// ==UserScript==
// @name        Yet Another Reddit Comment Overwriter
// @namespace   https://github.com/adriantache/YARCO/
// @description Local script to overwrite all your comments with random ASCII characters and delete them. This works because Reddit doesn't store editing history, so technically this is the only way to obfuscate the contents of the comments. Based on Reddit Overwrite script v.1.4.8.
// @include     https://*.reddit.com/user/*
// @include     http://*.reddit.com/user/*
// @version     0.1
// @run-at      document-start
// ==/UserScript==

// TODO separate overwrite and delete
// TODO only delete comments older than a day
// TODO only delete comments from a certain subreddit
// TODO check feedback for Reddit Overwrite for extra features
// TODO consider caching comments array
// TODO test Overview page
// TODO add STOP button
// TODO add optional confirmation dialog


// reddit username
unsafeWindow.user = '';
// array of comments (more precisely author tags)
unsafeWindow.comments = [];
// number of detected user comments
// TODO refactor this out
unsafeWindow.num_user_comments = 0;
// top section contents
unsafeWindow.span = '';

//TODO refactor these out
unsafeWindow.to_delete = [];
unsafeWindow.deleted = 0;

//EXTRA OPTIONS
let generate_individual_delete_buttons = false //disabled by default
let time_between_actions = 2000 //reddit API limit is 60 actions per minute so don't exceed that

// on page loaded, initialize the script
window.addEventListener("DOMContentLoaded", init_script, false);

function init_script(ev) {
    // get logged in username
    unsafeWindow.user = document.querySelector("span.user > a:not(.login-required)").innerHTML;

    // if not logged in exit
    if (!unsafeWindow.user) return;

    //retrieve all VISIBLE comments
    get_comments()

    // generate the top buttons
    generate_top_buttons();
}

function get_comments() {
    // find all author tags to eventually get comments
    let comments = document.querySelectorAll("a.author");

    // filter out other authors
    unsafeWindow.comments = [].filter.call(comments, filter_author)

    unsafeWindow.num_user_comments = unsafeWindow.comments.length;
}

// append buttons to page
function generate_top_buttons() {
    if (unsafeWindow.num_user_comments) {
        unsafeWindow.span = document.createElement("div");
        unsafeWindow.span.setAttribute('class', 'nextprev secure_delete_all');
        unsafeWindow.span.innerHTML = "";
        unsafeWindow.span.style.marginBottom = "10px";

        // make Overwrite and Delete All link
        let odlink = document.createElement("a");
        odlink.setAttribute('class', 'bylink');
        odlink.setAttribute('onClick', 'javascript:return recursive_process(true, true)');
        odlink.setAttribute('href', 'javascript:void(0)');
        odlink.style.marginLeft = "10px";
        odlink.appendChild(document.createTextNode('OVERWRITE AND DELETE ' +
            unsafeWindow.comments.length +
            ' COMMENTS'));
        unsafeWindow.span.appendChild(odlink);
        let br = document.createElement("br");
        unsafeWindow.span.appendChild(br);

        // make Overwrite All link
        let olink = document.createElement("a");
        olink.setAttribute('class', 'bylink');
        olink.setAttribute('onClick', 'javascript:return recursive_process(true, false)');
        olink.setAttribute('href', 'javascript:void(0)');
        olink.style.marginLeft = "10px";
        olink.style.position = "relative";
        olink.style.top = "5px";
        olink.appendChild(document.createTextNode('OVERWRITE ' +
            unsafeWindow.comments.length +
            ' COMMENTS'));
        unsafeWindow.span.appendChild(olink);
        let br2 = document.createElement("br");
        unsafeWindow.span.appendChild(br2);

        // make Delete All link
        let dlink = document.createElement("a");
        dlink.setAttribute('class', 'bylink');
        dlink.setAttribute('onClick', 'javascript:return recursive_process(false, true)');
        dlink.setAttribute('href', 'javascript:void(0)');
        dlink.style.marginLeft = "10px";
        dlink.style.position = "relative";
        dlink.style.top = "10px";
        dlink.appendChild(document.createTextNode('DELETE ' +
        unsafeWindow.comments.length +
        ' COMMENTS'));
        unsafeWindow.span.appendChild(dlink);
        
        // TODO test status message
        // let status_message = document.createTextNode("p");
        // status_message.innerHTML = "STATUS";
        // status_message.style.marginLeft = "10px";
        // status_message.style.position = "relative";
        // status_message.style.top = "10px";
        // unsafeWindow.span.appendChild(status_message);

        document.querySelector("div.content").insertBefore(unsafeWindow.span, document.querySelector("div.content").firstChild);

        //add per comment buttons (inactive by default)
        if(generate_individual_delete_buttons) generate_delete_buttons()
    } else if (unsafeWindow.span != null) {
        unsafeWindow.span.style.display = 'none';
    }
}

unsafeWindow.recursive_process = function (overwrite_all, delete_all) {
    //get comments again in case the user has scrolled and revealed more comments
    get_comments()

    let commentsArray = [];

    for (let i = 0; i < unsafeWindow.comments.length; i++) {
        //for each author, get ID of the input field of the comment
        let thing_id = comments[i].parentNode.parentNode.querySelector("form.usertext > input[name='thing_id']").value;

        if (commentsArray.indexOf(thing_id) == -1) {
            commentsArray.push(thing_id);
            //TODO refactor this out
            unsafeWindow.num_user_comments++;
        }
    }

    if (overwrite_all && delete_all) {
        overwrite_all(commentsArray, true);
    } else if (overwrite_all) {
        overwrite_all(commentsArray, false);
    } else if (delete_all) {
        delete_all(commentsArray);
    }
}

function overwrite_all(comments, also_delete) {
    //get next comment id
    let thing_id = comments.pop();

