/**
    * Licensed to jclouds, Inc. (jclouds) under one or more
    * contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  jclouds 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.jclouds.blobstore.options;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import java.io.UnsupportedEncodingException;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;
  
  /**
   * Contains options supported for HTTP GET operations. <h2>
   * Usage</h2> The recommended way to instantiate a {@link GetOptions} object is to statically import
   * GetOptions.Builder.* and invoke a static creation method followed by an instance mutator (if
   * needed):
   * <p/>
   * <code>
   * import static org.jclouds.blobstore.options.GetOptions.Builder.*
   * 
   * 
   * // this will get the first megabyte of an blob, provided it wasn't modified since yesterday
   * blob = blobStore.getBlob("container, "blobName",range(0,1024).ifUnmodifiedSince(new Date().minusDays(1)));
   * <code>
   * 
   * @author Adrian Cole
   * 
   */
  public class GetOptions {
  
     public static final GetOptions NONE = new GetOptions();
  
     private final List<String> ranges = new ArrayList<String>();
     private Date ifModifiedSince;
     private Date ifUnmodifiedSince;
     private String ifMatch;
     private String ifNoneMatch;
  
     /**
      * download the specified range of the object.
      * @param start first offset included in the response
      * @param end last offset included in the response (inclusive).
      * @return itself to enable daisy-chaining of expressions
      */
     public GetOptions range(long start, long end) {
        checkArgument(start >= 0, "start must be >= 0");
        checkArgument(end >= 0, "end must be >= 0");
        getRanges().add(String.format("%d-%d", start, end));
        return this;
     }
  
     /**
      * download the specified range of the object.
      */
     public GetOptions startAt(long start) {
        checkArgument(start >= 0, "start must be >= 0");
        getRanges().add(String.format("%d-", start));
        return this;
     }
  
  
     /**
      * download the specified range of the object starting from the end of the object.
      */
     public GetOptions tail(long length) {
        checkArgument(length >= 0, "length must be >= 0");
        getRanges().add(String.format("-%d", length));
        return this;
     }
  
     /**
      * Only return the object if it has changed since this time.
      * <p />
      * Not compatible with {@link #ifETagMatches(String)} or {@link #ifUnmodifiedSince(Date)}
      */
     public GetOptions ifModifiedSince(Date ifModifiedSince) {
        checkArgument(getIfMatch() == null, "ifETagMatches() is not compatible with ifModifiedSince()");
        checkArgument(getIfUnmodifiedSince() == null, "ifUnmodifiedSince() is not compatible with ifModifiedSince()");
        this.ifModifiedSince = checkNotNull(ifModifiedSince, "ifModifiedSince");
        return this;
     }
  
    /**
     * For use in the header If-Modified-Since
     * <p />
     * Return the object only if it has been modified since the specified time, otherwise return a
     * 304 (not modified).
     * 
     * @see GetOptions#ifModifiedSince(Date)
     */
    public Date getIfModifiedSince() {
       return this.ifModifiedSince;
    }
 
    /**
     * Only return the object if it hasn't changed since this time.
     * <p />
     * Not compatible with {@link #ifETagDoesntMatch(String)} or {@link #ifModifiedSince(Date)}
     */
    public GetOptions ifUnmodifiedSince(Date ifUnmodifiedSince) {
       checkArgument(getIfNoneMatch() == null, "ifETagDoesntMatch() is not compatible with ifUnmodifiedSince()");
       checkArgument(getIfModifiedSince() == null, "ifModifiedSince() is not compatible with ifUnmodifiedSince()");
       this.ifUnmodifiedSince = checkNotNull(ifUnmodifiedSince, "ifUnmodifiedSince");
       return this;
    }
 
    /**
     * For use in the header If-Unmodified-Since
     * <p />
     * Return the object only if it has not been modified since the specified time, otherwise return
     * a 412 (precondition failed).
     * 
     * @see GetOptions#ifUnmodifiedSince(Date)
     */
    public Date getIfUnmodifiedSince() {
       return this.ifUnmodifiedSince;
    }
 
    /**
     * The object's eTag hash should match the parameter <code>eTag</code>.
     * 
     * <p />
     * Not compatible with {@link #ifETagDoesntMatch(String)} or {@link #ifModifiedSince(Date)}
     * 
     * @param eTag
     *           hash representing the payload
     */
    public GetOptions ifETagMatches(String eTag) {
       checkArgument(getIfNoneMatch() == null, "ifETagDoesntMatch() is not compatible with ifETagMatches()");
       checkArgument(getIfModifiedSince() == null, "ifModifiedSince() is not compatible with ifETagMatches()");
       this.ifMatch = checkNotNull(eTag, "eTag");
       return this;
    }
 
