/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.apache.commons.vfs2;
  
  import java.nio.charset.Charset;
  import java.time.Duration;
  import java.util.Objects;
  import java.util.function.Function;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.time.DurationUtils;
  
  /**
   * Abstracts configuring {@link FileSystemOptions}s.
   */
  public abstract class FileSystemConfigBuilder {
  
      /** Default prefix to use when resolving system properties */
      private static final String PREFIX = "vfs.";
  
      /** The root URI of the file system */
      private static final String ROOTURI = "rootURI";
  
      /** The prefix to use when resolving system properties */
      private final String prefix;
  
      /**
       * Constructs builder with default prefix.
       *
       * @since 1.0
       */
      protected FileSystemConfigBuilder() {
          prefix = PREFIX;
      }
  
      /**
       * Constructs builder with specified component name.
       *
       * @param component component name to be used in prefix
       * @since 2.0
       */
      protected FileSystemConfigBuilder(final String component) {
          prefix = PREFIX + component;
      }
  
      /**
       * Gets a named option as a Boolean.
       *
       * @param fileSystemOptions file system options to query, may be null.
       * @param name the option name
       * @return the option in {@code opts} or system properties, otherwise null
       * @see #getBoolean(FileSystemOptions, String, Boolean)
       * @since 2.0
       */
      protected Boolean getBoolean(final FileSystemOptions fileSystemOptions, final String name) {
          return getBoolean(fileSystemOptions, name, null);
      }
  
      /**
       * Gets a named option as a Boolean.
       *
       * @param fileSystemOptions file system options to query, may be null.
       * @param name the option name
       * @param defaultValue value to return if option is not present
       * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
       * @see #getBoolean(FileSystemOptions, String, Boolean)
       * @since 2.0
       */
      protected boolean getBoolean(final FileSystemOptions fileSystemOptions, final String name,
          final boolean defaultValue) {
          return getBoolean(fileSystemOptions, name, Boolean.valueOf(defaultValue)).booleanValue();
      }
  
      /**
       * Gets a named option as a Boolean.
       *
       * @param fileSystemOptions file system options to query, may be null.
       * @param name the option name
       * @param defaultValue value to return if option is not present
       * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
       * @see #getBoolean(FileSystemOptions, String, Boolean)
       * @since 2.0
       */
      protected Boolean getBoolean(final FileSystemOptions fileSystemOptions, final String name,
          final Boolean defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Boolean::valueOf, Boolean.class);
     }
 
     /**
      * Gets a named option as a Byte.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getByte(FileSystemOptions, String, Byte)
      * @since 2.0
      */
     protected Byte getByte(final FileSystemOptions fileSystemOptions, final String name) {
         return getByte(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Byte.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getByte(FileSystemOptions, String, Byte)
      * @since 2.0
      */
     protected byte getByte(final FileSystemOptions fileSystemOptions, final String name, final byte defaultValue) {
         return getByte(fileSystemOptions, name, Byte.valueOf(defaultValue)).byteValue();
     }
 
     /**
      * Gets a named option as a Byte.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.0
      */
     protected Byte getByte(final FileSystemOptions fileSystemOptions, final String name, final Byte defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Byte::valueOf, Byte.class);
     }
 
     /**
      * Gets a named option as a Character.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getCharacter(FileSystemOptions, String, Character)
      * @since 2.0
      */
     protected Character getCharacter(final FileSystemOptions fileSystemOptions, final String name) {
         return getCharacter(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Character.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getCharacter(FileSystemOptions, String, Character)
      * @since 2.0
      */
     protected char getCharacter(final FileSystemOptions fileSystemOptions, final String name, final char defaultValue) {
         return getCharacter(fileSystemOptions, name, Character.valueOf(defaultValue)).charValue();
     }
 
     /**
      * Gets a named option as a Character.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.0
      */
     protected Character getCharacter(final FileSystemOptions fileSystemOptions, final String name,
         final Character defaultValue) {
         Character value = getParam(fileSystemOptions, name);
         if (value == null) {
             final String str = getProperty(name);
             if (StringUtils.isEmpty(str)) {
                 return defaultValue;
             }
             value = Character.valueOf(str.charAt(0));
         }
         return value;
     }
 
