Add -o option for redirecting output

src/invidious/helpers/logger.cr

@@ -0,0 +1,35 @@
+require "logger"
+
+class Invidious::LogHandler < Kemal::BaseLogHandler
+  def initialize(@io : IO = STDOUT)
+  end
+
+  def call(context : HTTP::Server::Context)
+    time = Time.now
+    call_next(context)
+    elapsed_text = elapsed_text(Time.now - time)
+
+    @io << time << ' ' << context.response.status_code << ' ' << context.request.method << ' ' << context.request.resource << ' ' << elapsed_text << '\n'
+
+    if @io.is_a? File
+      @io.flush
+    end
+
+    context
+  end
+
+  def write(message : String)
+    @io << message
+
+    if @io.is_a? File
+      @io.flush
+    end
+  end
+
+  private def elapsed_text(elapsed)
+    millis = elapsed.total_milliseconds
+    return "#{millis.round(2)}ms" if millis >= 1
+
+    "#{(millis * 1000).round(2)}µs"
+  end
+end