#!/bin/sh
set -eu

# Defaults match the compose topology; the BaoTa host runs MySQL outside Docker
# on the loopback, so host and port are overridable there.
mysql_host="${MYSQL_HOST:-mysql}"
mysql_port="${MYSQL_PORT:-3306}"

# The BaoTa host keeps one Go-style DSN instead of the compose MYSQL_* set, and
# its bundled client cannot speak caching_sha2_password, so the 8.x client has
# to be selectable. Explicit MYSQL_* values still win.
if [ -z "${MYSQL_USER:-}" ] && [ -n "${IM_DB_DSN:-}" ]; then
  dsn="${IM_DB_DSN}"
  MYSQL_USER="${dsn%%:*}"
  rest="${dsn#*:}"
  MYSQL_PASSWORD="${rest%@tcp(*}"
  hostport="${rest##*@tcp(}"
  hostport="${hostport%%)*}"
  mysql_host="${hostport%%:*}"
  mysql_port="${hostport##*:}"
  database="${dsn##*)/}"
  MYSQL_DATABASE="${database%%\?*}"
fi
mysql_bin="${MYSQL_CLIENT:-mysql}"

mysql_args="--host=${mysql_host} --port=${mysql_port} --user=${MYSQL_USER} --database=${MYSQL_DATABASE} --default-character-set=utf8mb4 --batch --skip-column-names"

until MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "SELECT 1" >/dev/null 2>&1; do
  sleep 2
done

MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "CREATE TABLE IF NOT EXISTS schema_migrations (version VARCHAR(255) NOT NULL PRIMARY KEY, checksum CHAR(64) NOT NULL, applied_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"

migrations_dir="${MIGRATIONS_DIR:-/migrations}"

for file in "${migrations_dir}"/*.sql; do
  version="$(basename "${file}")"
  checksum="$(sha256sum "${file}" | awk '{print $1}')"
  existing="$(MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "SELECT checksum FROM schema_migrations WHERE version='${version}'" 2>/dev/null || true)"
  if [ -n "${existing}" ]; then
    if [ "${existing}" != "${checksum}" ]; then
      echo "Migration checksum mismatch: ${version}" >&2
      exit 1
    fi
    echo "Already applied: ${version}"
    continue
  fi
  echo "Applying: ${version}"
  MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} < "${file}"
  MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "INSERT INTO schema_migrations(version,checksum) VALUES('${version}','${checksum}')"
done