const fs = require('fs')
const home_dir = require('os').homedir()
const path = require('path')

const exists = async file => {
    return new Promise(res => {
        fs.promises.stat(file).then(() => res(true)).catch(() => res(false))
    })
}

class ConfigManager {
    config_path = path.resolve(home_dir, '.config', 'pied-vcs.json')

    async initialize() {
        if ( !(await exists(this.config_path)) ) {
            console.error('Pied VCS configuration file does not exist!')
            console.log(`Please create the file "${this.config_path}" with your authentication token and server information.`)
            throw new Error('Missing pied-vcs.json file.')
        }

        this.config = require(this.config_path)

        const required_fields = ['token', 'mountpoint', 'data_server', 'stream_server']
        if ( !this.config || !required_fields.every(field => this.config[field]) ) {
            throw new Error('Invalid config.')
        }
    }
}

module.exports = exports = new ConfigManager()