implement remote object fetching!

this is most of the tricky parts of inbound federation :3

11 files changed, 307 insertions, 37 deletions

diff --git a/WpfTest/Model.php b/WpfTest/Model.php
index c006ffd..53b2d83 100644
--- a/WpfTest/Model.php
+++ b/WpfTest/Model.php
@@ -1,7 +1,28 @@
 <?php
 namespace WpfTest;
 
+use WpfTest\Model\FetchableModel;
+
 abstract class Model {
+    private bool $saved = false;
+
+    protected function setOwnerId(int $id) {
+    }
+
+    /**
+     * @return ?string a condition for a WHERE clause if this object already
+     *                 exists in the database, or null otherwise
+     */
+    protected function getUpdateWhereClause(\PDO $db): ?string {
+        if (isset($this->id) && static::find($this->{'id'}) != null) {
+            return 'id = ' . $this->{'id'};
+        }
+        return null;
+    }
+
+    /**
+     * Converts a field or type name into the version used in the database
+     */
     private static function mangleName(string $name): string {
         $chars = str_split($name);
         $chars[0] = strtolower($chars[0]);
@@ -14,6 +35,9 @@ abstract class Model {
         return implode($chars);
     }
 
+    /**
+     * Converts a database column name into the corresponding field name
+     */
     private static function unmangleName(string $name): string {
         $chars = str_split($name);
         for ($i = 0; $i < count($chars); $i++) {
@@ -29,7 +53,27 @@ abstract class Model {
         $props = $refl->getProperties();
         $result = [];
         foreach ($props as $p) {
-            $result[self::mangleName($p->getName())] = $p->getValue();
+            $pName = $p->getName();
+            if (!isset($this->{$pName}))
+                continue;
+            // we need to determine the plain value to insert ...
+            $value = $this->{$pName};
+            $discarded = false;
+            if ($value instanceof \DateTimeInterface) {
+                // datetime objects should be turned into iso 8601 timestamps
+                $value = $value->format('c');
+            } elseif ($value instanceof Model) {
+                // models should generally be turned into their id if there is one or removed if not
+                if (property_exists($value, 'id') && isset($value->id))
+                    $value = $value->{'id'}; // doing it like this to shut up the warning (lol)
+                else
+                    $discarded = true;
+            } elseif (is_array($value)) {
+                // arrays ought to be handled separately when saving (different db table)
+                $discarded = true;
+            }
+            if (!$discarded)
+                $result[self::mangleName($pName)] = $value;
         }
         return $result;
     }
@@ -55,8 +99,8 @@ abstract class Model {
                     throw $e;
                 $typeClass = $type->getName();
                 if (enum_exists($typeClass)) {
-                    // if it's an enum we can find the enum case with the same name
-                    $obj->{$name} = (new \ReflectionEnum($typeClass))->getCase($value)->getValue();
+                    // if it's a backed enum we can find the enum case with the same value
+                    $obj->{$name} = $typeClass::from($value);
                 } elseif (is_subclass_of($typeClass, Model::class) && is_int($value)) {
                     // if it's another model we can try to look it up by id automatically
                     $obj->{$name} = $typeClass::find($value);
@@ -66,23 +110,25 @@ abstract class Model {
                 }
             }
         }
-        // set up any extra-complicated fields if needed
-        $obj->hydrate($columns);
+        // set up any referenced fields if needed
+        $obj->hydrate();
+        $obj->saved = true;
         return $obj;
     }
 
     /**
-     * Initialises fields of the model that contain more complex objects
-     * @param array $row the row of the database
+     * Initialises fields of the model that contain referenced / foreign keyed objects
+     * which couldn't be initialised automatically
      * @return void
      */
-    protected function hydrate(array $row) {
+    protected function hydrate() {
     }
 