    /**
     * For use in the request header: If-Match
     * <p />
     * Return the object only if its payload tag (ETag) is the same as the eTag specified, otherwise
     * return a 412 (precondition failed).
     * 
     * @see GetOptions#ifETagMatches(String)
     */
    public String getIfMatch() {
       return this.ifMatch;
    }
 
    /**
     * The object should not have a eTag hash corresponding with the parameter <code>eTag</code>.
     * <p />
     * Not compatible with {@link #ifETagMatches(String)} or {@link #ifUnmodifiedSince(Date)}
     * 
     * @param eTag
     *           hash representing the payload
     */
    public GetOptions ifETagDoesntMatch(String eTag) {
       checkArgument(getIfMatch() == null, "ifETagMatches() is not compatible with ifETagDoesntMatch()");
       checkArgument(getIfUnmodifiedSince() == null, "ifUnmodifiedSince() is not compatible with ifETagDoesntMatch()");
       this.ifNoneMatch = checkNotNull(eTag, "eTag");
       return this;
    }
 
    /**
     * For use in the request header: If-None-Match
     * <p />
     * Return the object only if its payload tag (ETag) is different from the one specified,
     * otherwise return a 304 (not modified).
     * 
     * @see GetOptions#ifETagDoesntMatch(String)
     */
    public String getIfNoneMatch() {
       return this.ifNoneMatch;
    }
 
    public List<String> getRanges() {
       return ranges;
    }
 
    public static class Builder {
 
       /**
        * @see GetOptions#range(long, long)
        */
       public static GetOptions range(long start, long end) {
          GetOptions options = new GetOptions();
          return options.range(start, end);
       }
 
       /**
        * @see GetOptions#getIfModifiedSince()
        */
       public static GetOptions ifModifiedSince(Date ifModifiedSince) {
          GetOptions options = new GetOptions();
          return options.ifModifiedSince(ifModifiedSince);
       }
 
       /**
        * @see GetOptions#ifUnmodifiedSince(Date)
        */
       public static GetOptions ifUnmodifiedSince(Date ifUnmodifiedSince) {
          GetOptions options = new GetOptions();
          return options.ifUnmodifiedSince(ifUnmodifiedSince);
       }
 
       /**
        * @see GetOptions#ifETagMatches(String)
        */
       public static GetOptions ifETagMatches(String eTag) throws UnsupportedEncodingException {
          GetOptions options = new GetOptions();
          return options.ifETagMatches(eTag);
       }
 
       /**
        * @see GetOptions#ifETagDoesntMatch(String)
        */
       public static GetOptions ifETagDoesntMatch(String eTag) throws UnsupportedEncodingException {
          GetOptions options = new GetOptions();
          return options.ifETagDoesntMatch(eTag);
       }
 
    }
 
    @Override
    public int hashCode() {
       final int prime = 31;
       int result = 1;
       result = prime * result + ((ifMatch == null) ? 0 : ifMatch.hashCode());
       result = prime * result + ((ifModifiedSince == null) ? 0 : ifModifiedSince.hashCode());
       result = prime * result + ((ifNoneMatch == null) ? 0 : ifNoneMatch.hashCode());
       result = prime * result + ((ifUnmodifiedSince == null) ? 0 : ifUnmodifiedSince.hashCode());
       result = prime * result + ((ranges == null) ? 0 : ranges.hashCode());
       return result;
    }
 
    @Override
    public boolean equals(Object obj) {
       if (this == obj)
          return true;
       if (obj == null)
          return false;
       if (getClass() != obj.getClass())
          return false;
       GetOptions other = (GetOptions) obj;
       if (ifMatch == null) {
          if (other.ifMatch != null)
             return false;
       } else if (!ifMatch.equals(other.ifMatch))
          return false;
       if (ifModifiedSince == null) {
          if (other.ifModifiedSince != null)
             return false;
       } else if (!ifModifiedSince.equals(other.ifModifiedSince))
          return false;
       if (ifNoneMatch == null) {
          if (other.ifNoneMatch != null)
             return false;
       } else if (!ifNoneMatch.equals(other.ifNoneMatch))
          return false;
       if (ifUnmodifiedSince == null) {
          if (other.ifUnmodifiedSince != null)
             return false;
       } else if (!ifUnmodifiedSince.equals(other.ifUnmodifiedSince))
          return false;
       if (ranges == null) {
          if (other.ranges != null)
             return false;
       } else if (!ranges.equals(other.ranges))
          return false;
       return true;
    }
 
    @Override
    public String toString() {
       return "[ranges=" + ranges + ", ifModifiedSince=" + ifModifiedSince + ", ifUnmodifiedSince=" + ifUnmodifiedSince
                + ", ifMatch=" + ifMatch + ", ifNoneMatch=" + ifNoneMatch + "]";
    }
 
 }