added new logging system

api/src/services/logging/logger.ts

@@ -0,0 +1,67 @@
+export type LogLevel = 'debug' | 'info' | 'warn' | 'error';
+export type LogDepth = 'normal' | 'verbose';
+export type LogType = 'http' | 'app';
+
+export interface LogHeader {
+    timestamp: string;
+    level: LogLevel;
+    depth: LogDepth;
+    type: LogType; // 'http', 'app', 'db', etc.
+    user_id?: number;
+}
+
+export interface LogPayload {
+    message?: string;              // short human-friendly description
+    data?: Record<string, any>;    // type-specific rich data
+}
+
+// Environment defaults
+const CURRENT_DEPTH: LogDepth = (process.env.LOG_DEPTH as LogDepth) || 'normal';
+
+const DEPTH_ORDER: Record<LogDepth, number> = { normal: 0, verbose: 1 };
+
+function shouldLog(level: LogLevel, depth: LogDepth) {
+    return DEPTH_ORDER[depth] >= DEPTH_ORDER[CURRENT_DEPTH];
+}
+
+function emitLog(header: LogHeader, payload: LogPayload = {}) {
+    if (!shouldLog(header.level, header.depth)) return;
+
+    const logLine = { ...header, ...payload };
+    console.log(JSON.stringify(logLine));
+}
+
+export const logger = {
+    log(level: LogLevel, type: LogType, message: string, data?: Record<string, any>, depth: LogDepth = 'normal', context?: Partial<LogHeader>) {
+        const header: LogHeader = {
+            timestamp: new Date().toISOString(),
+            level,
+            depth,
+            type,
+            ...context,
+        };
+
+        const payload: LogPayload = {
+            message,
+            data,
+        };
+
+        emitLog(header, payload);
+    },
+
+    info(type: string, message: string, data?: Record<string, any>, depth: LogDepth = 'normal', context?: Partial<LogHeader>) {
+        this.log('info', type, message, data, depth, context);
+    },
+
+    debug(type: string, message: string, data?: Record<string, any>, depth: LogDepth = 'normal', context?: Partial<LogHeader>) {
+        this.log('debug', type, message, data, depth, context);
+    },
+
+    warn(type: string, message: string, data?: Record<string, any>, depth: LogDepth = 'normal', context?: Partial<LogHeader>) {
+        this.log('warn', type, message, data, depth, context);
+    },
+
+    error(type: string, message: string, data?: Record<string, any>, depth: LogDepth = 'normal', context?: Partial<LogHeader>) {
+        this.log('error', type, message, data, depth, context);
+    },
+}