post-commit

#!/usr/bin/env bash

# executables prefix
_prefix="/usr/bin"
# git executable
_git="$_prefix/git"

# branch from which to generate site
_origbranch="source"
# branch holding the generated site
_destbranch="master"

# directory holding the generated site -- should be outside this repo
_site="$("/bin/mktemp" -d /tmp/_site.XXXXXXXXX)"
# the current branch
_currbranch="$(/bin/grep "^*" < <("$_git" branch) | /usr/bin/cut -d' ' -f2)"

if [[ $_currbranch == $_origbranch ]]; then # we should generate the site
    # go to root dir of the repo
    cd "$("$_git" rev-parse --show-toplevel)"
    # generate the site
    jekyll build --destination "$_site"
    # switch to branch the site will be stored
    "$_git" checkout "$_destbranch"
    # overwrite existing files
    builtin shopt -s dotglob
    /bin/cp -rf "$_site"/* .
    builtin shopt -u dotglob
    # add any new files
    "$_git" add .
    # commit all changes with a default message
    "$_git" commit -a -m "updated site @ $(date +"%F %T")"
    # cleanup
    /bin/rm -rfv "$_site"
    # return
    "$_git" checkout "$_origbranch"
fi