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

    µBlock - a Chromium 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
*/

// For non background pages

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

(function() {

'use strict';

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

self.vAPI = self.vAPI || {};
self.vAPI.safari = true;

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

var messagingConnector = function(response) {
    if ( !response ) {
        return;
    }

    var channel, listener;

    if ( response.broadcast === true ) {
        for ( channel in vAPI.messaging.channels ) {
            listener = vAPI.messaging.channels[channel].listener;
            if ( typeof listener === 'function' ) {
                listener(response.msg);
            }
        }
        return;
    }

    if ( response.requestId ) {
        listener = vAPI.messaging.listeners[response.requestId];
        delete vAPI.messaging.listeners[response.requestId];
        delete response.requestId;
    }

    if ( !listener ) {
        channel = vAPI.messaging.channels[response.portName];
        listener = channel && channel.listener;
    }

    if ( typeof listener === 'function' ) {
        listener(response.msg);
    }
};

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

var uniqueId = function() {
    return parseInt(Math.random() * 1e10, 10).toString(36);
};

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

// relevant?
// https://developer.apple.com/library/safari/documentation/Tools/Conceptual/SafariExtensionGuide/MessagesandProxies/MessagesandProxies.html#//apple_ref/doc/uid/TP40009977-CH14-SW12
vAPI.messaging = {
    channels: {},
    listeners: {},
    requestId: 1,
    connectorId: uniqueId(),

    setup: function() {
        this.connector = function(msg) {
            // messages from the background script are sent to every frame,
            // so we need to check the connectorId to accept only
            // what is meant for the current context
            if (msg.name === vAPI.messaging.connectorId
                || msg.name === 'broadcast') {
                messagingConnector(msg.message);
            }
        };
        safari.self.addEventListener('message', this.connector, false);

        this.channels['vAPI'] = {
            listener: function(msg) {
                if (msg.cmd === 'runScript' && msg.details.code) {
                    Function(msg.details.code).call(self);
                }
            }
        };
    },
    close: function() {
        if (this.connector) {
            safari.self.removeEventListener('message', this.connector, false);
            this.connector = null;
            this.channels = {};
            this.listeners = {};
        }
    },
    channel: function(channelName, callback) {
        if ( !channelName ) {
            return;
        }

        this.channels[channelName] = {
            portName: channelName,
            listener: typeof callback === 'function' ? callback : null,
            send: function(message, callback) {
                if (!vAPI.messaging.connector) {
                    vAPI.messaging.setup();
                }

                message = {
                    portName: this.portName,
                    msg: message
                };

                if ( callback ) {
                    message.requestId = vAPI.messaging.requestId++;
                    vAPI.messaging.listeners[message.requestId] = callback;
                }

                // popover content doesn't know messaging...
                if (safari.extension.globalPage) {
                    if (!safari.self.visible) {
                        return;
                    }

                    safari.extension.globalPage.contentWindow
                        .vAPI.messaging.onMessage({
                            name: vAPI.messaging.connectorId,
                            message: message,
                            target: {
                                page: {
                                    dispatchMessage: function(name, msg) {
                                        messagingConnector(msg);
                                    }
                                }
                            }
                        });
                }
                else {
                    safari.self.tab.dispatchMessage(
                        vAPI.messaging.connectorId,
                        message
                    );
                }
            },
            close: function() {
                delete vAPI.messaging.channels[this.portName];
            }
        };

        return this.channels[channelName];
    }
};

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

// content scripts are loaded into extension pages by default, but they shouldn't

if (location.protocol === "safari-extension:") {
    return;
}

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

window.MutationObserver = window.MutationObserver || window.WebKitMutationObserver;

if (!window.MutationObserver) {
    // dummy, minimalistic shim for older versions (<6)
    // only supports node insertions, but currently we don't use it for anything else
    window.MutationObserver = function(handler) {
        this.observe = function(target) {
            target.addEventListener('DOMNodeInserted', function(e) {
                handler([{addedNodes: [e.target]}]);
            }, true);
        };
    };
}

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

var beforeLoadEvent = document.createEvent('Event');
beforeLoadEvent.initEvent('beforeload');

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

var frameId = window === window.top ? 0 : Date.now() % 1E5;
var linkHelper = document.createElement('a');
var onBeforeLoad = function(e, details) {
    if (e.url && e.url.slice(0, 5) === 'data:') {
        return;
    }

    linkHelper.href = details ? details.url : e.url;

    if (!/^https?:/.test(linkHelper.protocol)) {
        return;
    }

    if (details) {
        details.url = linkHelper.href;
    }
    else {
        details = {
            url: linkHelper.href
        };

        switch (e.target.nodeName.toLowerCase()) {
            case 'frame':
            case 'iframe':
                details.type = 'sub_frame';
                break;
            case 'script':
                details.type = 'script';
                break;
            case 'img':
            case 'input': // type=image
                details.type = 'image';
                break;
            case 'object':
            case 'embed':
                details.type = 'object';
                break;
            case 'link':
                var rel = e.target.rel.trim().toLowerCase();

                if (rel.indexOf('icon') > -1) {
                    details.type = 'image';
                    break;
                }
                else if (rel === 'stylesheet') {
                    details.type = 'stylesheet';
                    break;
                }
            default:
                details.type = 'other';
        }

