From 6825941c0b9890cb853be2463764708dd27a1e04 Mon Sep 17 00:00:00 2001
From: DualFroz <me@dualfroz.com>
Date: Sun, 6 Sep 2026 21:11:47 +0200
Subject: [PATCH] feat: add Prism, Instrumentation and Jobs

---
 lib/prism/instrumentation.rb | 121 +++++++++++++++++++++++++++++++++++
 lib/prism/jobs.rb            |  15 +++++
 lib/prism/mailer.rb          |  67 +++++++++++++++++++
 3 files changed, 203 insertions(+)
 create mode 100644 lib/prism/instrumentation.rb
 create mode 100644 lib/prism/jobs.rb
 create mode 100644 lib/prism/mailer.rb

diff --git a/lib/prism/instrumentation.rb b/lib/prism/instrumentation.rb
new file mode 100644
index 0000000..db1e8d7
--- /dev/null
+++ b/lib/prism/instrumentation.rb
@@ -0,0 +1,121 @@
+module Prism
+  # ActiveSupport::Notifications-lite: a process-wide publish/subscribe bus
+  # for cross-cutting events (queries, request dispatch, template renders).
+  # Instrumented code owns naming and payload shape; subscribers (loggers,
+  # metrics collectors, tests) opt into a subset by exact name or Regexp.
+  module Instrumentation
+    Event = Struct.new(:name, :payload, :duration, :time) do
+      def duration_ms
+        duration * 1000.0
+      end
+    end
+
+    class Subscriber
+      def initialize(pattern, block)
+        @pattern = pattern
+        @block = block
+      end
+
+      def match?(name)
+        case @pattern
+        when nil then true
+        when Regexp then @pattern.match?(name)
+        else @pattern.to_s == name
+        end
+      end
+
+      def call(event)
+        @block.call(event)
+      end
+    end
+
+    class Bus
+      def initialize
+        @subscribers = []
+        @mutex = Mutex.new
+      end
+
+      def subscribe(pattern = nil, &block)
+        raise ArgumentError, 'block required' unless block
+        subscriber = Subscriber.new(pattern, block)
+        @mutex.synchronize { @subscribers = @subscribers + [subscriber] }
+        subscriber
+      end
+
+      def unsubscribe(subscriber)
+        @mutex.synchronize { @subscribers = @subscribers - [subscriber] }
+      end
+
+      def subscribers
+        @mutex.synchronize { @subscribers.dup }
+      end
+
+      # Yields a mutable payload hash so instrumented code (and nested
+      # instrument calls further down the stack) can enrich it before the
+      # event is published. Always publishes, even when the block raises -
+      # the exception is recorded on the payload and re-raised afterward.
+      def instrument(name, payload = {})
+        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        time = Time.now
+        result = nil
+        begin
+          result = block_given? ? yield(payload) : nil
+          result
+        rescue StandardError => e
+          payload[:exception] = [e.class.name, e.message]
+          payload[:exception_object] = e
+          raise
+        ensure
+          duration = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
+          publish(Event.new(name, payload, duration, time))
+        end
+      end
+
+      private
+
+      def publish(event)
+        subscribers.each do |subscriber|
+          next unless subscriber.match?(event.name)
+          subscriber.call(event)
+        end
+      end
+    end
+
+    class << self
+      def bus
+        @bus ||= Bus.new
+      end
+
+      def instrument(name, payload = {}, &block)
+        bus.instrument(name, payload, &block)
+      end
+
+      def subscribe(pattern = nil, &block)
+        bus.subscribe(pattern, &block)
+      end
+
+      def unsubscribe(subscriber)
+        bus.unsubscribe(subscriber)
+      end
+    end
+
+    # Rails-style one-line-per-event logger: "  sql.prism (0.3ms)  SELECT posts".
+    # Attach once (typically in an initializer / Application setup); returns
+    # the underlying Subscriber so callers can #detach it later.
+    class LogSubscriber
+      def self.attach(io = $stdout, patterns: [nil])
+        patterns.map do |pattern|
+          Instrumentation.subscribe(pattern) { |event| io.puts(format_event(event)) }
+        end
+      end
+
+      def self.format_event(event)
+        ms = format('%.1f', event.duration_ms)
+        details = event.payload.reject { |key, _| key == :exception_object }
+                        .map { |key, value| "#{key}=#{value.inspect}" }.join(' ')
+        line = "  #{event.name} (#{ms}ms)"
+        details.empty? ? line : "#{line}  #{details}"
+      end
+    end
+  end
+end
diff --git a/lib/prism/jobs.rb b/lib/prism/jobs.rb
new file mode 100644
index 0000000..d2f9111
--- /dev/null
+++ b/lib/prism/jobs.rb
@@ -0,0 +1,15 @@
+require_relative 'jobs/job'
+require_relative 'jobs/queue'
+require_relative 'jobs/worker'
+
+module Prism
+  module Jobs
+    class << self
+      attr_writer :default_queue
+
+      def default_queue
+        @default_queue ||= Queue.new('db/jobs.pstore')
+      end
+    end
+  end
+end
diff --git a/lib/prism/mailer.rb b/lib/prism/mailer.rb
new file mode 100644
index 0000000..c1733fe
--- /dev/null
+++ b/lib/prism/mailer.rb
@@ -0,0 +1,67 @@
+require_relative 'mailer/message'
+require_relative 'mailer/delivery'
+require_relative 'mailer/delivery_job'
+require_relative 'mailer/base'
+require_relative 'mailer/preview'
+require_relative 'mailer/preview_app'
+
+module Prism
+  module Mailer
+    class << self
+      attr_accessor :smtp_settings
+
+      # Router used by Mailer::Base#url_for to build absolute links inside
+      # mail bodies, where there is no incoming request to pull a router off
+      # of. Set once, normally via Application#enable_mailer, e.g.
+      # `Prism::Mailer.router = BlogApp.router`.
+      attr_accessor :router
+      attr_writer :delivery_method, :default_url_options
+
+      def delivery_method
+        @delivery_method ||= :test
+      end
+
+      # App-wide fallback for Mailer::Base.default_url_options (host,
+      # protocol, port); a mailer class's own default_url_options take
+      # precedence when both are set.
+      def default_url_options
+        @default_url_options ||= {}
+      end
+
+      # Messages handed to Mailer.deliver! while delivery_method == :test
+      # pile up here instead of going out over the network, mirroring
+      # ActionMailer::Base.deliveries for assertions in tests.
+      def deliveries
+        @deliveries ||= []
+      end
+
+      def deliver!(message)
+        Instrumentation.instrument('deliver_mail.prism', subject: message.subject,
+                                                           to: message.to,
+                                                           delivery_method: delivery_method) do
+          case delivery_method
+          when :test
+            deliveries << message
+          when :smtp
+            deliver_via_smtp(message)
+          else
+            raise ArgumentError, "unknown Prism::Mailer.delivery_method #{delivery_method.inspect}"
+          end
+        end
+        message
+      end
+
+      private
+
+      def deliver_via_smtp(message)
+        require 'net/smtp'
+        settings = smtp_settings || {}
+        Net::SMTP.start(settings[:address] || 'localhost', settings[:port] || 25,
+                         settings[:domain] || 'localhost', settings[:user_name],
+                         settings[:password], settings[:authentication]) do |smtp|
+          smtp.send_message(message.to_s, message.from, message.all_recipients)
+        end
+      end
+    end
+  end
+end