// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
package org.xwt;

import java.net.*;
import java.io.*;
import java.util.*;
import org.xwt.js.*;
import org.xwt.util.*;
import org.bouncycastle.util.encoders.Base64;

/** encapsulates most of the proxy logic; some is shared in HTTP.java */
public class Proxy {
    
    public Proxy() { }
    
    /** the HTTP Proxy host to use */
    public String httpProxyHost = null;
    
    /** the HTTP Proxy port to use */
    public int httpProxyPort = -1;
    
    /** if a seperate proxy should be used for HTTPS, this is the hostname; otherwise, httpProxyHost is used */
    public String httpsProxyHost = null;
    
    /** if a seperate proxy should be used for HTTPS, this is the port */
    public int httpsProxyPort = -1;
    
    /** the SOCKS Proxy Host to use */
    public String socksProxyHost = null;
    
    /** the SOCKS Proxy Port to use */
    public int socksProxyPort = -1;
    
    /** hosts to be excluded from proxy use; wildcards permitted */
    public String[] excluded = null;
    
    /** the PAC script */
    public JS.Callable proxyAutoConfigFunction = null;
    
    public static Proxy detectProxyViaManual() {
        Proxy ret = new Proxy();
        
        ret.httpProxyHost = Platform.getEnv("http_proxy");
        if (ret.httpProxyHost != null) {
            if (ret.httpProxyHost.startsWith("http://")) ret.httpProxyHost = ret.httpProxyHost.substring(7);
            if (ret.httpProxyHost.endsWith("/")) ret.httpProxyHost = ret.httpProxyHost.substring(0, ret.httpProxyHost.length() - 1);
            if (ret.httpProxyHost.indexOf(':') != -1) {
                ret.httpProxyPort = Integer.parseInt(ret.httpProxyHost.substring(ret.httpProxyHost.indexOf(':') + 1));
                ret.httpProxyHost = ret.httpProxyHost.substring(0, ret.httpProxyHost.indexOf(':'));
            } else {
                ret.httpProxyPort = 80;
            }
        }
        
        ret.httpsProxyHost = Platform.getEnv("https_proxy");
        if (ret.httpsProxyHost != null) {
            if (ret.httpsProxyHost.startsWith("https://")) ret.httpsProxyHost = ret.httpsProxyHost.substring(7);
            if (ret.httpsProxyHost.endsWith("/")) ret.httpsProxyHost = ret.httpsProxyHost.substring(0, ret.httpsProxyHost.length() - 1);
            if (ret.httpsProxyHost.indexOf(':') != -1) {
                ret.httpsProxyPort = Integer.parseInt(ret.httpsProxyHost.substring(ret.httpsProxyHost.indexOf(':') + 1));
                ret.httpsProxyHost = ret.httpsProxyHost.substring(0, ret.httpsProxyHost.indexOf(':'));
            } else {
                ret.httpsProxyPort = 80;
            }
        }
        
        ret.socksProxyHost = Platform.getEnv("socks_proxy");
        if (ret.socksProxyHost != null) {
            if (ret.socksProxyHost.startsWith("socks://")) ret.socksProxyHost = ret.socksProxyHost.substring(7);
            if (ret.socksProxyHost.endsWith("/")) ret.socksProxyHost = ret.socksProxyHost.substring(0, ret.socksProxyHost.length() - 1);
            if (ret.socksProxyHost.indexOf(':') != -1) {
                ret.socksProxyPort = Integer.parseInt(ret.socksProxyHost.substring(ret.socksProxyHost.indexOf(':') + 1));
                ret.socksProxyHost = ret.socksProxyHost.substring(0, ret.socksProxyHost.indexOf(':'));
            } else {
                ret.socksProxyPort = 80;
            }
        }
        
        String noproxy = Platform.getEnv("no_proxy");
        if (noproxy != null) {
            StringTokenizer st = new StringTokenizer(noproxy, ",");
            ret.excluded = new String[st.countTokens()];
            for(int i=0; st.hasMoreTokens(); i++) ret.excluded[i] = st.nextToken();
        }
        
        if (ret.httpProxyHost == null && ret.socksProxyHost == null) return null;
        return ret;
    }
    
    public static JS.Scope proxyAutoConfigRootScope = new ProxyAutoConfigRootScope();
    public static JS.Callable getProxyAutoConfigFunction(String url) {
        try { 
            BufferedReader br = new BufferedReader(new InputStreamReader(new HTTP(url, true).GET()));
            String s = null;
            String script = "";
            while((s = br.readLine()) != null) script += s + "\n";
            if (Log.on) Log.log(Proxy.class, "successfully retrieved WPAD PAC:");
            if (Log.on) Log.log(Proxy.class, script);
            
