From 899e6cda02d3aa5b7bdf3d8dcbb9d630d231117a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Tue, 6 Aug 2024 20:11:07 +0200
Subject: [PATCH 01/10] Send Telemetry events

---
 lib/error_tracker.ex           | 12 +++++++++---
 lib/error_tracker/telemetry.ex | 11 +++++++++++
 2 files changed, 20 insertions(+), 3 deletions(-)
 create mode 100644 lib/error_tracker/telemetry.ex

diff --git a/lib/error_tracker.ex b/lib/error_tracker.ex
index 327ce86..3085c3c 100644
--- a/lib/error_tracker.ex
+++ b/lib/error_tracker.ex
@@ -66,6 +66,7 @@ defmodule ErrorTracker do
 
   alias ErrorTracker.Error
   alias ErrorTracker.Repo
+  alias ErrorTracker.Telemetry
 
   @doc """
   Report an exception to be stored.
@@ -110,9 +111,14 @@ defmodule ErrorTracker do
         conflict_target: :fingerprint
       )
 
-    error
-    |> Ecto.build_assoc(:occurrences, stacktrace: stacktrace, context: context, reason: reason)
-    |> Repo.insert!()
+    occurrence =
+      error
+      |> Ecto.build_assoc(:occurrences, stacktrace: stacktrace, context: context, reason: reason)
+      |> Repo.insert!()
+
+    Telemetry.execute_new_occurrence(occurrence)
+
+    occurrence
   end
 
   @doc """
diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
new file mode 100644
index 0000000..3df57db
--- /dev/null
+++ b/lib/error_tracker/telemetry.ex
@@ -0,0 +1,11 @@
+defmodule ErrorTracker.Telemetry do
+  @moduledoc """
+  TODO
+  """
+
+  def execute_new_occurrence(occurrence) do
+    measurements = %{system_time: System.system_time()}
+    metadata = %{occurrence: occurrence}
+    :telemetry.execute([:error_tracker, :new_occurrence], measurements, metadata)
+  end
+end

From 6bfd8f448e0bef7fd4dadb9ce052ac6cdf71decf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 11:38:00 +0200
Subject: [PATCH 02/10] Add more events

---
 lib/error_tracker.ex           | 42 ++++++++++++++++++++++++----------
 lib/error_tracker/repo.ex      |  4 ++++
 lib/error_tracker/telemetry.ex | 18 ++++++++++++---
 3 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/lib/error_tracker.ex b/lib/error_tracker.ex
index 3085c3c..c5d9fc7 100644
--- a/lib/error_tracker.ex
+++ b/lib/error_tracker.ex
@@ -105,18 +105,7 @@ defmodule ErrorTracker do
 
     context = Map.merge(get_context(), given_context)
 
-    error =
-      Repo.insert!(error,
-        on_conflict: [set: [status: :unresolved, last_occurrence_at: DateTime.utc_now()]],
-        conflict_target: :fingerprint
-      )
-
-    occurrence =
-      error
-      |> Ecto.build_assoc(:occurrences, stacktrace: stacktrace, context: context, reason: reason)
-      |> Repo.insert!()
-
-    Telemetry.execute_new_occurrence(occurrence)
+    {_error, occurrence} = upsert_error!(error, stacktrace, context, reason)
 
     occurrence
   end
@@ -186,4 +175,33 @@ defmodule ErrorTracker do
         {to_string(kind), to_string(other)}
     end
   end
+
+  defp upsert_error!(error, stacktrace, context, reason) do
+    existing_error = Repo.get_by(Error, fingerprint: error.fingerprint)
+
+    error =
+      Repo.insert!(error,
+        on_conflict: [set: [status: :unresolved, last_occurrence_at: DateTime.utc_now()]],
+        conflict_target: :fingerprint
+      )
+
+    occurrence =
+      error
+      |> Ecto.build_assoc(:occurrences, stacktrace: stacktrace, context: context, reason: reason)
+      |> Repo.insert!()
+
+    # If the error existed and was marked as resolved before this exception,
+    # sent a Telemetry event
+    if existing_error && existing_error.status == :resolved,
+      do: Telemetry.unresolved_error(error)
+
+    # If it is a new error, sent a Telemetry event
+    if is_nil(existing_error),
+      do: Telemetry.new_error(error)
+
+    # Always send a new occurrence Telemetry event
+    Telemetry.new_occurrence(occurrence)
+
+    {error, occurrence}
+  end
 end
diff --git a/lib/error_tracker/repo.ex b/lib/error_tracker/repo.ex
index fa29432..02bcb02 100644
--- a/lib/error_tracker/repo.ex
+++ b/lib/error_tracker/repo.ex
@@ -17,6 +17,10 @@ defmodule ErrorTracker.Repo do
     dispatch(:get!, [queryable, id], opts)
   end
 
