const State = require('../State')

class PackState extends State {
    async apply() {
        if ( !(await this.check()) ) {
            const path = await this._path()
            const destination = await this._destination()
            const type = await this._get_type()
            const cd_cmd = await this._host.get_directory_change_command(await path.parent())

            if ( type === 'tar' ) {
                const tar_cmd = `${cd_cmd} && tar czf "${destination.path}" "${path.name()}"`
                await this._host.run(tar_cmd)
            } else if ( type === 'zip' ) {
                const zip_cmd = `${cd_cmd} && zip -r "${destination.path}" "${path.name()}"`
                await this._host.run(zip_cmd)
            }
        }
    }

    async check() {
        const dest = await this._destination()
        return dest.is_valid()
    }

    async reverse() {
        if ( await this.check() ) {
            const destination = await this._destination()
            await destination.classify()
            if (destination.is_valid()) await destination.unlink()
        }
    }

    async _get_type() {
        if ( this._config.format ) {
            if ( this._config.format === 'tar' ) return 'tar'
            else if ( this._config.format === 'zip' ) return 'zip'
            throw new Error('Invalid unpack format: ' + this._config.type)
        } else {
            const dest = await this._destination()
            if ( dest.path.endsWith('.tar.gz') || dest.path.endsWith('.tgz') ) return 'tar'
            else if ( dest.path.endsWith('.zip') ) return 'zip'
            throw new Error(`Unable to determine unpack type from destination: ${dest}`)
        }
    }

    async _destination() {
        if ( !this._config.destination ) throw new Error('Missing destination config for PackState.')
        return await this._host.get_path(this._config.destination)
    }

    async _path() {
        const path = await this._host.get_path(this._config.path)
        await path.classify()
        if ( !path.is_valid() ) throw new Error(`Invalid path for PathState: ${path}`)
        return path
    }

    failure_message() {
        return `The archive "${this._config.destination}" does not exist on the host "${this._host.name}."`
    }

    check_message() {
        return this.failure_message()
    }
}

module.exports = exports = PackState