import { plainToInstance } from 'class-transformer';
import {
  IsEnum,
  IsInt,
  IsNotEmpty,
  IsOptional,
  IsString,
  Max,
  Min,
  validateSync,
} from 'class-validator';

export enum NodeEnv {
  Development = 'development',
  Production = 'production',
  Test = 'test',
}

class EnvironmentVariables {
  @IsEnum(NodeEnv)
  NODE_ENV: NodeEnv = NodeEnv.Development;

  @IsInt()
  @Min(1)
  @Max(65535)
  PORT: number = 7341;

  @IsOptional()
  @IsString()
  CORS_ORIGIN?: string;

  @IsString()
  DB_HOST: string = 'localhost';

  @IsInt()
  @Min(1)
  @Max(65535)
  DB_PORT: number = 3307;

  @IsString()
  DB_USERNAME: string = 'portfolio';

  @IsString()
  DB_PASSWORD: string = 'portfolio_secret';

  @IsString()
  DB_DATABASE: string = 'portfolio';

  @IsString()
  @IsNotEmpty()
  ADMIN_PASSWORD_HASH!: string;

  @IsString()
  @IsNotEmpty()
  JWT_SECRET!: string;

  @IsOptional()
  @IsString()
  JWT_EXPIRES_IN?: string;
}

export function validateEnv(config: Record<string, unknown>): EnvironmentVariables {
  const validated = plainToInstance(EnvironmentVariables, config, {
    enableImplicitConversion: true,
  });
  const errors = validateSync(validated, { skipMissingProperties: false });
  if (errors.length > 0) {
    throw new Error(`환경변수 검증 실패: ${errors.toString()}`);
  }
  return validated;
}