var https = require("https");
var path = require("path");
var fs = require("fs");

// The authentication key (API Key).
// Get your own by registering at https://app.pdf.co
const API_KEY = "***********************************";

// Direct URLs of files to merge. Supports documents, spreadsheets, images as sources.
// You can also upload your own file into PDF.co and use it as url. Check "Upload File" samples for code snippets: https://github.com/bytescout/pdf-co-api-samples/tree/master/File%20Upload/    
const SourceFiles = [
    "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/pdf-merge/sample1.pdf",
    "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/other/Input.xls",
    "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/doc-to-pdf/sample.docx",
    "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/image-to-pdf/image1.png",
    "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/image-to-pdf/image2.jpg"
];
// Destination PDF file name
const DestinationFile = "./result.pdf";

// Prepare request to `Merge Documents` API endpoint
var queryPath = `/v1/pdf/merge2`;

// JSON payload for api request
var jsonPayload = JSON.stringify({
    name: path.basename(DestinationFile), url: SourceFiles.join(","), async: true
});

var reqOptions = {
    host: "api.pdf.co",
    method: "POST",
    path: queryPath,
    headers: {
        "x-api-key": API_KEY,
        "Content-Type": "application/json",
        "Content-Length": Buffer.byteLength(jsonPayload, 'utf8')
    }
};
// Send request
var postRequest = https.request(reqOptions, (response) => {
    response.on("data", (d) => {
        // Parse JSON response
        var data = JSON.parse(d);
        if (data.error == false) {
            console.log(`Job #${data.jobId} has been created!`);
            checkIfJobIsCompleted(data.jobId, data.url);
        }
        else {
            // Service reported error
            console.log(data.message);
        }
    });
}).on("error", (e) => {
    // Request error
    console.log(e);
});

// Write request data
postRequest.write(jsonPayload);
postRequest.end();

function checkIfJobIsCompleted(jobId, resultFileUrl) {
    let queryPath = `/v1/job/check`;

    // JSON payload for api request
    let jsonPayload = JSON.stringify({
        jobid: jobId
    });

    let reqOptions = {
        host: "api.pdf.co",
        path: queryPath,
        method: "POST",
        headers: {
            "x-api-key": API_KEY,
            "Content-Type": "application/json",
            "Content-Length": Buffer.byteLength(jsonPayload, 'utf8')
        }
    };

    // Send request
    var postRequest = https.request(reqOptions, (response) => {
        response.on("data", (d) => {
            response.setEncoding("utf8");

            // Parse JSON response
            let data = JSON.parse(d);
            console.log(`Checking Job #${jobId}, Status: ${data.status}, Time: ${new Date().toLocaleString()}`);

            if (data.status == "working") {
                // Check again after 3 seconds
                setTimeout(function () { checkIfJobIsCompleted(jobId, resultFileUrl); }, 3000);
            }
            else if (data.status == "success") {
                // Download PDF file
                var file = fs.createWriteStream(DestinationFile);
                https.get(resultFileUrl, (response2) => {
                    response2.pipe(file)
                        .on("close", () => {
                            console.log(`Generated PDF file saved as "${DestinationFile}" file.`);
                        });
                });
            }
            else {
                console.log(`Operation ended with status: "${data.status}".`);
            }
        })
    });

    // Write request data
    postRequest.write(jsonPayload);
    postRequest.end();
}