setup-gh-pages

#!/usr/bin/env bash
#
# Run this script from within the root directory of the git clone of
# your package in order to create a gh-pages subdirectory, containing a
# checkout of your gh-pages branch. If no gh-pages branch exists, it
# also creates one.
#
# Copyright (c) 2018-2019 Max Horn
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public
# License along with this program; if not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
# Boston, MA 02110-1301, USA.
#

set -e

######################################################################
#
# Various little helper functions


# print notices in green
notice() {
    printf '\033[32m%s\033[0m\n' "$*"
}

# print warnings in yellow
warning() {
    printf '\033[33mWARNING: %s\033[0m\n' "$*"
}

# print error in red and exit
error() {
    printf '\033[31mERROR: %s\033[0m\n' "$*"
    exit 1
}

######################################################################

# error early on if there already is a gh-pages dir
[[ -d gh-pages ]] && error "You already have a gh-pages directory"

# TODO: make it configurable which remote is used (default: origin)
remote=${remote:-origin}

# TODO: make it configurable how/which gap is used
GAP=${GAP:-gap}

# Based on the git documentation and some experiments, `git worktree add`
# in git 2.7 and newer works as desired. It is possible that 2.6 also
# did, but since I can't easily test that right now, I'll err on the
# safe
git_major=$(git  --version | sed -E 's/[^0-9]+([0-9]+).*/\1/')
git_minor=$(git  --version | sed -E 's/[^0-9]+[0-9]+\.([0-9]+).*/\1/')
if [[ $git_major -gt 2 || ($git_major -eq 2 && $git_minor -ge 7) ]]
then
    UseWorktree=Yes
else
    UseWorktree=No
fi
notice "Detected git ${git_major}.${git_minor}, using git worktree: ${UseWorktree}"

# TODO: add /gh-pages/ to .gitignore if it is not already in there

if [[ ${UseWorktree} = No ]]
then
    # Create a fresh clone of your repository, and change into it
    url=$(git config --get remote.${remote}.url)
    git clone ${url} gh-pages
    cd gh-pages
fi

# Add a new remote pointing to the GitHubPagesForGAP repository
git remote add -f gh-gap https://github.com/gap-system/GitHubPagesForGAP 2>/dev/null || :


# if there is already a gh-pages branch, do nothing; otherwise, if
# there is a ${remote}/gh-pages branch, create `gh-pages` tracking
# the remote; otherwise, create a fresh `gh-pages` branch
IsNewBranch=No
if git rev-parse -q --verify gh-pages
then
    notice "Using existing gh-pages branch"
else
    # fetch remote changes, so that we can see if there
    # is a remote gh-pages branch
    git fetch ${remote}

    if git rev-parse -q --verify ${remote}/gh-pages
    then
        notice "Track existing remote gh-pages branch"
        git branch --track gh-pages ${remote}/gh-pages
    else
        notice "Create a fresh gh-pages branch"
        git branch --no-track gh-pages gh-gap/gh-pages

        # ... then push it and set up tracking
        git push --set-upstream ${remote} gh-pages

        # remember that this is a new branch
        IsNewBranch=Yes
    fi
fi

if [[ ${UseWorktree} = Yes ]]
then
    # create a new worktree and change into it
    git worktree add gh-pages gh-pages
    cd gh-pages
fi

if [[ ${IsNewBranch} = Yes ]]
then
    notice "Updating new gh-pages branch"

    cp -f ../PackageInfo.g ../README* .

    [[ -d doc ]] && git rm -rf doc
    mkdir -p doc/
    cp -f ../doc/*.{css,html,js,txt} doc/ || :

    [[ -d ../htm ]] && cp -r ../htm .

    ${GAP} update.g

    git add .
    git commit -m "Setup gh-pages based on GitHubPagesForGAP"
    git push --set-upstream ${remote} gh-pages
fi