#!/usr/bin/env bash
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(cd "${SCRIPT_DIR}/../.." && pwd)"
MIGRATIONS_DIR="${ROOT_DIR}/migrations"

load_database_url_from_env_file() {
  local env_file="$1"
  local line value
  while IFS= read -r line || [[ -n "${line}" ]]; do
    line="${line#"${line%%[![:space:]]*}"}"
    [[ -z "${line}" || "${line}" == \#* ]] && continue
    line="${line#export }"
    if [[ "${line}" == DATABASE_URL=* ]]; then
      value="${line#DATABASE_URL=}"
      value="${value%$'\r'}"
      value="${value%\"}"
      value="${value#\"}"
      value="${value%\'}"
      value="${value#\'}"
      printf '%s' "${value}"
      return 0
    fi
  done < "${env_file}"
  return 1
}

DATABASE_URL="${DATABASE_URL:-}"
if [[ -z "${DATABASE_URL}" && -f "${ROOT_DIR}/.env" ]]; then
  DATABASE_URL="$(load_database_url_from_env_file "${ROOT_DIR}/.env" || true)"
fi
if [[ -z "${DATABASE_URL}" ]]; then
  echo "DATABASE_URL is required (export it, or set it in ${ROOT_DIR}/.env)"
  exit 1
fi

if ! command -v psql >/dev/null 2>&1; then
  echo "psql not found in PATH"
  exit 127
fi

checksum_hex_of_file() {
  local file="$1"
  if command -v sha384sum >/dev/null 2>&1; then
    sha384sum "${file}" | awk '{print $1}'
    return 0
  fi
  if command -v openssl >/dev/null 2>&1; then
    openssl dgst -sha384 -binary "${file}" | xxd -p -c 256
    return 0
  fi
  echo "sha384sum or openssl is required to compute sqlx checksum" >&2
  return 127
}

TARGET_VERSION="${TARGET_VERSION:-}"
DRY_RUN="${DRY_RUN:-0}"

psql "${DATABASE_URL}" -v ON_ERROR_STOP=1 -c "CREATE TABLE IF NOT EXISTS _sqlx_migrations (version BIGINT PRIMARY KEY, description TEXT NOT NULL, installed_on TIMESTAMPTZ NOT NULL DEFAULT now(), success BOOLEAN NOT NULL, checksum BYTEA NOT NULL, execution_time BIGINT NOT NULL)"

shopt -s nullglob
migrations=( "${MIGRATIONS_DIR}/"*.sql )
if [[ ${#migrations[@]} -eq 0 ]]; then
  echo "No migration files found: ${MIGRATIONS_DIR}/*.sql"
  exit 1
fi

for file in "${migrations[@]}"; do
  base="$(basename "${file}")"
  version_str="${base%%_*}"
  version_num="$((10#${version_str}))"
  description="${base#*_}"
  description="${description%.sql}"

  if [[ -n "${TARGET_VERSION}" && "${version_num}" -gt "${TARGET_VERSION}" ]]; then
    continue
  fi

  applied="$(psql "${DATABASE_URL}" -At -c "SELECT 1 FROM _sqlx_migrations WHERE version=${version_num} AND success=true LIMIT 1" || true)"
  if [[ "${applied}" == "1" ]]; then
    continue
  fi

  echo "Applying ${version_str} (${base})"
  if [[ "${DRY_RUN}" == "1" ]]; then
    continue
  fi

  checksum="$(checksum_hex_of_file "${file}")"
  psql "${DATABASE_URL}" -v ON_ERROR_STOP=1 -f "${file}"
  psql "${DATABASE_URL}" -v ON_ERROR_STOP=1 -c "INSERT INTO _sqlx_migrations(version, description, success, checksum, execution_time) VALUES (${version_num}, '${description}', true, decode('${checksum}','hex'), 0) ON CONFLICT (version) DO NOTHING"
done

echo "Migrations completed"