/**
 *
 * make screenshots and log errors to
 * console
 * (c) 2019 - Leibniz-Insitut für Wissensmedien
 *
 */

const puppeteer = require('puppeteer');
const fs_bare = require("fs") // required for fs-extra
const fs = require("fs-extra")
const path = require("path")
const start_dir = process.cwd()
const start_file = path.join(start_dir,"lib","index.html")

const start_file_uri = path.join("file:///", start_file )

// define events and log them
const events = ["error","pageerror"]
function logPageEvent(event){
    if (event !== undefined){
     console.log(event.toString())
    }
}

async function makeScreenshot(href){

    const browser = await puppeteer.launch({args: [
        '–allow-file-access-from-files',
      ],});

    const page = await browser.newPage();

    await page.setViewport({width: 1024,height : 624})

    // register events
    for (var i = 0; i < events.length; i++) {
        page.on(events[i],logPageEvent)
    }
    page.once("load",logPageEvent)

    await page.goto(href)
    href = href.replace("file:///","")
    const fname = path.parse(href).name
    let fpath
    if (fname != "index"){
        image_url = href.replace(fname + ".html" ,"thumbnails/" + fname + ".png")
        fpath = href.replace(fname + ".html", "thumbnails")
    }
    else{
        image_url = href.replace(fname + ".html" ,"thumbnail.png")
        fpath = href.replace(fname + ".html", "")
    }
    // image_url = image_url.replace("file:///","")
    // fpath = fpath.replace("file:///","")

    page.removeAllListeners()

    fs.ensureDir(fpath)

    await page.screenshot({path: image_url});
    await browser.close();
}

/**
 *
 * collect all navigational links in all documents
 *
 * */

async function collectLinks(href,reflist)
{
    const browser = await puppeteer.launch();
    const page = await browser.newPage();


    await page.goto(href)
    let hrefs = await page.$$('a.wrapper')

    for (var i=0; i < hrefs.length; i++) {
        let hrefValue = await hrefs[i].getProperty('href')
        let linkText = await hrefValue.jsonValue();
        if (!linkText.startsWith("file:"))
        {
            continue;
        }
        if(linkText.endsWith("#")) continue;
        if(linkText.endsWith("index.html")){
            await collectLinks(linkText,reflist)
        }
        reflist.push(linkText)
    }

    await browser.close()
}

(async function(){
    var reflist = []
    let linkText = "file:///" + start_file.replace(/\\/g,"/")
    reflist.push(linkText)
    await collectLinks(start_file_uri,reflist)

    // sort by path length to get depth first
    reflist.sort(function(a,b){
        let al = a.split("/").length
        let bl = b.split("/").length

        if (al < bl)  {return  1 }
        if (al > bl)  {return -1 }
        if (al == bl) {return  0 }
    })
    for (var i=0;i<reflist.length; i++) {
        await makeScreenshot(reflist[i])
        console.log(i,reflist[i])
    }
})()