     public static function findWhere(string $whereClause, array $parameters): ?static {
         $classNameParts = explode('\\', static::class);
         $className = $classNameParts[count($classNameParts) - 1];
         $tableName = self::mangleName($className);
+
         $stmt = Db::getInstance()->getPdo()->prepare("SELECT * FROM $tableName WHERE $whereClause LIMIT 1");
         $stmt->execute($parameters);
         return static::fromDbRow($stmt->fetch(\PDO::FETCH_ASSOC));
@@ -92,6 +138,7 @@ abstract class Model {
         $classNameParts = explode('\\', static::class);
         $className = $classNameParts[count($classNameParts) - 1];
         $tableName = self::mangleName($className);
+
         $stmt = Db::getInstance()->getPdo()->prepare("SELECT * FROM $tableName WHERE $whereClause");
         $stmt->execute($parameters);
         return array_map(function ($row) {
@@ -102,4 +149,71 @@ abstract class Model {
     public static function find(int $id): ?static {
         return static::findWhere('id = ?', [$id]);
     }
+
+    /**
+     * Inserts or updates the model's corresponding database record.
+     * Also sets the model's id field if it has one.
+     */
+    public function save() {
+        // figure out all the parameters and such for the query
+        $paramData = $this->toDbRow();
+        $columnNames = array_keys($paramData);
+        $parameterNames = array_map(function (string $column) {
+            return ":$column";
+        }, $columnNames);
+        $columns = implode(', ', $columnNames);
+        $parameters = implode(', ', $parameterNames);
+
+        $classNameParts = explode('\\', static::class);
+        $className = $classNameParts[count($classNameParts) - 1];
+        $tableName = self::mangleName($className);
+
+        $db = Db::getInstance()->getPdo();
+
+        $whereClause = $this->getUpdateWhereClause($db);
+        $shouldUpdate = $whereClause != null;
+        $stmt = $db->prepare(
+            $shouldUpdate
+            ? "UPDATE $tableName SET ($columns) = ($parameters) WHERE $whereClause"
+            : "INSERT INTO $tableName ($columns) VALUES ($parameters)"
+        );
+
+        // pdo is really stupid and casts `false`/0 to an empty string, which breaks the query
+        // so i have to cast `false`s and `0`s manually. hooray
+        // i also have to convert backed enums to their value because they dont implement Stringable
+        $paramData = array_map(function ($item) {
+            if ($item === false || $item === 0)
+                return '0';
+            if (is_a($item, \BackedEnum::class))
+                return $item->value;
+            return $item;
+        }, $paramData);
+        // actually save it !!!! yay
+        $stmt->execute($paramData);
+
+        if (property_exists($this, 'id')) {
+            $this->id = $shouldUpdate
+                ? static::findWhere($whereClause, [])->id
+                : (int) $db->lastInsertId();
+        }
+
+        // recursively save inner models
+        // but not fetchable ones because they should really be saved separately
+        $reflProps = (new \ReflectionObject($this))->getProperties();
+        foreach ($reflProps as $reflProp) {
+            assert($reflProp instanceof \ReflectionProperty);
+            $reflType = $reflProp->getType();
+            $propName = $reflProp->getName();
+            if (!($reflType instanceof \ReflectionNamedType))
+                continue;
+            $type = $reflType->getName();
+            if (is_subclass_of($type, Model::class) && !is_subclass_of($type, FetchableModel::class)) {
+                if (property_exists($this, 'id'))
+                    $this->{$propName}->setOwnerId($this->id);
+                $this->{$propName}->save();
+            }
+        }
+
+        $this->saved = true;
+    }
 }
\ No newline at end of file
diff --git a/WpfTest/Model/Actor.php b/WpfTest/Model/Actor.php
index eaef99c..0b0e729 100644
--- a/WpfTest/Model/Actor.php
+++ b/WpfTest/Model/Actor.php
@@ -1,9 +1,9 @@
 <?php
 namespace WpfTest\Model;
 
-use WpfTest\Model;
+use WpfTest\RemoteFetchable;
 
-class Actor extends Model implements \JsonSerializable {
+class Actor extends FetchableModel implements \JsonSerializable {
     public ?int $id;
     public string $uri;
     public bool $isLocal = false;
@@ -20,6 +20,14 @@ class Actor extends Model implements \JsonSerializable {
     public ActorEndpoints $endpoints;
     public array $extensions = [];
 