     /**
      * Gets a named option as a Charset.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getCharset(FileSystemOptions, String, Charset)
      * @since 2.11.0
      */
     protected Charset getCharset(final FileSystemOptions fileSystemOptions, final String name) {
         return getCharset(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Charset.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.11.0
      */
     protected Charset getCharset(final FileSystemOptions fileSystemOptions, final String name, final Charset defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Charset::forName, Charset.class);
     }
 
     /**
      * Gets the target of this configuration.
      *
      * @return the specific file system class
      * @since 1.0
      */
     protected abstract Class<? extends FileSystem> getConfigClass();
 
     /**
      * Gets a named option as a Double.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getDouble(FileSystemOptions, String, Double)
      * @since 2.0
      */
     protected Double getDouble(final FileSystemOptions fileSystemOptions, final String name) {
         return getDouble(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Double.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getDouble(FileSystemOptions, String, Double)
      * @since 2.0
      */
     protected double getDouble(final FileSystemOptions fileSystemOptions, final String name,
         final double defaultValue) {
         return getDouble(fileSystemOptions, name, Double.valueOf(defaultValue)).doubleValue();
     }
 
     /**
      * Gets a named option as a Double.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.0
      */
     protected Double getDouble(final FileSystemOptions fileSystemOptions, final String name,
         final Double defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Double::valueOf, Double.class);
     }
 
     /**
      * Gets a named option as a Duration.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getLong(FileSystemOptions, String, Long)
      * @since 2.8.0
      */
     protected Duration getDuration(final FileSystemOptions fileSystemOptions, final String name) {
         return getDuration(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Duration.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.8.0
      */
     protected Duration getDuration(final FileSystemOptions fileSystemOptions, final String name,
         final Duration defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Duration::parse, Duration.class);
     }
 
     /**
      * Gets a named option as a Duration bound to the integer range.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getLong(FileSystemOptions, String, Long)
      * @since 2.8.0
      */
     protected Integer getDurationInteger(final FileSystemOptions fileSystemOptions, final String name) {
         return getDurationInteger(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Duration bound to the integer range.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.8.0
      */
     protected Integer getDurationInteger(final FileSystemOptions fileSystemOptions, final String name,
         final Duration defaultValue) {
         return DurationUtils.toMillisInt(getParam(fileSystemOptions, name, defaultValue, Duration::parse, Duration.class));
     }
 
     /**
      *Gets a named option as a Double.
      *
      * @param <E> enumeration type
      * @param enumClass class of enumeration type
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name *
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getEnum(Class, FileSystemOptions, String, Enum)
      * @throws IllegalArgumentException if option value is not a known enumeration.
      * @since 2.1
      */
     protected <E extends Enum<E>> E getEnum(final Class<E> enumClass, final FileSystemOptions fileSystemOptions,
         final String name) {
         return this.getEnum(enumClass, fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as an Enum.
      *
      * @param <E> enumeration type
      * @param enumClass class of enumeration type
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getEnum(Class, FileSystemOptions, String, Enum)
      * @throws IllegalArgumentException if option value is not a known enumeration.
      * @since 2.1
      */
     protected <E extends Enum<E>> E getEnum(final Class<E> enumClass, final FileSystemOptions fileSystemOptions,
         final String name, final E defaultValue) {
         E value = getParam(fileSystemOptions, name);
         if (value == null) {
             final String str = getProperty(name);
             if (str == null) {
                 return defaultValue;
             }
             value = Enum.valueOf(enumClass, str);
         }
         return value;
     }
 
     /**
      * Gets a named option as a Float.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getFloat(FileSystemOptions, String, Float)
      * @throws NumberFormatException if option value is not a valid float.
      * @since 2.0
      */
     protected Float getFloat(final FileSystemOptions fileSystemOptions, final String name) {
         return getFloat(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Float.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getFloat(FileSystemOptions, String, Float)
      * @throws NumberFormatException if option value is not a valid float.
      * @since 2.0
      */
     protected float getFloat(final FileSystemOptions fileSystemOptions, final String name, final float defaultValue) {
         return getFloat(fileSystemOptions, name, Float.valueOf(defaultValue)).floatValue();
     }
 
