import {Logger} from './Logger'
import {LogMessage} from './types'
import {Injectable} from '../../di'
import {universalPath} from '../support/path'
import {appPath, env} from '../../lifecycle/Application'
import {Writable} from 'stream'

/**
 * A Logger implementation that writes to a UniversalPath.
 */
@Injectable()
export class FileLogger extends Logger {
    private resolvedPath?: Writable

    /**
     * Get the re-usable write stream to the log file.
     * @protected
     */
    protected async getWriteStream(): Promise<Writable> {
        if ( !this.resolvedPath ) {
            let basePath = env('EXTOLLO_LOGGING_FILE')
            if ( basePath && !Array.isArray(basePath) ) {
                basePath = [basePath]
            }

            const resolvedPath = basePath ? universalPath(...basePath) : appPath('..', '..', 'extollo.log')

            if ( !(await resolvedPath.exists()) ) {
                await resolvedPath.concat('..').mkdir()
                await resolvedPath.write('')
            }

            this.resolvedPath = await resolvedPath.writeStream()
        }

        return this.resolvedPath
    }

    public async write(message: LogMessage): Promise<void> {
        const text = `${message.level} ${this.formatDate(message.date)} (${message.callerName || 'Unknown'}) ${message.output}`
        const stream = await this.getWriteStream()
        stream.write(text + '\n')
    }
}