From 415a0a96a76afbe7f1ad2f51862641793caf1b6c Mon Sep 17 00:00:00 2001
From: Jonas Kohl <git@jonaskohl.de>
Date: Sun, 8 Sep 2024 17:53:55 +0200
Subject: Initial commit

---
 src/application/.htaccess                          |   1 +
 src/application/mystic/forum/Database.php          | 318 +++++++++++++++++++++
 src/application/mystic/forum/attributes/Column.php |  11 +
 .../mystic/forum/attributes/NotNull.php            |   6 +
 .../mystic/forum/attributes/PrimaryKey.php         |   6 +
 .../mystic/forum/attributes/References.php         |  15 +
 src/application/mystic/forum/attributes/Table.php  |  10 +
 src/application/mystic/forum/orm/Entity.php        |   6 +
 src/application/mystic/forum/orm/Post.php          |  17 ++
 src/application/mystic/forum/orm/Topic.php         |  15 +
 src/application/mystic/forum/orm/User.php          |  17 ++
 src/application/mystic/forum/utils/ArrayUtils.php  |  33 +++
 src/application/mystic/forum/utils/StaticClass.php |  10 +
 src/application/mystic/forum/utils/StringUtils.php |  24 ++
 src/composer.json                                  |   7 +
 src/index.php                                      |  13 +
 16 files changed, 509 insertions(+)
 create mode 100644 src/application/.htaccess
 create mode 100644 src/application/mystic/forum/Database.php
 create mode 100644 src/application/mystic/forum/attributes/Column.php
 create mode 100644 src/application/mystic/forum/attributes/NotNull.php
 create mode 100644 src/application/mystic/forum/attributes/PrimaryKey.php
 create mode 100644 src/application/mystic/forum/attributes/References.php
 create mode 100644 src/application/mystic/forum/attributes/Table.php
 create mode 100644 src/application/mystic/forum/orm/Entity.php
 create mode 100644 src/application/mystic/forum/orm/Post.php
 create mode 100644 src/application/mystic/forum/orm/Topic.php
 create mode 100644 src/application/mystic/forum/orm/User.php
 create mode 100644 src/application/mystic/forum/utils/ArrayUtils.php
 create mode 100644 src/application/mystic/forum/utils/StaticClass.php
 create mode 100644 src/application/mystic/forum/utils/StringUtils.php
 create mode 100644 src/composer.json
 create mode 100644 src/index.php

(limited to 'src')

diff --git a/src/application/.htaccess b/src/application/.htaccess
new file mode 100644
index 0000000..b66e808
--- /dev/null
+++ b/src/application/.htaccess
@@ -0,0 +1 @@
+Require all denied
diff --git a/src/application/mystic/forum/Database.php b/src/application/mystic/forum/Database.php
new file mode 100644
index 0000000..f574386
--- /dev/null
+++ b/src/application/mystic/forum/Database.php
@@ -0,0 +1,318 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum;
+
+use DateTime;
+use DateTimeImmutable;
+use mystic\forum\attributes\Column;
+use mystic\forum\attributes\NotNull;
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\References;
+use mystic\forum\attributes\Table;
+use mystic\forum\orm\Entity;
+use mystic\forum\utils\ArrayUtils;
+use mystic\forum\utils\StringUtils;
+use PgSql\Connection;
+use ReflectionClass;
+use ReflectionNamedType;
+use ReflectionProperty;
+
+class Database {
+    private Connection $connection;
+
+    private const PRIMARY_KEY = 0b0000_0001;
+    private const NOT_NULL    = 0b0000_0010;
+    private const REFERENCES  = 0b0000_0100;
+
+    public function __construct(string $connectionString) {
+        $this->connection = \pg_connect($connectionString);
+    }
+
+    public static function getConnectionString(string $host, string $user, string $password, string $dbname, int $port = 5432): string {
+        return self::buildConnectionString([
+            "host" => $host,
+            "dbname" => $dbname,
+            "user" => $user,
+            "password" => $password,
+            "port" => strval($port),
+        ]);
+    }
+
+    public static function buildConnectionString(array $params): string {
+        $items = [];
+        foreach ($params as $key => $value) {
+            $items []= $key . "='" . self::escapeConnectionStringValue($value) . "'";
+        }
+        return implode(" ", $items);
+    }
+
+    private static function escapeConnectionStringValue(string $value): string {
+        return str_replace([
+            '\\',
+            "'",
+        ], [
+            '\\\\',
+            "\\'",
+        ], $value);
+    }
+
+    private static function getTableName(string $entityClassName): string {
+        $reflClass = new ReflectionClass($entityClassName);
+        $attrs = $reflClass->getAttributes(Table::class);
+        foreach ($attrs as $attr)
+            return $attr->newInstance()->tableName;
