window.displayIsReady = false;

let testMode = false;

const path = require('path');

// Source: https://stackoverflow.com/a/45130990
const { promisify } = require('util');
const { resolve } = require('path');
const fs = require('fs');
const readdir = promisify(fs.readdir);
const stat = promisify(fs.stat);

async function getFiles(dir) {
    const subdirs = await readdir(dir);
    const files = await Promise.all(subdirs.map(async (subdir) => {
        const res = resolve(dir, subdir);
        return (await stat(res)).isDirectory() ? getFiles(res) : res;
    }));
    return files.reduce((a, f) => a.concat(f), []);
}

function extToMime(ext) {
    if (ext.startsWith(".")) ext = ext.substring(1);

    switch (ext) {
        case "jpg":
        case "jpe":
        case "jpeg":
        case "jfif":
        case "jif":
        case "jfi":
            return "image/jpeg";

        case "png":
            return "image/png";

        case "webp":
            return "image/webp";

        case "gif":
            return "image/gif";

        case "swf":
            return "application/x-shockwave-flash";

        case "webm":
            return "video/webm";

        case "mp4":
        case "m4v":
        case "mp4v":
            return "video/mp4";
    }
}
// ------------------------------------

async function slideshowMain() {
    console.log("Slideshow: Flushing queue");
    window.displayQueue = [];

    console.log("Slideshow: Displaying loader");
    initiateLoad();

    let pageDerpibooru = 1;
    let pageLocal = 1;
    let seed = Buffer.from(crypto.getRandomValues(new Uint8Array(32))).toString("hex");

    console.log(config);

    async function loadNextPageDerpibooru() {
        if (!config.modules.derpibooru || !(config._sessionPreferences.sources === 0 || config._sessionPreferences.sources === 2)) return;
        console.log("Slideshow: Loading page " + pageDerpibooru + " from Derpibooru");

        let res = await fetch("https://derpibooru.org/api/v1/json/search/images/?q=" + (testMode ? "suggestive" : "explicit") + (
            config._sessionPreferences.content === 0 ?
                ",%20mime_type:image/*"
            : (config._sessionPreferences.content === 1 ?
                ",%20mime_type:video/*"
            :
                ""
            )
        ) + ",%20faved_by:" + encodeURIComponent(config.modules.derpibooru.source) + "&per_page=" + Math.round(50 * config.modules.derpibooru.proportion) + "&filter_id=56027&sf=random:" + seed + "&page=" + pageDerpibooru);
        let json = await res.json();

        if (json["images"].length === 0 && pageDerpibooru !== 1) {
            console.log("Slideshow: Reached the end of Derpibooru, wrapping around");
            pageDerpibooru = 1;
            await loadNextPageDerpibooru();
            return;
        }

        json["images"] = json["images"].map(i => {
            i["_source"] = "https://derpibooru.org/images/" + i["id"];
            return i;
        });

        window.displayQueue.push(...json["images"].map(i => {
            if (!config.modules.derpibooru['faunerie_cache']) return i;
            if (!fs.existsSync(config.modules.derpibooru['faunerie_cache'] + "/images/" + i['sha512_hash'].substring(0, 1) + "/" + i['sha512_hash'].substring(0, 2) + "/" + i['sha512_hash'].substring(0, 3) + "/10" + i['id'] + ".bin")) return i;
            i['view_url'] = "pbip://" + config.modules.derpibooru['faunerie_cache'] + "/images/" + i['sha512_hash'].substring(0, 1) + "/" + i['sha512_hash'].substring(0, 2) + "/" + i['sha512_hash'].substring(0, 3) + "/10" + i['id'] + ".bin";
            return i;
        }));
        window.displayQueue = window.displayQueue.sort(() => Math.random() - Math.random());
        pageDerpibooru++;
    }

    let fullList;

    if (config.modules.local && (config._sessionPreferences.sources === 1 || config._sessionPreferences.sources === 2)) {
        fullList = (await getFiles(config.modules.local.source)).filter(i => !path.basename(i).startsWith(".") && extToMime(path.extname(i)));
    }

    async function loadNextPageLocal() {
        if (!config.modules.derpibooru || !(config._sessionPreferences.sources === 1 || config._sessionPreferences.sources === 2)) return;
        console.log("Slideshow: Loading page " + pageLocal + " from local filesystem");

        let res = fullList.slice((pageLocal - 1) * Math.round(50 * config.modules.derpibooru.proportion), pageLocal * Math.round(50 * config.modules.derpibooru.proportion));
        let json = {
            images: res.map(i => {
                return {
                    _file: i,
                    id: path.basename(i),
                    mime_type: extToMime(path.extname(i)),
                    view_url: "file://" + encodeURI(i.replaceAll("\\", "/"))
                }
            })
        };

        if (json["images"].length === 0 && pageLocal !== 1) {
            console.log("Slideshow: Reached the end of local filesystem, wrapping around");
            pageLocal = 1;
            await loadNextPageLocal();
            return;
        }

        json["images"] = json["images"].map(i => {
            i["_source"] = i["_file"];
            return i;
        });

        window.displayQueue.push(...json["images"]);
        window.displayQueue = window.displayQueue.sort(() => Math.random() - Math.random()).filter(i => {
            if (config._sessionPreferences.content === 0) {
                return i.mime_type.startsWith("image/");
            } else if (config._sessionPreferences.content === 1) {
                return i.mime_type.startsWith("video/");
            } else {
                return true;
            }
        });
        pageLocal++;
    }

    console.log("Slideshow: Loading first page");
    await loadNextPageDerpibooru();
    await loadNextPageLocal();

    console.log("Slideshow: Starting slideshow");
    await startSlideshow(false, async () => {
        await loadNextPageDerpibooru();
        await loadNextPageLocal();
    });

    console.log("Slideshow: Removing loader");
    completeLoad();
    window.displayIsReady = true;
}

window.addEventListener("load", () => {
    setTimeout(async () => {
        window.config = await require('electron/renderer').ipcRenderer.invoke("getConfig");
        await slideshowMain();
    }, 1000);
});