export namespace Log {
    var currentLevel: Level = "INFO"

    if (process.env.NODE_ENV !== 'production') { 
        currentLevel = "DEBUG"
    }

    export type Level = "ERROR" | "WARN" | "INFO" | "DEBUG"

    export function setLevel(level: Level) {
        currentLevel = level
    }


    export interface LogArgs {
        [key: string]: string
    }

    export function Error(message: string, extras?: LogArgs) {
        doLog("ERROR", message, extras)
    }
    export function Warn(message: string, extras?: LogArgs) {
        doLog("WARN", message, extras)
    }
    export function Info(message: string, extras?: LogArgs) {
        doLog("INFO", message, extras)
    }
    export function Debug(message: string, extras?: LogArgs) {
        doLog("DEBUG", message, extras)
    }

    function doLog(level: Level, message: string, extras?: LogArgs) {
        var logLine = `[${level}] ${message}`

        if (extras) {
            Object.keys(extras).forEach((key) => {
                logLine = logLine + ` ${key}=${extras[key]}`
            })
        }

        if (levelToNumber(level) >= levelToNumber(currentLevel)) {
            console.log(logLine)
        }
    }

    function levelToNumber(level: Level): number {
        switch (level) {
            case "DEBUG":
                return 0
            case "INFO":
                return 1
            case "ERROR":
                return 2
            case "WARN":
                return 3
        }
    }
}