#!/bin/bash
set -e # Exit with nonzero exit code if anything fails

SOURCE_BRANCH="master"
TARGET_BRANCH="gh-pages"

function doCompile {
    cd site/_themes
    yarn
    yarn build
    mv dist/js ../assets/js/themes
    cd ../assets/js/themes
    FILE=../../../_includes/themes.html
    echo "" > $FILE
    for f in *.js; do
        echo "<script src=/assets/js/themes/$f></script>" >> $FILE
    done
    cd ../../../../
    bundle exec jekyll build
}

# Pull requests and commits to other branches shouldn't try to deploy, just build to verify
if [ "$TRAVIS_PULL_REQUEST" != "false" -o "$TRAVIS_BRANCH" != "$SOURCE_BRANCH" ]; then
    echo "Skipping deploy; just doing a build."
    doCompile
    exit 0
fi

# Save some useful information
REPO=`git config remote.origin.url`
SSH_REPO=${REPO/https:\/\/github.com\//git@github.com:}
SHA=`git rev-parse --verify HEAD`
OUT=_gh_pages

# Clone the existing gh-pages for this repo into dist/
# Create a new empty branch if gh-pages doesn't exist yet (should only happen on first deply)
git clone $REPO $OUT
cd $OUT
git checkout $TARGET_BRANCH || git checkout --orphan $TARGET_BRANCH

# Clean out existing contents except versions
mv versions ..
ls | xargs rm -rf
cd ..

# Run our compile script
doCompile

mv versions $OUT

# Now let's go have some fun with the cloned repo
cd $OUT
git config user.name "Travis CI"
git config user.email "$COMMIT_AUTHOR_EMAIL"

# If there are no changes to the compiled dist (e.g. this is a README update) then just bail.
if git diff --quiet; then
    echo "No changes to the output on this push; exiting."
    exit 0
fi

# Commit the "changes", i.e. the new version.
# The delta will show diffs between new and old versions.
git add -A .
git commit -m "Deploy to GitHub Pages: ${SHA}"

# Get the deploy key by using Travis's stored variables to decrypt deploy_key.enc
ENCRYPTED_KEY_VAR="encrypted_${ENCRYPTION_LABEL}_key"
ENCRYPTED_IV_VAR="encrypted_${ENCRYPTION_LABEL}_iv"
ENCRYPTED_KEY=${!ENCRYPTED_KEY_VAR}
ENCRYPTED_IV=${!ENCRYPTED_IV_VAR}
openssl aes-256-cbc -K $ENCRYPTED_KEY -iv $ENCRYPTED_IV -in ../deploy_key.enc -out ../deploy_key -d
chmod 600 ../deploy_key
eval `ssh-agent -s`
ssh-add ../deploy_key

# Now that we're all set up, we can push.
git push $SSH_REPO $TARGET_BRANCH