/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * 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, version 2 of the License.

 *

 * 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. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.bck2brwsr.launcher.impl;

import java.io.IOException;

import java.io.InputStream;

import java.io.UnsupportedEncodingException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.net.URL;

import java.util.Enumeration;

import javafx.scene.web.WebEngine;

import netscape.javascript.JSObject;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

public final class Console {

    public Console() {

    }

    @JavaScriptBody(args = {"elem", "attr"}, body = 

        "return elem[attr].toString();")

    private static Object getAttr(Object elem, String attr) {

        return InvokeJS.CObject.call("getAttr", elem, attr);

    }

    @JavaScriptBody(args = {"id", "attr", "value"}, body = 

        "window.document.getElementById(id)[attr] = value;")

    private static void setAttr(String id, String attr, Object value) {

        InvokeJS.CObject.call("setAttrId", id, attr, value);

    }

    @JavaScriptBody(args = {"elem", "attr", "value"}, body = 

        "elem[attr] = value;")

    private static void setAttr(Object id, String attr, Object value) {

        InvokeJS.CObject.call("setAttr", id, attr, value);

    }

    @JavaScriptBody(args = {}, body = "return; window.close();")

    private static void closeWindow() {}

    private static Object textArea;

    private static Object statusArea;

    private static void log(String newText) {

        if (textArea == null) {

            return;

        }

        String attr = "value";

        setAttr(textArea, attr, getAttr(textArea, attr) + "\n" + newText);

        setAttr(textArea, "scrollTop", getAttr(textArea, "scrollHeight"));

    }

    private static void beginTest(Case c) {

        Object[] arr = new Object[2];

        beginTest(c.getClassName() + "." + c.getMethodName(), c, arr);

        textArea = arr[0];

        statusArea = arr[1];

    }

    private static void finishTest(Case c, Object res) {

        if ("null".equals(res)) {

            setAttr(statusArea, "innerHTML", "Success");

        } else {

            setAttr(statusArea, "innerHTML", "Result " + res);

        }

        statusArea = null;

        textArea = null;

    }

    private static final String BEGIN_TEST =  

        "var ul = window.document.getElementById('bck2brwsr.result');\n"

        + "var li = window.document.createElement('li');\n"

        + "var span = window.document.createElement('span');"

        + "span.innerHTML = test + ' - ';\n"

        + "var details = window.document.createElement('a');\n"

        + "details.innerHTML = 'Details';\n"

        + "details.href = '#';\n"

        + "var p = window.document.createElement('p');\n"

        + "var status = window.document.createElement('a');\n"

        + "status.innerHTML = 'running';"

        + "details.onclick = function() { li.appendChild(p); li.removeChild(details); status.innerHTML = 'Run Again'; status.href = '#'; };\n"

        + "status.onclick = function() { c.again(arr); }\n"

        + "var pre = window.document.createElement('textarea');\n"

        + "pre.cols = 100;"

        + "pre.rows = 10;"

        + "li.appendChild(span);\n"

        + "li.appendChild(status);\n"

        + "var span = window.document.createElement('span');"

        + "span.innerHTML = ' ';\n"

        + "li.appendChild(span);\n"

        + "li.appendChild(details);\n"

        + "p.appendChild(pre);\n"

        + "ul.appendChild(li);\n"

        + "arr[0] = pre;\n"

        + "arr[1] = status;\n";

    @JavaScriptBody(args = { "test", "c", "arr" }, body = BEGIN_TEST)

    private static void beginTest(String test, Case c, Object[] arr) {

        InvokeJS.CObject.call("beginTest", test, c, arr);

    }

    private static final String LOAD_TEXT = 

          "var request = new XMLHttpRequest();\n"

        + "request.open('GET', url, true);\n"

        + "request.setRequestHeader('Content-Type', 'text/plain; charset=utf-8');\n"

        + "request.onreadystatechange = function() {\n"

        + "  if (this.readyState!==4) return;\n"

        + " try {"

        + "  arr[0] = this.responseText;\n"

        + "  callback.run__V();\n"

        + " } catch (e) { alert(e); }"

        + "};"

        + "request.send();";

    @JavaScriptBody(args = { "url", "callback", "arr" }, body = LOAD_TEXT)

    private static void loadText(String url, Runnable callback, String[] arr) throws IOException {

