/*******************************************************************************

    µBlock - a browser extension to block requests.
    Copyright (C) 2014 The µBlock authors

    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, 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see {http://www.gnu.org/licenses/}.

    Home: https://github.com/gorhill/uBlock
*/

/* global self, safari, SafariBrowserTab, µBlock */

// For background page

/******************************************************************************/

(function() {

    'use strict';

    var vAPI = self.vAPI = self.vAPI || {};

    vAPI.safari = true;

    /******************************************************************************/

    vAPI.app = {
        name: "µBlock",
        version: safari.extension.displayVersion
    };

    /******************************************************************************/

    vAPI.app.restart = function() {};

    /******************************************************************************/

    safari.extension.settings.addEventListener('change', function(e) {
        if(e.key === 'open_prefs') {
            vAPI.tabs.open({
                url: 'dashboard.html',
                active: true
            });
        }
    }, false);

    /******************************************************************************/

    vAPI.storage = {
        _storage: safari.extension.settings,
        QUOTA_BYTES: 52428800, // copied from Info.plist

        get: function(keys, callback) {
            if(typeof callback !== 'function') {
                return;
            }

            var i, value, result = {};

            if(keys === null) {
                for(i in this._storage) {
                    if(!this._storage.hasOwnProperty(i)) continue;
                    value = this._storage[i];

                    if(typeof value === 'string') {
                        result[i] = JSON.parse(value);
                    }
                }
            } else if(typeof keys === 'string') {
                value = this._storage[keys];

                if(typeof value === 'string') {
                    result[keys] = JSON.parse(value);
                }
            } else if(Array.isArray(keys)) {
                for(i = 0; i < keys.length; i++) {
                    value = this._storage[i];

                    if(typeof value === 'string') {
                        result[keys[i]] = JSON.parse(value);
                    }
                }
            } else if(typeof keys === 'object') {
                for(i in keys) {
                    if(!keys.hasOwnProperty(i)) continue;
                    value = this._storage[i];

                    if(typeof value === 'string') {
                        result[i] = JSON.parse(value);
                    } else {
                        result[i] = keys[i];
                    }
                }
            }

            callback(result);
        },

        set: function(details, callback) {
            for(var key in details) {
                if(!details.hasOwnProperty(key)) {
                    continue;
                }
                this._storage.setItem(key, JSON.stringify(details[key]));
            }

            if(typeof callback === 'function') {
                callback();
            }
        },

        remove: function(keys) {
            if(typeof keys === 'string') {
                keys = [keys];
            }

            for(var i = 0; i < keys.length; i++) {
                this._storage.removeItem(keys[i]);
            }
        },

        clear: function(callback) {
            this._storage.clear();
            callback();
        },

        getBytesInUse: function(keys, callback) {
            if(typeof callback !== 'function') {
                return;
            }

            var i;
            var size = 0;

            if(keys === null) {
                for(i in this._storage) {
                    size += (this._storage[i] || '').length;
                }
            } else {
                if(typeof keys === 'string') {
                    keys = [keys];
                }

                for(i = 0; i < keys.length; i++) {
                    size += (this._storage[keys[i]] || '').length;
                }
            }

            callback(size);
        }
    };

    /******************************************************************************/

    vAPI.tabs = {
        stack: {},
        stackId: 1
    };

    /******************************************************************************/

    vAPI.isNoTabId = function(tabId) {
        return tabId.toString() === '-1';
    };

    vAPI.noTabId = '-1';

    /******************************************************************************/

    vAPI.tabs.registerListeners = function() {
        safari.application.addEventListener('beforeNavigate', function(e) {
            if(!vAPI.tabs.popupCandidate || !e.target || e.url === 'about:blank') {
                return;
            }
            var url = e.url,
                tabId = vAPI.tabs.getTabId(e.target);
            var details = {
                url: url,
                tabId: tabId,
                sourceTabId: vAPI.tabs.popupCandidate
            };
            vAPI.tabs.popupCandidate = false;
            if(vAPI.tabs.onPopup(details)) {
                e.preventDefault();
                if(vAPI.tabs.stack[details.sourceTabId]) {
                    vAPI.tabs.stack[details.sourceTabId].activate();
                }
            }
        }, true);
        // onClosed handled in the main tab-close event
        // onUpdated handled via monitoring the history.pushState on web-pages
        // onPopup is handled in window.open on web-pages
    };