+    protected function getUpdateWhereClause(\PDO $db): ?string {
+        if (self::findWhere('uri = ?', [$this->uri]) != null)
+            return 'uri = ' . $db->quote($this->uri);
+        if (self::findWhere('id = ?', [$this->id]) != null)
+            return "id = $this->id";
+        return null;
+    }
+
     public static function findLocalByHandle(string $handle): ?self {
         return self::findWhere('is_local = true AND handle = ?', [$handle]);
     }
@@ -42,4 +50,8 @@ class Actor extends Model implements \JsonSerializable {
             ]
         ];
     }
+
+    public function hydrate() {
+        $this->endpoints = ActorEndpoints::findWhere('actor_id = ?', [$this->id]);
+    }
 }
\ No newline at end of file
diff --git a/WpfTest/Model/ActorEndpoints.php b/WpfTest/Model/ActorEndpoints.php
index 03dab9e..f6120d3 100644
--- a/WpfTest/Model/ActorEndpoints.php
+++ b/WpfTest/Model/ActorEndpoints.php
@@ -4,6 +4,7 @@ namespace WpfTest\Model;
 use WpfTest\Model;
 
 class ActorEndpoints extends Model {
+    public ?int $actorId;
     public string $basicFeed;
     public ?string $fullFeed;
     public ?string $follow;
@@ -12,4 +13,15 @@ class ActorEndpoints extends Model {
     public ?string $unblock;
     public ?string $subscribe;
     public ?string $unsubscribe;
+
+    protected function setOwnerId(int $id) {
+        $this->actorId = $id;
+    }
+
+    protected function getUpdateWhereClause($db): ?string {
+        if (self::findWhere('actor_id = ?', [$this->actorId]) != null) {
+            return "actor_id = $this->actorId";
+        }
+        return null;
+    }
 }
\ No newline at end of file
diff --git a/WpfTest/Model/FetchableModel.php b/WpfTest/Model/FetchableModel.php
new file mode 100644
index 0000000..44106d4
--- /dev/null
+++ b/WpfTest/Model/FetchableModel.php
@@ -0,0 +1,78 @@
+<?php
+namespace WpfTest\Model;
+
+use WpfTest\Model;
+use WpfTest\RemoteFetchable;
+
+abstract class FetchableModel extends Model implements RemoteFetchable {
+    private static \JsonMapper $mapper;
+
+    public static function __initStatic() {
+        self::$mapper = new \JsonMapper();
+        // this is unfortunately necessary to parse DateTime(Immutable)s properly
+        self::$mapper->bStrictObjectTypeChecking = false;
+    }
+
+    private static function fetchFromRemote(string $uri, bool $autoSave): ?static {
+        // fetch the object
+        $data = @file_get_contents($uri, context: stream_context_create(['http' => [
+            'header' => 'Accept: application/json'
+        ]]));
+        if ($data === false)
+            return null;
+        $data = json_decode($data);
+        if ($data === false)
+            return null;
+        // default everything nullable to null
+        $obj = new static();
+        $reflProps = (new \ReflectionClass(static::class))->getProperties();
+        foreach ($reflProps as $reflProp) {
+            assert($reflProp instanceof \ReflectionProperty); // for intellisense lmao
+            if ($reflProp->getType()->allowsNull()) {
+                $obj->{$reflProp->getName()} = null;
+            }
+        }
+        // rename 'self' to 'uri' because of reasons
+        if (property_exists($data, 'self')) {
+            $data->uri = $data->self;
+            unset($data->self);
+        }
+        // map all present fields
+        self::$mapper->map($data, $obj);
+        // (hopefully) recursively fetch any other fetchable models contained in this one
+        foreach ($reflProps as $reflProp) {
+            assert($reflProp instanceof \ReflectionProperty);
+            $reflType = $reflProp->getType();
+            $propName = $reflProp->getName();
+            if (!($reflType instanceof \ReflectionNamedType))
+                continue;
+            $type = $reflType->getName();
+            if (is_subclass_of($type, FetchableModel::class) && is_string($data->{$propName})) {
+                // try to avoid recursion
+                // TODO: make a better effort at avoiding recursion (e.g. when it's more than one step nested)
+                if ($data->{$propName} == $uri) {
+                    $obj->{$propName} = $obj;
+                } else {
+                    $obj->{$propName} = $type::findByUri($data->{$propName}, $autoSave);
+                }
+            }
+        }
+
+        if ($autoSave) {
+            $obj->save();
+        }
+
+        return $obj;
+    }
+
+    public static function findByUri(string $uri, bool $autoSave = true, bool $forceRefetch = false): ?static {
+        if (!$forceRefetch) {
+            $obj = static::findWhere('uri = ?', [$uri]);
+            if ($obj != null)
+                return $obj;
+        }
+        return static::fetchFromRemote($uri, $autoSave);
+    }
+}
+
+FetchableModel::__initStatic();
\ No newline at end of file
diff --git a/WpfTest/Model/Note.php b/WpfTest/Model/Note.php
index 85b3567..af2d2aa 100644
--- a/WpfTest/Model/Note.php
+++ b/WpfTest/Model/Note.php
@@ -2,9 +2,8 @@
 namespace WpfTest\Model;
 
