From 64cea557bebdb0a5b4f17362d8e66845b0a77113 Mon Sep 17 00:00:00 2001
From: Michael Manfre <mike@manfre.net>
Date: Mon, 5 Dec 2022 23:44:26 -0500
Subject: [PATCH] Collapse linkify mentions (#123)

---
 activities/models/post.py            |  6 +++++
 tests/activities/models/test_post.py | 35 +++++++++++++++++++-----
 tests/conftest.py                    | 40 ++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/activities/models/post.py b/activities/models/post.py
index daf61e8..55d2f65 100644
--- a/activities/models/post.py
+++ b/activities/models/post.py
@@ -276,6 +276,8 @@ class Post(StatorModel):
             possible_matches[mention.username] = url
             possible_matches[f"{mention.username}@{mention.domain_id}"] = url
 
+        collapse_name: dict[str, str] = {}
+
         def replacer(match):
             precursor = match.group(1)
             handle = match.group(2).lower()
@@ -284,6 +286,10 @@ class Post(StatorModel):
             else:
                 short_handle = handle
             if handle in possible_matches:
+                if short_handle not in collapse_name:
+                    collapse_name[short_handle] = handle
+                elif collapse_name.get(short_handle) != handle:
+                    short_handle = handle
                 return f'{precursor}<a href="{possible_matches[handle]}">@{short_handle}</a>'
             else:
                 return match.group()
diff --git a/tests/activities/models/test_post.py b/tests/activities/models/test_post.py
index 06d26ed..a5f2f79 100644
--- a/tests/activities/models/test_post.py
+++ b/tests/activities/models/test_post.py
@@ -32,7 +32,9 @@ def test_fetch_post(httpx_mock: HTTPXMock, config_system):
 
 
 @pytest.mark.django_db
-def test_linkify_mentions_remote(identity, remote_identity):
+def test_linkify_mentions_remote(
+    identity, identity2, remote_identity, remote_identity2
+):
     """
     Tests that we can linkify post mentions properly for remote use
     """
@@ -77,9 +79,28 @@ def test_linkify_mentions_remote(identity, remote_identity):
         == '<p>Hey <a href="https://remote.test/@test/">@test</a></p>'
     )
 
+    # Test that collapsing only applies to the first unique, short username
+    post = Post.objects.create(
+        content="<p>Hey @TeSt@remote.test and @test@remote2.test</p>",
+        author=identity,
+        local=True,
+    )
+    post.mentions.set([remote_identity, remote_identity2])
+    assert post.safe_content_remote() == (
+        '<p>Hey <a href="https://remote.test/@test/">@test</a> '
+        'and <a href="https://remote2.test/@test/">@test@remote2.test</a></p>'
+    )
+
+    post.content = "<p>Hey @TeSt, @Test@remote.test and @test</p>"
+    assert post.safe_content_remote() == (
+        '<p>Hey <a href="https://remote2.test/@test/">@test</a>, '
+        '<a href="https://remote.test/@test/">@test@remote.test</a> '
+        'and <a href="https://remote2.test/@test/">@test</a></p>'
+    )
+
 
 @pytest.mark.django_db
-def test_linkify_mentions_local(identity, remote_identity):
+def test_linkify_mentions_local(identity, identity2, remote_identity):
     """
     Tests that we can linkify post mentions properly for local use
     """
@@ -96,14 +117,16 @@ def test_linkify_mentions_local(identity, remote_identity):
     )
     # Test a full username (local)
     post = Post.objects.create(
-        content="<p>@test@example.com, welcome!</p>",
+        content="<p>@test@example.com, welcome! @test@example2.com @test@example.com</p>",
         author=identity,
         local=True,
     )
     post.mentions.add(identity)
-    assert (
-        post.safe_content_local()
-        == '<p><a href="/@test@example.com/">@test</a>, welcome!</p>'
+    post.mentions.add(identity2)
+    assert post.safe_content_local() == (
+        '<p><a href="/@test@example.com/">@test</a>, welcome!'
+        ' <a href="/@test@example2.com/">@test@example2.com</a>'
+        ' <a href="/@test@example.com/">@test</a></p>'
     )
     # Test a full username (remote) with no <p>
     post = Post.objects.create(
diff --git a/tests/conftest.py b/tests/conftest.py
index 80622f0..c67717c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -78,6 +78,12 @@ def domain() -> Domain:
     return Domain.objects.create(domain="example.com", local=True, public=True)
 
 
+@pytest.fixture
+@pytest.mark.django_db
+def domain2() -> Domain:
+    return Domain.objects.create(domain="example2.com", local=True, public=True)
+
+
 @pytest.fixture
 @pytest.mark.django_db
 def identity(user, domain) -> Identity:
@@ -95,6 +101,23 @@ def identity(user, domain) -> Identity:
     return identity
 
 
+@pytest.fixture
+@pytest.mark.django_db
+def identity2(user, domain2) -> Identity:
+    """
+    Creates a basic test identity with a user and domain.
+    """
+    identity = Identity.objects.create(
+        actor_uri="https://example2.com/@test@example2.com/",
+        username="test",
+        domain=domain2,
+        name="Test User Domain2",
+        local=True,
+    )
+    identity.users.set([user])
+    return identity
+
+
 @pytest.fixture
 def other_identity(user, domain) -> Identity:
     """
@@ -128,6 +151,23 @@ def remote_identity() -> Identity:
     )
 
 
+@pytest.fixture
+@pytest.mark.django_db
+def remote_identity2() -> Identity:
+    """
+    Creates a basic remote test identity with a domain.
+    """
+    domain = Domain.objects.create(domain="remote2.test", local=False)
+    return Identity.objects.create(
+        actor_uri="https://remote2.test/test-actor/",
+        profile_uri="https://remote2.test/@test/",
+        username="test",
+        domain=domain,
+        name="Test2 Remote User",
+        local=False,
+    )
+
+
 @pytest.fixture
 def stator(config_system) -> StatorRunner:
     """