// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.devtools.build.android.resources;

import com.google.common.base.MoreObjects;
import java.io.IOException;
import java.io.Writer;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.commons.InstructionAdapter;

/** Models an int field initializer. */
public final class IntFieldInitializer implements FieldInitializer {

  private final int value;
  private static final String DESC = "I";

  private IntFieldInitializer(int value) {
    this.value = value;
  }

  public static FieldInitializer of(String value) {
    return of(Integer.decode(value));
  }

  public static IntFieldInitializer of(int value) {
    return new IntFieldInitializer(value);
  }

  @Override
  public boolean writeFieldDefinition(
      String fieldName, ClassWriter cw, int accessLevel, boolean isFinal) {
    cw.visitField(accessLevel, fieldName, DESC, null, isFinal ? value : null).visitEnd();
    return !isFinal;
  }

  @Override
  public int writeCLInit(String fieldName, InstructionAdapter insts, String className) {
    insts.iconst(value);
    insts.putstatic(className, fieldName, DESC);
    // Just needs one stack slot for the iconst.
    return 1;
  }

  @Override
  public void writeInitSource(String fieldName, Writer writer, boolean finalFields)
      throws IOException {
    writer.write(
        String.format(
            "        public static %sint %s = 0x%x;\n",
            finalFields ? "final " : "", fieldName, value));
  }

  @Override
  public String toString() {
    return MoreObjects.toStringHelper(getClass()).add("value", value).toString();
  }

  @Override
  public int hashCode() {
    return value;
  }

  @Override
  public boolean equals(Object obj) {
    if (obj instanceof IntFieldInitializer) {
      IntFieldInitializer other = (IntFieldInitializer) obj;
      return value == other.value;
    }
    return false;
  }
}