+        return "public." . StringUtils::camelToSnake($reflClass->getShortName());
+    }
+
+    private static function getColumnName(ReflectionProperty &$prop): string {
+        $attrs = $prop->getAttributes(Column::class);
+        foreach ($attrs as $attr) {
+            $name = $attr->newInstance()->columnName;
+            if ($name !== null)
+                return $name;
+        }
+        return StringUtils::camelToSnake($prop->getName());
+    }
+
+    private static function getColumnType(ReflectionProperty &$prop): string {
+        $attrs = $prop->getAttributes(Column::class);
+        foreach ($attrs as $attr) {
+            $type = $attr->newInstance()->columnType;
+            if ($type !== null)
+                return $type;
+        }
+        $type = $prop->getType();
+        if (!($type instanceof ReflectionNamedType))
+            throw new \RuntimeException("Union types or intersection types cannot be converted to a "
+                . "database type. Please specify one manually using the #[Column] attribute!");
+        $typeName = $type->getName();
+        if (!$type->isBuiltin() && $typeName !== \DateTime::class && $typeName !== \DateTimeImmutable::class)
+            throw new \RuntimeException("User-defined types cannot be converted to a "
+                . "database type. Please specify one manually using the #[Column] attribute!");
+        switch ($typeName) {
+            case \DateTime::class:
+            case \DateTimeImmutable::class:
+                return "timestamp with time zone";
+            case "true":
+            case "false":
+            case "bool":
+                return "boolean";
+            case "float":
+                return "double precision";
+            case "int":
+                return "bigint";
+            case "string":
+            case "null":
+                return "text";
+            case "object":
+            case "array":
+            case "iterable":
+            case "callable":
+            case "mixed":
+            case "never":
+            case "void":
+            default:
+                throw new \RuntimeException("The type \"$typeName\" cannot be stored in the database");
+        }
+    }
+
+    private static function getColumnDefinitions(string $entityClassName): array {
+        $statements = [];
+
+        // TODO Foreign keys
+
+        $rflEntity = new \ReflectionClass($entityClassName);
+        $cols = self::getColumns($rflEntity);
+        foreach ($cols as $colName => $colInfo) {
+            $rflProp = new \ReflectionProperty($entityClassName, $colInfo["propertyName"]);
+            $colType = self::getColumnType($rflProp);
+            $statement = "$colName $colType";
+
+            if (($colInfo["flags"] & self::NOT_NULL) !== 0) {
+                $statement .= " NOT NULL";
+            }
+
+            if (($colInfo["flags"] & self::PRIMARY_KEY) !== 0) {
+                $statement .= " PRIMARY KEY";
+            }
+
+            if (($colInfo["flags"] & self::REFERENCES) !== 0) {
+                $statement .= " REFERENCES " . $colInfo["reference"];
+            }
+
+            $statements []= $statement;
+        }
+
+        return $statements;
+    }
+
+    private static function getColumns(ReflectionClass &$rflEntity): array {
+        return ArrayUtils::assocFromPairs(array_map(function(ReflectionProperty $prop): array {
+            $flags = 0;
+            $attrs = $prop->getAttributes();
+            $reference = "";
+            foreach ($attrs as $attr) {
+                $attrName = $attr->getName();
+                if ($attrName === PrimaryKey::class) {
+                    $flags |= self::PRIMARY_KEY;
+                } elseif ($attrName === NotNull::class) {
+                    $flags |= self::NOT_NULL;
+                } elseif ($attrName === References::class) {
+                    $flags |= self::REFERENCES;
+                    $reference = $attr->newInstance()->__toString();
+                }
+            }
+
+            return [self::getColumnName($prop), [
+                "propertyName" => $prop->getName(),
+                "flags" => $flags,
+                "reference" => $reference,
+            ]];
+        }, $rflEntity->getProperties(ReflectionProperty::IS_PUBLIC)));
+    }
+
+    private static function getPrimaryKeyColumn(array &$cols): ?string {
+        foreach ($cols as $col => ["flags" => $flags])
+            if (($flags & self::PRIMARY_KEY) !== 0)
+                return $col;
+        return null;
+    }
+
+    private static function stringifyValue(mixed $value): ?string {
+        if (is_null($value))
+            return null;
