/**
    * 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.http.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;
  
  import javax.ws.rs.core.HttpHeaders;
  
  import org.jclouds.date.DateService;
  import org.jclouds.date.internal.SimpleDateFormatDateService;
  
  import com.google.common.base.Joiner;
  import com.google.common.collect.Multimap;
  
  /**
   * Contains options supported for HTTP GET operations. <h2>
   * Usage</h2> The recommended way to instantiate a GetObjectOptions object is to statically import
   * GetObjectOptions.Builder.* and invoke a static creation method followed by an instance mutator
   * (if needed):
   * <p/>
   * <code>
   * import static org.jclouds.http.options.GetOptions.Builder.*
   * 
   * 
   * // this will get the first megabyte of an object.
   * blob = client.get("objectName",range(0,1024));
   * <code>
   * 
   * @author Adrian Cole
   * 
   */
  public class GetOptions extends BaseHttpRequestOptions {
     private final static DateService dateService = new SimpleDateFormatDateService();
     public static final GetOptions NONE = new GetOptions();
     private final List<String> ranges = new ArrayList<String>();
  
     @Override
     public Multimap<String, String> buildRequestHeaders() {
        Multimap<String, String> headers = super.buildRequestHeaders();
        String range = getRange();
        if (range != null)
           headers.put("Range", this.getRange());
        return headers;
     }
  
     /**
      * download the specified range of the object.
      */
     public GetOptions range(long start, long end) {
        checkArgument(start >= 0, "start must be >= 0");
        checkArgument(end >= 0, "end must be >= 0");
        ranges.add(String.format("%d-%d", start, end));
        return this;
     }
  
     /**
      * download the object offset at <code>start</code>
      */
     public GetOptions startAt(long start) {
        checkArgument(start >= 0, "start must be >= 0");
        ranges.add(String.format("%d-", start));
        return this;
     }
  
     /**
      * download the last <code>count</code> bytes of the object
      */
     public GetOptions tail(long count) {
        checkArgument(count > 0, "count must be > 0");
        ranges.add(String.format("-%d", count));
        return this;
     }
  
     /**
      * For use in the header Range
      * <p />
      * 
     * @see GetOptions#range(long, long)
     */
    public String getRange() {
       return (ranges.size() > 0) ? String.format("bytes=%s", Joiner.on(",").join(ranges)) : null;
    }
 
    /**
     * 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.headers.put(HttpHeaders.IF_MODIFIED_SINCE,
             dateService.rfc822DateFormat(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 #ifModifiedSince(Date)
     */
    public String getIfModifiedSince() {
       return this.getFirstHeaderOrNull(HttpHeaders.IF_MODIFIED_SINCE);
    }
 
    /**
     * 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.headers.put(HttpHeaders.IF_UNMODIFIED_SINCE,
             dateService.rfc822DateFormat(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 #ifUnmodifiedSince(Date)
     */
    public String getIfUnmodifiedSince() {
       return this.getFirstHeaderOrNull(HttpHeaders.IF_UNMODIFIED_SINCE);
    }
 
    /**
     * The object's eTag hash should match the parameter <code>eTag</code>.
     * 
     * <p />
     * Not compatible with {@link #ifETagDoesntMatch(byte[])} or {@link #ifModifiedSince(Date)}
     * 
     * @param eTag
     *           hash representing the payload
     * @throws UnsupportedEncodingException
     *            if there was a problem converting this into an S3 eTag string
     */
    public GetOptions ifETagMatches(String eTag) {
       checkArgument(getIfNoneMatch() == null, "ifETagDoesntMatch() is not compatible with ifETagMatches()");
       checkArgument(getIfModifiedSince() == null, "ifModifiedSince() is not compatible with ifETagMatches()");
       this.headers.put(HttpHeaders.IF_MATCH, String.format("\"%1$s\"", 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 #ifETagMatches(String)
     */
    public String getIfMatch() {
       return this.getFirstHeaderOrNull(HttpHeaders.IF_MATCH);
    }
 
    /**
     * 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
     * @throws UnsupportedEncodingException
     *            if there was a problem converting this into an S3 eTag string
     */
    public GetOptions ifETagDoesntMatch(String eTag) {
       checkArgument(getIfMatch() == null, "ifETagMatches() is not compatible with ifETagDoesntMatch()");
       checkArgument(getIfUnmodifiedSince() == null, "ifUnmodifiedSince() is not compatible with ifETagDoesntMatch()");
       this.headers.put(HttpHeaders.IF_NONE_MATCH, String.format("\"%1$s\"", checkNotNull(eTag, "ifETagDoesntMatch")));
       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 #ifETagDoesntMatch(String)
     */
    public String getIfNoneMatch() {
       return this.getFirstHeaderOrNull(HttpHeaders.IF_NONE_MATCH);
    }
 
    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#startAt(long)
        */
       public static GetOptions startAt(long start) {
          GetOptions options = new GetOptions();
          return options.startAt(start);
       }
 
       /**
        * @see GetOptions#tail(long)
        */
       public static GetOptions tail(long count) {
          GetOptions options = new GetOptions();
          return options.tail(count);
       }
 
       /**
        * @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) {
          GetOptions options = new GetOptions();
          return options.ifETagMatches(eTag);
       }
 
       /**
        * @see GetOptions#ifETagDoesntMatch(String)
        */
       public static GetOptions ifETagDoesntMatch(String eTag) {
          GetOptions options = new GetOptions();
          return options.ifETagDoesntMatch(eTag);
       }
 
    }
 
    @Override
    public int hashCode() {
       final int prime = 31;
       int result = super.hashCode();
       result = prime * result + ((ranges == null) ? 0 : ranges.hashCode());
       return result;
    }
 
    @Override
    public boolean equals(Object obj) {
       if (this == obj)
          return true;
       if (!super.equals(obj))
          return false;
       if (getClass() != obj.getClass())
          return false;
       GetOptions other = (GetOptions) obj;
       if (ranges == null) {
          if (other.ranges != null)
             return false;
       } else if (!ranges.equals(other.ranges))
          return false;
       return true;
    }
 
    @Override
    public String toString() {
       return "[matrixParameters=" + matrixParameters + ", formParameters=" + formParameters + ", queryParameters="
             + queryParameters + ", headers=" + headers + ", payload=" + payload + ", pathSuffix=" + pathSuffix
             + ", ranges=" + ranges + "]";
    }
 
 }