    /******************************************************************************/

    vAPI.tabs.getTabId = function(tab) {
        if(typeof tab.uBlockCachedID !== "undefined") {
            return tab.uBlockCachedID;
        }
        for(var i in vAPI.tabs.stack) {
            if(vAPI.tabs.stack[i] === tab) {
                return (tab.uBlockCachedID = +i);
            }
        }

        return -1;
    };

    /******************************************************************************/

    vAPI.tabs.get = function(tabId, callback) {
        var tab;

        if(tabId === null) {
            tab = safari.application.activeBrowserWindow.activeTab;
            tabId = this.getTabId(tab);
        } else {
            tab = this.stack[tabId];
        }

        if(!tab) {
            callback();
            return;
        }

        callback({
            id: tabId,
            index: tab.browserWindow.tabs.indexOf(tab),
            windowId: safari.application.browserWindows.indexOf(tab.browserWindow),
            active: tab === tab.browserWindow.activeTab,
            url: tab.url || "about:blank",
            title: tab.title
        });
    };

    /******************************************************************************/

    // properties of the details object:
    //   url: 'URL', // the address that will be opened
    //   tabId: 1, // the tab is used if set, instead of creating a new one
    //   index: -1, // undefined: end of the list, -1: following tab, or after index
    //   active: false, // opens the tab in background - true and undefined: foreground
    //   select: true // if a tab is already opened with that url, then select it instead of opening a new one

    vAPI.tabs.open = function(details) {
        if(!details.url) {
            return null;
        }
        // extension pages
        if(/^[\w-]{2,}:/.test(details.url) === false) {
            details.url = vAPI.getURL(details.url);
        }

        var curWin, tab;

        if(details.select) {
            tab = safari.application.browserWindows.some(function(win) {
                var rgxHash = /#.*/;
                // this is questionable
                var url = details.url.replace(rgxHash, '');

                for(var i = 0; i < win.tabs.length; i++) {
                    // Some tabs don't have a URL
                    if(win.tabs[i].url &&
                       win.tabs[i].url.replace(rgxHash, '') === url) {
                        win.tabs[i].activate();
                        return true;
                    }
                }
            });

            if(tab) {
                return;
            }
        }

        if(details.active === undefined) {
            details.active = true;
        }

        curWin = safari.application.activeBrowserWindow;

        // it must be calculated before opening a new tab,
        // otherwise the new tab will be the active tab here
        if(details.index === -1) {
            details.index = curWin.tabs.indexOf(curWin.activeTab) + 1;
        }

        tab = (details.tabId ? this.stack[details.tabId] : curWin.openTab(details.active ? 'foreground' : 'background'));

        if(details.index !== undefined) {
            curWin.insertTab(tab, details.index);
        }

        tab.url = details.url;
    };

    /******************************************************************************/

    vAPI.tabs.remove = function(tabIds) {
        if(tabIds instanceof SafariBrowserTab) {
            tabIds = this.getTabId(tabIds);
        }

        if(!Array.isArray(tabIds)) {
            tabIds = [tabIds];
        }

        for(var i = 0; i < tabIds.length; i++) {
            if(this.stack[tabIds[i]]) {
                this.stack[tabIds[i]].close();
            }
        }
    };

    /******************************************************************************/

    vAPI.tabs.reload = function(tabId) {
        var tab = this.stack[tabId];

        if(tab) {
            tab.url = tab.url;
        }
    };