            // MS CARP hack
            Vector carpHosts = new Vector();
            for(int i=0; i<script.length(); i++)
                if (script.regionMatches(i, "new Node(", 0, 9)) {
                    String host = script.substring(i + 10, script.indexOf('\"', i + 11));
                    if (Log.on) Log.log(Proxy.class, "Detected MS Proxy Server CARP Script, Host=" + host);
                    carpHosts.addElement(host);
                }
            if (carpHosts.size() > 0) {
                script = "function FindProxyForURL(url, host) {\nreturn \"";
                for(int i=0; i<carpHosts.size(); i++)
                    script += "PROXY " + carpHosts.elementAt(i) + "; ";
                script += "\";\n}";
                if (Log.on) Log.log(Proxy.class, "DeCARPed PAC script:");
                if (Log.on) Log.log(Proxy.class, script);
            }

            JS.CompiledFunction scr = JS.parse("PAC script at " + url, 0, new StringReader(script));
            scr.call(new JS.Array(), proxyAutoConfigRootScope);
            return (JS.Callable)proxyAutoConfigRootScope.get("FindProxyForURL");
        } catch (Exception e) {
            if (Log.on) {
                Log.log(Platform.class, "WPAD detection failed due to:");
                if (e instanceof JS.Exn) {
                    try {
                        org.xwt.js.JS.Array arr = new org.xwt.js.JS.Array();
                        arr.addElement(((JS.Exn)e).getObject());
                        // FIXME
                        //XWT.recursivePrintObject.call();
                    } catch (Exception e2) {
                        Log.log(Platform.class, e);
                    }
                }
                else Log.log(Platform.class, e);
            }
            return null;
        }
    }


    // Authorization ///////////////////////////////////////////////////////////////////////////////////

    public static class Authorization {

        static public String authorization = null;
        static public String authorization2 = null;
        static public Semaphore waitingForUser = new Semaphore();

        public static synchronized void getPassword(final String realm, final String style, final String proxyIP, String oldAuth) {

            // this handles cases where multiple threads hit the proxy auth at the same time -- all but one will block on the
            // synchronized keyword. If 'authorization' changed while the thread was blocked, it means that the user entered
            // a password, so we should reattempt authorization.

            if (authorization != oldAuth) return;
            if (Log.on) Log.log(Authorization.class, "displaying proxy authorization dialog");
            MessageQueue.add(new Message() {
                    public void perform() {
                        Box b = new Box();
                        Template.getTemplate("org.xwt.builtin.proxy_authorization", null).apply(b, null, null, null, 0, 0);
                        b.put("realm", realm);
                        b.put("proxyIP", proxyIP);
                    }
                });

            waitingForUser.block();
            if (Log.on) Log.log(Authorization.class, "got proxy authorization info; re-attempting connection");
            
        }
    }


    // ProxyAutoConfigRootScope ////////////////////////////////////////////////////////////////////

    public static class ProxyAutoConfigRootScope extends JS.Scope {

        public ProxyAutoConfigRootScope() { super(null); }
        
        // FIXME: needs "standard objects"

        public Object get(Object name) {
            if (name.equals("isPlainHostName")) return isPlainHostName;
            else if (name.equals("dnsDomainIs")) return dnsDomainIs;
            else if (name.equals("localHostOrDomainIs")) return localHostOrDomainIs;
            else if (name.equals("isResolvable")) return isResolvable;
            else if (name.equals("isInNet")) return isInNet;
            else if (name.equals("dnsResolve")) return dnsResolve;
            else if (name.equals("myIpAddress")) return myIpAddress;
            else if (name.equals("dnsDomainLevels")) return dnsDomainLevels;
            else if (name.equals("shExpMatch")) return shExpMatch;
            else if (name.equals("weekdayRange")) return weekdayRange;
            else if (name.equals("dateRange")) return dateRange;
            else if (name.equals("timeRange")) return timeRange;
            else if (name.equals("ProxyConfig")) return ProxyConfig;
            else return super.get(name);
        }
        
        private static final JS.Obj proxyConfigBindings = new JS.Obj();
        private static final JS.Obj ProxyConfig = new JS.Obj() {
                public Object get(Object name) {
                    if (name.equals("bindings")) return proxyConfigBindings;
                    return null;
                }
            };
        
        private static final JS.Callable isPlainHostName = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    return (args.elementAt(0).toString().indexOf('.') == -1) ? Boolean.TRUE : Boolean.FALSE;
                }
            };
        
        private static final JS.Callable dnsDomainIs = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    return (args.elementAt(0).toString().endsWith(args.elementAt(1).toString())) ? Boolean.TRUE : Boolean.FALSE;
                }
            };
        
