Merged in feature/MAPG-43-workout-concept-for-handling-db (pull request #54)

Feature/MAPG-43 workout concept for handling db

composer.json

@@ -4,8 +4,7 @@
   "description": "MapGuesser Application",
   "license": "GNU GPL 3.0",
   "require": {
-    "vlucas/phpdotenv": "^4.1",
-    "romanpitak/php-rest-client": "^1.2"
+    "vlucas/phpdotenv": "^4.1"
   },
   "require-dev": {},
   "autoload": {

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "3778b9431ef3d22705bdbf1653102a1a",
+    "content-hash": "29431cf83ee884f01ee954b1068c0ccc",
     "packages": [
         {
             "name": "phpoption/phpoption",
@@ -61,51 +61,6 @@
             ],
             "time": "2020-03-21T18:07:53+00:00"
         },
-        {
-            "name": "romanpitak/php-rest-client",
-            "version": "v1.2.1",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/romanpitak/PHP-REST-Client.git",
-                "reference": "728b6c44040a13daeb8033953f5f3cdd3dde1980"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/romanpitak/PHP-REST-Client/zipball/728b6c44040a13daeb8033953f5f3cdd3dde1980",
-                "reference": "728b6c44040a13daeb8033953f5f3cdd3dde1980",
-                "shasum": ""
-            },
-            "require": {
-                "ext-curl": "*",
-                "php": ">=5.3.3"
-            },
-            "type": "library",
-            "autoload": {
-                "psr-4": {
-                    "RestClient\\": "src/"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Roman Piták",
-                    "email": "roman@pitak.net",
-                    "homepage": "http://pitak.net",
-                    "role": "Developer"
-                }
-            ],
-            "description": "REST client library.",
-            "homepage": "https://github.com/romanpitak/PHP-REST-Client",
-            "keywords": [
-                "client",
-                "http",
-                "rest"
-            ],
-            "time": "2015-02-19T15:32:16+00:00"
-        },
         {
             "name": "symfony/polyfill-ctype",
             "version": "v1.17.0",

main.php

@@ -15,4 +15,11 @@ if (!empty($_ENV['DEV'])) {
     ini_set('display_errors', '0');
 }
 
+class Container
+{
+    static MapGuesser\Interfaces\Database\IConnection $dbConnection;
+}
+
+Container::$dbConnection = new MapGuesser\Database\Mysql\Connection($_ENV['DB_HOST'], $_ENV['DB_USER'], $_ENV['DB_PASSWORD'], $_ENV['DB_NAME']);
+
 session_start();

src/Controller/ControllerInterface.php

@@ -1,8 +0,0 @@
-<?php namespace MapGuesser\Controller;
-
-use MapGuesser\View\ViewBase;
-
-interface ControllerInterface
-{
-    public function run(): ViewBase;
-}

src/Controller/GameController.php

@@ -1,15 +1,15 @@
 <?php namespace MapGuesser\Controller;
 
+use MapGuesser\Database\Query\Select;
+use MapGuesser\Interfaces\Controller\IController;
+use MapGuesser\Interfaces\Database\IResultSet;
 use MapGuesser\Util\Geo\Bounds;
 use MapGuesser\View\HtmlView;
 use MapGuesser\View\JsonView;
-use MapGuesser\View\ViewBase;
-use mysqli;
+use MapGuesser\Interfaces\View\IView;
 
-class GameController implements ControllerInterface
+class GameController implements IController
 {
-    private mysqli $mysql;
-
     private bool $jsonResponse;
 
     // demo map
@@ -17,12 +17,10 @@ class GameController implements ControllerInterface
 
     public function __construct($jsonResponse = false)
     {
-        $this->mysql = new mysqli($_ENV['DB_HOST'], $_ENV['DB_USER'], $_ENV['DB_PASSWORD'], $_ENV['DB_NAME']);
-
         $this->jsonResponse = $jsonResponse;
     }
 