    /******************************************************************************/

    vAPI.tabs.injectScript = function(tabId, details, callback) {
        var tab;

        if(tabId) {
            tab = this.stack[tabId];
        } else {
            tab = safari.application.activeBrowserWindow.activeTab;
        }

        if(details.file) {
            var xhr = new XMLHttpRequest();
            xhr.open('GET', details.file, true);
            xhr.addEventListener("readystatechange", function() {
                if(this.readyState === 4) {
                    details.code = xhr.responseText;
                    tab.page.dispatchMessage('broadcast', {
                        channelName: 'vAPI',
                        msg: {
                            cmd: 'injectScript',
                            details: details
                        }
                    });
                    if(typeof callback === 'function') {
                        setTimeout(callback, 13);
                    }
                }
            });
            xhr.send();
        }
    };

    /******************************************************************************/

    // bind tabs to unique IDs

    (function() {
        var wins = safari.application.browserWindows,
            i = wins.length,
            j;

        while(i--) {
            j = wins[i].tabs.length;

            while(j--) {
                vAPI.tabs.stack[vAPI.tabs.stackId++] = wins[i].tabs[j];
            }
        }
    })();

    /******************************************************************************/

    safari.application.addEventListener('open', function(e) {
        // ignore windows
        if(e.target instanceof SafariBrowserTab) {
            vAPI.tabs.stack[vAPI.tabs.stackId++] = e.target;
        }
    }, true);

    /******************************************************************************/

    safari.application.addEventListener('close', function(e) {
        // ignore windows
        if(!(e.target instanceof SafariBrowserTab)) {
            return;
        }

        var tabId = vAPI.tabs.getTabId(e.target);

        if(tabId !== -1) {
            // to not add another listener, put this here
            // instead of vAPI.tabs.registerListeners
            if(typeof vAPI.tabs.onClosed === 'function') {
                vAPI.tabs.onClosed(tabId);
            }

            delete vAPI.tabIcons[tabId];
            delete vAPI.tabs.stack[tabId];
        }
    }, true);

    /******************************************************************************/

    // update badge when tab is activated
    safari.application.addEventListener('activate', function(e) {
        // ignore windows
        if(!(e.target instanceof SafariBrowserTab)) {
            return;
        }

        // update the badge, when tab is selected
        vAPI.setIcon();
    }, true);

    /******************************************************************************/

    // reload the popup when that is opened
    safari.application.addEventListener('popover', function(e) {
        var w = e.target.contentWindow, body = w.document.body, child;
        while(child = body.firstChild) {
            body.removeChild(child);
        }
        w.location.reload();
    }, true);

    /******************************************************************************/

    vAPI.tabIcons = { /*tabId: {badge: 0, img: suffix}*/ };
    vAPI.setIcon = function(tabId, iconStatus, badge) {
        var curTabId = vAPI.tabs.getTabId(
            safari.application.activeBrowserWindow.activeTab
        );

        // from 'activate' event
        if(tabId === undefined) {
            tabId = curTabId;
        } else {
            if(badge && /\D/.test(badge)) {
                badge = 999;
            }

            vAPI.tabIcons[tabId] = {
                badge: badge || 0,
                img: iconStatus === 'on' ? '' : '-off'
            };
        }

        if(tabId !== curTabId) {
            return;
        }

        // if the selected tab has the same ID, then update the badge too,
        // or always update it when changing tabs ('activate' event)
        var items = safari.extension.toolbarItems;
        var i = items.length;

        while(i--) {
            if(items[i].browserWindow === safari.application.activeBrowserWindow) {
                var icon = vAPI.tabIcons[tabId];
                items[i].badge = icon && icon.badge || 0;
                // TODO: a disabled icon for Safari
                // items[i].img = vAPI.getURL(icon.img);
                return;
            }
        }
    };

    /******************************************************************************/

    vAPI.messaging = {
        listeners: {},
        defaultHandler: null,
        NOOPFUNC: function() {}, 
        UNHANDLED: 'vAPI.messaging.notHandled'
    };

    /******************************************************************************/

    vAPI.messaging.listen = function(listenerName, callback) {
        this.listeners[listenerName] = callback;
    };

    /******************************************************************************/

    var CallbackWrapper = function(request, port) {
        // No need to bind every single time
        this.callback = this.proxy.bind(this);
        this.messaging = vAPI.messaging;
        this.init(request, port);
    };
    CallbackWrapper.junkyard = [];

