/**
    * 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.aws.util;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static org.jclouds.aws.reference.AWSConstants.PROPERTY_HEADER_TAG;
  
  import java.util.Map;
  
  import javax.annotation.Resource;
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Provider;
  import javax.inject.Singleton;
  
  import org.jclouds.aws.domain.AWSError;
  import org.jclouds.aws.domain.Region;
  import org.jclouds.aws.xml.ErrorHandler;
  import org.jclouds.domain.Location;
  import org.jclouds.domain.LocationScope;
  import org.jclouds.http.HttpRequest;
  import org.jclouds.http.HttpResponse;
  import org.jclouds.http.functions.ParseSax;
  import org.jclouds.http.functions.ParseSax.Factory;
  import org.jclouds.http.utils.ModifyRequest;
  import org.jclouds.logging.Logger;
  import org.jclouds.rest.RequestSigner;
  import org.jclouds.rest.internal.GeneratedHttpRequest;
  
  import com.google.common.base.Function;
  import com.google.common.collect.ImmutableMultimap;
  import com.google.common.collect.ImmutableMultimap.Builder;
  import com.google.common.collect.Iterables;
  import com.google.common.collect.Multimap;
  
  /**
   * Needed to sign and verify requests and responses.
   * 
   * @author Adrian Cole
   */
  @Singleton
  public class AWSUtils {
     @Singleton
     public static class GetRegionFromLocation implements Function<Location, String> {
        public String apply(Location location) {
           String region = location.getScope() == LocationScope.REGION ? location.getId() : location.getParent().getId();
           return region;
        }
     }
  
     private final RequestSigner signer;
     private final ParseSax.Factory factory;
     private final Provider<ErrorHandler> errorHandlerProvider;
     private final String requestId;
     private final String requestToken;
  
     @Resource
     protected Logger logger = Logger.NULL;
  
     @Inject
     AWSUtils(@Named(PROPERTY_HEADER_TAG) String headerTag, RequestSigner signer, Factory factory,
           Provider<ErrorHandler> errorHandlerProvider) {
        this.signer = signer;
        this.factory = factory;
        this.errorHandlerProvider = errorHandlerProvider;
        this.requestId = String.format("x-%s-request-id", headerTag);
        this.requestToken = String.format("x-%s-id-2", headerTag);
     }
  
     public AWSError parseAWSErrorFromContent(HttpRequest request, HttpResponse response) {
        // HEAD has no content
        if (response.getPayload() == null)
           return null;
        // Eucalyptus and Walrus occasionally return text/plain
        if (response.getPayload().getContentMetadata().getContentType() != null
              && response.getPayload().getContentMetadata().getContentType().indexOf("text/plain") != -1)
           return null;
        try {
           AWSError error = (AWSError) factory.create(errorHandlerProvider.get()).setContext(request).apply(response);
           if (error.getRequestId() == null)
              error.setRequestId(response.getFirstHeaderOrNull(requestId));
           error.setRequestToken(response.getFirstHeaderOrNull(requestToken));
          if ("SignatureDoesNotMatch".equals(error.getCode())) {
             error.setStringSigned(signer.createStringToSign(request));
             error.setSignature(signer.sign(error.getStringSigned()));
          }
          return error;
       } catch (RuntimeException e) {
          logger.warn(e, "error parsing error");
          return null;
       }
    }
 
    public static <R extends HttpRequest> R indexStringArrayToFormValuesWithStringFormat(R request, String format,
          Object input) {
       checkArgument(checkNotNull(input, "input") instanceof String[], "this binder is only valid for String[] : "
             + input.getClass());
       String[] values = (String[]) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       for (int i = 0; i < values.length; i++) {
          builder.put(String.format(format, (i + 1)), checkNotNull(values[i], format.toLowerCase() + "s[" + i + "]"));
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    // TODO: make this more dynamic
    public static boolean isRegion(String regionName) {
       return Region.DEFAULT_REGIONS.contains(regionName);
    }
 