        InvokeJS.CObject.call("loadText", url, new Run(callback), arr);

    }

    public static void runHarness(String url) throws IOException {

        new Console().harness(url);

    }

    public void harness(String url) throws IOException {

        log("Connecting to " + url);

        Request r = new Request(url);

    }

    private static class Request implements Runnable {

        private final String[] arr = { null };

        private final String url;

        private Case c;

        private int retries;

        private Request(String url) throws IOException {

            this.url = url;

            loadText(url, this, arr);

        }

        private Request(String url, String u) throws IOException {

            this.url = url;

            loadText(u, this, arr);

        }

        @Override

        public void run() {

            try {

                if (c == null) {

                    String data = arr[0];

                    if (data == null) {

                        log("Some error exiting");

                        closeWindow();

                        return;

                    }

                    if (data.isEmpty()) {

                        log("No data, exiting");

                        closeWindow();

                        return;

                    }

                    c = Case.parseData(data);

                    beginTest(c);

                    log("Got \"" + data + "\"");

                } else {

                    log("Processing \"" + arr[0] + "\" for " + retries + " time");

                }

                Object result = retries++ >= 10 ? "java.lang.InterruptedException:timeout" : c.runTest();

                finishTest(c, result);

                String u = url + "?request=" + c.getRequestId() + "&result=" + result;

                new Request(url, u);

            } catch (Exception ex) {

                if (ex instanceof InterruptedException) {

                    log("Re-scheduling in 100ms");

                    schedule(this, 100);

                    return;

                }

                log(ex.getClass().getName() + ":" + ex.getMessage());

            }

        }

    }

    private static String encodeURL(String r) throws UnsupportedEncodingException {

        final String SPECIAL = "%$&+,/:;=?@";

        StringBuilder sb = new StringBuilder();

        byte[] utf8 = r.getBytes("UTF-8");

        for (int i = 0; i < utf8.length; i++) {

            int ch = utf8[i] & 0xff;

            if (ch < 32 || ch > 127 || SPECIAL.indexOf(ch) >= 0) {

                final String numbers = "0" + Integer.toHexString(ch);

                sb.append("%").append(numbers.substring(numbers.length() - 2));

            } else {

                if (ch == 32) {

                    sb.append("+");

                } else {

                    sb.append((char)ch);

                }

            }

        }

        return sb.toString();

    }

    static String invoke(String clazz, String method) throws 

    ClassNotFoundException, InvocationTargetException, IllegalAccessException, 

    InstantiationException, InterruptedException {

        final Object r = new Case(null).invokeMethod(clazz, method);

        return r == null ? "null" : r.toString().toString();

    }

    /** Helper method that inspects the classpath and loads given resource

     * (usually a class file). Used while running tests in Rhino.

     * 

     * @param name resource name to find

     * @return the array of bytes in the given resource

     * @throws IOException I/O in case something goes wrong

     */

    public static byte[] read(String name) throws IOException {

        URL u = null;

        Enumeration<URL> en = Console.class.getClassLoader().getResources(name);

        while (en.hasMoreElements()) {

            u = en.nextElement();

        }

        if (u == null) {

            throw new IOException("Can't find " + name);

        }

        try (InputStream is = u.openStream()) {

            byte[] arr;

            arr = new byte[is.available()];

            int offset = 0;

            while (offset < arr.length) {

                int len = is.read(arr, offset, arr.length - offset);

                if (len == -1) {

                    throw new IOException("Can't read " + name);

                }

                offset += len;

            }

            return arr;

        }

    }

    @JavaScriptBody(args = {}, body = "vm.desiredAssertionStatus = true;")

    private static void turnAssetionStatusOn() {

    }

    @JavaScriptBody(args = {"r", "time"}, body =

        "return window.setTimeout(function() { r.run__V(); }, time);")

    private static Object schedule(Runnable r, int time) {

        return InvokeJS.CObject.call("schedule", new Run(r), time);

    }

    private static final class Case {

        private final Object data;

        private Object inst;

        private Case(Object data) {

            this.data = data;

        }

        public static Case parseData(String s) {

            return new Case(toJSON(s));

        }

        public String getMethodName() {

            return (String) value("methodName", data);