    CallbackWrapper.factory = function(request, port) {
        var wrapper = CallbackWrapper.junkyard.pop();
        if(wrapper) {
            wrapper.init(request, port);
            return wrapper;
        }
        return new CallbackWrapper(request, port);
    };
    CallbackWrapper.prototype.init = function(request, port) {
        this.request = request;
        this.port = port;
    };
    CallbackWrapper.prototype.proxy = function(response) {
        this.port.dispatchMessage(this.request.name, {
            requestId: this.request.message.requestId,
            channelName: this.request.message.channelName,
            msg: response !== undefined ? response: null
        });
        this.port = this.request = null;
        CallbackWrapper.junkyard.push(this);
    };

    vAPI.messaging.onMessage = function(request) {
        var callback = vAPI.messaging.NOOPFUNC;
        if(request.message.requestId !== undefined) {
            callback = CallbackWrapper.factory(request, request.target.page).callback;
        }

        var sender = {
            tab: {
                id: vAPI.tabs.getTabId(request.target)
            }
        };

        // Specific handler
        var r = vAPI.messaging.UNHANDLED;
        var listener = vAPI.messaging.listeners[request.message.channelName];
        if(typeof listener === 'function') {
            r = listener(request.message.msg, sender, callback);
        }
        if(r !== vAPI.messaging.UNHANDLED) {
            return;
        }

        // Default handler
        r = vAPI.messaging.defaultHandler(request.message.msg, sender, callback);
        if(r !== vAPI.messaging.UNHANDLED) {
            return;
        }

        console.error('µBlock> messaging > unknown request: %o', request.message);

        // Unhandled:
        // Need to callback anyways in case caller expected an answer, or
        // else there is a memory leak on caller's side
        callback();
    };

    /******************************************************************************/

    vAPI.messaging.setup = function(defaultHandler) {
        // Already setup?
        if(this.defaultHandler !== null) {
            return;
        }

        if(typeof defaultHandler !== 'function') {
            defaultHandler = function() {
                return vAPI.messaging.UNHANDLED;
            };
        }
        this.defaultHandler = defaultHandler;

        // the third parameter must stay false (bubbling), so later
        // onBeforeRequest will use true (capturing), where we can invoke
        // stopPropagation() (this way this.onMessage won't be fired)
        safari.application.addEventListener('message', this.onMessage, false);
    };

    /******************************************************************************/

    vAPI.messaging.broadcast = function(message) {
        message = {
            broadcast: true,
            msg: message
        };

        for(var tabId in vAPI.tabs.stack) {
            vAPI.tabs.stack[tabId].page.dispatchMessage('broadcast', message);
        }
    };

    /******************************************************************************/

    vAPI.net = {};

    /******************************************************************************/

    // Fast `contains`

    Array.prototype.contains = function(a) {
        var b = this.length;
        while(b--) {
            if(this[b] === a) {
                return true;
            }
        }
        return false;
    };

    /******************************************************************************/

    vAPI.net.registerListeners = function() {
        var µb = µBlock;

        // Until Safari has more specific events, those are instead handled
        // in the onBeforeRequestAdapter; clean them up so they're garbage-collected
        vAPI.net.onBeforeSendHeaders = null;
        vAPI.net.onHeadersReceived = null;

        var onBeforeRequest = vAPI.net.onBeforeRequest,
            onBeforeRequestClient = onBeforeRequest.callback,
            blockableTypes = onBeforeRequest.types;

