import { context, trace } from '@opentelemetry/api';
import moment from 'moment';
import path from 'path';
import winston from 'winston';
import { getTraceInfoHeader } from "./tracing";
import { B3_INFO_KEY, B3_TRACE_ID_LENGTH_KEY } from "./UoaB3Propagator";
import { UoaLogger } from "./UoaLogger";

const defaultLogPattern = '%date [%thread] %level %class - [[[%traceId,%spanId,%info]]] %message'
const uoaLogLevels = {
    error: 0,
    warn: 1,
    audit: 2,
    info: 3,
    debug: 4
}

const uoaLoggingFormat = function (callingModule: NodeJS.Module) {
    return winston.format.printf((logInfo: any) => {
        let logPattern = process.env.loggingPattern ? process.env.loggingPattern : defaultLogPattern;

        const logReplacements = getLogReplacementValues(callingModule, logInfo);
        logReplacements.forEach((value, key) => {
            logPattern = logPattern.replace(key, value);
        });

        return logPattern;
    });
}

function getLogReplacementValues(callingModule: NodeJS.Module, logInfo: any): Map<string, string> {
    const parts = callingModule.filename.substring(0, callingModule.filename.lastIndexOf('.js')).split(path.sep);
    const moduleParts = parts.slice(parts.indexOf('src'));

    let traceId = '-';
    let spanId = '-';
    const currentContext = trace.getSpanContext(context.active());
    if (currentContext) {
        traceId = currentContext.traceId;
        spanId = currentContext.spanId;
    }

    let info = '-';
    const infoHeader = context.active().getValue(B3_INFO_KEY);
    if (getTraceInfoHeader()) {
        info = getTraceInfoHeader();
    } else if (infoHeader) {
        info = infoHeader.toString();
    }

    let message = '-';
    if (logInfo.message != null) {
        message = logInfo.message;
    }

    const traceIdLength: number = <number>context.active().getValue(B3_TRACE_ID_LENGTH_KEY);

    let logReplacements: Map<string, string> = new Map<string, string>();
    logReplacements.set('%date', moment().toISOString());
    logReplacements.set('%thread', '-');
    logReplacements.set('%level', logInfo.level.toUpperCase());
    logReplacements.set('%class', moduleParts.join('.'));
    logReplacements.set('%traceId', traceId.slice(traceId.length - traceIdLength));
    logReplacements.set('%spanId', spanId);
    logReplacements.set('%info', info);
    logReplacements.set('%message', message.replace(/\n/g, ''));

    return logReplacements;
}

module.exports = function (callingModule: NodeJS.Module) {
    return new UoaLogger({
        levels: uoaLogLevels,
        transports: [
            new winston.transports.Console({
                level: process.env.loggingLevel ? process.env.loggingLevel.toLowerCase() : 'info'
            })
        ],
        format: uoaLoggingFormat(callingModule)
    });
}