     /**
      * Gets a named option as a Float.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @throws NumberFormatException if option value is not a valid float.
      * @since 2.0
      */
     protected Float getFloat(final FileSystemOptions fileSystemOptions, final String name, final Float defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Float::valueOf, Float.class);
     }
 
     /**
      * Gets a named option as an Integer.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getInteger(FileSystemOptions, String, Integer)
      * @throws NumberFormatException if option value is not a valid integer.
      * @since 2.0
      */
     protected Integer getInteger(final FileSystemOptions fileSystemOptions, final String name) {
         return getInteger(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as an Integer.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getInteger(FileSystemOptions, String, Integer)
      * @throws NumberFormatException if option value is not a valid integer.
      * @since 2.0
      */
     protected int getInteger(final FileSystemOptions fileSystemOptions, final String name, final int defaultValue) {
         return getInteger(fileSystemOptions, name, Integer.valueOf(defaultValue)).intValue();
     }
 
     /**
      * Gets a named option as an Integer.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @throws NumberFormatException if option value is not a valid integer.
      * @since 2.0
      */
     protected Integer getInteger(final FileSystemOptions fileSystemOptions, final String name,
         final Integer defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Integer::valueOf, Integer.class);
     }
 
     /**
      * Gets a named option as a Long.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getLong(FileSystemOptions, String, Long)
      * @throws NumberFormatException if option value is not a valid long.
      * @since 2.0
      */
     protected Long getLong(final FileSystemOptions fileSystemOptions, final String name) {
         return getLong(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Long.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getLong(FileSystemOptions, String, Long)
      * @throws NumberFormatException if option value is not a valid long.
      * @since 2.0
      */
     protected long getLong(final FileSystemOptions fileSystemOptions, final String name, final long defaultValue) {
         return getLong(fileSystemOptions, name, Long.valueOf(defaultValue)).longValue();
     }
 
     /**
      * Gets a named option as a Long.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @throws NumberFormatException if option value is not a valid long.
      * @since 2.0
      */
     protected Long getLong(final FileSystemOptions fileSystemOptions, final String name, final Long defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Long::valueOf, Long.class);
     }
 
     /**
      * Gets a named parameter.
      *
      * @param <T> The expected return type.
      * @param fileSystemOptions file system options to query, may be null.
      * @param name get option with this name
      * @return the named option or null
      * @since 1.0
      */
     protected <T> T getParam(final FileSystemOptions fileSystemOptions, final String name) {
         return fileSystemOptions == null ? null : fileSystemOptions.getOption(getConfigClass(), name);
     }
 
     /**
      * Gets a named parameter.
      *
      * @param <T> The expected return type.
      * @param fileSystemOptions file system options to query, may be null.
      * @param name get option with this name
      * @param defaultValue value to use if the system property value is null.
      * @param function Builds an instance of T from a system property String value.
      * @param returnType TODO
      * @return the named option or null
      * @since 2.8.0
      */
     private <T> T getParam(final FileSystemOptions fileSystemOptions, final String name, final T defaultValue, final Function<String, T> function,
             final Class<T> returnType) {
         T value = getParam(fileSystemOptions, name);
         if (value == null) {
             final String str = getProperty(name);
             if (str == null) {
                 return defaultValue;
             }
             value = function.apply(str);
         }
         return returnType == null ? null : returnType.isInstance(value) ? value : function.apply(Objects.toString(value));
     }
 
     /**
      * Gets a named parameter.
      *
      * @param <T> The expected return type.
      * @param fileSystemOptions file system options to query, may be null.
      * @param name get option with this name
      * @param defaultValue The default value if absent.
      * @return the named option or {@code defaultValue}.
      * @since 2.10.0
      */
     protected <T> T getParamOrDefault(final FileSystemOptions fileSystemOptions, final String name, final T defaultValue) {
         return fileSystemOptions == null ? defaultValue : fileSystemOptions.getOptionOrDefault(getConfigClass(), name, defaultValue);
     }
 
     /**
      * Gets the system property for the given name.
      *
      * @param name The name to lookup combined with the prefix.
      * @return a system property or null
      * @since 2.1
      */
     private String getProperty(final String name) {
         return System.getProperty(toPropertyKey(name));
     }
 