+  def get_by(queryable, filters, opts \\ []) do
+    dispatch(:get_by, [queryable, filters], opts)
+  end
+
   def all(queryable, opts \\ []) do
     dispatch(:all, [queryable], opts)
   end
diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 3df57db..6e97061 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -3,9 +3,21 @@ defmodule ErrorTracker.Telemetry do
   TODO
   """
 
-  def execute_new_occurrence(occurrence) do
+  @doc false
+  def new_error(error) do
     measurements = %{system_time: System.system_time()}
-    metadata = %{occurrence: occurrence}
-    :telemetry.execute([:error_tracker, :new_occurrence], measurements, metadata)
+    :telemetry.execute([:error_tracker, :new_error], measurements, %{error: error})
+  end
+
+  @doc false
+  def unresolved_error(error) do
+    measurements = %{system_time: System.system_time()}
+    :telemetry.execute([:error_tracker, :unresolved_error], measurements, %{error: error})
+  end
+
+  @doc false
+  def new_occurrence(occurrence) do
+    measurements = %{system_time: System.system_time()}
+    :telemetry.execute([:error_tracker, :new_occurrence], measurements, %{occurrence: occurrence})
   end
 end

From 801f1c406276bf34ed86d16efb9f34ba510450e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 11:58:35 +0200
Subject: [PATCH 03/10] Emit resolve/unresolve events

---
 lib/error_tracker.ex           | 10 ++++++++--
 lib/error_tracker/telemetry.ex |  6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/error_tracker.ex b/lib/error_tracker.ex
index c5d9fc7..5b4a719 100644
--- a/lib/error_tracker.ex
+++ b/lib/error_tracker.ex
@@ -119,7 +119,10 @@ defmodule ErrorTracker do
   def resolve(error = %Error{status: :unresolved}) do
     changeset = Ecto.Changeset.change(error, status: :resolved)
 
-    Repo.update(changeset)
+    with {:ok, updated_error} <- Repo.update(changeset) do
+      Telemetry.resolved_error(updated_error)
+      {:ok, updated_error}
+    end
   end
 
   @doc """
@@ -128,7 +131,10 @@ defmodule ErrorTracker do
   def unresolve(error = %Error{status: :resolved}) do
     changeset = Ecto.Changeset.change(error, status: :unresolved)
 
-    Repo.update(changeset)
+    with {:ok, updated_error} <- Repo.update(changeset) do
+      Telemetry.unresolved_error(updated_error)
+      {:ok, updated_error}
+    end
   end
 
   @doc """
diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 6e97061..a50eda3 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -15,6 +15,12 @@ defmodule ErrorTracker.Telemetry do
     :telemetry.execute([:error_tracker, :unresolved_error], measurements, %{error: error})
   end
 
+  @doc false
+  def resolved_error(error) do
+    measurements = %{system_time: System.system_time()}
+    :telemetry.execute([:error_tracker, :unresolved_error], measurements, %{error: error})
+  end
+
   @doc false
   def new_occurrence(occurrence) do
     measurements = %{system_time: System.system_time()}

From 55aaf4a2e1861e7e026d4cf78ceae021be1420fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 11:59:45 +0200
Subject: [PATCH 04/10] Update event name

---
 lib/error_tracker/telemetry.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index a50eda3..500c588 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -18,7 +18,7 @@ defmodule ErrorTracker.Telemetry do
   @doc false
   def resolved_error(error) do
     measurements = %{system_time: System.system_time()}
-    :telemetry.execute([:error_tracker, :unresolved_error], measurements, %{error: error})
+    :telemetry.execute([:error_tracker, :resolved_error], measurements, %{error: error})
   end
 
   @doc false

From 58e60a5b3171306a9da7ae4d6e34efd3bf57a672 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 12:01:18 +0200
Subject: [PATCH 05/10] Update events

---
 lib/error_tracker/telemetry.ex | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 500c588..9a46539 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -6,24 +6,28 @@ defmodule ErrorTracker.Telemetry do
   @doc false
   def new_error(error) do
     measurements = %{system_time: System.system_time()}
-    :telemetry.execute([:error_tracker, :new_error], measurements, %{error: error})
+    metadata = %{error: error}
+    :telemetry.execute([:error_tracker, :error, :new], measurements, metadata)
   end
 
