import chalk from "chalk";
import { setImmediate } from "node:timers";

type ChalkFunction = (...msgs: unknown[]) => string;
type PrimitiveItems = unknown[];

interface UnknownConversion<T> {
    condition: (arg: unknown) => boolean;
    converter: (arg: T) => string;
}

/**
 * A source for pretty and cool and fun logging
 */
class Logging {

    /** Can I be seen by the console and listeners? */
    visible: boolean
    /** What is my name? */
    source: string
    /** Should I use bright colors over dull ones? */
    bright: boolean = true;

    /**
     * Create a logging source
     * ```ts
     * const log = new Logging("Main");
     * 
     * log.i("Hello World!");
     * ```
     * @param source Module identifier. Used in every line to identify the module that sent the message.
     * @param silent Set to false to log a message when the logger instantiates. Useful for debugging.
     * @returns A source for logging messages to the console. Functions for info, warnings, errors, debug statements, and network events are provided and have shorthands.
     */
    constructor(source: string, silent?: boolean, bright?: boolean) {
        this.visible = true;
        this.source = source;
        if (typeof bright == 'boolean') this.bright = bright;

        if (typeof silent == 'boolean' && !silent) this.info(`Instantiated logging for ${this.source}`);
    }

    #log(type: MessageType, chalkColor: ChalkFunction, ...msgs: PrimitiveItems) {
        if (!this.visible) return;
        const func = () => {
            
            let typestr: string;
            switch (type) {
                case MessageType.Info:
                    typestr = '[INFO]';
                    break;
                case MessageType.Warn:
                    typestr = '[WARN]';
                    break;
                case MessageType.Error:
                    typestr = '[ERROR]';
                    break;
                case MessageType.Debug:
                    typestr = '[DEBUG]';
                    break;
                case MessageType.Network:
                    typestr = '[NETWORK]';
                    break;
                default:
                    typestr = '[UNKNOWN]';
                    break;
            }

            const time = new Date();
            let timeFormatted;
            switch (LoggingConfiguration.timeFormat) {
                case TimeFormat.Unix:
                    timeFormatted = time.getTime();
                    break;
                case TimeFormat.Local:
                    timeFormatted = performance.now();
                    break;
                default:
                    timeFormatted = time.toISOString();
            }

            const conversions = [
                {
                    condition: arg => arg instanceof Error,
                    converter: arg => arg.stack || arg.message
                } as UnknownConversion<Error>,
                {
                    condition: arg => arg == null,
                    converter: arg => JSON.stringify(arg)
                } as UnknownConversion<null>,
                {
                    condition: arg => typeof arg == 'object',
                    converter: arg => JSON.stringify(arg)
                } as UnknownConversion<object>,
            ];
            function convertToString(arg: unknown) {
                for (const conversion of conversions) 
                    if (conversion.condition(arg)) 
                        return (conversion.converter as (arg: unknown) => string)(arg);
                        // gpt-4o idea cuz my brain has the `stupid` type

                return String(arg); // fallback
            }

            const str = msgs.map(val => convertToString(val)).join(' ');
            const msg = chalk.gray(`${timeFormatted} `) + chalkColor(chalk.inverse(`${this.source} ${typestr}`) + ` ${str}`);
            console.log(msg);

            try {
                LoggingListeners.emit('basic', msg);
                LoggingListeners.emit('type', str, type, this.source, time);
            } catch (err) {
                console.error(`(FALLBACK ERROR) Callback failed! Stack: ${(err as Error).stack}`);
            }
        }

        if (LoggingConfiguration.logTiming == LogTiming.Sync) func();
        else setImmediate(func);
    }

    /**
     * 
     * @param type The kind of message to log
     * @param msgs Your message(s)
     */
    log(type: MessageType, ...msgs: PrimitiveItems) {
        if (type == MessageType.Info) this.i(...msgs);
        if (type == MessageType.Warn) this.w(...msgs);
        if (type == MessageType.Error) this.e(...msgs);
        if (type == MessageType.Debug) this.d(...msgs);
        if (type == MessageType.Network) this.n(...msgs);
    }