     /**
      * Gets the root URI of the file system.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @return The root URI, or null.
      * @since 2.0
      */
     public String getRootURI(final FileSystemOptions fileSystemOptions) {
         return getString(fileSystemOptions, ROOTURI);
     }
 
     /**
      * Gets a named option as a Short.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getShort(FileSystemOptions, String, Short)
      * @throws NumberFormatException if option value is not a valid short.
      * @since 2.0
      */
     protected Short getShort(final FileSystemOptions fileSystemOptions, final String name) {
         return getShort(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a Short.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @see #getShort(FileSystemOptions, String, Short)
      * @throws NumberFormatException if option value is not a valid short
      * @since 2.0
      */
     protected short getShort(final FileSystemOptions fileSystemOptions, final String name, final short defaultValue) {
         return getShort(fileSystemOptions, name, Short.valueOf(defaultValue)).shortValue();
     }
 
     /**
      * Gets a named option as a Short.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @throws NumberFormatException if option value is not a valid short
      * @since 2.0
      */
     protected Short getShort(final FileSystemOptions fileSystemOptions, final String name, final Short defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, Short::valueOf, Short.class);
     }
 
     /**
      * Gets a named option as a String.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @return the option in {@code opts} or system properties, otherwise null
      * @see #getString(FileSystemOptions, String, String)
      * @since 2.0
      */
     protected String getString(final FileSystemOptions fileSystemOptions, final String name) {
         return getString(fileSystemOptions, name, null);
     }
 
     /**
      * Gets a named option as a String.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option name
      * @param defaultValue value to return if option is not present
      * @return the option in {@code opts} or system properties, otherwise {@code defaultValue}
      * @since 2.0
      */
     protected String getString(final FileSystemOptions fileSystemOptions, final String name,
         final String defaultValue) {
         return getParam(fileSystemOptions, name, defaultValue, String::valueOf, String.class);
     }
 
     /**
      * Checks the named setting specified.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the option to check in {@code opts} or system properties
      * @return true if option exists
      * @since 2.0
      */
     protected boolean hasObject(final FileSystemOptions fileSystemOptions, final String name) {
         return hasParam(fileSystemOptions, name) || System.getProperties().containsKey(toPropertyKey(name));
     }
 
     /**
      * Checks if option exists.
      *
      * @param fileSystemOptions file system options to query, may be null.
      * @param name the name to look up in {@code opts}
      * @return true if opts have the named parameter
      * @since 1.0
      */
     protected boolean hasParam(final FileSystemOptions fileSystemOptions, final String name) {
         return fileSystemOptions != null && fileSystemOptions.hasOption(getConfigClass(), name);
     }
 
     /**
      * Sets the named parameter.
      *
      * @param fileSystemOptions the file system options to modify
      * @param name set option with this name
      * @param value boolean value to set
      * @since 2.1
      */
     protected void setParam(final FileSystemOptions fileSystemOptions, final String name, final boolean value) {
         setParam(fileSystemOptions, name, Boolean.valueOf(value));
     }
 
     /**
      * Sets the named parameter.
      *
      * @param fileSystemOptions the file system options to modify
      * @param name set option with this name
      * @param value object value to set
      * @since 1.0
      */
     protected void setParam(final FileSystemOptions fileSystemOptions, final String name, final Object value) {
         Objects.requireNonNull(fileSystemOptions, "fileSystemOptions").setOption(getConfigClass(), name, value);
     }
 
     /**
      * Sets the root URI of the file system.
      *
      * @param fileSystemOptions the file system options to modify
      * @param rootURI The creator name to be associated with the file.
      * @since 2.0
      */
     public void setRootURI(final FileSystemOptions fileSystemOptions, final String rootURI) {
         setParam(fileSystemOptions, ROOTURI, rootURI);
     }
 
     /**
      * Converts the given primitive boolean to a Boolean object.
      *
      * @param value a primitive boolean.
      * @return the given primitive boolean as Boolean object.
      * @since 2.7.0
      */
     protected Boolean toBooleanObject(final boolean value) {
         return value ? Boolean.TRUE : Boolean.FALSE;
     }
 
     /**
      * Converts the given name into a System property key.
      *
      * @param name a name to combine with the builder prefix
      * @return name of system property
      * @since 2.1
      */
     private String toPropertyKey(final String name) {
         return prefix + name;
     }
 
 }