#!/bin/bash
set -e

## Set the old version that we want to upgrade from.
TO_VERSION=$(pacman -Q postgresql | grep -Po '(?<=postgresql )[0-9]\.[0-9]')
to_major=$(echo "$TO_VERSION" | awk -F'.' '{print $1}')
to_minor=$(echo "$TO_VERSION" | awk -F'.' '{print $2}')
if [[ ${to_major} -ne 9 ]]; then
	echo "WARNING: major upgrade detected, aborting..."
	exit 1
fi
from_major="${to_major}"
from_minor="$((to_minor - 1))"
export FROM_VERSION="${from_major}.${from_minor}"

# free space check
used_space=$(df --local --output=pcent /var/lib/postgres/ | grep -Po '[0-9]{1,3}(?=%)')
if [[ ${used_space} -ge 50 ]]; then
	echo "ERROR: not enough free space for upgrade with backup, aborting..."
	exit 2
fi

pacman -S --needed postgresql-old-upgrade
chown postgres:postgres /var/lib/postgres/
if [[ -d "/var/lib/postgres/data-${FROM_VERSION}" ]]; then
	echo "ERROR: backup data-${FROM_VERSION} directory already exists, aborting..."
	exit 3
fi
su - postgres -c "mv /var/lib/postgres/data /var/lib/postgres/data-${FROM_VERSION}"
su - postgres -c 'mkdir /var/lib/postgres/data'
su - postgres -c "initdb --locale $LANG -E UTF8 -D /var/lib/postgres/data"
vimdiff "/var/lib/postgres/data/pg_hba.conf" "/var/lib/postgres/data-${FROM_VERSION}/pg_hba.conf"
vimdiff "/var/lib/postgres/data/postgresql.conf" "/var/lib/postgres/data-${FROM_VERSION}/postgresql.conf"
cp -avx "/var/lib/postgres/data-${FROM_VERSION}/server.crt" "/var/lib/postgres/data/server.crt"
cp -avx "/var/lib/postgres/data-${FROM_VERSION}/server.key" "/var/lib/postgres/data/server.key"
systemctl stop postgresql.service
su - postgres -c "pg_upgrade -b /opt/pgsql-${FROM_VERSION}/bin/ -B /usr/bin/ -d /var/lib/postgres/data-${FROM_VERSION} -D /var/lib/postgres/data"
systemctl daemon-reload
systemctl start postgresql.service
su - postgres -c '/var/lib/postgres/analyze_new_cluster.sh'
su - postgres -c '/var/lib/postgres/delete_old_cluster.sh'