    /** Logging Function */
    i(...msgs: PrimitiveItems) {this.info(...msgs);}
    /** Logging Function */
    info(...msgs: PrimitiveItems) {
        if (!MessageTypeVisibility.Info) return;
        this.#log(MessageType.Info, chalk.whiteBright, ...msgs);
    }
    
    /** Logging Function */
    w(...msgs: PrimitiveItems) {this.warn(...msgs);}
    /** Logging Function */
    warn(...msgs: PrimitiveItems) {
        if (!MessageTypeVisibility.Warn) return;
        this.#log(MessageType.Warn, chalk.yellowBright, ...msgs);
    }
    
    /** Logging Function */
    e(...msgs: PrimitiveItems) {this.error(...msgs);}
    /** Logging Function */
    error(...msgs: PrimitiveItems) {
        if (!MessageTypeVisibility.Error) return;
        this.#log(MessageType.Error, chalk.redBright, ...msgs);
    }
    
    /** Logging Function */
    d(...msgs: PrimitiveItems) {this.debug(...msgs);}
    /** Logging Function */
    debug(...msgs: PrimitiveItems) {
        if (!MessageTypeVisibility.Debug) return;
        this.#log(MessageType.Debug, chalk.greenBright, ...msgs);
    }
    
    /** Logging Function */
    n(...msgs: PrimitiveItems) {this.network(...msgs);}
    /** Logging Function */
    network(...msgs: PrimitiveItems) {
        if (!MessageTypeVisibility.Network) return;
        this.#log(MessageType.Network, chalk.cyanBright, ...msgs);
    }

}

/** Useful for conditional logging with the `log` function */
enum MessageType {
    Info,
    Warn,
    Error,
    Debug,
    Network
}

/** Enable/disable logging of certain message types across all logging sources */
const MessageTypeVisibility = {
    Info: true,
    Warn: true,
    Error: true,
    Debug: true,
    Network: true
}

// 'On Message' event listeners
type BasicListener = (msg: string) => unknown;
type TypeListener = (msg: string, type: MessageType, source: string, time: Date) => unknown;
type Listener = BasicListener | TypeListener;
type ListenerType = 'basic' | 'type';

const basicListeners = new Set<Listener>();
const typeListeners = new Set<Listener>();

class ListenersBase {
    onmsg(type: 'basic', cb: BasicListener): void
    onmsg(type: 'type', cb: TypeListener): void
    onmsg(type: ListenerType, cb: Listener) {
        if (type == 'basic') basicListeners.add(cb);
        else if (type == 'type') typeListeners.add(cb);
    }

    offmsg(type: 'basic', cb: BasicListener): void
    offmsg(type: 'type', cb: TypeListener): void
    offmsg(type: ListenerType, cb: Listener) {
        if (type == 'basic') basicListeners.delete(cb);
        else if (type == 'type') typeListeners.delete(cb);
    }

    emit(type: 'basic', msg: string, msgtype?: MessageType, source?: string, time?: Date): void
    emit(type: 'type', msg: string, msgtype: MessageType, source: string, time: Date): void
    emit(type: ListenerType, msg: string, msgtype: MessageType, source: string, time: Date) {
        if (type == 'basic') 
            for (const cb of basicListeners) (cb as BasicListener)(msg);
        if (type == 'type') 
            for (const cb of typeListeners) (cb as TypeListener)(msg, msgtype, source, time);
    }
}
const LoggingListeners: ListenersBase = new ListenersBase();

enum LogTiming {
    Sync,
    Deferred
}
enum TimeFormat {
    Utc,
    Unix,
    Local
}

class LoggingConfigurationBase {

    #timing: LogTiming = LogTiming.Sync;

    #timeType: TimeFormat = TimeFormat.Utc;

    get timeFormat(): TimeFormat { return this.#timeType }
    set timeFormat(data: TimeFormat) { this.#timeType = data }

    get logTiming(): LogTiming { return this.#timing; }
    set logTiming(data: LogTiming) { this.#timing = data }

}
const LoggingConfiguration: LoggingConfigurationBase = new LoggingConfigurationBase();

export { MessageType, TimeFormat, LogTiming, MessageTypeVisibility, LoggingListeners, LoggingConfiguration };
export default Logging;