/*
    * Copyright 2020 SPF4J.
    *
    * 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 org.spf4j.base;
  
  import java.util.function.Supplier;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import javax.annotation.Nullable;
  import javax.annotation.ParametersAreNonnullByDefault;
  import org.checkerframework.checker.nullness.qual.NonNull;
  
  /**
   *
   * @author Zoltan Farkas
   */
  @ParametersAreNonnullByDefault
  public final class Env {
  
    private Env() { }
  
    public static int getValue(final String envname, final int defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue;
      } else {
        return Integer.parseInt(v);
      }
    }
  
    public static float getValue(final String envname, final float defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue;
      } else {
        return Float.parseFloat(v);
      }
    }
  
    public static double getValue(final String envname, final double defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue;
      } else {
        return Float.parseFloat(v);
      }
    }
  
    public static boolean getValue(final String envname, final boolean defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue;
      } else {
        return Boolean.parseBoolean(v);
      }
    }
  
    @NonNull
    public static String getValue(final String envname, final String defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue;
      } else {
        return v;
      }
    }
  
    @NonNull
    public static String getValue(final String envname, final Supplier<String> defaultValue) {
      String v = System.getenv(envname);
      if (v == null) {
        return defaultValue.get();
      } else {
        return v;
      }
    }
  
    @NonNull
    public static String getSystemProperty(final String name, final String[] deprecatedAliases,
            final String defaultValue) {
      String val = getSystemProperty(name, deprecatedAliases);
      if (val != null) {
        return val;
      }
      return defaultValue;
    }
  
   @Nullable
   public static String getSystemProperty(final String name, final String... deprecatedAliases) {
     String val = System.getProperty(name);
     if (val != null) {
       return val;
     }
     for (String key : deprecatedAliases) {
       val = System.getProperty(key);
       if (val != null) {
         Logger.getLogger(Env.class.getName()).log(Level.WARNING,
                 "Use {0} system property instead of {1}", new Object[] {name, key});
         return val;
       }
     }
     return null;
   }
 }