const fs = require('fs')
const moment = require('moment');

function get_data() {
    const now = moment();
    const weekYear = now.isoWeekYear()
    const weekNumber = now.isoWeek()
    const filename = `./data/current.json`

    if(!fs.existsSync(filename)) {
        // create data of this week
        clear()
    }
    const content = fs.readFileSync(filename).toString();
    json =  JSON.parse(content)

    return json;
}

function clear() {

  const now = moment();
    const weekYear = now.isoWeekYear()
    const weekNumber = now.isoWeek()

    const filename = `./data/current.json`
    fs.writeFileSync(`./data/${weekYear}-${weekNumber}.json`, fs.readFileSync(filename).toString())

    let tmp_json = JSON.parse(fs.readFileSync("./example.json").toString())

    tmp_json['ganshi'] = generateRandomString(8)
    tmp_json['yuedui'] = generateRandomString(8)
    tmp_json['sheyuan'] = generateRandomString(8)

    fs.writeFileSync(filename, JSON.stringify(tmp_json))
}

function generateRandomString(length) {
    let result = '';
    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const charactersLength = characters.length;
  
    for (let i = 0; i < length; i++) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength));
    }
  
    return result;
  }
  

module.exports = { get_data, clear }