// IndexImportMediawiki.java
// -------------------------
// (C) 2009 by Michael Peter Christen; mc@yacy.net
// first published 04.05.2009 on http://yacy.net
// Frankfurt, Germany
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.Date;

import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;

import net.yacy.cora.date.GenericFormatter;
import net.yacy.cora.document.encoding.UTF8;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.cora.protocol.ClientIdentification;
import net.yacy.cora.protocol.HeaderFramework;
import net.yacy.cora.protocol.RequestHeader;
import net.yacy.cora.protocol.http.HTTPClient;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.data.TransactionManager;
import net.yacy.data.WorkTables;
import net.yacy.document.importer.MediawikiImporter;
import net.yacy.kelondro.blob.Tables.Row;
import net.yacy.search.Switchboard;
import net.yacy.server.serverObjects;
import net.yacy.server.serverSwitch;

/**
 * Import of MediaWiki dump files in the local index.
 */
public class IndexImportMediawiki_p {

	/**
	 * Run conditions :
	 * - no MediaWiki import thread is running : allow to start a new import by filling the "file" parameter
	 * - the MediaWiki import thread is running : returns monitoring information.
	 * @param header servlet request header
	 * @param post request parameters. Supported keys :
	 *            <ul>
	 *            <li>file : a dump URL or file path on this YaCy server local file system</li>
	 *            <li>iffresh : when set to true, the dump file is imported only if its last modified date is unknown or after the last import trial date on this same file.  </li>
	 *            <li>report : when set, display the currently running thread monitoring info, or the last import report when no one is running.
	 *            Ignored when no import thread is known.</li>
	 *            </ul>
	 * @param env server environment
	 * @return the servlet answer object
	 */
    public static serverObjects respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
        final serverObjects prop = new serverObjects();
        final Switchboard sb = (Switchboard) env;

        if (MediawikiImporter.job != null && (MediawikiImporter.job.isAlive() || (post != null && post.containsKey("report")))) {
            /* one import is running, or report was explicitly requested : no option to insert anything */
            prop.put("import", 1);
            /* Only refresh automatically when the job is running */
            prop.put("refresh", MediawikiImporter.job.isAlive() ? 1 : 0);
            final String jobErrorMessage = MediawikiImporter.job.status();
            if( jobErrorMessage != null && !jobErrorMessage.isEmpty()) {
            	prop.put("import_status", 1);
            	prop.put("import_status_message", jobErrorMessage);
            }
            prop.put("import_thread", MediawikiImporter.job.isAlive() ? 2 : 0);
            prop.put("import_dump", MediawikiImporter.job.source());
            prop.put("import_count", MediawikiImporter.job.count());
            prop.put("import_speed", MediawikiImporter.job.speed());
            prop.put("import_runningHours", (MediawikiImporter.job.runningTime() / 60) / 60);
            prop.put("import_runningMinutes", (MediawikiImporter.job.runningTime() / 60) % 60);
            prop.put("import_remainingHours", (MediawikiImporter.job.remainingTime() / 60) / 60);
            prop.put("import_remainingMinutes", (MediawikiImporter.job.remainingTime() / 60) % 60);
        } else {
            prop.put("import", 0);
            prop.put("refresh", 0);
           	prop.put("import_prevReport", MediawikiImporter.job != null ? 1 : 0);
            if (post == null) {
                prop.put("import_status", 0);
                
                /* Acquire a transaction token for the next POST form submission */
                final String token = TransactionManager.getTransactionToken(header);
                prop.put(TransactionManager.TRANSACTION_TOKEN_PARAM, token);
                prop.put("import_" + TransactionManager.TRANSACTION_TOKEN_PARAM, token);
                
            } else {
                if (post.containsKey("file")) {
                	/* Check the transaction is valid */
                	TransactionManager.checkPostTransaction(header, post);
                	
                    String file = post.get("file");
					MultiProtocolURL sourceURL = null;
					int status = 0;
					String sourceFilePath = "";
					final Row lastExecutedCall = WorkTables.selectLastExecutedApiCall("IndexImportMediawiki_p.html", post, sb);
					Date lastExecutionDate = null;
					if (lastExecutedCall != null) {
						lastExecutionDate = lastExecutedCall.get(WorkTables.TABLE_API_COL_DATE_LAST_EXEC, (Date) null);
					}
					try {
						sourceURL = new MultiProtocolURL(file);
						if(sourceURL.isFile()) {
							final File sourcefile = sourceURL.getFSFile();
							sourceFilePath = sourcefile.getAbsolutePath();
							if (!sourcefile.exists()) {
								status = 2;
							} else if (!sourcefile.canRead()) {
								status = 3;
							} else if (sourcefile.isDirectory()) {
								status = 4;
							}
						}
						
						if (status == 0 && post.getBoolean("iffresh")) {
							long lastModified = getLastModified(sourceURL);
							if (lastExecutionDate != null && lastModified != 0L
									&& lastModified <= lastExecutionDate.getTime()) {
								status = 5;
								prop.put("import_status_lastImportDate",
										GenericFormatter.FORMAT_SIMPLE.format(lastExecutionDate));
								