-    public function run(): ViewBase
+    public function run(): IView
     {
         $bounds = $this->getMapBounds();
 
@@ -45,10 +43,11 @@ class GameController implements ControllerInterface
 
     private function getMapBounds(): Bounds
     {
-        $stmt = $this->mysql->prepare('SELECT bound_south_lat, bound_west_lng, bound_north_lat, bound_east_lng FROM maps WHERE id=?');
-        $stmt->bind_param("i", $this->mapId);
-        $stmt->execute();
-        $map = $stmt->get_result()->fetch_assoc();
+        $select = new Select(\Container::$dbConnection, 'maps');
+        $select->columns(['bound_south_lat', 'bound_west_lng', 'bound_north_lat', 'bound_east_lng']);
+        $select->whereId($this->mapId);
+
+        $map = $select->execute()->fetch(IResultSet::FETCH_ASSOC);
 
         $bounds = Bounds::createDirectly($map['bound_south_lat'], $map['bound_west_lng'], $map['bound_north_lat'], $map['bound_east_lng']);
 

src/Controller/PositionController.php

@@ -1,27 +1,22 @@
 <?php namespace MapGuesser\Controller;
 
+use MapGuesser\Database\Query\Select;
+use MapGuesser\Http\Request;
+use MapGuesser\Interfaces\Controller\IController;
+use MapGuesser\Interfaces\Database\IResultSet;
 use MapGuesser\Util\Geo\Position;
 use MapGuesser\View\JsonView;
-use MapGuesser\View\ViewBase;
-use mysqli;
-use RestClient\Client;
+use MapGuesser\Interfaces\View\IView;
 
-class PositionController implements ControllerInterface
+class PositionController implements IController
 {
     const NUMBER_OF_ROUNDS = 5;
     const MAX_SCORE = 1000;
 
-    private mysqli $mysql;
-
     // demo map
     private int $mapId = 1;
 
-    public function __construct()
-    {
-        $this->mysql = new mysqli($_ENV['DB_HOST'], $_ENV['DB_USER'], $_ENV['DB_PASSWORD'], $_ENV['DB_NAME']);
-    }
-
-    public function run(): ViewBase
+    public function run(): IView
     {
         if (!isset($_SESSION['state']) || $_SESSION['state']['mapId'] !== $this->mapId) {
             $data = ['error' => 'No valid session found!'];
@@ -120,45 +115,34 @@ class PositionController implements ControllerInterface
 
     private function selectNewPlace(array $exclude): array
     {
-        $condition = '';
-        $params = ['i', &$this->mapId];
-        if (($numExcluded = count($exclude)) > 0) {
-            $condition .= ' AND id NOT IN (' . implode(',', array_fill(0, $numExcluded, '?')) . ')';
-            $params[0] .= str_repeat('i', $numExcluded);
-            foreach ($exclude as &$placeId) {
-                $params[] = &$placeId;
-            }
-        }
+        $select = new Select(\Container::$dbConnection, 'places');
+        $select->columns(['id', 'lat', 'lng']);
+        $select->where('id', 'NOT IN', $exclude);
+        $select->where('map_id', '=', $this->mapId);
 
-        $stmt = $this->mysql->prepare('SELECT COUNT(*) AS num FROM places WHERE map_id=? ' . $condition . '');
-        call_user_func_array([$stmt, 'bind_param'], $params);
-        $stmt->execute();
-        $numberOfPlaces = $stmt->get_result()->fetch_assoc()['num'];
+        $numberOfPlaces = $select->count();
         $randomOffset = random_int(0, $numberOfPlaces - 1);
 
-        $params[0] .= 'i';
-        $params[] = &$randomOffset;
+        $select->orderBy('id');
+        $select->limit(1, $randomOffset);
 
-        $stmt = $this->mysql->prepare('SELECT id, lat, lng FROM places WHERE map_id=? ' . $condition . ' ORDER BY id LIMIT 1 OFFSET ?');
-        call_user_func_array([$stmt, 'bind_param'], $params);
-        $stmt->execute();
+        $place = $select->execute()->fetch(IResultSet::FETCH_ASSOC);
 