        }

        public String getClassName() {

            return (String) value("className", data);

        }

        public int getRequestId() {

            Object v = value("request", data);

            if (v instanceof Number) {

                return ((Number)v).intValue();

            }

            return Integer.parseInt(v.toString());

        }

        public String getHtmlFragment() {

            return (String) value("html", data);

        }

        void again(Object[] arr) {

            try {

                textArea = arr[0];

                statusArea = arr[1];

                setAttr(textArea, "value", "");

                runTest();

            } catch (Exception ex) {

                log(ex.getClass().getName() + ":" + ex.getMessage());

            }

        }

        private Object runTest() throws IllegalAccessException, 

        IllegalArgumentException, ClassNotFoundException, UnsupportedEncodingException, 

        InvocationTargetException, InstantiationException, InterruptedException {

            if (this.getHtmlFragment() != null) {

                setAttr("bck2brwsr.fragment", "innerHTML", this.getHtmlFragment());

            }

            log("Invoking " + this.getClassName() + '.' + this.getMethodName() + " as request: " + this.getRequestId());

            Object result = invokeMethod(this.getClassName(), this.getMethodName());

            setAttr("bck2brwsr.fragment", "innerHTML", "");

            log("Result: " + result);

            result = encodeURL("" + result);

            log("Sending back: ...?request=" + this.getRequestId() + "&result=" + result);

            return result;

        }

        private Object invokeMethod(String clazz, String method)

        throws ClassNotFoundException, InvocationTargetException,

        InterruptedException, IllegalAccessException, IllegalArgumentException,

        InstantiationException {

            Method found = null;

            Class<?> c = Class.forName(clazz);

            for (Method m : c.getMethods()) {

                if (m.getName().equals(method)) {

                    found = m;

                }

            }

            Object res;

            if (found != null) {

                try {

                    if ((found.getModifiers() & Modifier.STATIC) != 0) {

                        res = found.invoke(null);

                    } else {

                        if (inst == null) {

                            inst = c.newInstance();

                        }

                        res = found.invoke(inst);

                    }

                } catch (Throwable ex) {

                    if (ex instanceof InvocationTargetException) {

                        ex = ((InvocationTargetException) ex).getTargetException();

                    }

                    if (ex instanceof InterruptedException) {

                        throw (InterruptedException)ex;

                    }

                    res = ex.getClass().getName() + ":" + ex.getMessage();

                }

            } else {

                res = "Can't find method " + method + " in " + clazz;

            }

            return res;

        }

        @JavaScriptBody(args = "s", body = "return eval('(' + s + ')');")

        private static Object toJSON(String s) {

            return InvokeJS.CObject.call("toJSON", s);

        }

        @JavaScriptBody(args = {"p", "d"}, body = 

              "var v = d[p];\n"

            + "if (typeof v === 'undefined') return null;\n"

            + "return v.toString();"

        )

        private static Object value(String p, Object d) {

            return ((JSObject)d).getMember(p);

        }

    }

    private static String safe(String txt) {

        return "try {" + txt + "} catch (err) { alert(err); }";

    }

    static {

        turnAssetionStatusOn();

    }

    private static final class InvokeJS {

        static final JSObject CObject = initJS();

        @JavaScriptBody(args = {  }, body = "return null;")

        private static JSObject initJS() {

            WebEngine web = (WebEngine) System.getProperties().get("webEngine");

            return (JSObject) web.executeScript("(function() {"

                + "var CObject = {};"

                + "CObject.getAttr = function(elem, attr) { return elem[attr].toString(); };"

                + "CObject.setAttrId = function(id, attr, value) { window.document.getElementById(id)[attr] = value; };"

                + "CObject.setAttr = function(elem, attr, value) { elem[attr] = value; };"

                + "CObject.beginTest = function(test, c, arr) {" + safe(BEGIN_TEST) + "};"

                + "CObject.loadText = function(url, callback, arr) {" + safe(LOAD_TEXT.replace("run__V", "run")) + "};"

                + "CObject.schedule = function(r, time) { return window.setTimeout(function() { r.run(); }, time); };"

                + "CObject.toJSON = function(s) { return eval('(' + s + ')'); };"

                + "return CObject;"

            + "})(this)");

        }

    }

}