    public static <R extends HttpRequest> R indexIterableToFormValuesWithPrefix(R request, String prefix, Object input) {
       checkArgument(checkNotNull(input, "input") instanceof Iterable<?>, "this binder is only valid for Iterable<?>: "
             + input.getClass());
       Iterable<?> values = (Iterable<?>) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       int i = 0;
       for (Object o : values) {
          builder.put(prefix + "." + (i++ + 1), checkNotNull(o.toString(), prefix.toLowerCase() + "s[" + i + "]"));
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    public static <R extends HttpRequest> R indexStringArrayToFormValuesWithPrefix(R request, String prefix, Object input) {
       checkArgument(checkNotNull(input, "input") instanceof String[], "this binder is only valid for String[] : "
             + input.getClass());
       String[] values = (String[]) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       for (int i = 0; i < values.length; i++) {
          builder.put(prefix + "." + (i + 1), checkNotNull(values[i], prefix.toLowerCase() + "s[" + i + "]"));
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    public static <R extends HttpRequest> R indexMapToFormValuesWithPrefix(R request, String prefix, String keySuffix, String valueSuffix, Object input) {
       checkArgument(checkNotNull(input, "input") instanceof Map<?, ?>, "this binder is only valid for Map<?,?>: " + input.getClass());
       Map<?, ?> map = (Map<?, ?>) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       int i = 1;
       for (Map.Entry<?, ?> e : map.entrySet()) {
          builder.put(prefix + "." + i + "." + keySuffix, checkNotNull(e.getKey().toString(), keySuffix.toLowerCase() + "s[" + i + "]"));
          if (e.getValue() != null) {
             builder.put(prefix + "." + i + "." + valueSuffix, e.getValue().toString());
          }
          i++;
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    @SuppressWarnings("unchecked")
    public static <R extends HttpRequest> R indexMultimapToFormValuesWithPrefix(R request, String prefix, String keySuffix, String valueSuffix, Object input) {
       checkArgument(checkNotNull(input, "input") instanceof Multimap<?, ?>, "this binder is only valid for Multimap<?,?>: " + input.getClass());
       Multimap<Object, Object> map = (Multimap<Object, Object>) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       int i = 1;
       for (Object k : map.keySet()) {
          builder.put(prefix + "." + i + "." + keySuffix, checkNotNull(k.toString(), keySuffix.toLowerCase() + "s[" + i + "]"));
          int j = 1;
          for (Object v : map.get(k)) {
             builder.put(prefix + "." + i + "." + valueSuffix + "." + j, v.toString());
             j++;
          }
          i++;
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    @SuppressWarnings("unchecked")
    public static <R extends HttpRequest> R indexMapOfIterableToFormValuesWithPrefix(R request, String prefix, String keySuffix, String valueSuffix, Object input) {
       checkArgument(checkNotNull(input, "input") instanceof Map<?, ?>, "this binder is only valid for Map<?,Iterable<?>>: " + input.getClass());
       Map<Object, Iterable<Object>> map = (Map<Object, Iterable<Object>>) input;
       Builder<String, String> builder = ImmutableMultimap.<String, String> builder();
       int i = 1;
       for (Object k : map.keySet()) {
          builder.put(prefix + "." + i + "." + keySuffix, checkNotNull(k.toString(), keySuffix.toLowerCase() + "s[" + i + "]"));
          if (!Iterables.isEmpty(map.get(k))) {
             int j = 1;
             for (Object v : map.get(k)) {
                builder.put(prefix + "." + i + "." + valueSuffix + "." + j, v.toString());
                j++;
             }
          }
          i++;
       }
       ImmutableMultimap<String, String> forms = builder.build();
       return forms.size() == 0 ? request : ModifyRequest.putFormParams(request, forms);
    }
 
    public static String getRegionFromLocationOrNull(Location location) {
       return location.getScope() == LocationScope.ZONE ? location.getParent().getId() : location.getId();
    }
 
    // there may not be a region, and in this case we do-not encode it into the string
    public static String[] parseHandle(String id) {
       String[] parts = checkNotNull(id, "id").split("/");
       return (parts.length == 1) ? new String[] { null, id } : parts;
    }
 
    public static String findRegionInArgsOrNull(GeneratedHttpRequest<?> gRequest) {
       for (Object arg : gRequest.getArgs()) {
          if (arg instanceof String) {
             String regionName = (String) arg;
             // TODO regions may not be amazon regions!
             // take from a configured value
             if (isRegion(regionName))
                return regionName;
          }
       }
       return null;
    }
 }