Fix some errors, style updates

backend/src/logger.ts

@@ -0,0 +1,104 @@
+import {
+    writeFile
+} from 'node:fs';
+
+const log = ( ...msg: string[] ) => {
+    output( 'log', log.caller.toString(), ...msg );
+};
+
+const info = ( ...msg: string[] ) => {
+    output( 'info', log.caller.toString(), ...msg );
+};
+
+const debug = ( ...msg: string[] ) => {
+    output( 'debug', log.caller.toString(), ...msg );
+};
+
+const warn = ( ...msg: string[] ) => {
+    output( 'warn', log.caller.toString(), ...msg );
+};
+
+const error = ( ...msg: string[] ) => {
+    output( 'error', log.caller.toString(), ...msg );
+};
+
+const fatal = ( ...msg: string[] ) => {
+    output( 'fatal', log.caller.toString(), ...msg );
+};
+
+
+let loc = 'stderr';
+let lev = 0;
+type LogLevel = 'debug' | 'info' | 'log' | 'warn' | 'error' | 'fatal';
+const levels = [
+    'debug',
+    'info',
+    'log',
+    'warn',
+    'error',
+    'fatal'
+];
+
+const configure = ( location: 'stderr' | 'file', minLevel: LogLevel, file?: string ) => {
+    if ( location === 'file' && !file ) {
+        throw new Error( 'File parameter required when location is "file"' );
+    }
+
+    loc = location === 'stderr' ? 'stderr' : file;
+    lev = levels.indexOf( minLevel );
+};
+
+
+const logfile: string[] = [];
+
+const output = ( level: LogLevel, caller: string, ...message: string[] ) => {
+    if ( levels.indexOf( level ) < lev ) {
+        return;
+    }
+
+    const msg = message.join( ' ' );
+    const out = `[${ level.toUpperCase() }] (${ new Date().toISOString() }) in ${ caller }: ${ msg }`;
+
+    if ( loc === 'stderr' ) {
+        console.error( out );
+    } else {
+        logfile.push( out );
+        save();
+    }
+};
+
+let isSaving = false;
+let waitingOnSave = false;
+
+const save = () => {
+    if ( isSaving ) {
+        waitingOnSave = true;
+
+        return;
+    }
+
+    isSaving = true;
+    writeFile( loc, JSON.stringify( logfile ), err => {
+        if ( err )
+            console.error( '[LOGGER] Failed to save with error ' + err );
+
+        if ( waitingOnSave ) {
+            waitingOnSave = false;
+            isSaving = false;
+            save();
+        }
+
+        isSaving = false;
+    } );
+};
+
+
+export default {
+    log,
+    info,
+    debug,
+    warn,
+    error,
+    fatal,
+    configure
+};