/*
 * Copyright 2012 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.template.soy.base.internal;

import com.google.common.base.Preconditions;

import java.util.Objects;

/**
 * Abstract base implementation of SoyFileSupplier.
 *
 * <p> Important: Do not use outside of Soy code (treat as superpackage-private).
 *
 */
public abstract class AbstractSoyFileSupplier implements SoyFileSupplier {

  /** Whether this input file is only included because it's a dependency. */
  protected final SoyFileKind soyFileKind;

  /** Returns the file path (used for messages only). */
  protected final String filePath;


  /**
   * @param soyFileKind The kind of this input Soy file.
   * @param filePath The path to the Soy file, used for as a unique map/set key and for messages.
   */
  public AbstractSoyFileSupplier(SoyFileKind soyFileKind, String filePath) {
    this.soyFileKind = soyFileKind;
    Preconditions.checkState(
        filePath != null && !filePath.isEmpty(), "Soy file path must be non-null and non-empty.");
    this.filePath = filePath;
  }


  @Override public SoyFileKind getSoyFileKind() {
    return soyFileKind;
  }


  @Override public String getFilePath() {
    return filePath;
  }


  /**
   * Tests equality based on the file path. This allows deduping of suppliers that refer to the
   * same underlying file.
   *
   * <p> NOTE: This will consider different file supplier implementations and different file kinds
   * as distinct since they behave differently. The caller may want to explicitly check for
   * filename collisions afterwards in case the same file is used with different supplier
   * subclasses or file kinds.
   */
  @Override public boolean equals(Object other) {
    if (other instanceof AbstractSoyFileSupplier && other.getClass() == this.getClass()) {
      AbstractSoyFileSupplier otherSupplier = (AbstractSoyFileSupplier) other;
      return filePath.equals(otherSupplier.filePath) && soyFileKind == otherSupplier.soyFileKind;
    }
    return false;
  }


  /**
   * Hashes based on the file path.
   */
  @Override public int hashCode() {
    return Objects.hash(filePath, soyFileKind, this.getClass());
  }
}