1 files changed, 136 insertions, 0 deletions
diff --git a/activities/search.py b/activities/search.py
new file mode 100644
index 0000000..e192b94
--- /dev/null
+++ b/activities/search.py
@@ -0,0 +1,136 @@
+import httpx
+from asgiref.sync import async_to_sync
+
+from activities.models import Hashtag, Post
+from core.ld import canonicalise
+from users.models import Domain, Identity, IdentityStates
+from users.models.system_actor import SystemActor
+
+
+class Searcher:
+    """
+    Captures the logic needed to search - reused in the UI and API
+    """
+
+    def __init__(self, query: str, identity: Identity | None):
+        self.query = query.strip().lower()
+        self.identity = identity
+
+    def search_identities_handle(self) -> set[Identity]:
+        """
+        Searches for identities by their handles
+        """
+
+        # Short circuit if it's obviously not for us
+        if "://" in self.query:
+            return set()
+
+        # Try to fetch the user by handle
+        handle = self.query.lstrip("@")
+        results: set[Identity] = set()
+        if "@" in handle:
+            username, domain = handle.split("@", 1)
+
+            # Resolve the domain to the display domain
+            domain_instance = Domain.get_domain(domain)
+            try:
+                if domain_instance is None:
+                    raise Identity.DoesNotExist()
+                identity = Identity.objects.get(
+                    domain=domain_instance, username=username
+                )
+            except Identity.DoesNotExist:
+                if self.identity is not None:
+                    # Allow authenticated users to fetch remote
+                    identity = Identity.by_username_and_domain(
+                        username, domain, fetch=True
+                    )
+                    if identity and identity.state == IdentityStates.outdated:
+                        async_to_sync(identity.fetch_actor)()
+                else:
+                    identity = None
+            if identity:
+                results.add(identity)
+
+        else:
+            for identity in Identity.objects.filter(username=handle)[:20]:
+                results.add(identity)
+            for identity in Identity.objects.filter(username__startswith=handle)[:20]:
+                results.add(identity)
+        return results
+
+    def search_url(self) -> Post | Identity | None:
+        """
+        Searches for an identity or post by URL.
+        """
+
+        # Short circuit if it's obviously not for us
+        if "://" not in self.query:
+            return None
+
+        # Fetch the provided URL as the system actor to retrieve the AP JSON
+        try:
+            response = async_to_sync(SystemActor().signed_request)(
+                method="get",
+                uri=self.query,
+            )
+        except (httpx.RequestError, httpx.ConnectError):
+            return None
+        if response.status_code >= 400:
+            return None
+        document = canonicalise(response.json(), include_security=True)
+        type = document.get("type", "unknown").lower()
+
+        # Is it an identity?
+        if type == "person":
+            # Try and retrieve the profile by actor URI
+            identity = Identity.by_actor_uri(document["id"], create=True)
+            if identity and identity.state == IdentityStates.outdated:
+                async_to_sync(identity.fetch_actor)()
+            return identity
+
+        # Is it a post?
+        elif type == "note":
+            # Try and retrieve the post by URI
+            # (we do not trust the JSON we just got - fetch from source!)
+            try:
+                return Post.by_object_uri(document["id"], fetch=True)
+            except Post.DoesNotExist:
+                return None
+
+        # Dunno what it is
+        else:
+            return None
+
+    def search_hashtags(self) -> set[Hashtag]:
+        """
+        Searches for hashtags by their name
+        """
+
+        # Short circuit out if it's obviously not a hashtag
+        if "@" in self.query or "://" in self.query:
+            return set()
+
+        results: set[Hashtag] = set()
+        name = self.query.lstrip("#")
+        for hashtag in Hashtag.objects.public().hashtag_or_alias(name)[:10]:
+            results.add(hashtag)
+        for hashtag in Hashtag.objects.public().filter(hashtag__startswith=name)[:10]:
+            results.add(hashtag)
+        return results
+
+    def search_all(self):
+        """
+        Returns all possible results for a search
+        """
+        results = {
+            "identities": self.search_identities_handle(),
+            "hashtags": self.search_hashtags(),
+            "posts": set(),
+        }
+        url_result = self.search_url()
+        if isinstance(url_result, Identity):
+            results["identities"].add(url_result)
+        if isinstance(url_result, Post):
+            results["posts"].add(url_result)
+        return results