#!/bin/bash
set -e
set -x

if [ -z $1 ] || [ $1 == "--help" ] || [ $1 == "-h" ]
then cat <<EOF
usage : packager VERSION [BRANCH] [TAG]"
- VERSION is the version number of the package to create, we expect
    there is a tag named mathcomp-\$VERSION which archive we can
    download from github
- BRANCH is the name of a branch where we can find accurate local opam
    files. Actually, this may only matter for the Coq version dependencies
    located in the ssreflect package. Default value is "mathcomp-\$VERSION"
- TAG is the name of the tag used to build the archive, this is
    particularily useful for generating the package for the odd order
    theorem if we want to keep it separate from the rest of mathcomp
    e.g. "packager 1.6.1 mathcomp-odd-order.1.6.1 mathcomp-odd-order.1.6.1"
    Default value is "mathcomp-\$VERSION"
EOF
     exit 0
else
VERSION=$1
fi

if [ -z $2 ]
then BRANCH="mathcomp-$VERSION"
else BRANCH=$2
fi
# verify whether $BRANCH exists
git rev-parse --verify $BRANCH

if [ -z $3 ]
then TAG="mathcomp-$VERSION"
else TAG=$3
fi
# verify whether $TAG exists
git rev-parse --verify $TAG

ARCHIVEURL="https://github.com/math-comp/math-comp/archive/$TAG.tar.gz"
GITROOT=$(git rev-parse --show-toplevel)

# we build the url file content and the list of packages, and where to put them
if [ $VERSION == "dev" ]
then
# variables useful for package construction
  URLLINE="src: \"git+https://github.com/math-comp/math-comp.git\""
  PKGS=$(sed -r "s/.*mathcomp\.([^\.]*)*.*/\1/" $GITROOT/mathcomp/all/all.v \
        | paste -sd " " -)
  PKGPREFIX="$GITROOT/opam/extra-dev/packages"
else
  ARCHIVE=$(mktemp)
  PREFIX=$(echo math-comp-$TAG | sed "s/\+/-/")
  git archive --format=tgz --output=$ARCHIVE \
      --prefix=$PREFIX/ $TAG # reproduce github archive
  SUM=$(sha256sum $ARCHIVE | cut -d " " -f 1)
  EXTRACTED=$(mktemp -d)
  tar -C $EXTRACTED -zxvf $ARCHIVE
# variables useful for package construction
  URLLINE="src: \"$ARCHIVEURL\""
  CHECKSUMLINE="checksum: \"sha256=$SUM\""
  PKGS=$(ls -fs -d -1 $EXTRACTED/*/*.opam \
        | sed -r "s?.*coq-mathcomp-([^/]+).opam?\1?" \
        | paste -sd " " -)
  PKGPREFIX="$GITROOT/opam/released/packages"
fi

# for each package, we pick the corresponding opam and descr file and
# rewrite them to adapt them to single package construction and
# version numbers
for pkg in $PKGS
do pkgdir="$PKGPREFIX/coq-mathcomp-$pkg/coq-mathcomp-$pkg.$VERSION"
   mkdir -p $pkgdir
   if [ $VERSION == "dev" ]
   then cp $GITROOT/coq-mathcomp-$pkg.opam $pkgdir/opam
   else git show "$BRANCH:coq-mathcomp-$pkg.opam" > $pkgdir/opam
        sed -r "/^version/d" -i $pkgdir/opam
   fi
   echo "" >> $pkgdir/opam
   echo "url {" >> $pkgdir/opam
   echo $URLLINE >> $pkgdir/opam
   if [ $VERSION != "dev" ]
   then echo $CHECKSUMLINE >> $pkgdir/opam
   fi
   echo "}" >> $pkgdir/opam
done

# finally test the existence of the archive
wget --spider $ARCHIVEURL