/*
    * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway
    * Copyright (C) 2010  Mickael Guessant
    *
    * This program is free software; you can redistribute it and/or
    * modify it under the terms of the GNU General Public License
    * as published by the Free Software Foundation; either version 2
    * of the License, or (at your option) any later version.
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   */
  
  package davmail.exchange.graph;
  
  import davmail.Settings;
  import davmail.exchange.ews.ExtendedFieldURI;
  import davmail.exchange.ews.FieldURI;
  import davmail.exchange.ews.IndexedFieldURI;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.client.methods.HttpRequestBase;
  import org.apache.http.client.utils.URIBuilder;
  import org.apache.http.entity.ByteArrayEntity;
  import org.codehaus.jettison.json.JSONException;
  import org.codehaus.jettison.json.JSONObject;
  
  import java.io.IOException;
  import java.net.URISyntaxException;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Build Microsoft graph request
   */
  public class GraphRequestBuilder {
  
      String method = "POST";
      String baseUrl = Settings.GRAPH_URL;
      String version = "beta";
      String mailbox;
      String objectType;
  
      String childType;
  
      String filter;
  
      Set<FieldURI> expandFields;
  
      String accessToken;
  
      JSONObject jsonBody = null;
      private String objectId;
  
      /**
       * Set property in Json body.
       * @param name property name
       * @param value property value
       * @throws JSONException on error
       */
      public GraphRequestBuilder setProperty(String name, String value) throws JSONException {
          if (jsonBody == null) {
              jsonBody = new JSONObject();
          }
          jsonBody.put(name, value);
          return this;
      }
  
      /**
       * Set epxand fields (returning attributes).
       * @param expandFields set of fields to return
       * @return this
       */
      public GraphRequestBuilder setExpandFields(Set<FieldURI> expandFields) {
          this.expandFields = expandFields;
          return this;
      }
  
      public GraphRequestBuilder setObjectType(String objectType) {
          this.objectType = objectType;
          return this;
      }
  
      public GraphRequestBuilder setChildType(String childType) {
          this.childType = childType;
          return this;
      }
  
      public GraphRequestBuilder setFilter(String filter) {
          this.filter = filter;
          return this;
     }
 
     public GraphRequestBuilder setAccessToken(String accessToken) {
         this.accessToken = accessToken;
         return this;
     }
 
     public GraphRequestBuilder setMethod(String method) {
         this.method = method;
         return this;
     }
 
     public GraphRequestBuilder setMailbox(String mailbox) {
         this.mailbox = mailbox;
         return this;
     }
 
     public GraphRequestBuilder setObjectId(String objectId) {
         this.objectId = objectId;
         return this;
     }
 
     /**
      * Build request path based on version, username, object type and object id.
      * @return request path
      */
     protected String buildPath() {
         StringBuilder buffer = new StringBuilder();
         buffer.append("/").append(version);
         if (mailbox != null) {
             buffer.append("/users/").append(mailbox);
         } else {
             buffer.append("/me");
         }
         if (objectType != null) {
             buffer.append("/").append(objectType);
         }
         if (objectId != null) {
             buffer.append("/").append(objectId);
         }
         if (childType != null) {
             buffer.append("/").append(childType);
         }
 
         return buffer.toString();
     }
 
     /**
      * Compute expand parameters from properties.
      * @return $expand value
      */
     private String buildExpand() {
         ArrayList<String> singleValueProperties = new ArrayList<>();
         ArrayList<String> multiValueProperties = new ArrayList<>();
         for (FieldURI fieldURI : expandFields) {
             if (fieldURI instanceof ExtendedFieldURI) {
                 singleValueProperties.add(fieldURI.getGraphId());
             } else if (fieldURI instanceof IndexedFieldURI) {
                 multiValueProperties.add(fieldURI.getGraphId());
             }
         }
         StringBuilder expand = new StringBuilder();
         if (!singleValueProperties.isEmpty()) {
             expand.append("singleValueExtendedProperties($filter=");
             appendExpandProperties(expand, singleValueProperties);
             expand.append(")");
         }
         if (!multiValueProperties.isEmpty()) {
             if (!singleValueProperties.isEmpty()) {
                 expand.append(",");
             }
             expand.append("multiValueExtendedProperties($filter=");
             appendExpandProperties(expand, multiValueProperties);
             expand.append(")");
         }
         return expand.toString();
     }
 
     protected void appendExpandProperties(StringBuilder buffer, List<String> properties) {
         boolean first = true;
         for (String id : properties) {
             if (first) {
                 first = false;
             } else {
                 buffer.append(" or ");
             }
             buffer.append("id eq '").append(id).append("'");
         }
     }
 
 
     /**
      * Build http request.
      * @return Http request
      * @throws IOException on error
      */
     public HttpRequestBase build() throws IOException {
         try {
             URIBuilder uriBuilder = new URIBuilder(baseUrl).setPath(buildPath());
             if (expandFields != null) {
                 uriBuilder.addParameter("$expand", buildExpand());
             }
 
             if (filter != null) {
                 uriBuilder.addParameter("$filter", filter);
             }
 
             HttpRequestBase httpRequest;
             if ("POST".equals(method)) {
                 httpRequest = new HttpPost(uriBuilder.build());
                 if (jsonBody != null) {
                     ((HttpPost) httpRequest).setEntity(new ByteArrayEntity(jsonBody.toString().getBytes(StandardCharsets.UTF_8)));
                 }
             } else {
                 // default to GET request
                 httpRequest = new HttpGet(uriBuilder.build());
             }
             httpRequest.setHeader("Content-Type", "application/json");
             httpRequest.setHeader("Authorization", "Bearer " + accessToken);
 
             return httpRequest;
         } catch (URISyntaxException e) {
             throw new IOException(e.getMessage(), e);
         }
     }
 
 }