-        return $stmt->get_result()->fetch_assoc();
+        return $place;
     }
 
     private function getPanorama(Position $position): ?string
     {
-        $query = [
+        $request = new Request('https://maps.googleapis.com/maps/api/streetview/metadata', Request::HTTP_GET);
+        $request->setQuery([
             'key' => $_ENV['GOOGLE_MAPS_SERVER_API_KEY'],
             'location' => $position->getLat() . ',' . $position->getLng(),
             'source' => 'outdoor'
-        ];
+        ]);
 
-        $client = new Client('https://maps.googleapis.com/maps/api/streetview');
-        $request = $client->newRequest('metadata?' . http_build_query($query));
-        $response = $request->getResponse();
+        $response = $request->send();
 
-        $panoData = json_decode($response->getParsedResponse(), true);
+        $panoData = json_decode($response->getBody(), true);
 
         if ($panoData['status'] !== 'OK') {
             return null;
@@ -172,10 +156,10 @@ class PositionController implements ControllerInterface
         return $realPosition->calculateDistanceTo($guessPosition);
     }
 
-    private function calculateScore(float $distance, float $area)
+    private function calculateScore(float $distance, float $area): int
     {
         $goodness = 1.0 - ($distance / sqrt($area));
 
-        return round(pow(static::MAX_SCORE, $goodness));
+        return (int) round(pow(static::MAX_SCORE, $goodness));
     }
 }

src/Database/Mysql/Connection.php

@@ -0,0 +1,114 @@
+<?php namespace MapGuesser\Database\Mysql;
+
+use MapGuesser\Interfaces\Database\IConnection;
+use MapGuesser\Interfaces\Database\IResultSet;
+use MapGuesser\Interfaces\Database\IStatement;
+use mysqli;
+
+class Connection implements IConnection
+{
+    private mysqli $connection;
+
+    public function __construct(string $host, string $user, string $password, string $db, int $port = -1, string $socket = null)
+    {
+        if ($port < 0) {
+            $port = ini_get('mysqli.default_port');
+        }
+
+        if ($socket === null) {
+            $socket = ini_get('mysqli.default_socket');
+        }
+
+        $this->connection = new mysqli($host, $user, $password, $db, $port, $socket);
+
+        if ($this->connection->connect_error) {
+            throw new \Exception('Connection failed: ' . $this->connection->connect_error);
+        }
+
+        if (!$this->connection->set_charset('utf8mb4')) {
+            throw new \Exception($this->connection->error);
+        }
+    }
+
+    public function __destruct()
+    {
+        $this->connection->close();
+    }
+
+    public function startTransaction(): void
+    {
+        if (!$this->connection->autocommit(false)) {
+            throw new \Exception($this->connection->error);
+        }
+    }
+
+    public function commit(): void
+    {
+        if (!$this->connection->commit() || !$this->connection->autocommit(true)) {
+            throw new \Exception($this->connection->error);
+        }
+    }
+
+    public function rollback(): void
+    {
+        if (!$this->connection->rollback() || !$this->connection->autocommit(true)) {
+            throw new \Exception($this->connection->error);
+        }
+    }
+
+    public function query(string $query): ?IResultSet
+    {
+        if (!($result = $this->connection->query($query))) {
+            throw new \Exception($this->connection->error . '. Query: ' . $query);
+        }
+
+        if ($result !== true) {
+            return new ResultSet($result);
+        }
+
+        return null;
+    }
+
+    public function multiQuery(string $query): array
+    {
+        if (!$this->connection->multi_query($query)) {
+            throw new \Exception($this->connection->error . '. Query: ' . $query);
+        }
+
+        $ret = [];
+        do {
+            if ($result = $this->connection->store_result()) {
+                $ret[] = new ResultSet($result);
+            } else {
+                $ret[] = null;
+            }
+
+            $this->connection->more_results();
+        } while ($this->connection->next_result());
+
+        if ($this->connection->error) {
+            throw new \Exception($this->connection->error  . '. Query: ' . $query);
+        }
+
+        return $ret;
+    }
+
+    public function prepare(string $query): IStatement
+    {
+        if (!($stmt = $this->connection->prepare($query))) {
+            throw new \Exception($this->connection->error . '. Query: ' . $query);
+        }
+
+        return new Statement($stmt);
+    }
+
+    public function lastId(): int
+    {
+        return $this->connection->insert_id;
+    }
+
+    public function getAffectedRows(): int
+    {
+        return $this->connection->affected_rows;
+    }
+}

