import {Level, type Options, type Writer} from './types'
import {get_color} from './color'

export const writers = new Map<string, Writer>
export let options: Options = {
    format: "[$time] $level $namespace :",
    pad_level: true,
    verbose: true,
}

export class Logger {
    constructor(
        private readonly _namespace: string
    ) {}

    public get namespace() : string {
        return this._namespace
    }

    public extend(sub_namespace: string) : Logger {
        return new Logger(`${this.namespace}:${sub_namespace}`)
    }

    public debug(...data: any[]) : void {
        log(data, Level.DEBUG, this._namespace)
    }

    public trace(...data: any[]) : void {
        log(data, Level.TRACE, this._namespace)
    }

    public info(...data: any[]) : void {
        log(data, Level.INFO, this._namespace)
    }

    public warn(...data: any[]) : void {
        log(data, Level.WARNING, this._namespace)
    }

    public error(...data: any[]) : void {
        log(data, Level.ERROR, this._namespace)
    }
}

function log(message: any[], level: Level, namespace: string) : void {
    if (writers.size === 0) {
        if (options.verbose) console.log("No writer subscribed, discard message")
        return
    }

    // Format header of log
    const head = options.format
        .replace("$time", new Date().toISOString())
        .replace("$namespace", namespace)

    let lvl = get_string(level)
    if (!options.pad_level) lvl = lvl.trimEnd()

    const head_color = head.replace('$level', get_color(level)(lvl))
    const head_bw = head.replace('$level', lvl)

    for (const [name, writer] of writers.entries()) {
        const options = writer.options
        if (options?.minLevel > level) {
            if (options.verbose) console.log(`Writer's level is lower, discard message for ${name}`)
            continue
        }
        writer.log(level, options?.with_color ? head_color : head_bw, ...message)
    }
}

function get_string(level: Level) : string {
    switch (level) {
        case Level.DEBUG: return "DEBUG  "
        case Level.TRACE: return "TRACE  "
        case Level.INFO: return "INFO   "
        case Level.WARNING: return "WARNING"
        case Level.ERROR: return "ERROR  "
    }
}