+        elseif (is_bool($value))
+            return $value ? "true" : "false";
+        elseif (is_scalar($value))
+            return strval($value);
+        elseif (is_a($value, \DateTimeInterface::class))
+            return $value->format("c");
+        else
+            throw new \RuntimeException("Don't know how to stringify " . is_object($value) ? get_class($value) : gettype($value));
+    }
+
+    private static function assignValue(Entity &$entity, array $colProps, ?string $value): void {
+        $propName = $colProps["propertyName"];
+        $prop = new \ReflectionProperty($entity, $propName);
+
+        $type = $prop->getType();
+        $typedValue = null;
+        if (!($type instanceof ReflectionNamedType))
+            throw new \RuntimeException("Union types or intersection types cannot be converted to from a database type.");
+        $typeName = $type->getName();
+        if (!$type->isBuiltin() && $typeName !== \DateTime::class && $typeName !== \DateTimeImmutable::class)
+            throw new \RuntimeException("User-defined types cannot be converted to from a database type.");
+        switch ($typeName) {
+            case \DateTime::class:
+                $typedValue = new \DateTime($value);
+                break;
+            case \DateTimeImmutable::class:
+                $typedValue = new \DateTimeImmutable($value);
+                break;
+            case "true":
+            case "false":
+            case "bool":
+                $typedValue = in_array(strtolower($value), ["true","yes","on","1"]) ? true : (in_array(strtolower($value), ["false","no","off","0"]) ? false : null);
+                break;
+            case "float":
+                $typedValue = floatval($value);
+                break;
+            case "int":
+                $typedValue = intval($value);
+                break;
+            case "string":
+            case "null":
+                $typedValue = strval($value);
+                break;
+            case "object":
+            case "array":
+            case "iterable":
+            case "callable":
+            case "mixed":
+            case "never":
+            case "void":
+            default:
+                throw new \RuntimeException("The type \"$typeName\" cannot be restored from the database");
+        }
+        $entity->{$propName} = $typedValue;
+    }
+
+    private static function getColumnValues(Entity &$entity, array &$cols): array {
+        $values = [];
+
+        foreach ($cols as $colInfo) {
+            $values []= self::stringifyValue($entity->{$colInfo["propertyName"]} ?? null);
+        }
+
+        return $values;
+    }
+
+    public function insert(Entity &$entity): void {
+        $entityClassName = get_class($entity);
+        $tableName = self::getTableName($entityClassName);
+        $reflClass = new ReflectionClass($entityClassName);
+        $cols = self::getColumns($reflClass);
+        $query = "INSERT INTO $tableName VALUES (" . implode(",", ArrayUtils::fill(fn($i) => "$" . ($i + 1), count($cols))) . ");";
+        $result = \pg_query_params($this->connection, $query, self::getColumnValues($entity, $cols));
+        if ($result === false)
+            throw new \RuntimeException("Insert failed: " . \pg_last_error($this->connection));
+        \pg_free_result($result);
+    }
+
+    public function fetch(Entity &$entity): bool {
+        $entityClassName = get_class($entity);
+        $tableName = self::getTableName($entityClassName);
+        $reflClass = new ReflectionClass($entityClassName);
+        $cols = self::getColumns($reflClass);
+        $primaryCol = self::getPrimaryKeyColumn($cols);
+        if ($primaryCol === null)
+            throw new \RuntimeException("Fetching an entity requires a primary key column to be specified");
+        $query = "SELECT * FROM $tableName WHERE $primaryCol = \$1 LIMIT 1;";
+        $result = \pg_query_params($this->connection, $query, [ $entity->{$cols[$primaryCol]["propertyName"]} ]);
+        if ($result === false)
+            throw new \RuntimeException("Fetch failed: " . \pg_last_error($this->connection));
+        $row = \pg_fetch_assoc($result);
+        \pg_free_result($result);
+        if ($row === false)
+            return false;
+        foreach ($cols as $colName => $colProps)
+            self::assignValue($entity, $colProps, $row[$colName]);
+        return true;
+    }
+
+    public function update(Entity &$entity): bool {
+        $tableName = self::getTableName(get_class($entity));
+        $reflClass = new ReflectionClass($entity);
+        $cols = self::getColumns($reflClass);
