/*
 * Copyright 2015 Webindex authors (see AUTHORS)
 * 
 * Licensed 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 webindex.data.util;

import java.io.IOException;
import java.text.ParseException;

import org.apache.commons.io.IOUtils;
import org.archive.io.ArchiveRecord;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import webindex.core.models.Link;
import webindex.core.models.Page;
import webindex.core.models.URL;

public class ArchiveUtil {

  private static final Logger log = LoggerFactory.getLogger(ArchiveUtil.class);

  public static Page buildPage(ArchiveRecord archiveRecord) throws IOException, ParseException {
    if (archiveRecord.getHeader().getMimetype().equalsIgnoreCase("application/json")) {
      byte[] rawData = IOUtils.toByteArray(archiveRecord, archiveRecord.available());
      if (rawData.length == 0) {
        return Page.EMPTY;
      }
      String jsonString = new String(rawData);
      if (jsonString.isEmpty()) {
        return Page.EMPTY;
      }
      JSONObject json;
      try {
        json = new JSONObject(new String(rawData));
      } catch (JSONException e) {
        throw new ParseException(e.getMessage(), 0);
      }
      String rawPageUrl = archiveRecord.getHeader().getUrl();
      URL pageUrl;
      try {
        pageUrl = URL.from(rawPageUrl);
      } catch (IllegalArgumentException e) {
        return Page.EMPTY;
      } catch (Exception e) {
        log.error("Unexpected exception while parsing raw page URL: " + rawPageUrl, e);
        return Page.EMPTY;
      }
      Page page = new Page(pageUrl.toUri());
      page.setCrawlDate(archiveRecord.getHeader().getDate());
      try {
        JSONObject responseMeta =
            json.getJSONObject("Envelope").getJSONObject("Payload-Metadata")
                .getJSONObject("HTTP-Response-Metadata");

        if (archiveRecord.getHeader().getMimetype().equals("application/json")) {
          try {
            JSONArray links = responseMeta.getJSONObject("HTML-Metadata").getJSONArray("Links");
            for (int i = 0; i < links.length(); i++) {
              JSONObject link = links.getJSONObject(i);
              if (link.has("path") && link.get("path").equals("A@/href") && link.has("url")) {
                String anchorText = "";
                if (link.has("text")) {
                  anchorText = link.getString("text");
                } else if (link.has("title")) {
                  anchorText = link.getString("title");
                }
                String rawLinkUrl = link.getString("url");
                URL linkUrl;
                try {
                  linkUrl = URL.from(rawLinkUrl);
                  if (!page.getDomain().equals(linkUrl.getDomain())) {
                    page.addOutbound(Link.of(linkUrl, anchorText));
                  }
                } catch (IllegalArgumentException e) {
                  log.debug("Failed to parse link: " + rawLinkUrl);
                } catch (Exception e) {
                  log.error("Unexpected exception while parsing link URL: " + rawLinkUrl, e);
                }
              }
            }
          } catch (JSONException e) {
            log.debug("Exception trying retrieve links", e);
          }
        }
        try {
          page.setTitle(responseMeta.getJSONObject("HTML-Metadata").getJSONObject("Head")
              .getString("Title"));
        } catch (JSONException e) {
          log.debug("Failed to retrieve title", e);
        }
        try {
          page.setServer(responseMeta.getJSONObject("Headers").getString("Server"));
        } catch (JSONException e) {
          log.debug("Failed to retrieve server", e);
        }
      } catch (JSONException e) {
        log.debug("Exception trying retrieve responseMeta", e);
      }
      return page;
    }
    return Page.EMPTY;
  }

  public static Page buildPageIgnoreErrors(ArchiveRecord record) {
    try {
      return buildPage(record);
    } catch (Exception e) {
      log.info("Exception parsing ArchiveRecord with url {} due to {}",
          record.getHeader().getUrl(), e.getMessage());
      return Page.EMPTY;
    }
  }
}