import type { Level, Logger } from './types';

export abstract class BaseLogger<Args extends unknown[] = unknown[]>
    implements Logger<Args>
{
    constructor(protected readonly name: string) {}

    /**
     * Log a debug level message.
     * Appropriate for verbose logging that explains steps/details of the inner state of
     * a code unit.
     *
     * Example uses include in a size-constrain datastructure, logging when the size
     * exceeds the threshold and elements are removed, or in a virtual scrolling
     * component logging when a scroll event causes a new page of elements to be loaded.
     *
     * @param args Arguments to log (same as console.debug)
     * @return empty string (for use in brackets {} in svelte components)
     */
    debug(...args: Args): string {
        return this.log('debug', ...args);
    }

    /**
     * Log an info level message.
     * Appropriate for informational messages that may be relevant to consumers of a code
     * unit.
     *
     * Example uses include a router logging when transitions occur or a button logging
     * clicks.
     *
     * @param args Arguments to log (same as console.info)
     * @return empty string (for use in brackets {} in svelte components)
     */
    info(...args: Args): string {
        return this.log('info', ...args);
    }

    /**
     * Log a warn level message.
     * Appropriate for situations where state has been (or likely will be) corrupted or
     * invariants have been broken.
     *
     * Example uses include a data structure warning when it is used before being fully
     * initialized.
     *
     * @param args Arguments to log (same as console.warn)
     * @return empty string (for use in brackets {} in svelte components)
     */
    warn(...args: Args): string {
        return this.log('warn', ...args);
    }

    /**
     * Log an error message.
     * Appropriate for thrown errors or situations where the apps breaks or has to
     * engage in fallback behavior to avoid a more catastrophic failure.
     *
     * @param args Arguments to log (same as console.error)
     * @return empty string (for use in brackets {} in svelte components)
     */
    error(...args: Args): string {
        return this.log('error', ...args);
    }

    protected abstract log(method: Level, ...args: Args): string;
}