#!/bin/bash

# Pulls latest changes from pelican git repos in use and then publishes the resulting site if there are new commits
# in either the theme or content. Also, runs a check against the last set of known future posts, and if they have
# come due, do a deploy.
#
# Assumes that your theme and content exist in separate repositories. In the case of S3/CloudFront deployments,
# assumes that you are using aws-cli to manage them. Update as needed if you do something else.
#
#
# Leave these next three variables alone.
PRETEND="$PRETEND" # Optionally, you can feed this environment variable to test the script without actually deploying.
DEPLOY=0 # Will we deploy?
LASTDATEEVAL="" # Used when reviewing scheduled posts.
# ---------------------------------------------
# Set the below variables according to your system needs.
# ---------------------------------------------
# Absolute path to your pelican theme directory
THEMEDIR='/path/to/theme/repo'
# Absolute path to your pelican content repo.
CONTENTDIR='/path/to/pelican/repo'
# Path to virtualenv where you have pelican installed.
VIRTENVPATH='/path/to/pelican/virtualenv/bin/activate'
# If using CloudFront and would like automatic invalidations on a deploy include the distribution id here.
CFDISTID=""
# Target you use for your deploy. So if you usually run 'make s3_upload', you should assign this variable to 's3_upload'.
MAKETARGET='s3_upload'

# ----------------------------------------------
# Here we go!
# ----------------------------------------------

echo "Starting auto publish at $(date)"

if [ -n "$PRETEND" ]; then
	if [[ "$PRETEND" == "1" ]]; then
		echo "Pretend mode activated. Will treat any actual deployment as a dry run. NOTE: You will need to manually deploy if you expected changes to be done on this run."
	fi
else
	PRETEND="0"
fi

# ----------------------------------------------
# Function for checking and storing next date for scheduled post in the future..
# ----------------------------------------------
check_for_posts_in_waiting () {
	LASTDATEEVAL="" #Setting this back to zero.
	IFS=$'\n'
	my_array=(`find $CONTENTDIR/content -name "*.md" | xargs grep -ihe "^date: " | sort --stable --reverse --key=2,3 | sed 's/date: //g' | sed 's/Date: //g'`)
	num_posts=${#my_array[@]}
	echo "Retrieved $num_posts for evaluation..."
	for i in ${my_array[@]}; do
		if [[ $i > $(date +"%Y-%m-%d %H:%M:%S") ]]; then
			echo "We have a future date. Stashing it."
			LASTDATEEVAL="$i"
		else
			if [[ -n "$LASTDATEEVAL" ]]; then
				echo "Last future date found was $LASTDATEEVAL. Storing..."
				echo "$LASTDATEEVAL" > "$CONTENTDIR/.lastdateeval"
			else
				echo "No future posts found. Closing down."
				echo "" > "$CONTENTDIR/.lastdateeval"
			fi
			break
		fi
	done
}


# Check if we have a previous date eval record we can use.
echo "Checking for previous date eval..."
if [ -f ${CONTENTDIR}/.lastdateeval ]; then
	LASTDATEEVAL=`cat ${CONTENTDIR}/.lastdateeval`
	if [[ -z "$LASTDATEEVAL" ]]; then
		echo "There were no previously scheduled future posts to evaluate. Moving on."
	else
		echo "Loading up last date eval of '$LASTDATEEVAL' for comparison..."
	fi
else
	echo "We've never done a date eval before, assume we're going to deploy."
	DEPLOY=1
	touch ${CONTENTDIR}/.lastdateeval
fi

if [[ -n "$LASTDATEEVAL" ]]; then
	if [[ "$LASTDATEEVAL" < $(date +'%Y-%m-%d %H:%M:%S') ]]; then
		echo "We definitely have posts pending for deployment."
		DEPLOY=1
	fi
fi


echo "Fetching current state of theme repo..."
cd ${THEMEDIR}
FLEXREF=`git --no-pager log --oneline -n1`
echo "Update theme..."
echo "Pull updates for $(pwd)"
git pull
FLEXREFNEW=`git --no-pager log --oneline -n1`
if [[ "$FLEXREF" != "$FLEXREFNEW" ]]; then
	echo "Found new commits in theme repo. Setting deploy mode to YES..."
	DEPLOY=1
else
	echo "No new commits for theme."
fi
echo "Update content..."
cd ${CONTENTDIR}
BLOGREF=`git --no-pager log --oneline -n1`
echo "Pull updates for $(pwd)"
git pull
BLOGREFNEW=`git --no-pager log --oneline -n1`
if [[ "$BLOGREF" != "$BLOGREFNEW" ]]; then
	echo "Found new commits in content repo. Setting deploy mode to YES..."
	DEPLOY=1
else
	echo "No new content."
fi

# Set up last date eval record for next run.
check_for_posts_in_waiting

if [[ "$DEPLOY" == 1 ]]; then
	echo "Site has new content or design. Beginning deploy process."
	echo "Activate virtualenv..."
	source ${VIRTENVPATH}
	echo "Publish content..."
	if [[ "$PRETEND" != "1" ]]; then
		echo "DEBUG: Trying to run make from `pwd`..."
		cd ${CONTENTDIR} && make ${MAKETARGET}
		if [ -n "$CFDISTID" ]; then
			echo "Sending invalidation to CF..."
			aws cloudfront create-invalidation --distribution-id ${CFDISTID} --paths "/*"
		fi
	else
		echo "Pretending to deploy..."
	fi
	echo "Cleaning up..."
	make clean
	echo "Deactivate virtualenv"
	deactivate
else
	echo "No new content or design. Skipping deploy."
fi
echo "Done! Completed at $(date)"
exit 0