import * as fs from "fs";

export function readData(path: string, cb: (errOrData) => void): void {
    fs.readFile(path, 'utf8', (err, data) => {
        if (err)
            return cb(err)
        let testData = JSON.parse(data).data
        cb(testData)
    })
}

export function createObject<T>(base: any, extend: any): T {
    return Object.assign(base, extend)
}

export function getPassedTime(startMs: number, endMs: number = null): string {
    if (endMs == null)
        endMs = Date.now()
    let totalTime = endMs - startMs
    if (totalTime === Number.NaN || totalTime < 0)
        totalTime = 0;
    let timeStr = totalTime + ""
    if (totalTime < 1000)
        timeStr = totalTime + ' ms'
    else if (totalTime < 1000*60)
        timeStr = Math.floor(totalTime / 1000) + ' sec'
    else if (totalTime < 1000*60*60)
        timeStr = Math.floor(totalTime / (1000*60)) + ' min'
    else //if (totalTime < 1000*60*60*24)
        timeStr = Math.floor(totalTime / (1000*60*60)) + ' h'
    return timeStr
}

export function dumpError(err, logger = null): string {
    if (logger === null)
        logger = console
    let output = ''
    // log() with 1 argument is only available on console logger. debug()/error() on winston & console
    if (!err)
        return output
    if (typeof err === 'object' && err.stack) {
        logger.error('Error:');
        output += 'Error:\r\n'
        if (err.message) {
            logger.error('Message: ' + err.message)
            output += 'Message: ' + err.message + '\r\n'
        }
        if (err.stack) {
            logger.error('Stacktrace:')
            logger.error('====================')
            logger.error(err.stack);
            output += 'Stacktrace:\r\n====================\r\n' + JSON.stringify(err.stack, null, 4)
        }
    }
    else {
        logger.error(err);
        output += JSON.stringify(err, null, 4)
    }
    output += '\r\n'
    return output
}

export function assertUnreachableCode(x: never): never {
    throw new Error("Unexpected object: " + x);
}