        var onBeforeRequestAdapter = function(e) {
            if(e.name !== "canLoad") {
                return;
            }
            e.stopPropagation && e.stopPropagation();
            switch(e.message.type) {
                case "main_frame":
                    vAPI.tabs.onNavigation({
                        url: e.message.url,
                        frameId: 0,
                        tabId: vAPI.tabs.getTabId(e.target)
                    });
                    // Don't break here; let main_frame go through
                case "popup":
                    if(e.message.url === 'about:blank') {
                        vAPI.tabs.popupCandidate = vAPI.tabs.getTabId(e.target);
                        e.message = true;
                        return;
                    }
                    else {
                        e.message = !vAPI.tabs.onPopup({
                            url: e.message.url,
                            tabId: 0,
                            sourceTabId: vAPI.tabs.getTabId(e.target)
                        });
                    }
                    break;
                case "popstate":
                    vAPI.tabs.onUpdated(vAPI.tabs.getTabId(e.target), {
                        url: e.message.url
                    }, {
                        url: e.message.url
                    });
                    break;
                default:
                    e.message.hostname = µb.URI.hostnameFromURI(e.message.url);
                    e.message.tabId = vAPI.tabs.getTabId(e.target);
                    var blockVerdict = onBeforeRequestClient(e.message);
                    if(blockVerdict && blockVerdict.cancel) {
                        e.message = false;
                        return;
                    } else {
                        e.message = true;
                        return;
                    }
            }
            return;
        };
        safari.application.addEventListener("message", onBeforeRequestAdapter, true);
    };

    /******************************************************************************/

    vAPI.contextMenu = {
        contextMap: {
            frame: 'insideFrame',
            link: 'linkHref',
            image: 'srcUrl',
            editable: 'editable'
        }
    };

    /******************************************************************************/

    vAPI.contextMenu.create = function(details, callback) {
        var contexts = details.contexts;
        var menuItemId = details.id;
        var menuTitle = details.title;

        if(Array.isArray(contexts) && contexts.length) {
            contexts = contexts.indexOf('all') === -1 ? contexts : null;
        } else {
            // default in Chrome
            contexts = ['page'];
        }

        this.onContextMenu = function(e) {
            var uI = e.userInfo;

            if(!uI || /^https?:\/\//i.test(uI.pageUrl) === false) {
                return;
            }

            if(contexts) {
                var invalidContext = true;
                var ctxMap = vAPI.contextMenu.contextMap;

                for(var i = 0; i < contexts.length; i++) {
                    var ctx = contexts[i];

                    if(ctx === 'audio' || ctx === 'video') {
                        if(uI[ctxMap['image']] && uI.tagName === ctx) {
                            invalidContext = false;
                            break;
                        }
                    } else if(uI[ctxMap[ctx]]) {
                        invalidContext = false;
                        break;
                    } else if(ctx === 'page') {
                        if(!(uI.insideFrame || uI.linkHref || uI.mediaType || uI.editable)) {
                            invalidContext = false;
                            break;
                        }
                    }
                }

                if(invalidContext) {
                    return;
                }
            }

            e.contextMenu.appendContextMenuItem(menuItemId, menuTitle);
        };

        this.onContextMenuCmd = function(e) {
            if(e.command === menuItemId) {
                var tab = e.currentTarget.activeBrowserWindow.activeTab;
                e.userInfo.menuItemId = menuItemId;
                callback(e.userInfo, tab ? {
                    id: vAPI.tabs.getTabId(tab),
                    url: tab.url
                } : undefined);
            }
        };

        safari.application.addEventListener('contextmenu', this.onContextMenu);
        safari.application.addEventListener('command', this.onContextMenuCmd);
    };

    /******************************************************************************/

    vAPI.contextMenu.remove = function() {
        safari.application.removeEventListener('contextmenu', this.onContextMenu);
        safari.application.removeEventListener('command', this.onContextMenuCmd);
        this.onContextMenu = null;
        this.onContextMenuCmd = null;
    };

    /******************************************************************************/

    vAPI.lastError = function() {
        return null;
    };

    /******************************************************************************/

    // This is called only once, when everything has been loaded in memory after
    // the extension was launched. It can be used to inject content scripts
    // in already opened web pages, to remove whatever nuisance could make it to
    // the web pages before uBlock was ready.

    vAPI.onLoadAllCompleted = function() {};

    /******************************************************************************/

    vAPI.punycodeHostname = function(hostname) {
        return hostname;
    };

    vAPI.punycodeURL = function(url) {
        return url;
    };

    /******************************************************************************/

})();