deploy

#!/usr/bin/env bash

#---------------------------------------------------------------------
usage ()
{
	cat <<EOT

${0##*/}
    Designed to perform all the necessary steps to update a local
    copy of the project from the remote repo, which is assumed to
    be "ahead" of the local copy. Mainly intended for use in
    staging and production environments to ensure that code "pushes"
    are performed consistently every time. Should be run from the
    project root folder.

Usage:
    bin/${0##*/} [tag|branch|sha|ref] [dev|prod|staging]

    \$1 = The new commit to which to update.
          Will be merged into the current branch/commit.
          Default: (The remote tracking branch for the
                   currently-checked-out branch.)
    \$2 = The local config file "environment" to use.
          Default: $APP_ENV if set, 'prod' if not.

Environment Variables:
          APP_ENV = If set and \$2 is blank, will be used as the active
                    environment for the update run.
    LOADSYS_EMAIL = If set, an email report for the update run will be
                    generated and sent to the email address contained within.

EOT

	exit ${1:-0}  # Exit with code 0 unless an arg is passed to the method.
}
if [ "$1" = '-h' ]; then
	usage
fi


echo "## Starting update process."

# Set variables.
DIR="$( cd -P "$( dirname "$0" )"/.. >/dev/null 2>&1 && pwd )"
BIN_DIR="$DIR/bin"
CONFIG_DIR="$DIR/config"
MIGRATION_DIR="$CONFIG_DIR/Migrations"
SLEEP_TIME=10
EXISTINGCOMMIT=$( git rev-parse HEAD )
EXISTINGBRANCH=$( git rev-parse --abbrev-ref HEAD )

if [ -d "$MIGRATION_DIR" ] && [ "$(ls -A $MIGRATION_DIR)" ]; then
	DB_UPDATES_METHOD='migrations'
else
	DB_UPDATES_METHOD='none'
fi


# Input processing.
if [ $1 ]; then
	ARG_NEWCOMMIT=$1
else
	#Ref: http://stackoverflow.com/a/9753364/70876
	ARG_NEWCOMMIT=$( git rev-parse --abbrev-ref --symbolic-full-name @{u} )
fi

if [ $2 ]; then
	ARG_APPENV="$2"
elif [ -n "$APP_ENV" ]; then
	ARG_APPENV="$APP_ENV"
else
	ARG_APPENV="prod"
fi


#@TODO: Maybe check for an executable `scripts/pre-deploy` project-specific script and run it? Abort this script if the pre-deploy exists non-zero?


# Check for local changes that would cause a merge (without -f) to fail later.
$BIN_DIR/git-localchanges
if [ $? -gt 0 ]; then
	echo "!! You will need to resolve any differences between the working copy  !!"
	echo "!! and the active commit before proceeding with the update.           !!"
	echo ""
	exit 1
fi


# Backup the live DB.
$BIN_DIR/db-backup
echo ''
echo "## Sleeping for ${SLEEP_TIME} seconds to consider the backup size."
echo "##   (Press Ctrl-C to abort the update)..."
echo "##   (Press ENTER to continue immediately)..."
echo ''
read -t ${SLEEP_TIME} NOTUSED


# Save the "current" commit for later.
echo "## Current commit is $EXISTINGBRANCH ($EXISTINGCOMMIT)";


# Update repository.
echo "## Pulling changes from remote repo.";
git fetch origin refs/heads/*:refs/remotes/origin/* +refs/tags/*:refs/tags/*


# Apply database updates, one way or another.
if [ "$DB_UPDATES_METHOD" = 'migrations' ]; then
	echo "## Deferring database migrations until after merge."
elif [ "$DB_UPDATES_METHOD" = 'none' ]; then
	echo "## Could not automatically determine database change tracking system."
	read -p "## Make sure any pending DB changes have been made and press [ENTER] to continue."
fi


# This if() should really be looking to see if we're being asked to fast
# forward on the same branch, or switch to the HEAD of a different branch.
# if [ "$ARG_NEWCOMMIT" = "origin/master" ]; then
	echo "## Merging upstream changes from: $ARG_NEWCOMMIT";
	git merge $ARG_NEWCOMMIT
# else
# 	echo "## Checking out new commit: $ARG_NEWCOMMIT";
# 	git checkout $ARG_NEWCOMMIT
# fi


echo "## New commit is now active:";
GIT_LOG=$( git log -1 )
echo "${GIT_LOG}"


if [ "$DB_UPDATES_METHOD" = 'migrations' ]; then
	echo "## Applying database migrations."
	$BIN_DIR/migrations
fi

# Make sure any external packages are installed and available.
# The current environment can export a COMPOSER_NODEV flag to disable
# the installation of require-dev dependencies.
composer install --no-interaction


# Purge cache folders.
$BIN_DIR/cache-clear


# Send an email report if the ENV var is set in Config/env_vars.txt
if [ -n "${LOADSYS_EMAIL}" ]; then
	echo "## Generating email report."
	MSG_BODY=$( mktemp -t "${0##*/}.email_report.XXXXXXXXXX" )

	cat > "$MSG_BODY" <<-EOD
	A code push has been completed for ${LOADSYS_PROJECT_NAME}.

	(Previous commit: ${EXISTINGCOMMIT})

	-------------------------------------------------------

	${GIT_LOG}

	EOD

	bin/email "${LOADSYS_EMAIL}" "${LOADSYS_PROJECT_NAME}: Code push complete" "${MSG_BODY}"
	rm -f "${MSG_BODY}"
fi


#@TODO: Maybe check for an executable `scripts/post-deploy` project-specific script and run it?


echo "## Update process complete.";