/*
 * Copyright 2015-present Facebook, 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.facebook.buck.util.environment;

import com.google.common.collect.ImmutableMap;

/** Represents the CPU architecture of a system. */
public enum Architecture {
  AARCH64("aarch64"),
  ARM("arm"),
  ARMEB("armeb"),
  I386("i386"),
  MIPS("mips"),
  MIPS64("mips64"),
  MIPSEL("mipsel"),
  MIPSEL64("mipsel64"),
  POWERPC("powerpc"),
  PPC64("ppc64"),
  UNKNOWN("unknown"),
  X86_64("x86_64");

  /** Maps names as used in the os.arch property to Architecture values. */
  private static ImmutableMap<String, Architecture> nameToValueMap;

  static {
    // Initialize nameToValueMap
    ImmutableMap.Builder<String, Architecture> builder = ImmutableMap.builder();
    for (Architecture arch : Architecture.values()) {
      builder.put(arch.toString(), arch);
    }
    // Also add a few aliases
    builder.put("amd64", X86_64);
    builder.put("arm64", AARCH64);
    nameToValueMap = builder.build();
  }

  private Architecture(String name) {
    this.name = name;
  }

  public static Architecture detect() {
    String javaName = System.getProperty("os.arch");
    Architecture result = nameToValueMap.get(javaName);
    if (result == null) {
      return UNKNOWN;
    } else {
      return result;
    }
  }

  @Override
  public String toString() {
    return name;
  }

  private String name;
}