package common;
   
   import org.flywaydb.core.Flyway;
   import org.flywaydb.core.api.configuration.FluentConfiguration;
   import org.flywaydb.core.api.output.MigrateResult;
   import usecase.auth.Pbkdf2PasswordHash;
   
   import javax.annotation.Resource;
   import javax.ejb.TransactionManagement;
  import javax.ejb.TransactionManagementType;
  import javax.enterprise.context.ApplicationScoped;
  import javax.enterprise.context.Initialized;
  import javax.enterprise.event.Observes;
  import javax.sql.DataSource;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.SQLException;
  import java.util.Map;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipInputStream;
  
  @TransactionManagement(TransactionManagementType.BEAN)
  class FlywayMigrator {
  
      private Path uploadRoot = Path.of(System.getProperty("openejb.home"), "uploads");
  
      @Resource(name = "shareboardDB")
      private DataSource dataSource;
  
      public void postConstruct(@Observes @Initialized(ApplicationScoped.class) Object o) throws IOException, SQLException {
          if (dataSource == null) {
              throw new RuntimeException("Cannot migrate, no datasource configured!");
          }
          FluentConfiguration config = Flyway.configure()
                  .dataSource(dataSource)
                  .validateOnMigrate(false)
                  .locations("classpath:db/migration");
          Flyway flyway = new Flyway(config);
          MigrateResult migrate = flyway.migrate();
          if(!migrate.migrations.isEmpty()){
              /*add pictures*/
              Files.createDirectories(uploadRoot);
  
              InputStream resourceAsStream = getClass().getClassLoader().getResourceAsStream("sample/pictures.zip");
              if(resourceAsStream == null){
                  throw new RuntimeException("pictures.zip not found");
              }
  
              try(ZipInputStream zipStream = new ZipInputStream(resourceAsStream)){
                  ZipEntry entry = zipStream.getNextEntry();
                  byte[] buffer = new byte[1024];
                  while (entry != null) {
                      File newFile = new File(uploadRoot.toFile(), entry.getName());
                      // fix for Windows-created archives
                      File parent = newFile.getParentFile();
                      if (!parent.isDirectory() && !parent.mkdirs()) {
                          throw new IOException("Failed to create directory " + parent);
                      }
  
                      // write file content
                      try(FileOutputStream fos = new FileOutputStream(newFile)){
                          int len;
                          while ((len = zipStream.read(buffer)) > 0) {
                              fos.write(buffer, 0, len);
                          }
                          entry = zipStream.getNextEntry();
                      }
                  }
              }
  
              /*set passwords (sql script scrambles the binary fields, TODO fix)*/
              try(Connection con = dataSource.getConnection()){
                  Map<String, String> credentials = Map.of(
                          "test","test",
                          "test2","test",
                          "Nibiru","informatica",
                          "admin","admin");
                  for (Map.Entry<String, String> entry : credentials.entrySet()) {
                      String name = entry.getKey();
                      String pass = entry.getValue();
                      try (PreparedStatement ps = con.prepareStatement("UPDATE user SET password=?, salt=? WHERE username = ?")) {
                          Pbkdf2PasswordHash.HashedPassword hashAndSalt = new Pbkdf2PasswordHash().generate(pass);
                          ps.setBytes(1,hashAndSalt.getPassword());
                          ps.setBytes(2, hashAndSalt.getSalt());
                          ps.setString(3,name);
                          ps.executeUpdate();
                      }
                  }
  
              }
          }
      }
  }