Remove writers from lib

Closes #4

src/logger.ts

@@ -0,0 +1,77 @@
+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 $namespace :",
+}
+
+export class Logger {
+    private readonly _namespace: string
+
+    constructor(namespace: string) {
+        this._namespace = namespace
+    }
+
+    public get namespace() : string {
+        return this._namespace
+    }
+
+    public extend(sub_namespace: string) : Logger {
+        return new Logger(`${this.namespace}:${sub_namespace}`)
+    }
+
+    public debug(...data: any[]) : void {
+        log(data, Level.DEBUG, this._namespace)
+    }
+
+    public trace(...data: any[]) : void {
+        log(data, Level.TRACE, this._namespace)
+    }
+
+    public info(...data: any[]) : void {
+        log(data, Level.INFO, this._namespace)
+    }
+
+    public warn(...data: any[]) : void {
+        log(data, Level.WARNING, this._namespace)
+    }
+
+    public error(...data: any[]) : void {
+        log(data, Level.ERROR, this._namespace)
+    }
+}
+
+function log(message: any[], level: Level, namespace: string) : void {
+    if (writers.size === 0) return
+
+    // Format header of log
+    const head = options.format
+        .replace("$time", new Date().toISOString())
+        .replace("$namespace", namespace)
+    const head_bw = head.replace('$level', level_to_string(level, false))
+    const head_color = head.replace("$level", level_to_string(level, true))
+
+    for (const writer of writers.values()) {
+        writer.log(level, writer.options.with_color ? head_color : head_bw, ...message)
+    }
+}
+
+function level_to_string(level: Level, with_color: boolean) : string {
+    const str = get_string(level)
+
+    if (!with_color) return str
+
+    const color = get_color(level)
+    return color(str)
+}
+
+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  "
+    }
+}