const { app, BrowserWindow } = require('electron');
const {randomUUID} = require("node:crypto");
const { Command } = require('commander');
const express = require('express');
const multer = require('multer');
const path = require("path");
const fs = require("fs");

function writeFile(ext,data)
{
    let file = randomUUID() + "." + ext;
    fs.writeFileSync(
        path
            .resolve(
                __dirname,
                "./output/",
                file
            ),
        data
    );
    return file;
}

/**
 * @param {{type,website,range,background,size}} options 
 * @returns {Promise<[Buffer,string]>}
 */
async function generatePDF(options) {
    const win = new BrowserWindow({
        webPreferences:{
            contextIsolation: true,
            nodeIntegration: false,
            disableDialogs: false,
            webSecurity: true
        },
        show: false,
        width: options.width,
        height: options.height
    });


    await new Promise(ok => {
        win.webContents.addListener("did-finish-load",()=>{
            ok()
        });
        win.webContents.addListener("did-fail-load",()=>{
            console.error("Hata oluştu")
        });

        if(options.htmlcontent)
        {
            win.loadURL(`data:text/html;base64,${Buffer.from(options.htmlcontent).toString("base64")}`);
        }else{
            win.loadURL(options.endpoint);
        }
    })


    let result = await new Promise(result => {
        switch(options.type)
        {
            case "mhtml":{
                win.webContents.savePage(path.resolve(__dirname, randomUUID() + ".mhtml"),"HTMLOnly");
                break;
            }
            case "image":{
                win.webContents.setZoomFactor(Math.max(0, Math.min(3.0, options.zoom)))
                win.webContents.capturePage().then(e => {
                    let binary = e.toPNG();
                    result([binary, "png"]);
                });
                break;
            }
            case "pdf":{
                win.webContents.printToPDF({
                    printBackground: true,
                    displayHeaderFooter: false,
                    scale: options.scale,
                    landscape: options.landscape,
                    pageSize: options.pageSize,
                    pageRanges: options.pageRanges
                }).then(data => {
                    result([data, "pdf"]);
                });
                break;
            }
        }
    });
    win.destroy();

    return result;
};

app.disableDomainBlockingFor3DAPIs();
app.disableHardwareAcceleration();

app.addListener("window-all-closed",function(){

});


async function main()
{
    await new Promise(ok => {
        app.whenReady().then(() => {
            ok()
        });
    });


    let port = express();


    port.use(express.static(path.resolve(__dirname,"./output/"),{
        acceptRanges: true,
        cacheControl: true,
        etag: true,
        lastModified: true
    }))
    port.use(express.static(path.resolve(__dirname,"./public/"),{
        acceptRanges: true,
        cacheControl: true,
        etag: true,
        lastModified: true
    }))

    port.use(function(request, response, next){
        response.header("Access-Control-Allow-Origin","*");
        response.header("Access-Control-Allow-Headers","*");
        response.header("Access-Control-Allow-Methods","GET, POST, OPTION");
        next();
    });

    let memory = multer({storage: multer.memoryStorage()}).none();

    port.post("/pdf", memory,async (request, response) => {

        let {
            width,
            height,
            scale,
            content: htmlcontent,
            endpoint,
            isLandscape,
            pageSize,
            pageRanges,
            output
        } = request.body;

        output = output || "content";

        let [content, extension] = await generatePDF({
            htmlcontent,
            endpoint,
            type: "pdf",
            landscape: isLandscape || false,
            scale: scale || 1.0,
            width: width || 1920,
            height: height || 1080,
            pageSize: pageSize || "A4",
            range: pageRanges || ""
        });

        switch(output)
        {
            case "json":{
                let image = writeFile(extension,content);
                response.json({
                    status: "success",
                    data: image,
                    type: "pdf"
                });
                break;
            }
            case "json+base64":{
                response.json({
                    status: "success",
                    data: `data:application/pdf;base64,${content.toString("base64")}`,
                    type: "pdf"
                });
                break;
            }
            case "content":{
                response.contentType(extension);
                response.end(content);
                break;
            }
        }
    });

    port.post("/image", memory,async (request, response) => {
        let {
            width,
            height,
            zoom,
            content: htmlcontent,
            endpoint,
            output
        } = request.body;

        output = output || "content";

        let [content, extension] = await generatePDF({
            htmlcontent,
            endpoint,
            type: "image",
            zoom: zoom || 1.0,
            width: width || 1920,
            height: height || 1080
        });

        switch(output)
        {
            case "json":{
                let image = writeFile(extension,content);
                response.json({
                    status: "success",
                    data: image,
                    type: "image"
                });
                break;
            }
            case "json+base64":{
                response.json({
                    status: "success",
                    data: `data:image/png;base64,${content.toString("base64")}`,
                    type: "image"
                });
                break;
            }
            case "content":{
                response.contentType(extension);
                response.end(content);
                break;
            }
        }
    });
    port.listen(8473);
}
process.nextTick(main);