/// <reference path="type.d.ts" />
const fs = require("fs")

class Template implements OpenSubmitterTemplateProtocol {

  config: TemplateConfig = {

    // Name and description to display in OpenSubmitter's UI:
    name: 'Basic Template Example (puppeteer)',
    description: 'Open a websites with puppeteer-chromium in headless mode and write output to different files',

    // Based on this setting, OpenSubmitter will inject Puppeteer's page object into this template
    capabilities: ['puppeteer'],

    // This tells OpenSubmitter that the user is allowed to specify amount of threads:
    multiThreadingEnabled: true,

    // User's settings for OpenSubmitter UI:
    userSettings: [
        {
            // A text input with a button which opens "create a file" dialog
            type: 'OutputFile',
            name: 'outputFile',
            title: 'Where to write the output of the download',
            fileName: "",
            required: false,
            uiWidth: 100
        },{
            // Multi-lined text input with pre-filled value
            type: 'Textarea',
            name: 'websites',
            title: 'Websites list, one per line',
            value: 'https://www.google.com/\nhttps://www.github.com/\nhttps://www.bing.com/'
        }
    ]
  };

  // Dummy variable, will be overridden by OpenSubmitter with Puppeteer's page object
  page = null;


  // This method should generate tasks before OpenSubmitter starts executing them
  async generateTasks(...args: any): Promise<TemplateTask[]> {

    // "OutputFile" user settings value from the config above
    const fileName = this.config.userSettings.find(setting => setting.name === 'outputFile').fileName;

    // "Textarea" user settings value from the config
    const websiteValue = this.config.userSettings.find(setting => setting.name === 'websites').value;

    // Splitting websites list by new line
    const websitesList = websiteValue.toString().split("\n")

    const result: TemplateTask[] = [];

    // Iterating through websites list
    for (const website of websitesList) {
        // Validate the website address
        if (!/^(https?:\/\/)?([\da-z.-]+)\.([a-z.]{2,6})([\/\w .-]*)*\/?$/.test(website)) continue;

        // Add website's address and unique text file name to the task
        result.push({
            data: {
                url: website,
                // If file path is specified, return file path + website address without special characters
                // Otherwise have an empty fileName
                fileName: fileName && fileName.length > 0 ?
                    (fileName + "." + website.replace(/[^a-zA-Z0-9]/g, '') + ".txt") :
                    null
            }
        })
    }

    return result;

  }

  // Running the task previously generated in "generateTasks" function
  // Each task is executed in a separate thread.
  async runTask(task: TemplateTask) {

    // Navigate to the task's page
    try {
        this.log(`navigating to ${task.data.url}...`);
        await this.page.goto(task.data.url, {
            waitUntil: "networkidle0",
            timeout: 20000
        });
    } catch (e) {
        this.log('err while loading the page: ' + e);
    }

    // Get the HTML contents of the page
    const result = await this.page.content();

    // If user has provided an output file path, save contents there
    if (task.data.fileName) {
        fs.writeFileSync(task.data.fileName, result);
    }
  }

  log(msg: string) {
    console.log(msg);
  }

}