From 429e5c6a3652fc4349c8e71700327494f22ee79b Mon Sep 17 00:00:00 2001
From: "Brian P. Holt" <bholt+github@planetholt.com>
Date: Tue, 10 Jan 2023 18:09:50 -0600
Subject: [PATCH] provide a LoggerFactory[F] given a Trace[F]

---
 .../typelevel/log4cats/natchez/package.scala  | 84 ++++++++++++-------
 1 file changed, 53 insertions(+), 31 deletions(-)

diff --git a/core/shared/src/main/scala/org/typelevel/log4cats/natchez/package.scala b/core/shared/src/main/scala/org/typelevel/log4cats/natchez/package.scala
index b812848..7914985 100644
--- a/core/shared/src/main/scala/org/typelevel/log4cats/natchez/package.scala
+++ b/core/shared/src/main/scala/org/typelevel/log4cats/natchez/package.scala
@@ -4,43 +4,65 @@ import _root_.natchez._
 import cats._
 import cats.syntax.all._
 import org.typelevel.log4cats.extras.LogLevel
+import org.typelevel.log4cats.natchez.TraceLogger._
 
 package object natchez {
-  /**
-   * `LogLevel` as an OpenTelemetry `SeverityNumber`
-   *
-   * See https://opentelemetry.io/docs/reference/specification/logs/data-model/#field-severitynumber
-   *
-   * @return LogLevel as an OpenTelemetry SeverityNumber, converted to the TraceValue ADT
-   */
-  private val logLevelToSeverityNumber: LogLevel => TraceValue = {
-    case LogLevel.Trace => 1
-    case LogLevel.Debug => 5
-    case LogLevel.Info => 9
-    case LogLevel.Warn => 13
-    case LogLevel.Error => 17
-  }
+  implicit def traceLoggerFactory[F[_] : Trace : Applicative]: LoggerFactory[F] = new LoggerFactory[F] {
+    override def getLoggerFromName(name: String): SelfAwareStructuredLogger[F] =
+      new TraceLogger[F] with SelfAwareStructuredLogger[F] {
+        // if LoggerFactory didn't require the Loggers it returns
+        // to be _self aware_ structured loggers, we'd omit these. 🤷
+        override def isTraceEnabled: F[Boolean] = true.pure[F]
+        override def isDebugEnabled: F[Boolean] = true.pure[F]
+        override def isInfoEnabled: F[Boolean] = true.pure[F]
+        override def isWarnEnabled: F[Boolean] = true.pure[F]
+        override def isErrorEnabled: F[Boolean] = true.pure[F]
+      }
 
-  /**
-   * `LogLevel` as an OpenTelemetry `SeverityText`
-   *
-   * See https://opentelemetry.io/docs/reference/specification/logs/data-model/#field-severitytext
-   * and https://opentelemetry.io/docs/reference/specification/logs/data-model/#displaying-severity
-   *
-   * @return LogLevel as an OpenTelemetry SeverityNumber, converted to the TraceValue ADT
-   */
-  private val logLevelToSeverityText: LogLevel => TraceValue = {
-    case LogLevel.Trace => "TRACE"
-    case LogLevel.Debug => "DEBUG"
-    case LogLevel.Info => "INFO"
-    case LogLevel.Warn => "WARN"
-    case LogLevel.Error => "ERROR"
+    override def fromName(name: String): F[SelfAwareStructuredLogger[F]] = getLoggerFromName(name).pure[F]
   }
 
-  private val mapContextToTraceValue: Map[String, String] => List[(String, TraceValue)] =
-    _.toList.nested.map(TraceValue.StringValue).value
+  implicit def traceLogger[F[_] : Trace : Applicative]: StructuredLogger[F] = new TraceLogger[F]
+}
+
+package natchez {
+  object TraceLogger {
+    /**
+     * `LogLevel` as an OpenTelemetry `SeverityNumber`
+     *
+     * See https://opentelemetry.io/docs/reference/specification/logs/data-model/#field-severitynumber
+     *
+     * @return LogLevel as an OpenTelemetry SeverityNumber, converted to the TraceValue ADT
+     */
+    private[TraceLogger] val logLevelToSeverityNumber: LogLevel => TraceValue = {
+      case LogLevel.Trace => 1
+      case LogLevel.Debug => 5
+      case LogLevel.Info => 9
+      case LogLevel.Warn => 13
+      case LogLevel.Error => 17
+    }
+
+    /**
+     * `LogLevel` as an OpenTelemetry `SeverityText`
+     *
+     * See https://opentelemetry.io/docs/reference/specification/logs/data-model/#field-severitytext
+     * and https://opentelemetry.io/docs/reference/specification/logs/data-model/#displaying-severity
+     *
+     * @return LogLevel as an OpenTelemetry SeverityNumber, converted to the TraceValue ADT
+     */
+    private[TraceLogger] val logLevelToSeverityText: LogLevel => TraceValue = {
+      case LogLevel.Trace => "TRACE"
+      case LogLevel.Debug => "DEBUG"
+      case LogLevel.Info => "INFO"
+      case LogLevel.Warn => "WARN"
+      case LogLevel.Error => "ERROR"
+    }
+
+    private[TraceLogger] val mapContextToTraceValue: Map[String, String] => List[(String, TraceValue)] =
+      _.toList.nested.map(TraceValue.StringValue.apply).value
+  }
 
-  implicit def TraceLogger[F[_] : Trace : Applicative]: StructuredLogger[F] = new StructuredLogger[F] {
+  class TraceLogger[F[_] : Trace : Applicative] extends StructuredLogger[F] {
     private def log(logLevel: LogLevel,
                     ctx: Map[String, String],
                     maybeThrowable: Option[Throwable],