				                /* the import is not performed, but we increase here the api call count */
								if(sb.tables != null) {
									byte[] lastExecutedCallPk = lastExecutedCall.getPK();
									if(lastExecutedCallPk != null && !post.containsKey(WorkTables.TABLE_API_COL_APICALL_PK)) {
										post.add(WorkTables.TABLE_API_COL_APICALL_PK, UTF8.String(lastExecutedCallPk));
									}
									sb.tables.recordAPICall(post, "IndexImportMediawiki_p.html", WorkTables.TABLE_API_TYPE_DUMP, "MediaWiki Dump Import for " + sourceURL);
								}
							}
						}
					} catch (MalformedURLException e) {
						status = 1;
					}
					if (status == 0) {
		                /* store this call as an api call */
						if(sb.tables != null) {
							/* We avoid creating a duplicate of any already recorded API call with the same parameters */
							if(lastExecutedCall != null && !post.containsKey(WorkTables.TABLE_API_COL_APICALL_PK)) {
								byte[] lastExecutedCallPk = lastExecutedCall.getPK();
								if(lastExecutedCallPk != null) {
									post.add(WorkTables.TABLE_API_COL_APICALL_PK, UTF8.String(lastExecutedCallPk));
								}
							}
							sb.tables.recordAPICall(post, "IndexImportMediawiki_p.html", WorkTables.TABLE_API_TYPE_DUMP, "MediaWiki Dump Import for " + sourceURL);
						}
						
						MediawikiImporter.job = new MediawikiImporter(sourceURL, sb.surrogatesInPath);
						MediawikiImporter.job.start();
						prop.put("import_dump", MediawikiImporter.job.source());
						prop.put("import_thread", 1);
						prop.put("import", 1);
						prop.put("refresh", 1);
					} else {
						prop.put("import_status", status);
						prop.put("import_status_sourceFile", sourceFilePath);
						
		                /* Acquire a transaction token for the next POST form submission */
		                final String token = TransactionManager.getTransactionToken(header);
		                prop.put(TransactionManager.TRANSACTION_TOKEN_PARAM, token);
		                prop.put("import_" + TransactionManager.TRANSACTION_TOKEN_PARAM, token);
					}
                    prop.put("import_count", 0);
                    prop.put("import_speed", 0);
                    prop.put("import_runningHours", 0);
                    prop.put("import_runningMinutes", 0);
                    prop.put("import_remainingHours", 0);
                    prop.put("import_remainingMinutes", 0);
                }
            }
        }
        return prop;
    }
    
    /**
     * @param fileURL the file URL. Must not be null.
     * @return the last modified date for the file at fileURL, or 0L when unknown or when an error occurred
     */
	private static long getLastModified(MultiProtocolURL fileURL) {
		long lastModified = 0l;
		try {
			if (fileURL.isHTTP() || fileURL.isHTTPS()) {
				/* http(s) : we do not use MultiprotocolURL.lastModified() which always returns 0L for these protocols */
				HTTPClient httpClient = new HTTPClient(ClientIdentification.yacyInternetCrawlerAgent);
				HttpResponse headResponse = httpClient.HEADResponse(fileURL, false);
				if (headResponse != null && headResponse.getStatusLine() != null
						&& headResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
					Header lastModifiedHeader = headResponse
							.getFirstHeader(HeaderFramework.LAST_MODIFIED);
					if (lastModifiedHeader != null) {
						Date lastModifiedDate = HeaderFramework.parseHTTPDate(lastModifiedHeader.getValue());
						if(lastModifiedDate != null) {
							lastModified = lastModifiedDate.getTime();
						}
					}
				}
			} else {
				lastModified = fileURL.lastModified();
			}
		} catch (IOException ignored) {
			ConcurrentLog.warn("IndexImportMediawiki_p", "Could not retrieve last modified date for dump file at " + fileURL);
		}
		return lastModified;
	}
}