src/Database/Mysql/ResultSet.php

@@ -0,0 +1,62 @@
+<?php namespace MapGuesser\Database\Mysql;
+
+use MapGuesser\Interfaces\Database\IResultSet;
+use mysqli_result;
+
+class ResultSet implements IResultSet
+{
+    private mysqli_result $result;
+
+    public function __construct(mysqli_result $result)
+    {
+        $this->result = $result;
+    }
+
+    public function fetch(int $type = IResultSet::FETCH_ASSOC)
+    {
+        return $this->result->fetch_array($this->convertFetchType($type));
+    }
+
+    public function fetchAll(int $type = IResultSet::FETCH_ASSOC)
+    {
+        return $this->result->fetch_all($this->convertFetchType($type));
+    }
+
+    public function fetchOneColumn(string $valueName, string $keyName = null)
+    {
+        $array = [];
+
+        while ($r = $this->fetch(IResultSet::FETCH_ASSOC)) {
+            if (isset($keyName)) {
+                $array[$r[$keyName]] = $r[$valueName];
+            } else {
+                $array[] = $r[$valueName];
+            }
+        }
+
+        return $array;
+    }
+
+    private function convertFetchType(int $type): int
+    {
+        switch ($type) {
+            case IResultSet::FETCH_ASSOC:
+                $internal_type = MYSQLI_ASSOC;
+                break;
+
+            case IResultSet::FETCH_BOTH:
+                $internal_type = MYSQLI_BOTH;
+                break;
+
+            case IResultSet::FETCH_NUM:
+                $internal_type = MYSQLI_NUM;
+                break;
+
+            default:
+                $internal_type = MYSQLI_BOTH;
+                break;
+        }
+
+        return $internal_type;
+    }
+}

src/Database/Mysql/Statement.php

@@ -0,0 +1,79 @@
+<?php namespace MapGuesser\Database\Mysql;
+
+use MapGuesser\Interfaces\Database\IResultSet;
+use MapGuesser\Interfaces\Database\IStatement;
+use mysqli_stmt;
+
+class Statement implements IStatement
+{
+    private mysqli_stmt $stmt;
+
+    public function __construct(mysqli_stmt $stmt)
+    {
+        $this->stmt = $stmt;
+    }
+
+    public function __destruct()
+    {
+        $this->stmt->close();
+    }
+
+    public function execute(array $params = []): ?IResultSet
+    {
+        if ($params) {
+            $ref_params = [''];
+
+            foreach ($params as &$param) {
+                $type = gettype($param);
+
+                switch ($type) {
+                    case 'integer':
+                    case 'double':
+                    case 'string':
+                        $t = $type[0];
+                        break;
+
+                    case 'NULL':
+                        $t = 's';
+                        break;
+
+                    case 'boolean':
+                        $param = (string) (int) $param;
+                        $t = 's';
+                        break;
+
+                    case 'array':
+                        $param = json_encode($param);
+                        $t = 's';
+                        break;
+                }
+
+                if (!isset($t)) {
+                    throw new \Exception('Data type ' . $type . ' not supported!');
+                }
+
+                $ref_params[] = &$param;
+                $ref_params[0] .= $t;
+            }
+
+            if (!call_user_func_array([$this->stmt, 'bind_param'], $ref_params)) {
+                throw new \Exception($this->stmt->error);
+            }
+        }
+
+        if (!$this->stmt->execute()) {
+            throw new \Exception($this->stmt->error);
+        }
+
+        if ($result_set = $this->stmt->get_result()) {
+            return new ResultSet($result_set);
+        }
+
+        return null;
+    }
+
+    public function getAffectedRows(): int
+    {
+        return $this->stmt->affected_rows;
+    }
+}