+        $primaryCol = self::getPrimaryKeyColumn($cols);
+        if ($primaryCol === null)
+            throw new \RuntimeException("Updating an entity requires a primary key column to be specified");
+
+        $filteredCols = array_filter(ArrayUtils::asPairs($cols), function($pair) {
+            return ($pair[1]["flags"] & self::PRIMARY_KEY) === 0;
+        });
+        $colDef = implode(", ", array_map(function(array $pair): string {
+            return implode("=", [ $pair[0], '$' . $pair[1] ]);
+        }, $filteredCols));
+        $query = "UPDATE $tableName SET $colDef WHERE $primaryCol = \$1;";
+        $result = \pg_query_params($this->connection, $query, array_map(fn($c) => $entity->{$c["propertyName"]}, $filteredCols));
+        if ($result === false)
+            throw new \RuntimeException("Update failed: " . \pg_last_error($this->connection));
+        $num_affected_rows = \pg_affected_rows($result);
+        \pg_free_result($result);
+        return $num_affected_rows >= 1;
+    }
+
+    public function ensureTable(string $entityClassName): void {
+        $tableName = self::getTableName($entityClassName);
+        $colDefs = self::getColumnDefinitions($entityClassName);
+        $query = "CREATE TABLE IF NOT EXISTS $tableName ();";
+        foreach ($colDefs as $colDef)
+            $query .= "ALTER TABLE $tableName ADD COLUMN IF NOT EXISTS $colDef;";
+        $result = \pg_query($this->connection, $query);
+        if ($result === false)
+            throw new \RuntimeException("Table creation failed: " . \pg_last_error($this->connection));
+        \pg_free_result($result);
+    }
+}
diff --git a/src/application/mystic/forum/attributes/Column.php b/src/application/mystic/forum/attributes/Column.php
new file mode 100644
index 0000000..aee47a2
--- /dev/null
+++ b/src/application/mystic/forum/attributes/Column.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace mystic\forum\attributes;
+
+#[\Attribute(\Attribute::TARGET_PROPERTY)]
+class Column {
+    public function __construct(
+        public readonly ?string $columnName = null,
+        public readonly ?string $columnType = null,
+    ) {}
+}
diff --git a/src/application/mystic/forum/attributes/NotNull.php b/src/application/mystic/forum/attributes/NotNull.php
new file mode 100644
index 0000000..2c90da0
--- /dev/null
+++ b/src/application/mystic/forum/attributes/NotNull.php
@@ -0,0 +1,6 @@
+<?php
+
+namespace mystic\forum\attributes;
+
+#[\Attribute(\Attribute::TARGET_PROPERTY)]
+class NotNull {}
diff --git a/src/application/mystic/forum/attributes/PrimaryKey.php b/src/application/mystic/forum/attributes/PrimaryKey.php
new file mode 100644
index 0000000..a8f0fc7
--- /dev/null
+++ b/src/application/mystic/forum/attributes/PrimaryKey.php
@@ -0,0 +1,6 @@
+<?php
+
+namespace mystic\forum\attributes;
+
+#[\Attribute(\Attribute::TARGET_PROPERTY)]
+class PrimaryKey {}
diff --git a/src/application/mystic/forum/attributes/References.php b/src/application/mystic/forum/attributes/References.php
new file mode 100644
index 0000000..ac431ff
--- /dev/null
+++ b/src/application/mystic/forum/attributes/References.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace mystic\forum\attributes;
+
+#[\Attribute(\Attribute::TARGET_PROPERTY)]
+class References {
+    public function __construct(
+        public readonly string $foreignTableName,
+        public readonly ?string $foreignColumnName = null,
+    ) {}
+
+    public function __toString(): string {
+        return $this->foreignTableName . ($this->foreignColumnName !== null ? " ({$this->foreignColumnName})" : "");
+    }
+}
diff --git a/src/application/mystic/forum/attributes/Table.php b/src/application/mystic/forum/attributes/Table.php
new file mode 100644
index 0000000..60fe1ae
--- /dev/null
+++ b/src/application/mystic/forum/attributes/Table.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace mystic\forum\attributes;
+
+#[\Attribute(\Attribute::TARGET_CLASS)]
+class Table {
+    public function __construct(
+        public readonly string $tableName,
+    ) {}
+}
diff --git a/src/application/mystic/forum/orm/Entity.php b/src/application/mystic/forum/orm/Entity.php
new file mode 100644
index 0000000..9afc1b3
--- /dev/null
+++ b/src/application/mystic/forum/orm/Entity.php
@@ -0,0 +1,6 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\orm;
+
+abstract class Entity {}
diff --git a/src/application/mystic/forum/orm/Post.php b/src/application/mystic/forum/orm/Post.php
new file mode 100644
index 0000000..db297e5
--- /dev/null
+++ b/src/application/mystic/forum/orm/Post.php
@@ -0,0 +1,17 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\orm;
+
