const fs = require('fs');
var request = require('request');

const kb = require('../utils/kb-util.js');


// const https = require("https");


/* TODO: ?? parallel read
  // var request = require('request-promise');
  var calls = [
    request({
        url: 'https://storage.googleapis.com/pythia-files/uploads/json/emarket-keywords.json',
        // headers: { ... }
    }),
    request({
        url: 'https://storage.googleapis.com/pythia-files/uploads/json/emarket-products.json',
        // headers: { ... }
    }),
    // + linked-terms and replaces
    // and more..
  ];
  
  Promise.all(calls).then(function(results) {
    // do something with results[0]
    // do something with results[1]
    // ...
  });
*/


/** create entity file from url
 * used for entities like 'linked-words', 'synonyms', etc.
 * 
 * @param {string} entity: use the entity name 
 * @param {string} url: prepared entity json-file in remote server
 */
function create(entity, url) {
    request(url,
        function (error, response, body) {
            if (!error && response.statusCode == 200) {
                // body is a ready json-string; no need to parse and (re-)stringify
                try {
                    fs.writeFileSync(`${__dirname}/../../data/${entity}.json`, body, 'utf-8');
                    // file written successfully
                } catch (err) {
                    console.error(err);
                }
            }
        }
    );
}

function get_data_structure() {
    // data structure is an array of `{ url:.., expiration:.., path:.. }` objects
}

function set_data_structure(node) {

}


function load_products(url) {
    request(url,
        function (error, response, body) {
            if (!error && response.statusCode == 200) {
                // body is a ready json-string; no need to parse and (re-)stringify
                json = JSON.parse(body);
                newJson = [];

                // TODO:
                // + attach handle synonyms
                // + mark brand-names
                // + attach category-names and SAP-categories
                // + construct combo words
                // + remove non-important words
                // + normalize popularity

                json.forEach( p => {
                    newJson.push({
                        id: p.id,
                        w: p.w,
                        kb: kb.keyboardize(kb.clean(p.w))
                    });
                });
                
                try {

                    fs.writeFileSync(
                        `${__dirname}/../../data/products.json`,
                        JSON.stringify(newJson),
                        'utf-8'
                    );
                    return true;    // file written successfully

                } catch (err) {
                    console.error(err);
                    return false;
                }
            }
        }
    );
}


// create data
// testing an implemenatatin of a custom local-fs-cache system
function random() {
    var data = [];
    for( let i = 0; i < (Math.floor(Math.random() * 100) +15) ; i++) {
        data.push({ id: i, x5: i*5 });
    }
    
    try {
        fs.writeFileSync(__dirname + '/../data/random.json', JSON.stringify(data), 'utf-8');
        // file written successfully
    } catch (err) {
        console.error(err);
    }
}


module.exports = {
    create,
    random,
    load_products
}