/*
 * Copyright (C) 2008-2017, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.juick.www;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Optional;

/**
 *
 * @author Ugnich Anton
 */
public class Utils {

    private static final Logger logger = LoggerFactory.getLogger(Utils.class);

    public static String getCookie(HttpServletRequest request, String name) {
        Cookie cookies[] = request.getCookies();
        if (cookies != null) {
            return Arrays.stream(cookies).filter(c ->
                    c.getName().equals(name)).findAny().map(Cookie::getValue).orElse(null);
        }
        return null;
    }



    public static void sendTemporaryRedirect(HttpServletResponse response, String location) {
        response.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
        response.setHeader("Location", location);
    }

    public static void sendPermanentRedirect(HttpServletResponse response, String location) {
        response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
        response.setHeader("Location", location);
    }

    public static String getPartFilename(Part part) {
        for (String cd : part.getHeader("content-disposition").split(";")) {
            if (cd.trim().startsWith("filename")) {
                String filename = cd.substring(cd.indexOf('=') + 1).trim().replace("\"", StringUtils.EMPTY);
                return filename.substring(filename.lastIndexOf('/') + 1).substring(filename.lastIndexOf('\\') + 1); // MSIE fix.
            }
        }
        return null;
    }

    public static void replyJSON(HttpServletRequest request, HttpServletResponse response, String json) throws IOException {
        response.setContentType("application/json; charset=UTF-8");
        response.setHeader("Access-Control-Allow-Origin", "*");

        String callback = request.getParameter("callback");
        if (callback != null && (callback.length() > 64 || !callback.matches("[a-zA-Z0-9\\-\\_]+"))) {
            callback = null;
        }

        PrintWriter out = response.getWriter();
        try {
            if (callback != null) {
                out.print(callback + "(");
                out.print(json);
                out.print(")");
            } else {
                out.print(json);
            }
        } finally {
            out.close();
        }
    }

    public static String encodeSphinx(String str) {
        return str.replaceAll("@", "\\\\@");
    }

    public static String fetchURL(String url) {
        try {
            URLConnection c = new URL(url).openConnection();
            return IOUtils.toString(c.getInputStream(), StandardCharsets.UTF_8);
        } catch (IOException e) {
            logger.warn("fetchURL", e);
            return null;
        }
    }
    /**
     * Returns the viewName to return for coming back to the sender url
     *
     * @param request Instance of {@link HttpServletRequest} or use an injected instance
     * @return Optional with the view name. Recomended to use an alternativa url with
     * {@link Optional#orElse(java.lang.Object)}
     */
    public static Optional<String> getPreviousPageByRequest(HttpServletRequest request)
    {
        return Optional.ofNullable(request.getHeader("Referer")).map(requestUrl -> "redirect:" + requestUrl);
    }
}