hack-off

#!/usr/bin/env bash
set -euo pipefail

DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )

. "$DIR/common-setup.sh"

REPO="$1"

if [ ! -d "$REPO" ] ; then
    echo "Error: no such directory: $REPO"
    exit 1
fi

DIFF="$(git -C "$REPO" diff HEAD)"
DIFF_ERR=$?
STATUS="$(git -C "$REPO" status --porcelain --ignored)"
STATUS_ERR=$?

if [ "$DIFF_ERR" -ne 0 -o "$STATUS_ERR" -ne 0 ] ; then
    >&2 echo "Error: could not determine whether $REPO contains unsaved modifications"
    exit 1
elif [ -n "$DIFF" -o -n "$STATUS" ] ; then
    >&2 echo "$DIFF"
    >&2 echo "$STATUS"
    >&2 echo "Error: $REPO contains unsaved modifications"
    exit 1
fi

git -C "$REPO" fetch --all

for b in $(git -C "$REPO" for-each-ref --format='%(refname:short)' refs/heads/) ; do
    LOCAL_REV="$(git -C "$REPO" rev-parse "$b")"
    [ $? -eq 0 ] || exit 1
    for r in $(git -C "$REPO" remote) ; do
        REMOTE_MERGE_REV="$(git -C "$REPO" merge-base "$LOCAL_REV" "remotes/$r/$b")"
        if [ $? -ne 0 ] ; then
            >&2 echo "Error: problem retrieving branch \"$r\" from remote \"$r\""
            exit 1
        elif [ "$REMOTE_MERGE_REV" != "$LOCAL_REV" ] ; then
            >&2 echo "Error: branch \"$b\" has not been pushed to remote \"$r\""
            exit 1
        fi
    done
done

# If we've gotten here, we're pretty sure this is safe
get_git_manifest "$REPO"
GIT_MANIFEST="$OUTPUT_GIT_MANIFEST"
GIT_MANIFEST_TYPE="$OUTPUT_GIT_MANIFEST_TYPE"

NEEDS_DEFAULT_NIX="$(if [ -f "$REPO/default.nix" ] ; then echo 1 ; fi)"
rm -rf "$REPO"
mkdir "$REPO"
if [ -n "$NEEDS_DEFAULT_NIX" ] ; then
    git_thunk "$GIT_MANIFEST_TYPE" >"$REPO/default.nix"
fi
echo "$GIT_MANIFEST" >"$REPO/$GIT_MANIFEST_TYPE.json"