package at.asitplus.eidas.specific.connector;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Properties;

import org.apache.commons.lang3.StringUtils;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertiesPropertySource;

import at.gv.egiz.components.spring.api.SpringBootApplicationContextInitializer;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class MsSpecificSpringBootApplicationContextInitializer extends
    SpringBootApplicationContextInitializer {

  private static final String SYSTEMD_PROP_NAME = "eidas.ms.configuration";
  private static final String PATH_FILE_PREFIX = "file:";
  
  @Override
  public void initialize(ConfigurableApplicationContext applicationContext) {    
    String configPath = System.getProperty(SYSTEMD_PROP_NAME);
    if (StringUtils.isNotEmpty(configPath)) {
      log.debug("Find configuration-source from SystemD Property: '{}' ...", SYSTEMD_PROP_NAME);      
      if (configPath.startsWith(PATH_FILE_PREFIX)) {
        configPath = configPath.substring(PATH_FILE_PREFIX.length());
        
      }      
      injectConfiguration(configPath, applicationContext);            

    } else {
      log.info("Find NO SystemD Property: '{}' Maybe no configuration available", SYSTEMD_PROP_NAME);
      
    }
    
    super.initialize(applicationContext);
        
  }
  
  private void injectConfiguration(String configPath, ConfigurableApplicationContext applicationContext) {
    InputStream is = null;
    try {
      Path path = Paths.get(configPath);
      if (Files.exists(path)) {
        File file = new File(configPath);             
        Properties props = new Properties();
        is = new FileInputStream(file);
        props.load(is);      
        MutablePropertySources sources = applicationContext.getEnvironment().getPropertySources();       
        sources.addFirst(new PropertiesPropertySource(SYSTEMD_PROP_NAME, props));
        log.info("Set configuration-source from SystemD-Property: {}", SYSTEMD_PROP_NAME);
      
      } else {
        log.error("Configuration from SystemD Property: '{}' at Location: {} DOES NOT exist", 
            SYSTEMD_PROP_NAME, configPath);
        
      }
      
    } catch (IOException e) {
      log.error("Configuration from SystemD Property: '{}' at Location: {} CAN NOT be loaded", 
          SYSTEMD_PROP_NAME, configPath, e);
      
    } finally {
      try {
        if (is != null) {
          is.close();
          
        }        
      } catch (IOException e) {
        log.error("Can not close InputStream of configLoader: {}", configPath, e);
        
      }
    }        
  }
}