 use WpfTest\Db;
-use WpfTest\Model;
 
-class Note extends Model implements \JsonSerializable {
+class Note extends FetchableModel implements \JsonSerializable {
     public ?int $id;
     public string $uri;
     public \DateTimeImmutable $created;
@@ -30,7 +29,15 @@ class Note extends Model implements \JsonSerializable {
     public array $attachments = [];
     public array $extensions = [];
 
-    protected function hydrate(array $row) {
+    protected function getUpdateWhereClause(\PDO $db): ?string {
+        if (self::findWhere('uri = ?', [$this->uri]) != null)
+            return 'uri = ' . $db->quote($this->uri);
+        if (self::findWhere('id = ?', [$this->id]) != null)
+            return "id = $this->id";
+        return null;
+    }
+
+    protected function hydrate() {
         $this->privacy = NotePrivacy::findWhere('note_id = ?', [$this->id]);
         $this->formattedContent = $this->findFormattedContents();
         $this->mentions = $this->findMentions();
@@ -74,14 +81,7 @@ class Note extends Model implements \JsonSerializable {
             }, $this->mentions),
             'inReplyTo' => $this->inReplyTo?->uri,
             'threadApex' => $this->threadApex?->uri,
-            'privacy' => [
-                'scope' => $this->privacy->scope->name,
-                'alsoVisibleTo' => $this->privacy->alsoVisibleTo,
-                'indexable' => $this->privacy->indexable,
-                'canReshare' => $this->privacy->canReshare->name,
-                'canReply' => $this->privacy->canReply->name,
-                'canOtherInteract' => $this->privacy->canOtherInteract->name
-            ],
+            'privacy' => $this->privacy,
             'attachments' => array_map(function (NoteAttachment $attachment) {
                 return [
                     'type' => $attachment->type,
diff --git a/WpfTest/Model/NoteAttachment.php b/WpfTest/Model/NoteAttachment.php
index b07d595..16947c5 100644
--- a/WpfTest/Model/NoteAttachment.php
+++ b/WpfTest/Model/NoteAttachment.php
@@ -4,8 +4,20 @@ namespace WpfTest\Model;
 use WpfTest\Model;
 
 class NoteAttachment extends Model {
+    public ?int $noteId;
     public int $index;
     public string $type;
     public string $href;
     public ?string $description;
+
+    protected function setOwnerId(int $id) {
+        $this->noteId = $id;
+    }
+
+    protected function getUpdateWhereClause($db): ?string {
+        if (self::findWhere('note_id = ?', [$this->noteId]) != null) {
+            return "note_id = $this->noteId";
+        }
+        return null;
+    }
 }
\ No newline at end of file
diff --git a/WpfTest/Model/NotePrivacy.php b/WpfTest/Model/NotePrivacy.php
index b7ed58a..b955447 100644
--- a/WpfTest/Model/NotePrivacy.php
+++ b/WpfTest/Model/NotePrivacy.php
@@ -3,14 +3,37 @@ namespace WpfTest\Model;
 
 use WpfTest\Model;
 
