#!/bin/sh

set -eo pipefail

if [ "${S3_ACCESS_KEY_ID}" == "**None**" ]; then
  echo "Warning: You did not set the S3_ACCESS_KEY_ID environment variable."
fi

if [ "${S3_SECRET_ACCESS_KEY}" == "**None**" ]; then
  echo "Warning: You did not set the S3_SECRET_ACCESS_KEY environment variable."
fi

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

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

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

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

if [ "${S3_IAMROLE}" != "true" ]; then
  # env vars needed for aws tools - only if an IAM role is not used
  export AWS_ACCESS_KEY_ID=$S3_ACCESS_KEY_ID
  export AWS_SECRET_ACCESS_KEY=$S3_SECRET_ACCESS_KEY
  export AWS_DEFAULT_REGION=$S3_REGION
fi

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

if [ "${S3_FILENAME}" == "**None**" ]; then
  echo "Finding latest backup"
  S3_FILENAME=$(aws $AWS_ARGS s3 ls s3://$S3_BUCKET/$S3_PREFIX/ | sort | tail -n 1 | awk '{ print $4 }')
fi

MYSQL_HOST_OPTS="${MYSQL_OPTS} -h $MYSQL_HOST -P $MYSQL_PORT -u$MYSQL_USER -p$MYSQL_PASSWORD"

echo "Fetching ${S3_FILENAME} from S3"

aws $AWS_ARGS s3 cp s3://$S3_BUCKET/$S3_PREFIX/${S3_FILENAME} dump.sql.gz
gzip -d dump.sql.gz

echo "Restoring ${S3_FILENAME}"

mysql $MYSQL_HOST_OPTS < dump.sql

echo "MySQL Restore complete"