#! /bin/sh

set -e
set -x
set -o pipefail

if [ "${S3_ACCESS_KEY_ID}" = "**None**" ]; then
  echo "You need to set the S3_ACCESS_KEY_ID environment variable."
  exit 1
fi

if [ "${S3_SECRET_ACCESS_KEY}" = "**None**" ]; then
  echo "You need to set the S3_SECRET_ACCESS_KEY environment variable."
  exit 1
fi

if [ "${S3_BUCKET}" = "**None**" ]; then
  echo "You need to set the S3_BUCKET environment variable."
  exit 1
fi

if [ "${POSTGRES_DATABASE}" = "**None**" ]; then
  echo "You need to set the POSTGRES_DATABASE environment variable."
  exit 1
fi

if [ "${POSTGRES_HOST}" = "**None**" ]; then
  if [ -n "${POSTGRES_PORT_5432_TCP_ADDR}" ]; then
    POSTGRES_HOST=$POSTGRES_PORT_5432_TCP_ADDR
    POSTGRES_PORT=$POSTGRES_PORT_5432_TCP_PORT
  else
    echo "You need to set the POSTGRES_HOST environment variable."
    exit 1
  fi
fi

if [ "${POSTGRES_USER}" = "**None**" ]; then
  echo "You need to set the POSTGRES_USER environment variable."
  exit 1
fi

if [ "${POSTGRES_PASSWORD}" = "**None**" ]; then
  echo "You need to set the POSTGRES_PASSWORD environment variable or link to a container named POSTGRES."
  exit 1
fi

if [ "${S3_ENDPOINT}" == "**None**" ]; then
  AWS_ARGS=""
else
  AWS_ARGS="--endpoint-url ${S3_ENDPOINT}"
fi

# env vars needed for aws tools
export AWS_ACCESS_KEY_ID=$S3_ACCESS_KEY_ID
export AWS_SECRET_ACCESS_KEY=$S3_SECRET_ACCESS_KEY
export AWS_DEFAULT_REGION=$S3_REGION

export PGPASSWORD=$POSTGRES_PASSWORD
POSTGRES_HOST_OPTS="-h $POSTGRES_HOST -p $POSTGRES_PORT -U $POSTGRES_USER"

echo "Finding latest backup"

LATEST_BACKUP=$(aws $AWS_ARGS s3 ls s3://$S3_BUCKET/$S3_PREFIX/ | sort | tail -n 1 | awk '{ print $4 }')

echo "Fetching ${LATEST_BACKUP} from S3"

aws $AWS_ARGS s3 cp s3://$S3_BUCKET/$S3_PREFIX/${LATEST_BACKUP} dump.sql.gz
gzip -d dump.sql.gz

if [ "${DROP_PUBLIC}" == "yes" ]; then
	echo "Recreating the public schema"
	psql $POSTGRES_HOST_OPTS -d "$POSTGRES_DATABASE" -c "drop schema public cascade; create schema public;"
fi

echo "Restoring ${LATEST_BACKUP} to ${POSTGRES_DATABASE} on ${POSTGRES_HOST}:${POSTGRES_PORT} with user ${POSTGRES_USER}"

set +e
psql $POSTGRES_HOST_OPTS -d postgres -c "SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = '$POSTGRES_DATABASE' AND pid <> pg_backend_pid();"
psql $POSTGRES_HOST_OPTS -d postgres -c "DROP DATABASE IF EXISTS \"$POSTGRES_DATABASE\";"
psql $POSTGRES_HOST_OPTS -d postgres -c "CREATE DATABASE \"$POSTGRES_DATABASE\";"
psql $POSTGRES_HOST_OPTS -d postgres -c "GRANT ALL PRIVILEGES ON DATABASE \"$POSTGRES_DATABASE\" TO $POSTGRES_USER;"

set -e
psql $POSTGRES_HOST_OPTS -d "$POSTGRES_DATABASE" -c "CREATE EXTENSION IF NOT EXISTS citext;"
psql $POSTGRES_HOST_OPTS -d "$POSTGRES_DATABASE" -c "ALTER EXTENSION citext SET SCHEMA public;"
psql $POSTGRES_HOST_OPTS -d "$POSTGRES_DATABASE" -c "CREATE EXTENSION IF NOT EXISTS plpgsql;"
pg_restore -V
pg_restore $POSTGRES_HOST_OPTS --no-owner --single-transaction -n public -v -d "$POSTGRES_DATABASE" dump.sql

echo "Restore complete"