package net.i2p.router.web;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import net.i2p.servlet.util.ServletUtil;
import net.i2p.util.RandomSource;

/**
 * Copied and modded from I2PTunnel IndexBean (GPL)
 * @author zzz
 */
public class CSSHelper extends HelperBase {

    private static final Map<String, Boolean> _UACache = new ConcurrentHashMap<String, Boolean>();

    public static final String PROP_UNIVERSAL_THEMING = "routerconsole.universal.theme";
    public static final String PROP_THEME_NAME = "routerconsole.theme";
    /**  @since 0.9.33 moved from ConfigUIHelper */
    public static final String PROP_THEME_PFX = PROP_THEME_NAME + '.';
    public static final String DEFAULT_THEME = "light";
    public static final String ALT_THEME = "dark";
    public static final String BASE_THEME_PATH = "/themes/console/";
    private static final String FORCE = "classic";
    public static final String PROP_REFRESH = "routerconsole.summaryRefresh";
    public static final String DEFAULT_REFRESH = "15";
    public static final int MIN_REFRESH = 3;
    public static final String PROP_DISABLE_REFRESH = "routerconsole.summaryDisableRefresh";
    private static final String PROP_XFRAME = "routerconsole.disableXFrame";
    public static final String PROP_FORCE_MOBILE_CONSOLE = "routerconsole.forceMobileConsole";
    /** @since 0.9.32 */
    public static final String PROP_EMBED_APPS = "routerconsole.embedApps";
    /** @since 0.9.36 */
    public static final String PROP_DISABLE_OLD = "routerconsole.disableOldThemes";
    public static final boolean DEFAULT_DISABLE_OLD = true;

    private static final String _consoleNonce = Long.toString(RandomSource.getInstance().nextLong());

    /**
     *  formerly stored in System.getProperty("router.consoleNonce")
     *  @since 0.9.4
     */
    public static String getNonce() { 
        return _consoleNonce;
    }

    public String getTheme(String userAgent) {
        String url = BASE_THEME_PATH;
        if (userAgent != null && userAgent.contains("MSIE") && !userAgent.contains("Trident/6") &&
            !_context.getProperty(PROP_DISABLE_OLD, DEFAULT_DISABLE_OLD)) {
            url += FORCE + "/";
        } else {
            // This is the first thing to use _context on most pages
            if (_context == null)
                throw new IllegalStateException("No contexts. This is usually because the router is either starting up or shutting down.");
            String theme = _context.getProperty(PROP_THEME_NAME, DEFAULT_THEME);
            // remap deprecated themes
            if (theme.equals("midnight")) {
                if (_context.getProperty(PROP_DISABLE_OLD, DEFAULT_DISABLE_OLD))
                    theme = "dark";
            } else if (theme.equals("classic")) {
                if (_context.getProperty(PROP_DISABLE_OLD, DEFAULT_DISABLE_OLD))
                    theme = "light";
            }
            url += theme + "/";
        }
        return url;
    }

    /**
     * Returns whether app embedding is enabled or disabled
     * @since 0.9.32
     */
    public boolean embedApps() {
        return _context.getBooleanProperty(PROP_EMBED_APPS);
    }

    /**
     * change default language for the router AND save it
     * @param lang xx OR xx_XX OR xxx OR xxx_XX
     */
    public void setLang(String lang) {
        // Protected with nonce in css.jsi
        if (lang != null && lang.length() >= 2 && lang.length() <= 6 &&
            lang.replaceAll("[a-zA-Z_]", "").length() == 0) {
            Map<String, String> m = new HashMap<String, String>(2);
            int under = lang.indexOf('_');
            if (under < 0) {
                m.put(Messages.PROP_LANG, lang.toLowerCase(Locale.US));
                m.put(Messages.PROP_COUNTRY, "");
                _context.router().saveConfig(m, null);
            } else if (under > 0 && lang.length() > under + 1) {
                m.put(Messages.PROP_LANG, lang.substring(0, under).toLowerCase(Locale.US));
                m.put(Messages.PROP_COUNTRY, lang.substring(under + 1).toUpperCase(Locale.US));
                _context.router().saveConfig(m, null);
            }
        }
    }

    /**
     * needed for conditional css loads for zh
     * @return two-letter only, lower-case
     */
    public String getLang() {
        return Messages.getLanguage(_context);
    }

    /**
     *  Show / hide news on home page
     *  @param val if non-null, "1" to show, else hide
     *  @since 0.8.12
     */
    public void setNews(String val) {
        // Protected with nonce in css.jsi
        if (val != null)
            NewsHelper.showNews(_context, val.equals("1"));
    }

    /**
     *  Should we send X_Frame_Options=SAMEORIGIN
     *  Default true
     *  @since 0.9.1
     */
    public boolean shouldSendXFrame() {
        return !_context.getBooleanProperty(PROP_XFRAME);
    }

    /** change refresh and save it */
    public void setRefresh(String r) {
        try {
            if (Integer.parseInt(r) < MIN_REFRESH)
                r = Integer.toString(MIN_REFRESH);
            _context.router().saveConfig(PROP_REFRESH, r);
        } catch (RuntimeException e) {
        }
    }

    /** @return refresh time in seconds, as a string */
    public String getRefresh() {
        String r = _context.getProperty(PROP_REFRESH, DEFAULT_REFRESH);
        try {
            if (Integer.parseInt(r) < MIN_REFRESH)
                r = Integer.toString(MIN_REFRESH);
        } catch (RuntimeException e) {
            r = Integer.toString(MIN_REFRESH);
        }
        return r;
    }

    /**
     * change disable refresh boolean and save it
     * @since 0.9.1
     */
    public void setDisableRefresh(String r) {
        String disableRefresh = "false";
        if ("0".equals(r))
            disableRefresh = "true";
        _context.router().saveConfig(PROP_DISABLE_REFRESH, disableRefresh);
    }

    /**
     * @return true if refresh is disabled
     * @since 0.9.1
     */
    public boolean getDisableRefresh() {
        return _context.getBooleanProperty(PROP_DISABLE_REFRESH);
    }

    /** translate the title and display consistently */
    public String title(String s) {
         StringBuilder buf = new StringBuilder(128);
         buf.append("<title>")
            .append(_t("I2P Router Console"))
            .append(" - ")
            .append(_t(s))
            .append("</title>");
         return buf.toString();
    }

    /**
     *  Should we allow a refreshing IFrame?
     *  @since 0.8.5
     */
    public boolean allowIFrame(String ua) {
        boolean forceMobileConsole = _context.getBooleanProperty(PROP_FORCE_MOBILE_CONSOLE);
        if (forceMobileConsole)
            return false;
        if (ua == null)
            return true;
        Boolean brv = _UACache.get(ua);
        if (brv != null)
            return brv.booleanValue();
        boolean rv = shouldAllowIFrame(ua);
        _UACache.put(ua, Boolean.valueOf(rv));
        return rv;
    }

    private static boolean shouldAllowIFrame(String ua) {
        return !ServletUtil.isSmallBrowser(ua);
    }
}
