// ==UserScript==
// @name         ImagesInChat
// @namespace    https://github.com/Drumber
// @version      0.2.7
// @description  Better chat for itslearning
// @author       Drumber
// @match        https://*.itslearning.com/*
// @updateURL    https://raw.githubusercontent.com/Drumber/itslearning-UserScripts/master/itslearning-ImagesInChat.user.js
// @downloadURL  https://raw.githubusercontent.com/Drumber/itslearning-UserScripts/master/itslearning-ImagesInChat.user.js
// @require      https://gist.github.com/raw/2625891/waitForKeyElements.js
// @require      https://openuserjs.org/src/libs/sizzle/GM_config.js
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// ==/UserScript==

/* Config stuff */
// register menu command
GM_registerMenuCommand('Script Settings', () => {
    // open GM_config dialog
    GM_config.open();
});

// initialize and construct config
GM_config.init(
{
    'id': 'Settings',
    'title': 'Script Settings',
    'fields':
    {
        'image-viewer':
        {
            'label': 'Enable image viewer',
            'type': 'checkbox',
            'default': 'true'
        },
        'lazy-loading':
        {
            'label': 'Image lazy-loading',
            'type': 'checkbox',
            'default': 'true'
        },
        'image-paste':
        {
            'label': 'Paste images in chat (Chrome only)',
            'type': 'checkbox',
            'default': 'true'
        },
        'image-drop':
        {
            'label': 'Drag & Drop files in chat',
            'type': 'checkbox',
            'default': 'true'
        },
        'send-on-enter':
        {
            'label': 'Send message with Enter',
            'type': 'checkbox',
            'default': 'true'
        }
    },
    'events': // callback functions
    {
        'open': function() { GM_config.frame.setAttribute('style', 'width: 300px; height: 500px; inset: 20px 20px auto auto; z-index: 9999; position: fixed; overflow: auto; max-width: 95%; max-height: 95%;'); }
    },
    'css': '#Settings { background: #212121 !important; color: #ffffff !important; } #Settings .reset { color: #ffffff !important; }'
});


(function() {
    'use strict';
    console.log("Images-In-Chat script is activated...");
    // trigger function when a message element was found
    waitForKeyElements(".c-messages__attachment .c-messages__attachment-content", processMessageElement);
    // add file paste listener
    window.addEventListener("paste", (event) => onPasteEvent(event), false);
    // add file-drop listener when message body was added
    waitForKeyElements(".c-messages__body.c-messages__body--scroll.c-conversation", onMessageBodyAdded);
})();

function processMessageElement(jNode) {
    // expects div with class ".c-messages__header-thread_name"
    var msg = jNode[0];
    // find anchor child element
    var imgAnchor = msg.getElementsByTagName("a")[0];
    // check if attachment anchor element exists and if
    // there is not already an added img element
    if(imgAnchor && !msg.getElementsByTagName("img")[0]) {
        // try to get attachment url
        var imgUrl = imgAnchor.href;
        if(imgUrl) {
            // remove "Download=1" attribute
            imgUrl = imgUrl.replace("&Download=1");
            // create new img element
            var img = document.createElement("img");
            img.src = imgUrl;
            // TODO: maybe reduce image size
            if(GM_config.get('lazy-loading')) {
                // lazy loading on supported browsers
                img.loading = "lazy";
            }
            // set onclick event if image-viewer is enabled
            if(GM_config.get('image-viewer')) {
                img.onclick = function() {
                    showImage(this);
                }
            }
            // add img elemt to parent of message
            msg.parentElement.appendChild(img);
            //console.log("Found and added image to message.", imgUrl);
            // remove img on invalid image type
            img.onerror = function() {
                msg.parentElement.removeChild(img);
                //console.log("Removed invalid image.", img);
            }
        }
    }
}

function showImage(eventImage) {
    var img = eventImage.cloneNode(true); // clone image element
    img.loading = "eager"; // load image right away