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\References;
+use mystic\forum\attributes\Table;
+
+#[Table("public.posts")]
+class Post extends Entity {
+    #[PrimaryKey] public string $id;
+    public string $content;
+    #[References("public.users")] public string $authorId;
+    public \DateTimeImmutable $postDate;
+    #[References("public.topics")] public string $topicId;
+}
diff --git a/src/application/mystic/forum/orm/Topic.php b/src/application/mystic/forum/orm/Topic.php
new file mode 100644
index 0000000..202fc50
--- /dev/null
+++ b/src/application/mystic/forum/orm/Topic.php
@@ -0,0 +1,15 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\orm;
+
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\Table;
+
+#[Table("public.topics")]
+class Topic extends Entity {
+    #[PrimaryKey]
+    public string $id;
+    public string $title;
+    public \DateTimeImmutable $creationDate;
+}
diff --git a/src/application/mystic/forum/orm/User.php b/src/application/mystic/forum/orm/User.php
new file mode 100644
index 0000000..3b531b4
--- /dev/null
+++ b/src/application/mystic/forum/orm/User.php
@@ -0,0 +1,17 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\orm;
+
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\Table;
+
+#[Table("public.users")]
+class User extends Entity {
+    #[PrimaryKey]
+    public string $id;
+    public string $name;
+    public string $displayName;
+    public \DateTimeImmutable $created;
+    public string $passwordHash;
+}
diff --git a/src/application/mystic/forum/utils/ArrayUtils.php b/src/application/mystic/forum/utils/ArrayUtils.php
new file mode 100644
index 0000000..ed77c6d
--- /dev/null
+++ b/src/application/mystic/forum/utils/ArrayUtils.php
@@ -0,0 +1,33 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\utils;
+
+final class ArrayUtils {
+    use StaticClass;
+
+    public static function repeat(mixed $value, int $count): array {
+        $arr = [];
+        for ($i = 0; $i < $count; ++$i)
+            $arr []= $value;
+        return $arr;
+    }
+
+    public static function fill(\Closure $factory, int $count): array {
+        $arr = [];
+        for ($i = 0; $i < $count; ++$i)
+            $arr []= $factory($i, $count);
+        return $arr;
+    }
+
+    public static function assocFromPairs(array $pairs): array {
+        return array_combine(array_column($pairs, 0), array_column($pairs, 1));
+    }
+
+    public static function asPairs(array $arr): array {
+        $out = [];
+        foreach ($arr as $k => $v)
+            $out []= [$k, $v];
+        return $out;
+    }
+}
diff --git a/src/application/mystic/forum/utils/StaticClass.php b/src/application/mystic/forum/utils/StaticClass.php
new file mode 100644
index 0000000..e55ada9
--- /dev/null
+++ b/src/application/mystic/forum/utils/StaticClass.php
@@ -0,0 +1,10 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\utils;
+
+trait StaticClass {
+    public function __construct() {
+        throw new \RuntimeException("Cannot instantiate static class " . self::class);
+    }
+}
diff --git a/src/application/mystic/forum/utils/StringUtils.php b/src/application/mystic/forum/utils/StringUtils.php
new file mode 100644
index 0000000..7d4bf9d
--- /dev/null
+++ b/src/application/mystic/forum/utils/StringUtils.php
@@ -0,0 +1,24 @@
+<?php
+declare(strict_types=1);
+
+namespace mystic\forum\utils;
+
+final class StringUtils {
+    use StaticClass;
+
+    public static function camelToSnake(string $camelCase): string {
+        $result = '';
+
+        for ($i = 0; $i < strlen($camelCase); $i++) {
+            $char = $camelCase[$i];
+
+            if (ctype_upper($char)) {
+                $result .= '_' . strtolower($char);
+            } else {
+                $result .= $char;
+            }
+        }
+
+        return ltrim($result, '_');
+    }
+}
diff --git a/src/composer.json b/src/composer.json
new file mode 100644
index 0000000..93c4e2f
--- /dev/null
+++ b/src/composer.json
@@ -0,0 +1,7 @@
+{
+    "autoload": {
+        "psr-4": {
+            "mystic\\forum\\": "application/mystic/forum/"
+        }
+    }
+}
diff --git a/src/index.php b/src/index.php
new file mode 100644
index 0000000..62a300a
--- /dev/null
+++ b/src/index.php
@@ -0,0 +1,13 @@
+<?php
+
+use mystic\forum\Database;
+use mystic\forum\orm\Post;
+use mystic\forum\orm\Topic;
+use mystic\forum\orm\User;
+
+require_once __DIR__ . "/vendor/autoload.php";
+
+$db = new Database(Database::getConnectionString("db", "postgres", "postgres", "postgres"));
+$db->ensureTable(User::class);
+$db->ensureTable(Topic::class);
+$db->ensureTable(Post::class);
-- 
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