    //overwrite the next comment in the stack
    overwrite_comment(thing_id);

    //if also deleting, add a timeout and delete the comment
    if (also_delete) unsafeWindow.setTimeout(delete_comment(thing_id), time_between_actions);

    //if there are still comments left, get next comment
    //increase timeout if also deleting 
    if (comments.length) unsafeWindow.setTimeout(overwrite_all, also_delete ? time_between_actions * 2 : time_between_actions, comments);
}

function delete_all(comments) {
    delete_comment(comments.pop());

    //if there are still comments left, get next comment 
    if (comments.length) unsafeWindow.setTimeout(delete_all, time_between_actions, comments);
}

function overwrite_comment(thing_id) {
    try {
        //find edit form (hidden on page but active)
        let edit_form = document.querySelector("input[name='thing_id'][value='" + thing_id + "']").parentNode;

        //if comment is currently being edited, cancel out of that 
        let edit_cancel_btn = edit_form.querySelector("div.usertext-edit > div.bottom-area > div.usertext-buttons > button.cancel");
        edit_cancel_btn.click();

        //find edit button and click it
        let edit_btn = edit_form.parentNode.querySelector("ul > li > a.edit-usertext");
        if (edit_btn) edit_btn.click();

        //find edit textbox and replace the string with random chars
        let edit_textbox = edit_form.querySelector("div.usertext-edit > div > textarea");
        let repl_str = '';
        let chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz><.-,+!#$%^&*();:[]~";
        for (let i = 0; i < edit_textbox.value.length; i++) {
            if (edit_textbox.value.substr(i, 1) == '\n') {
                repl_str += '\n';
            } else {
                let random_char = Math.floor(Math.random() * chars.length);
                repl_str += chars.charAt(random_char, 1);
            }
        }

        //set edited value to the random string
        edit_textbox.value = repl_str;

        //find save comment button and click it
        let edit_save_btn = edit_form.querySelector("div.usertext-edit > div.bottom-area > div.usertext-buttons > button.save");
        edit_save_btn.click();
    } catch (e) {
        alert("Error interacting with overwrite form: " + e);
    }
}

function delete_comment(thing_id) {
    try {
        // get current status of comment editing box to prevent deleting comment before overwrite is complete
        let thing = document.querySelector("input[name='thing_id'][value='" + thing_id + "']");
        let status = thing.parentNode.querySelector("div.usertext-edit > div.bottom-area > div.usertext-buttons > span.status").innerHTML;

        if (status.indexOf("error") != -1) {
            alert("Failed to overwrite comment " + thing_id + " due to an unknown reddit error, skipping.");
            return;
        }

        // if status is submitting, there may be an internet connectivity error, so we retry
        if (status.indexOf("submitting") != -1) {
            unsafeWindow.setTimeout(delete_comment, time_between_actions * 5, thing_id);
            return;
        }

        // find delete button and click it and then yes confirmation button
        let del_form = thing.parentNode.parentNode.querySelector("ul.buttons > li > form.del-button");
        unsafeWindow.toggle(del_form.querySelector("span.main > a"));
        del_form.querySelector("span.error > a.yes").click();

    } catch (e) {
        alert("Error deleting comment: " + e);
    }
}

//(UTILITY FUNCTIONS)
function filter_author(comment) {
    return comment.innerHTML == unsafeWindow.user
}


//[UNUSED FUNCTIONS]
//Add a "SECURE DELETE" button near each comment delete button
//TODO refactor this
//TODO add overwrite button
function generate_delete_buttons() {

    for (let i = 0; i < comments.length; i++) {
        // skip comments by anyone else
        if (comments[i].innerHTML != unsafeWindow.user) continue;

        try {
            // get the parent
            let main_parent = comments[i].parentNode.parentNode;
            let thing_id = main_parent.querySelector("form > input[name='thing_id']").value;
            let list = main_parent.querySelector("ul.flat-list");

            // if it already contains the tag, skip
            if (list.querySelector("li.secure_delete")) continue;

            unsafeWindow.num_user_comments++;

            let addedlink = document.createElement("li");
            addedlink.setAttribute('class', 'secure_delete');

            let dlink = document.createElement("a");
            dlink.setAttribute('class', 'bylink secure_delete');
            // TODO test let here
            dlink.setAttribute('onClick', 'javascript:var ret = overwrite_comment("' + thing_id + '", false);');
            dlink.setAttribute('href', 'javascript:void(0)');
            dlink.appendChild(document.createTextNode('SECURE DELETE'));
            addedlink.appendChild(dlink);

            main_parent.querySelector("ul.flat-list").appendChild(addedlink);
        } catch (e) {
            alert("Error adding Secure Delete links to comments.\nError: " + e + " Stack:" + e.stack);
        }
    }
}