$FC could not be found" >&2
    exit 1
fi

with_x11="/usr/X11/lib"
with_sm="/usr/local/sm"
fflags=(-Wall -Wextra -ff2c -fdefault-double-8 -fdefault-real-8)
gcc_version=$($FC --version | head -n 1 | awk -F' ' '{ print $4 }')
gcc_major="${gcc_version%%\.*}"

# Handle GCC 10 requirements
if (( $gcc_major >= 10 )); then
    fflags+=(--allow-argument-mismatch)
fi

# Generate new argv list, with elements split on '='
argv=()
for x in $@; do
    if [[ "$x" =~ .*=.* ]]; then
        key="${x%=*}"
        value="${x#*=}"
        argv+=($key)
        argv+=($value)
    else
        argv+=($x)
    fi
done


# Parse arguments
i=0
nargs=${#argv[@]}
while [[ $i < $nargs ]]; do
    key="${argv[$i]}"
    value="${argv[$i+1]}"
    case "$key" in
        --help|-h)
            do_help
            exit 0
            ;;
        --prefix)
            prefix="$value"
            (( i++ ))
            ;;
        --bindir)
            bindir="$value"
            (( i++ ))
            ;;
        --datadir)
            datadir="$value"
            (( i++ ))
            ;;
        --with-x11)
            with_x11="$value"
            (( i++ ))
            ;;
        --with-sm)
            with_sm="$value"
            (( i++ ))
            ;;
    esac
    (( i++ ))
done

# Assign default paths if not modified by the user
[[ -z "${prefix}" ]] && prefix="/usr/local"
[[ -z "${bindir}" ]] && bindir="${prefix}/bin"
[[ -z "${datadir}" ]] && datadir="${prefix}/share/moog"

# Convert fortran flag array to string
fflags="${fflags[@]}"

# Populate templates
sed "s|@PREFIX@|${prefix}|g;\
    s|@BINDIR@|${bindir}|g;\
    s|@DATADIR@|${datadir}|g;\
    s|@FFLAGS@|${fflags}|g;\
    s|@WITH_X11@|${with_x11}|g;\
    s|@WITH_SM@|${with_sm}|g;\
    s|@FC@|${FC}|g;\
    " Makefile.in > Makefile
sed "s|@MOOGPATH_DEFAULT@|${datadir}/|" Moog.f.in > Moog.f

# Dump
printf "
Configured with:

GCC version ........... $gcc_version
Fortran compiler ...... $FC
Installation prefix ... $prefix
X11 library ........... $with_x11
SuperMongo library .... $with_sm

Run 'make' to compile
Run 'make install' to install
"