import {LoggingLevel, LogMessage} from './types'
import * as color from 'colors/safe'
import {Awaitable} from '../support/types'

/**
 * Base class for an application logger.
 */
export abstract class Logger {
    /**
     * Write the given message to the log destination.
     * @param {LogMessage} message
     * @return Promise<void>
     */
    public abstract write(message: LogMessage): Awaitable<void>;

    /**
     * Format the date object to the string output format.
     * @param {Date} date
     * @return string
     */
    protected formatDate(date: Date): string {
        const hours = date.getHours()
        const minutes = date.getMinutes()
        const seconds = date.getSeconds()
        return `${date.getFullYear()}-${date.getMonth()+1}-${date.getDate()} ${hours > 9 ? hours : '0' + hours}:${minutes > 9 ? minutes : '0' + minutes}:${seconds > 9 ? seconds : '0' + seconds}`
    }

    /**
     * Given a logging level, get the display string of that level.
     * @param {LoggingLevel} level
     * @return string
     */
    protected levelDisplay(level: LoggingLevel): string {
        switch (level) {
        case LoggingLevel.Success:
            return color.green('success')
        case LoggingLevel.Error:
            return color.red('  error')
        case LoggingLevel.Warning:
            return color.yellow('warning')
        case LoggingLevel.Info:
            return color.blue('   info')
        case LoggingLevel.Debug:
            return color.cyan('  debug')
        case LoggingLevel.Verbose:
            return color.gray('verbose')
        case LoggingLevel.Silent:
            return color.gray(' silent')
        }
    }
}