    // remove any existing dialog
    var existingDialog = document.getElementById("custom-image-viewer");
    if(existingDialog) {
        document.body.removeChild(existingDialog);
    }

    var dialog = document.createElement("div");
    dialog.id = "custom-image-viewer";
    var ds = dialog.style; // dialog style
    ds.overflow = "hidden";
    ds.display = "block";
    ds.position = "fixed";
    ds.left = "50%";
    ds.top = "50%";
    ds.transform = "translate(-50%, -50%)";
    ds.zIndex = "9999";
    ds.maxWidth = "95%";
    ds.maxHeight = "95%";
    ds.background = "rgba(10,10,10,0.8)";
    ds.padding = "10px";
    ds.borderRadius = "10px";

    // get actual image size
    var w = img.naturalWidth;
    var h = img.naturalHeight;

    var ims = img.style; // image style
    ims.maxWidth = "none";
    ims.cursor = "zoom-in";
    ims.transform = "rotate(0deg)";
    // set width and height of the image and dialog
    ims.width = `${w}px`;
    ims.height = `${h}px`;
    ds.width = `${w + 40}px`;
    ds.height = `${h + 60}px`;

    var imgWrapper = document.createElement("div");
    imgWrapper.style.cssText = "overflow: auto; height: 95%; width: 100%;";
    imgWrapper.appendChild(img);

    var btnStyle = "color: #ffffff; font-size: 24px; background: 0; border: none;";
    // close button
    var closeBtn = document.createElement("button");
    closeBtn.innerHTML = "✕";
    closeBtn.style.cssText = btnStyle;
    closeBtn.onclick = function() {
        document.body.removeChild(dialog); // remove dialog
    }

    // rotate left button
    var rotateLbtn = document.createElement("button");
    rotateLbtn.style.cssText = btnStyle;
    rotateLbtn.innerHTML = "↺";
    rotateLbtn.onclick = function() {
        var oldAngle = parseInt(ims.transform.replace("rotate(", "").replace("deg)", ""));
        ims.transform = `rotate(${oldAngle - 90}deg)`;
    }

    // rotate right button
    var rotateRbtn = document.createElement("button");
    rotateRbtn.style.cssText = btnStyle;
    rotateRbtn.innerHTML = "↻";
    rotateRbtn.onclick = function() {
        var oldAngle = parseInt(ims.transform.replace("rotate(", "").replace("deg)", ""));
        ims.transform = `rotate(${oldAngle + 90}deg)`;
    }

    var dialogHead = document.createElement("div");
    dialogHead.style.cssText = "width: 100%; height: 30px; display: flex; padding-bottom: 5px; flex-direction: row; flex-wrao: nowrap; justify-content: flex-end;";
    dialogHead.appendChild(rotateLbtn);
    dialogHead.appendChild(rotateRbtn);
    dialogHead.appendChild(closeBtn);

    dialog.appendChild(dialogHead);
    dialog.appendChild(imgWrapper);

    // add zoom on image click
    img.onclick = function(e) {
        if(ims.width != `${w}px`) {
            // reset image size
            ims.width = `${w}px`;
            ims.height = `${h}px`;
        } else {
            var scaleFactor = 2;
            ims.width = `${w * scaleFactor}px`;
            ims.height = `${h * scaleFactor}px`;

            // scroll to click position
            imgWrapper.scrollTo(e.x, e.y);

            img.addEventListener('mousemove', function moveListener(e) {
                // remove listener
                if(ims.width == `${w}px`) {
                    img.removeEventListener('mousemove', moveListener);
                    return;
                }
                // scroll to mouse pos
                var deltaX = (e.x - window.innerWidth / 2) / 2;
                var deltaY = (e.y - window.innerHeight / 2) / 2;
                imgWrapper.scrollBy(deltaX, deltaY);
            });
        }
    }

    // animate if supported by browser
    if(dialog.animate) {
        dialog.animate([
            { transform: 'translate(-50%, -50%) scale(0.5)', opacity: '0.75' },
            { transform: 'translate(-50%, -50%) scale(1)', opacity: '1' }
            ], {
            duration: 200
        });
    }

    // show dialog
    document.body.appendChild(dialog);

    // add close listener when clicked outside
    window.onclick = function(event) {
        // check if clicked element is a descendant of the dialog
        if(dialog.contains(event.target) == false) {
            try {
                document.body.removeChild(dialog);
            } catch(error) {}
        }
    }
}


function onMessageBodyAdded(jNode) {
    var msgBody = jNode[0];
    if(msgBody) {
        // set up file drop events
        msgBody.addEventListener("drop", dropHandler);
        msgBody.addEventListener("dragover", dragOverHandler);
        msgBody.addEventListener("dragleave", dragEndHandler);
        msgBody.addEventListener("dragend", dragEndHandler);
        msgBody.addEventListener("drop", dragEndHandler);

