6 files changed, 143 insertions, 0 deletions
diff --git a/u/trace/log/ansi.ts b/u/trace/log/ansi.ts
new file mode 100644
index 0000000..7ff16a3
--- /dev/null
+++ b/u/trace/log/ansi.ts
@@ -0,0 +1,15 @@
+export const ANSI = {
+    RESET: '\x1b[0m',
+    BOLD: '\x1b[1m',
+    DIM: '\x1b[2m',
+    RED: '\x1b[31m',
+    GREEN: '\x1b[32m',
+    YELLOW: '\x1b[33m',
+    BLUE: '\x1b[34m',
+    MAGENTA: '\x1b[35m',
+    CYAN: '\x1b[36m',
+    WHITE: '\x1b[37m',
+    BRIGHT_RED: '\x1b[91m',
+    BRIGHT_YELLOW: '\x1b[93m',
+    GRAY: '\x1b[90m',
+};
diff --git a/u/trace/log/index.ts b/u/trace/log/index.ts
new file mode 100644
index 0000000..670e333
--- /dev/null
+++ b/u/trace/log/index.ts
@@ -0,0 +1,5 @@
+export * from './ansi.js';
+export * from './level.js';
+export * from './logger.js';
+export * from './pretty_json_console.js';
+export * from './trace.js';
diff --git a/u/trace/log/level.ts b/u/trace/log/level.ts
new file mode 100644
index 0000000..027dd71
--- /dev/null
+++ b/u/trace/log/level.ts
@@ -0,0 +1,19 @@
+export enum LogLevel {
+    UNKNOWN = 'UNKNOWN',
+    INFO = 'INFO',
+    WARN = 'WARN',
+    DEBUG = 'DEBUG',
+    ERROR = 'ERROR',
+    SYS = 'SYS',
+}
+
+export const logLevelOrder: Array<LogLevel> = [
+    LogLevel.DEBUG,
+    LogLevel.INFO,
+    LogLevel.WARN,
+    LogLevel.ERROR,
+    LogLevel.SYS,
+];
+
+export const isLogLevel = (l: unknown): l is LogLevel =>
+    typeof l === 'string' && logLevelOrder.some((level) => level === l);
diff --git a/u/trace/log/logger.ts b/u/trace/log/logger.ts
new file mode 100644
index 0000000..3ced60a
--- /dev/null
+++ b/u/trace/log/logger.ts
@@ -0,0 +1,5 @@
+import { LogLevel } from './level.js';
+
+export interface ILogger {
+    readonly log: (level: LogLevel, ...args: string[]) => void;
+}
diff --git a/u/trace/log/pretty_json_console.ts b/u/trace/log/pretty_json_console.ts
new file mode 100644
index 0000000..758af51
--- /dev/null
+++ b/u/trace/log/pretty_json_console.ts
@@ -0,0 +1,39 @@
+import { ANSI, LogLevel, ILogger } from './index.js';
+
+export class PrettyJsonConsoleLogger implements ILogger {
+    public log(level: LogLevel, ...trace: string[]) {
+        const message = JSON.stringify(
+            {
+                level,
+                trace,
+            },
+            null,
+            4,
+        );
+        const styled = `${this.getStyle(level)}${message}${ANSI.RESET}\n`;
+        this.getStream(level)(styled);
+    }
+
+    private getStream(level: LogLevel) {
+        if (level === LogLevel.ERROR) {
+            return console.error;
+        }
+        return console.log;
+    }
+
+    private getStyle(level: LogLevel) {
+        switch (level) {
+            case LogLevel.UNKNOWN:
+            case LogLevel.INFO:
+                return `${ANSI.MAGENTA}`;
+            case LogLevel.DEBUG:
+                return `${ANSI.CYAN}`;
+            case LogLevel.WARN:
+                return `${ANSI.BRIGHT_YELLOW}`;
+            case LogLevel.ERROR:
+                return `${ANSI.BRIGHT_RED}`;
+            case LogLevel.SYS:
+                return `${ANSI.DIM}${ANSI.BLUE}`;
+        }
+    }
+}
diff --git a/u/trace/log/trace.ts b/u/trace/log/trace.ts
new file mode 100644
index 0000000..3f9f1b2
--- /dev/null
+++ b/u/trace/log/trace.ts
@@ -0,0 +1,60 @@
+import { isDebug, ITrace, ITraceWith, memoize, Supplier } from '@emprespresso/pengueno';
+import { ILogger, isLogLevel, LogLevel, logLevelOrder, PrettyJsonConsoleLogger } from './index.js';
+
+export type LogTraceSupplier = ITraceWith<Supplier<string>> | ITraceWith<Error>;
+
+export class LogTrace implements ITrace<LogTraceSupplier> {
+    constructor(
+        private readonly logger: ILogger = new PrettyJsonConsoleLogger(),
+        private readonly traces: Array<LogTraceSupplier> = [defaultTrace],
+        private readonly defaultLevel: LogLevel = LogLevel.INFO,
+        private readonly allowedLevels: Supplier<Set<LogLevel>> = defaultAllowedLevelsSupplier,
+    ) {}
+
+    public traceScope(trace: LogTraceSupplier): ITrace<LogTraceSupplier> {
+        return new LogTrace(this.logger, this.traces.concat(trace), this.defaultLevel, this.allowedLevels);
+    }
+
+    public trace(trace: LogTraceSupplier) {
+        const { traces, level: _level } = this.foldTraces(this.traces.concat(trace));
+        if (!this.allowedLevels().has(_level)) return;
+
+        const level = _level === LogLevel.UNKNOWN ? this.defaultLevel : _level;
+        this.logger.log(level, ...traces);
+    }
+
+    private foldTraces(_traces: Array<LogTraceSupplier>) {
+        const _logTraces = _traces.map((trace) => (typeof trace === 'function' ? trace() : trace));
+        const _level = _logTraces
+            .filter((trace) => isLogLevel(trace))
+            .reduce((acc, level) => Math.max(logLevelOrder.indexOf(level), acc), -1);
+        const level = logLevelOrder[_level] ?? LogLevel.UNKNOWN;
+
+        const traces = _logTraces
+            .filter((trace) => !isLogLevel(trace))
+            .map((trace) => {
+                if (typeof trace === 'object') {
+                    return `TracedException.Name = ${trace.name}, TracedException.Message = ${trace.message}, TracedException.Stack = ${trace.stack}`;
+                }
+                return trace;
+            });
+        return {
+            level,
+            traces,
+        };
+    }
+}
+
+const defaultTrace = () => `TimeStamp = ${new Date().toISOString()}`;
+const defaultAllowedLevels = memoize(
+    (isDebug: boolean) =>
+        new Set([
+            LogLevel.UNKNOWN,
+            ...(isDebug ? [LogLevel.DEBUG] : []),
+            LogLevel.INFO,
+            LogLevel.WARN,
+            LogLevel.ERROR,
+            LogLevel.SYS,
+        ]),
+);
+const defaultAllowedLevelsSupplier = () => defaultAllowedLevels(isDebug());