   @doc false
   def unresolved_error(error) do
     measurements = %{system_time: System.system_time()}
-    :telemetry.execute([:error_tracker, :unresolved_error], measurements, %{error: error})
+    metadata = %{error: error}
+    :telemetry.execute([:error_tracker, :error, :unresolved], measurements, metadata)
   end
 
   @doc false
   def resolved_error(error) do
     measurements = %{system_time: System.system_time()}
-    :telemetry.execute([:error_tracker, :resolved_error], measurements, %{error: error})
+    metadata = %{error: error}
+    :telemetry.execute([:error_tracker, :error, :resolved], measurements, metadata)
   end
 
   @doc false
   def new_occurrence(occurrence) do
     measurements = %{system_time: System.system_time()}
-    :telemetry.execute([:error_tracker, :new_occurrence], measurements, %{occurrence: occurrence})
+    metadata = %{occurrence: occurrence}
+    :telemetry.execute([:error_tracker, :occurrence, :new], measurements, metadata)
   end
 end

From d2fc4896aadaaac646647b102376ff88d74b3c67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 12:10:17 +0200
Subject: [PATCH 06/10] Add telemetry documentation

---
 lib/error_tracker/telemetry.ex | 41 +++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 9a46539..1f58327 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -1,6 +1,45 @@
 defmodule ErrorTracker.Telemetry do
   @moduledoc """
-  TODO
+  Telemetry events of ErrorTracker.
+
+  ErrorTracker emits some events to allow third parties to receive information
+  of errors and occurrences stored.
+
+  We emit four type of events which allows to track the lifetime of errors of
+  your application.
+
+  ### Error events
+
+  Those occur during the lifetime of an error:
+
+  * `[:error_tracker, :error, :new]`: is emitted when a new error is stored and
+  no previous occurrences were known.
+
+  * `[:error_tracker, :error, :resolved]`: is emitted when a new error is marked
+  as resolved on the UI.
+
+  * `[:error_tracker, :error, :unresolved]`: is emitted when a new error is
+  marked as unresolved on the UI or a new occurrence is registered, moving the
+  error to the unresolved state.
+
+  ### Occurrence events
+
+  There is only one event emitted for occurrences:
+
+  * `[:error_tracker, :occurrence, :new]`: is emitted when a new occurrence is
+  stored.
+
+  ### Measures and metadata
+
+  Each event is emitted with some measures and metadata, which can be used to
+  receive information without having to query the database again:
+
+  | event                                   | measures       | metadata      |
+  | --------------------------------------- | -------------- | ------------- |
+  | `[:error_tracker, :error, :new]`        | `:system_time` | `:error`      |
+  | `[:error_tracker, :error, :unresolved]` | `:system_time` | `:error`      |
+  | `[:error_tracker, :error, :resolved]`   | `:system_time` | `:error`      |
+  | `[:error_tracker, :occurrence, :new]`   | `:system_time` | `:occurrence` |
   """
 
   @doc false

From 92146f0b9f17336185ed282a993cc0590381ff9a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 12:15:49 +0200
Subject: [PATCH 07/10] Update documentation

---
 guides/Getting Started.md      | 8 ++++++++
 lib/error_tracker/telemetry.ex | 3 ---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/guides/Getting Started.md b/guides/Getting Started.md
index 64a7d5d..19745f8 100644
--- a/guides/Getting Started.md	
+++ b/guides/Getting Started.md	
@@ -126,3 +126,11 @@ You can also use `ErrorTracker.report/3` and set some custom context that will b
 ErrorTracker also provides a dashboard built with Phoenix LiveView that can be used to see and manage the recorded errors.
 
 This is completely optional, and you can find more information about it in the `ErrorTracker.Web` module documentation.
+
+## Notifications
+
+We currently do not support notifications out of the box.
+
+However, we provideo some detailed Telemetry events that you may use to implement your own notifications following your custom rules and notification channels.
+
+If you want to take a look at the events you can attach to, take a look at `ErrorTracker.Telemetry` module documentation.
diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 1f58327..19fe2d0 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -5,9 +5,6 @@ defmodule ErrorTracker.Telemetry do
   ErrorTracker emits some events to allow third parties to receive information
   of errors and occurrences stored.
 