        // This can run even before the first DOMSubtreeModified event fired
        if (firstMutation) {
            firstMutation();
        }
    }

    // tabId is determined in the background script
    // details.tabId = null;
    details.frameId = frameId;
    details.parentFrameId = frameId ? 0 : -1;
    details.timeStamp = Date.now();

    var response = safari.self.tab.canLoad(e, details);

    if (!response) {
        if (details.type === 'main_frame') {
            window.stop();
        }
        else {
            e.preventDefault();
        }

        return false;
    }
    // local mirroring, response is a data: URL here
    else if (typeof response === 'string' && details.type === 'script') {
        // Content Security Policy with disallowed inline scripts may break things
        e.preventDefault();
        details = document.createElement('script');
        details.textContent = atob(response.slice(response.indexOf(',', 20) + 1));

        if (e.target.hasAttribute('defer') && document.readyState === 'loading') {
            var jsOnLoad = function(ev) {
                this.removeEventListener(ev.type, jsOnLoad, true);
                this.body.removeChild(this.body.appendChild(details));
            };

            document.addEventListener('DOMContentLoaded', jsOnLoad, true);
        }
        else {
            e.target.parentNode.insertBefore(details, e.target);
            details.parentNode.removeChild(details);
        }
    }
};

document.addEventListener('beforeload', onBeforeLoad, true);

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

// block pop-ups, intercept xhr requests, and apply site patches
var firstMutation = function() {
    document.removeEventListener('DOMSubtreeModified', firstMutation, true);
    firstMutation = null;
    var randEventName = parseInt(Math.random() * 1e15, 10).toString(36);

    window.addEventListener(randEventName, function(e) {
        var result = onBeforeLoad(beforeLoadEvent, e.detail);

        if (result === false) {
            e.detail.url = false;
        }
    }, true);

    // the extension context is unable to reach the page context,
    // also this only works when Content Security Policy allows inline scripts
    var tmpJS = document.createElement('script');
    var tmpScript = ["(function() {",
        "var block = function(u, t) {",
            "var e = document.createEvent('CustomEvent'),",
                "d = {url: u, type: t};",
            "e.initCustomEvent('" + randEventName + "', !1, !1, d);",
            "dispatchEvent(e);",
            "return d.url === !1;",
        "}, wo = open, xo = XMLHttpRequest.prototype.open;",
        "open = function(u) {",
            "return block(u, 'popup') ? null : wo.apply(this, [].slice.call(arguments));",
        "};",
        "XMLHttpRequest.prototype.open = function(m, u, s) {",
            "return xo.apply(this, block(u, 'xmlhttprequest') ? ['HEAD', u, s] : [].slice.call(arguments));",
        "};"
    ];

    if (vAPI.sitePatch
        && !safari.self.tab.canLoad(beforeLoadEvent, {isWhiteListed: location.href})) {
        tmpScript.push('(' + vAPI.sitePatch + ')();');
    }

    tmpScript.push("})();");
    tmpJS.textContent = tmpScript.join('');
    document.documentElement.removeChild(document.documentElement.appendChild(tmpJS));
};

document.addEventListener('DOMSubtreeModified', firstMutation, true);

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

var onContextMenu = function(e) {
    var details = {
        tagName: e.target.tagName.toLowerCase(),
        pageUrl: location.href,
        insideFrame: window !== window.top
    };

    details.editable = details.tagName === 'textarea' || details.tagName === 'input';

    if ('checked' in e.target) {
        details.checked = e.target.checked;
    }

    if (details.tagName === 'a') {
        details.linkUrl = e.target.href;
    }

    if ('src' in e.target) {
        details.srcUrl = e.target.src;

        if (details.tagName === 'img') {
            details.mediaType = 'image';
        }
        else if (details.tagName === 'video' || details.tagName === 'audio') {
            details.mediaType = details.tagName;
        }
    }

    safari.self.tab.setContextMenuEventUserInfo(e, details);
};

self.addEventListener('contextmenu', onContextMenu, true);

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

// 'main_frame' simulation
if (frameId === 0) {
    onBeforeLoad(beforeLoadEvent, {
        url: location.href,
        type: 'main_frame'
    });
}

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

self.vAPI.canExecuteContentScript = function() {
    return /^https?:/.test(location.protocol);
};

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

})();

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