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

// `request` module is required for file upload.
// Use "npm install request" command to install.
var request = require("request");

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

// Encoded Source PDF file. This PDF is Encrypted with AES128 algorithm.
// 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 SourceFileUrl = "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/encryption/sample_encrypted_aes128.pdf";

// Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
const Pages = "";

// Refer to documentations for more info. https://apidocs.pdf.co/32-1-user-controlled-data-encryption-and-decryption
const Profiles = "{ 'DataDecryptionAlgorithm': 'AES128', 'DataDecryptionKey': 'HelloThisKey1234', 'DataDecryptionIV': 'TreloThisKey1234' }";


// Prepare request to `PDF To JPEG` API endpoint
var queryPath = `/v1/pdf/convert/to/jpg`;

// JSON payload for api request
var jsonPayload = JSON.stringify({
    pages: Pages, url: SourceFileUrl, profiles: Profiles, 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.error(e);
});

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

function checkIfJobIsCompleted(jobId, resultFileUrlJson) {
    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, resultFileUrlJson)} , 3000);
            }
            else if (data.status == "success") {

                request({ method: 'GET', uri: resultFileUrlJson, gzip: true },
                    function (error, response, body) {

                        // Parse JSON response
                        let respJsonFileArray = JSON.parse(body);
                        let page = 1;

                        respJsonFileArray.forEach((url) => {
                            var localFileName = `./page${page}.jpg`;
                            var file = fs.createWriteStream(localFileName);
                            https.get(url, (response2) => {
                                response2.pipe(file)
                                    .on("close", () => {
                                        console.log(`Generated JPEG file saved as "${localFileName} file."`);
                                    });
                            });
                            page++;
                        }, this);

                    });
            }
            else {
                console.log(`Operation ended with status: "${data.status}".`);
            }
        })
    });
    
    // Write request data
    postRequest.write(jsonPayload);
    postRequest.end();
}