-  We emit four type of events which allows to track the lifetime of errors of
-  your application.
-
   ### Error events
 
   Those occur during the lifetime of an error:

From 2ae60ee08b14fa2c8ef0eb85838a32b13c98c187 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 12:24:24 +0200
Subject: [PATCH 08/10] Log telemetry events on dev script

---
 dev.exs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/dev.exs b/dev.exs
index b09a6c6..a714943 100644
--- a/dev.exs
+++ b/dev.exs
@@ -149,6 +149,30 @@ defmodule ErrorTrackerDevWeb.Endpoint do
   def maybe_exception(conn, _), do: conn
 end
 
+defmodule ErrorTrackerDev.Telemetry do
+  require Logger
+
+  def start do
+    :telemetry.attach_many(
+      "error-tracker-events",
+      [
+        [:error_tracker, :error, :new],
+        [:error_tracker, :error, :resolved],
+        [:error_tracker, :error, :unresolved],
+        [:error_tracker, :occurrence, :new]
+      ],
+      &__MODULE__.handle_event/4,
+      []
+    )
+
+    Logger.info("Telemtry attached")
+  end
+
+  def handle_event(event, measure, metadata, _opts) do
+    dbg([event, measure, metadata])
+  end
+end
+
 defmodule Migration0 do
   use Ecto.Migration
 
@@ -165,6 +189,8 @@ Task.async(fn ->
     ErrorTrackerDevWeb.Endpoint
   ]
 
+  ErrorTrackerDev.Telemetry.start()
+
   {:ok, _} = Supervisor.start_link(children, strategy: :one_for_one)
 
   # Automatically run the migrations on boot

From 14c189c0fb07114ec7b558d27e303f209b041ce2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 12:36:15 +0200
Subject: [PATCH 09/10] Update docs

---
 lib/error_tracker/telemetry.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/error_tracker/telemetry.ex b/lib/error_tracker/telemetry.ex
index 19fe2d0..94f31e7 100644
--- a/lib/error_tracker/telemetry.ex
+++ b/lib/error_tracker/telemetry.ex
@@ -7,7 +7,7 @@ defmodule ErrorTracker.Telemetry do
 
   ### Error events
 
-  Those occur during the lifetime of an error:
+  Those occur during the life cycle of an error:
 
   * `[:error_tracker, :error, :new]`: is emitted when a new error is stored and
   no previous occurrences were known.

From 210f158f2255ebff8a8ab8f708ac5d252a850d25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20de=20Arriba?= <oscar@dearriba.es>
Date: Wed, 7 Aug 2024 19:10:01 +0200
Subject: [PATCH 10/10] Only get status from existing error

---
 lib/error_tracker.ex      | 15 +++++++++------
 lib/error_tracker/repo.ex |  4 ++--
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/lib/error_tracker.ex b/lib/error_tracker.ex
index 5b4a719..b755c67 100644
--- a/lib/error_tracker.ex
+++ b/lib/error_tracker.ex
@@ -64,6 +64,8 @@ defmodule ErrorTracker do
   """
   @type context :: %{String.t() => any()}
 
+  import Ecto.Query
+
   alias ErrorTracker.Error
   alias ErrorTracker.Repo
   alias ErrorTracker.Telemetry
@@ -183,7 +185,8 @@ defmodule ErrorTracker do
   end
 
   defp upsert_error!(error, stacktrace, context, reason) do
-    existing_error = Repo.get_by(Error, fingerprint: error.fingerprint)
+    existing_status =
+      Repo.one(from e in Error, where: [fingerprint: ^error.fingerprint], select: e.status)
 
     error =
       Repo.insert!(error,
@@ -198,12 +201,12 @@ defmodule ErrorTracker do
 
     # If the error existed and was marked as resolved before this exception,
     # sent a Telemetry event
-    if existing_error && existing_error.status == :resolved,
-      do: Telemetry.unresolved_error(error)
-
     # If it is a new error, sent a Telemetry event
-    if is_nil(existing_error),
-      do: Telemetry.new_error(error)
+    case existing_status do
+      :resolved -> Telemetry.unresolved_error(error)
+      :unresolved -> :noop
+      nil -> Telemetry.new_error(error)
+    end
 
     # Always send a new occurrence Telemetry event
     Telemetry.new_occurrence(occurrence)
diff --git a/lib/error_tracker/repo.ex b/lib/error_tracker/repo.ex
index 02bcb02..ab8c448 100644
--- a/lib/error_tracker/repo.ex
+++ b/lib/error_tracker/repo.ex
@@ -17,8 +17,8 @@ defmodule ErrorTracker.Repo do
     dispatch(:get!, [queryable, id], opts)
   end
 
-  def get_by(queryable, filters, opts \\ []) do
-    dispatch(:get_by, [queryable, filters], opts)
+  def one(queryable, opts \\ []) do
+    dispatch(:one, [queryable], opts)
   end
 
   def all(queryable, opts \\ []) do