kz.greetgo.file_storage.impl.FileStorageBuilderImpl Maven / Gradle / Ivy

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package kz.greetgo.file_storage.impl;

import com.mongodb.client.MongoCollection;
import kz.greetgo.file_storage.errors.*;
import org.bson.Document;

import javax.sql.DataSource;
import java.util.List;
import java.util.Random;
import java.util.function.Function;
import java.util.function.Supplier;

class FileStorageBuilderImpl implements FileStorageBuilder {

  boolean mandatoryName = false;
  boolean mandatoryMimeType = false;

  boolean fixed = false;

  void checkFix() {
    if (fixed) {
      throw new MultipleBuilderUsage();
    }
  }

  @Override
  public FileStorageBuilder mandatoryName(boolean mandatoryName) {
    checkFix();
    this.mandatoryName = mandatoryName;
    return this;
  }

  @Override
  public FileStorageBuilder mandatoryMimeType(boolean mandatoryMimeType) {
    checkFix();
    this.mandatoryMimeType = mandatoryMimeType;
    return this;
  }

  int fileIdLength = 13 + 50;

  private static boolean nullOrEmpty(String str) {
    return str == null || str.length() == 0;
  }

  public void checkName(String name) {
    if (mandatoryName && nullOrEmpty(name)) {
      throw new NoFileName();
    }
  }

  class DefaultIdGenerator implements Supplier {
    @SuppressWarnings("SpellCheckingInspection")
    private static final String ENG = "abcdefghijklmnopqrstuvwxyz";
    private static final String DEG = "0123456789";
    private final char[] ALL = (ENG + ENG.toUpperCase() + DEG).toCharArray();
    private final Random RND = new Random();

    @Override
    public String get() {
      final int len = 13;
      char[] ret = new char[len];
      int length = ALL.length;
      for (int i = 0; i < len; i++) {
        ret[i] = ALL[RND.nextInt(length)];
      }
      return new String(ret);
    }
  }

  Supplier idGenerator = new DefaultIdGenerator();

  @SuppressWarnings({"FieldCanBeLocal", "unused"})
  private boolean setIdGeneratorWasCalled = false;

  @Override
  public FileStorageBuilder setIdGenerator(int idLength, Supplier idGenerator) {
    if (idLength < 7) {
      throw new IllegalArgumentException("Must be idLength >= 7: idLength = " + idLength);
    }

    if (idGenerator == null) {
      throw new NullPointerException("idGenerator == null");
    }

    setIdGeneratorWasCalled = true;
    fileIdLength = idLength;
    this.idGenerator = idGenerator;
    return this;
  }

  Function mimeTypeValidator = null;

  @Override
  public FileStorageBuilder mimeTypeValidator(Function validator) {
    mimeTypeValidator = validator;
    return this;
  }

  Function mimeTypeExtractor = null;

  @Override
  public FileStorageBuilder mimeTypeExtractor(Function mimeTypeExtractor) {
    this.mimeTypeExtractor = mimeTypeExtractor;
    return this;
  }

  @Override
  public FileStorageBuilder configureFrom(FileStorageBuilderConfigurator configurator) {
    configurator.configure(this);
    return this;
  }

  void checkMimeType(String mimeType) {
    if (mandatoryMimeType && nullOrEmpty(mimeType)) {
      throw new NoFileMimeType();
    }
    if (mimeTypeValidator == null) {
      return;
    }

    try {
      if (mimeTypeValidator.apply(mimeType)) {
        return;
      }
    } catch (RuntimeException e) {
      if (e instanceof UnknownMimeType) {
        throw e;
      }
      throw new UnknownMimeType(mimeType, e);
    }

    throw new UnknownMimeType(mimeType);
  }

  boolean storageTypeSelected = false;

  @Override
  public FileStorageBuilderMonoDb inDb(DataSource dataSource) {
    checkStorageTypeSelected();
    storageTypeSelected = true;
    return new FileStorageBuilderMonoDbImpl(this, dataSource);
  }

  private void checkStorageTypeSelected() {
    if (storageTypeSelected) {
      throw new StorageTypeAlreadySelected();
    }
  }

  @Override
  public FileStorageBuilderMultiDb inMultiDb(List dataSourceList) {
    checkStorageTypeSelected();
    storageTypeSelected = true;
    return new FileStorageBuilderMultiDbImpl(this, dataSourceList);
  }

  @Override
  public FileStorageBuilderInMongodb inMongodb(MongoCollection collection) {
    checkStorageTypeSelected();
    storageTypeSelected = true;
    return new FileStorageBuilderInMongodbImpl(this, collection);
  }
}