        // set up send on enter events
        var msgFields = document.getElementsByClassName("emoji-wysiwyg-editor instant-message-editor");
        for(var i = 0; i < msgFields.length; i++) {
            var field = msgFields[i];
            field.addEventListener("keydown", onMessagesKey);
        }
    }
}

function dropHandler(e) {
    if(!GM_config.get('image-drop')) return;
    e.preventDefault();
    // get list of drop items
    var items = e.dataTransfer.items;
    if(items) {
        // use DataTransferItemList interface
        for(var i = 0; i < items.length; i++) {
            if(items[i].kind != "file") continue; // continue if item is not a file
            var blob = items[i].getAsFile();
            sendFileBlob(blob);
        }
    } else {
        // use DataTransfer interface
        var files = e.dataTransfer.files;
        for(var j = 0; j < files.length; j++) {
            sendFileBlob(files[j]);
        }
    }
}

function dragOverHandler(e) {
    if(!GM_config.get('image-drop')) return;
    e.preventDefault();
    // show drop effect
    e.dataTransfer.dropEffect = "copy";
    if(document.getElementById("drop-overlay")) return; // return if overlay already exists
    // add semi transparent filter
    var msgBody = document.getElementsByClassName("c-messages__body c-messages__body--scroll c-conversation")[0];
    if(msgBody) {
        msgBody.style.filter = "opacity(70%) blur(2px)";
    }
}

function dragEndHandler(e) {
    if(!GM_config.get('image-drop')) return;
    e.preventDefault();
    var msgBody = document.getElementsByClassName("c-messages__body c-messages__body--scroll c-conversation")[0];
    if(msgBody) {
        msgBody.style.filter = "none";
    }
}


/* Gets triggered when user tries to paste something. Works only on Chrome based browsers.
 * If the pasted file is an image, it will be send as an attachment. */
function onPasteEvent(pasteEvent) {
    var items = pasteEvent.clipboardData.items;
    if(!items || !GM_config.get('image-paste')) return;
    for(var i = 0; i < items.length; i++) {
        if(items[i].type.indexOf("image") == -1) continue; // continue if file is not an image
        var blob = items[i].getAsFile();
        sendFileBlob(blob);
    }
}

function sendFileBlob(blob) {
    // constuct object to simulate a FileList
    var fileList = [blob];
    var fileObj = {files: fileList};

    var bindings = getSendBtnBinding();
    if(bindings.userCanSendMessagesInThread() == true) {
        var threadId = bindings.params.currentThread().instantMessageThreadId;
        // t: object contains 'input' element with type 'file'
        // r: undefined
        // i: thread id
        // o: undefined
        // c: undefined
        bindings.uploadAttachments(fileObj, undefined, threadId, undefined, undefined);
    }
}


function onMessagesKey(e) {
    if(e.shiftKey || !GM_config.get('send-on-enter')) return; // do nothing if shift key is pressed or feature is disabled
    if(e.keyCode === 13 || e.key === "Enter") {
        var btn = document.getElementsByClassName("c-modern__button c-modern__button--confirm u-fr u-no-wrap js-im-send")[0];
        if(btn) {
            btn.click();
        }
    }
}


function getSendBtnBinding() {
    var btn = document.getElementsByClassName("c-modern__button c-modern__button--confirm u-fr u-no-wrap js-im-send")[0];
    return ko.dataFor(btn);
}


// Get all functions which were binded using knockout.js
// interesting code lines: instantmessageapp.js line 4122
    // first we need some element that has a binding, e.g. the 'send' button
    //var sendBtn = document.getElementsByClassName("c-modern__button c-modern__button--confirm u-fr u-no-wrap js-im-send")[0];
    // next we get the data from knockout
    //var data = ko.dataFor(sendBtn);

// other solution to access all kinds of api functions: require.s.contexts._.defined
// e.g.: require.s.contexts._.defined["js/utils/instantmessage-api"]