        private static final JS.Callable localHostOrDomainIs = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    return (args.elementAt(0).toString().equals(args.elementAt(1).toString()) || 
                            (args.elementAt(0).toString().indexOf('.') == -1 && args.elementAt(1).toString().startsWith(args.elementAt(0).toString()))) ?
                        Boolean.TRUE : Boolean.FALSE;
                }
            };
        
        private static final JS.Callable isResolvable = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    try {
                        return (InetAddress.getByName(args.elementAt(0).toString()) != null) ? Boolean.TRUE : Boolean.FALSE;
                    } catch (UnknownHostException e) {
                        return Boolean.FALSE;
                    }
                }
            };
        
        private static final JS.Callable isInNet = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    if (args.length() != 3) return Boolean.FALSE;
                    try {
                        byte[] host = InetAddress.getByName(args.elementAt(0).toString()).getAddress();
                        byte[] net = InetAddress.getByName(args.elementAt(1).toString()).getAddress();
                        byte[] mask = InetAddress.getByName(args.elementAt(2).toString()).getAddress();
                        return ((host[0] & mask[0]) == net[0] &&
                                (host[1] & mask[1]) == net[1] &&
                                (host[2] & mask[2]) == net[2] &&
                                (host[3] & mask[3]) == net[3]) ?
                            Boolean.TRUE : Boolean.FALSE;
                    } catch (Exception e) {
                        throw new JS.Exn("exception in isInNet(): " + e);
                    }
                }
            };
        
        private static final JS.Callable dnsResolve = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    try {
                        return InetAddress.getByName(args.elementAt(0).toString()).getHostAddress();
                    } catch (UnknownHostException e) {
                        return null;
                    }
                }
            };
        
        private static final JS.Callable myIpAddress = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    try {
                        return InetAddress.getLocalHost().getHostAddress();
                    } catch (UnknownHostException e) {
                        if (Log.on) Log.log(this, "strange... host does not know its own address");
                        return null;
                    }
                }
            };
        
        private static final JS.Callable dnsDomainLevels = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    String s = args.elementAt(0).toString();
                    int i = 0;
                    while((i = s.indexOf('.', i)) != -1) i++;
                    return new Integer(i);
                }
            };
        
        private static boolean match(String[] arr, String s, int index) {
            if (index >= arr.length) return true;
            for(int i=0; i<s.length(); i++) {
                String s2 = s.substring(i);
                if (s2.startsWith(arr[index]) && match(arr, s2.substring(arr[index].length()), index + 1)) return true;
            }
            return false;
        }
        
        private static final JS.Callable shExpMatch = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    StringTokenizer st = new StringTokenizer(args.elementAt(1).toString(), "*", false);
                    String[] arr = new String[st.countTokens()];
                    String s = args.elementAt(0).toString();
                    for (int i=0; st.hasMoreTokens(); i++) arr[i] = st.nextToken();
                    return match(arr, s, 0) ? Boolean.TRUE : Boolean.FALSE;
                }
            };
        
        public static String[] days = { "SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT" };
        
        private static final JS.Callable weekdayRange = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    TimeZone tz = (args.length() < 3 || args.elementAt(2) == null || !args.elementAt(2).equals("GMT")) ? TimeZone.getTimeZone("UTC") : TimeZone.getDefault();
                    Calendar c = new GregorianCalendar();
                    c.setTimeZone(tz);
                    c.setTime(new java.util.Date());
                    java.util.Date d = c.getTime();
                    int day = d.getDay();
                    
                    String d1s = args.elementAt(0).toString().toUpperCase();
                    intint = 0, d2 = 0;
                    for(int i=0; i<days.length; i++) if (days[i].equals(d1s)) d1 = i;
                    
                    if (args.length() == 1)
                        return d1 == day ? Boolean.TRUE : Boolean.FALSE;
                    
                    String d2s = args.elementAt(1).toString().toUpperCase();
                    for(int i=0; i<days.length; i++) if (days[i].equals(d2s)) d2 = i;
                    
                    return
                        ((d1 <= d2 && day >= d1 && day <= d2) ||
                         (d1 > d2 && (day >= d1 || day <= d2))) ?
                        Boolean.TRUE : Boolean.FALSE;
                }
            };
        
        private static final JS.Callable dateRange = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    throw new JS.Exn("XWT does not support dateRange() in PAC scripts");
                }
            };
        
        private static final JS.Callable timeRange = new JS.Callable() {
                public Object call(org.xwt.js.JS.Array args) throws JS.Exn {
                    throw new JS.Exn("XWT does not support timeRange() in PAC scripts");
                }
            };
        
    }

}