Components.utils.import("resource://gre/modules/AddonManager.jsm");

 Components.utils.import("resource://gre/modules/Services.jsm");

 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

 const Cc = Components.classes;

 const Ci = Components.interfaces;

 const NS_XHTML = "http://www.w3.org/1999/xhtml";

 var gDBStarted = false;

 var gRootURI = null;

 XPCOMUtils.defineLazyGetter(this, "ScriptDB", function() {

   try {

     var loader = Cc["@mozilla.org/moz/jssubscript-loader;1"].

                  getService(Ci.mozIJSSubScriptLoader);

     var scope = {};

     loader.loadSubScript(gRootURI.spec + "includes/scriptdb.js", scope);

     gDBStarted = true;

     return scope.ScriptDatabase;

   }

   catch (e) {

     LOGE("Exception loading database", e);

   }

 });

 function LOG(aStr) {

   dump("SLMNKY: " + aStr + "\n");

 }

 function LOGE(aStr, aException) {

   dump("SLMNKY: " + aStr + ": " + aException + "\n");

   if ("stack" in aException)

     dump(aException.stack);

 }

 function getManagerStyles() {

   return "#category-scripts > .category-icon,\

           .addon[type=user-script] .icon,\

           #detail-view[type=user-script] #detail-icon {\

             list-style-image: url(" + gRootURI.spec + "images/script.png)\

           }";

 }

 function ExtendedStringBundle(aBase) {

   this.basebundle = aBase;

   this.strings = {};

 }

 ExtendedStringBundle.prototype = {

   strings: null,

   basebundle: null,

   GetStringFromName: function(aName) {

     if (aName in this.strings)

       return this.strings[aName];

     return this.basebundle.GetStringFromName(aName);

   },

   formatStringFromName: function(aName, aArgs, aLength) {

     return this.basebundle.formatStringFromName(aName, aArgs, aLength);

   }

 };

 var WindowObserver = {

   addToAddonsManager: function(aWindow) {

     var window = aWindow.wrappedJSObject;

     try {

       var bundle = new ExtendedStringBundle(window.gStrings.ext);

       bundle.strings["header-user-script"] = "User Scripts";

       window.gStrings.ext = bundle;

       var plugins = window.document.getElementById("category-plugins");

       var scripts = window.document.createElement("richlistitem");

       scripts.setAttribute("id", "category-scripts");

       scripts.setAttribute("value", "addons://list/user-script");

       scripts.setAttribute("class", "category");

       scripts.setAttribute("name", "User Scripts");

       plugins.parentNode.insertBefore(scripts, plugins);

       var styles = window.document.createElementNS(NS_XHTML, "style");

       styles.setAttribute("id", "script-styles");

       styles.setAttribute("type", "text/css");

       styles.appendChild(window.document.createTextNode(getManagerStyles()));

       window.document.documentElement.appendChild(styles);

     }

     catch (e) {

       LOGE("Exception in injectIntoAddonsManager", e);

     }

   },

   findAllAddonsManagers: function() {

     var managers = [];

     var windows = Services.wm.getEnumerator("navigator:browser");

     while (windows.hasMoreElements()) {

       var window = windows.getNext().QueryInterface(Ci.nsIDOMWindow);

       window.gBrowser.browsers.forEach(function(aBrowser) {

         if (aBrowser.currentURI.spec == "about:addons")

           managers.push(aBrowser.contentWindow);

       });

     }

     return managers;

   },

   addToAddonsManagers: function() {

     var managers = this.findAllAddonsManagers();

     managers.forEach(function(aWindow) {

       this.addToAddonsManager(aWindow);

     }, this);

   },

   removeFromAddonsManagers: function() {

     var managers = this.findAllAddonsManagers();

     managers.forEach(function(aWindow) {

       var window = aWindow.wrappedJSObject;

       var scripts = window.document.getElementById("category-scripts");

       scripts.parentNode.removeChild(scripts);

       var styles = window.document.getElementById("script-styles");

       styles.parentNode.removeChild(styles);

       window.gStrings.ext = window.gStrings.ext.basebundle;

     });

   },

   installPrompt: function(aWindow) {

     var window = aWindow.wrappedJSObject;

     window.addEventListener("load", function() {

       if (!Services.prompt.confirm(window, "Install Script?", "Do you want to install this user script?"))

         return;

       ScriptDB.installScript(window.document.body.textContent,

                              aWindow.document.documentURIObject);

     }, false);

   },

   injectScripts: function(aWindow, aScripts) {

     var safeWin = new XPCNativeWrapper(aWindow.wrappedJSObject);

     aScripts.forEach(function(aScript) {

       LOG("Injecting " + aScript.name);

       var sandbox = new Components.utils.Sandbox(safeWin);

       sandbox.window = safeWin;

       sandbox.document = sandbox.window.document;

       sandbox.unsafeWindow = aWindow.wrappedJSObject;

       sandbox.__proto__ = safeWin;

       var code = "(function(){" + aScript.script + "})()";

       try {

         Components.utils.evalInSandbox(code, sandbox, "1.8");

       }

       catch(e) {

         LOGE("Exception in injected script", e);

       }

     });

   },

   observe: function(aSubject, aTopic, aData) {

     try {

       var window = aSubject;

       var uri = window.document.documentURIObject;

       switch (aTopic) {

       case "content-document-global-created":

         LOG("Content window loaded: " + uri.spec);

         var scripts = ScriptDB.getScriptsForURI(uri);

         if (scripts.length > 0) {

           window.addEventListener("DOMContentLoaded", function() {

             WindowObserver.injectScripts(window, scripts);

           }, false);

         }

         if (uri.spec.substring(uri.spec.length - 8) == ".user.js" &&

             !ScriptDB.hasScript(uri))

           this.installPrompt(window);

         break;

       case "chrome-document-global-created":

         LOG("Chrome window loaded: " + uri.spec);

         if (uri.spec == "about:addons") {

           window.addEventListener("load", function() {

             WindowObserver.addToAddonsManager(window);

           }, false);

         }

         break;

       }

     }

     catch (e) {

       LOGE("Exception in observe", e);

     }

   }

 };

 var AddonProvider = {

   getAddonByID: function(aId, aCallback) {

     aCallback(ScriptDB.getScript(aId));

   },

   getAddonsByTypes: function(aTypes, aCallback) {

     if (aTypes && aTypes.indexOf("user-script") < 0)

       aCallback([]);

     else

       aCallback(ScriptDB.getAllScripts());

   }

 };

 function startup(aParams) {

   LOG("startup");

   try {

     gRootURI = Services.io.newFileURI(aParams.installPath);

     Services.obs.addObserver(WindowObserver, "content-document-global-created", false);

     Services.obs.addObserver(WindowObserver, "chrome-document-global-created", false);

     AddonManagerPrivate.registerProvider(AddonProvider);

     WindowObserver.addToAddonsManagers();

   }

   catch (e) {

     LOGE("Exception during startup", e);

   }

 }

 function shutdown() {

   LOG("shutdown");

   try {

     WindowObserver.removeFromAddonsManagers();

     AddonManagerPrivate.unregisterProvider(AddonProvider);

     Services.obs.removeObserver(WindowObserver, "content-document-global-created");

     Services.obs.removeObserver(WindowObserver, "chrome-document-global-created");

     if (gDBStarted)

       ScriptDB.shutdown();

   }

   catch (e) {

     LOGE("Exception during shutdown", e);

   }

 }