#!/bin/zsh

set -e

sudo true

last-word() {
    last=
    for i in $*; do
        last=$i
    done
    print $last
}

install-ghc() {
    ver=${1/ghc-/}
    print "===> GHC $ver"
    sudo stow -d /opt -t /usr/local $1
    if [[ $ver == 6.8.3 ]] || [[ $ver == 6.10.4 ]]; then
        export runhaskell=/opt/ghc-6.12.3/bin/runhaskell
    else
        export runhaskell=/usr/local/bin/runhaskell
    fi
    rehash
    cabal install random extensible-exceptions >& /dev/null || true
    if [[ $(last-word $(ghc --version)) != $ver ]] && [[ $ver != head ]]; then
        print 'Version mismatch!'
        remove-ghc
        exit 1
    fi
}

remove-ghc() {
    sudo stow -d /opt -t /usr/local -D $1
    export runhaskell=runhaskell
    rehash
    print
}

find-package() {
    last-word $(sed '/using$/{N;s/\n/ /}' log|grep "using $1")
}

run-cabal() {
    rm -rf dist
    if $runhaskell Setup.lhs configure $* --user -v 2>&1 | grep Flags >&2 &&
       $runhaskell Setup.lhs build >&2; then
        print "OK, $(find-package base) $(find-package extensible-exceptions)"
    else
        print 'Failed!'
    fi
}

build-quickcheck() {
    print -n "Base-4: "
    run-cabal -fbase4
    print -n "Base-3: "
    run-cabal -f-base4
    print -n "No options: "
    run-cabal
}

rm -f log
for i in /opt/ghc-*; do
    ghc=$(basename $i)
    install-ghc $ghc
    build-quickcheck 2>>log
    remove-ghc $ghc
done

print "===> System GHC: v$(last-word $(ghc --version))"
build-quickcheck 2>>log