// ==UserScript==
// @name     ao3 subscribe to feed
// @version  1
// @require  http://crypto.stanford.edu/sjcl/sjcl.js
// @grant    GM.getValue
// @grant    GM.setValue
// @include  https://archiveofourown.org/works/*
// ==/UserScript==
// User script for Firefox

// Password management

async function decodeOrPrompt(targVar, userPrompt, setValVarName, encKey) {
    if (targVar) {
        targVar = unStoreAndDecrypt(targVar, encKey);
    }
    else {
        targVar = prompt(
            userPrompt + ' not set for ' + location.hostname + '. Please enter it now:',
            ''
        );
        await GM.setValue(setValVarName, encryptAndStore(targVar, encKey));
    }
    return targVar;
}

function encryptAndStore(clearText, encKey) {
    return JSON.stringify(sjcl.encrypt(encKey, clearText));
}

function unStoreAndDecrypt(jsonObj, encKey) {
    return sjcl.decrypt(encKey, JSON.parse(jsonObj));
}

async function getCredentials() {
    var encKey = await GM.getValue("encKey", "");
    var usr = await GM.getValue("ttrssUser", "");
    var pword = await GM.getValue("ttrssPass", "");

    if (!encKey) {
        encKey = prompt(
            'Script key not set for ' + location.hostname + '. Please enter a random string:',
            ''
        );
        await GM.setValue("encKey", encKey);

        usr = pword = "";   // New key makes prev stored values (if any) unable to decode.
    }
    usr = await decodeOrPrompt(usr, "TTRSS user", "ttrssUser", encKey);
    pword = await decodeOrPrompt(pword, "TTRSS password", "ttrssPass", encKey);
    return { usr: usr, pword: pword };
}

// Function to add a button to the <ul> element
function addSubscriptionButton() {
    const ulElement = document.querySelector("ul.work");
    if (ulElement) {
        const newLi = document.createElement("li");
        const button = document.createElement("button");
        button.textContent = "Subscribe to RSS";
        button.onclick = async function () {
            // Extract work_id from the URL
            const workIdMatch = window.location.href.match(/works\/(\d+)/);
            if (workIdMatch) {
                const workId = workIdMatch[1];
                const rssURL = `https://nas.franpenedo.com/rss-bridge/?action=display&bridge=AO3Bridge&context=Work&id=${workId}&format=atom`;

                // Call the login method to get a session ID
                try {
                    const sessionID = await loginToTinyTinyRSS();

                    // Subscribe to the RSS feed using the session ID
                    try {
                        await subscribeToFeed(rssURL, sessionID);
                        alert("Subscribed successfully!");
                    } catch (error) {
                        alert("Error subscribing to feed: " + error);
                    }
                } catch (error) {
                    alert("Error logging in: " + error);
                }
            } else {
                alert("Unable to extract work_id from the URL.");
            }
        };

        newLi.appendChild(button);
        ulElement.appendChild(newLi);
    }
}

// Function to simulate a login to Tiny Tiny RSS
async function loginToTinyTinyRSS() {
    const creds = await getCredentials();
    const loginResponse = await fetch("https://news.nas.franpenedo.com/api/", {
        method: "POST",
        headers: {
            "Content-Type": "application/x-www-form-urlencoded",
        },
        body: JSON.stringify({ op: "login", user: creds.usr, password: creds.pword }),
    });

    const data = await loginResponse.json();
    if (data.content.hasOwnProperty("session_id")) {
        return data.content.session_id;
    } else {
        console.log(data);
        throw new Error("Login failed");
    }
}

// Function to subscribe to an RSS feed in Tiny Tiny RSS
async function subscribeToFeed(feedURL, sessionID) {
    const subscribeResponse = await fetch("https://news.nas.franpenedo.com/api/", {
        method: "POST",
        headers: {
            "Content-Type": "application/x-www-form-urlencoded",
        },
        body: JSON.stringify({ op: "subscribeToFeed", feed_url: feedURL, category_id: 11, sid: sessionID }),
    });

    const subscribeData = await subscribeResponse.json();
    if (subscribeData.content.status.code !== 1) {
        console.log(subscribeData);
        throw new Error("Subscription failed");
    }
}

// Call the function to add the button
addSubscriptionButton();