import fs from 'fs'
import readline from 'readline'
import iconv from 'iconv-lite'

ipcMain.on('readfile', async (event, arg) => {
    await readLines()
    event.sender.send('readfile-reply', 'complete')
})

function readLines() {
    return new Promise((resolve, reject) => {
        stream = fs.createReadStream(filePath).pipe(iconv.decodeStream('shift-jis'))
        let reader = readline.createInterface(stream, {})
        reader
            .on('line', line => {
                insertLine(line)
            })
            .on('close', () => {
                resolve() // "Resolve" in the close event.
            })
            .on('error', function(err) {
                reject(err)
            })
    })
}