-class NotePrivacy extends Model {
+class NotePrivacy extends Model implements \JsonSerializable {
+    public ?int $noteId;
     public NotePrivacyScope $scope;
     /**
      * @var Actor[]
      */
     public array $alsoVisibleTo = [];
     public bool $indexable;
-    public NotePrivacyInteractors $canReshare = NotePrivacyInteractors::all;
-    public NotePrivacyInteractors $canReply = NotePrivacyInteractors::all;
-    public NotePrivacyInteractors $canOtherInteract = NotePrivacyInteractors::all;
+    public NotePrivacyInteractors $canReshare = NotePrivacyInteractors::ALL;
+    public NotePrivacyInteractors $canReply = NotePrivacyInteractors::ALL;
+    public NotePrivacyInteractors $canOtherInteract = NotePrivacyInteractors::ALL;
+
+    protected function setOwnerId(int $id) {
+        $this->noteId = $id;
+    }
+
+    protected function getUpdateWhereClause($db): ?string {
+        if (self::findWhere('note_id = ?', [$this->noteId]) != null) {
+            return "note_id = $this->noteId";
+        }
+        return null;
+    }
+
+    public function jsonSerialize(): array {
+        return [
+            'scope' => $this->scope->value,
+            'alsoVisibleTo' => $this->alsoVisibleTo,
+            'indexable' => $this->indexable,
+            'canReshare' => $this->canReshare->value,
+            'canReply' => $this->canReply->value,
+            'canOtherInteract' => $this->canOtherInteract->value
+        ];
+    }
 }
\ No newline at end of file
diff --git a/WpfTest/Model/NotePrivacyInteractors.php b/WpfTest/Model/NotePrivacyInteractors.php
index ff4d7fa..917d90a 100644
--- a/WpfTest/Model/NotePrivacyInteractors.php
+++ b/WpfTest/Model/NotePrivacyInteractors.php
@@ -1,9 +1,9 @@
 <?php
 namespace WpfTest\Model;
 
-enum NotePrivacyInteractors {
-    case all;
-    case followers;
-    case mutuals;
-    case none;
+enum NotePrivacyInteractors: string {
+    case ALL = 'all';
+    case FOLLOWERS = 'followers';
+    case MUTUALS = 'mutuals';
+    case NONE = 'none';
 }
\ No newline at end of file
diff --git a/WpfTest/Model/NotePrivacyScope.php b/WpfTest/Model/NotePrivacyScope.php
index 3134c26..44c9344 100644
--- a/WpfTest/Model/NotePrivacyScope.php
+++ b/WpfTest/Model/NotePrivacyScope.php
@@ -1,9 +1,9 @@
 <?php
 namespace WpfTest\Model;
 
-enum NotePrivacyScope {
-    case public;
-    case followers;
-    case mutuals;
-    case none;
+enum NotePrivacyScope: string {
+    case PUBLIC = 'public';
+    case FOLLOWERS = 'followers';
+    case MUTUALS = 'mutuals';
+    case NONE = 'none';
 }
\ No newline at end of file
diff --git a/WpfTest/RemoteFetchable.php b/WpfTest/RemoteFetchable.php
new file mode 100644
index 0000000..0782e7e
--- /dev/null
+++ b/WpfTest/RemoteFetchable.php
@@ -0,0 +1,21 @@
+<?php
+namespace WpfTest;
+
+interface RemoteFetchable {
+    /**
+     * Fetches the object by its URI from the remote server.
+     * @param string $uri the URI of the remote object
+     * @param bool $autoSave whether to automatically save the fetched object to the database
+     * @return static
+     */
+    //public static function fetchFromRemote(string $uri, bool $autoSave);
+
+    /**
+     * Finds the object locally by its URI or fetches it remotely if not found.
+     * @param string $uri the URI identifier of the object
+     * @param bool $autoSave whether to automatically save the object (if fetched) to the database
+     * @param bool $forceRefetch whether to forcibly refetch the object even if it's in the database
+     * @return static
+     */
+    public static function findByUri(string $uri, bool $autoSave = true, bool $forceRefetch = false);
+}
\ No newline at end of file
diff --git a/routes/note.php b/routes/note.php
index e43c2a1..65b9313 100644
--- a/routes/note.php
+++ b/routes/note.php
@@ -1,9 +1,7 @@
 <?php
 
 use WpfTest\HttpResponseStatus\NotFound;
-use WpfTest\Model\Actor;
 use WpfTest\Model\Note;
-use WpfTest\Model\NoteAttachment;
 use WpfTest\Router;
 
 Router::getInstance()->mount('/post/:id', function (array $args) {