src/Database/Query/Modify.php

@@ -0,0 +1,157 @@
+<?php namespace MapGuesser\Database\Query;
+
+use MapGuesser\Interfaces\Database\IConnection;
+use MapGuesser\Interfaces\Database\IResultSet;
+use MapGuesser\Database\Utils;
+
+class Modify
+{
+    private IConnection $connection;
+
+    private string $table;
+
+    private string $idName = 'id';
+
+    private array $attributes = [];
+
+    private array $original = [];
+
+    private bool $autoIncrement = false;
+
+    public function __construct(IConnection $connection, string $table)
+    {
+        $this->connection = $connection;
+        $this->table = $table;
+    }
+
+    public function setIdName(string $idName): Modify
+    {
+        $this->idName = $idName;
+
+        return $this;
+    }
+
+    public function setAutoIncrement(bool $autoIncrement = true): Modify
+    {
+        $this->autoIncrement = $autoIncrement;
+
+        return $this;
+    }
+
+    public function fill(array $attributes): Modify
+    {
+        $this->attributes = array_merge($this->attributes, $attributes);
+
+        return $this;
+    }
+
+    public function set(string $name, $value): Modify
+    {
+        $this->attributes[$name] = $value;
+
+        return $this;
+    }
+
+    public function setId($id): Modify
+    {
+        $this->attributes[$this->idName] = $id;
+
+        return $this;
+    }
+
+    public function save(): void
+    {
+        if (isset($this->attributes[$this->idName])) {
+            $this->update();
+        } else {
+            $this->insert();
+        }
+    }
+
+    public function delete(): void
+    {
+        if (!isset($this->attributes[$this->idName])) {
+            throw new \Exception('No primary key specified!');
+        }
+
+        $query = 'DELETE FROM ' . Utils::backtick($this->table) . ' WHERE ' . Utils::backtick($this->idName) . '=?';
+
+        $stmt = $this->connection->prepare($query);
+        $stmt->execute([$this->idName => $this->attributes[$this->idName]]);
+    }
+
+    private function insert(): void
+    {
+        if (!$this->autoIncrement) {
+            $this->attributes[$this->idName] = $this->generateKey();
+        }
+
+        $set = $this->generateColumnsWithBinding(array_keys($this->attributes));
+
+        $query = 'INSERT INTO ' . Utils::backtick($this->table) . ' SET ' . $set;
+
+        $stmt = $this->connection->prepare($query);
+        $stmt->execute($this->attributes);
+
+        if ($this->autoIncrement) {
+            $this->attributes[$this->idName] = $this->connection->lastId();
+        }
+    }
+
+    private function update(): void
+    {
+        $diff = $this->generateDiff();
+
+        if (count($diff) === 0) {
+            return;
+        }
+
+        $set = $this->generateColumnsWithBinding(array_keys($diff));
+
+        $query = 'UPDATE ' . Utils::backtick($this->table) . ' SET ' . $set . ' WHERE ' . Utils::backtick($this->idName) . '=?';
+
+        $stmt = $this->connection->prepare($query);
+        $stmt->execute(array_merge($diff, [$this->idName => $this->attributes[$this->idName]]));
+    }
+
+    private function readFromDB(array $columns): void
+    {
+        $select = (new Select($this->connection, $this->table))
+            ->setIdName($this->idName)
+            ->whereId($this->attributes[$this->idName])
+            ->columns($columns);
+
+        $this->original = $select->execute()->fetch(IResultSet::FETCH_ASSOC);
+    }
+
+    private function generateDiff(): array
+    {
+        $this->readFromDB(array_keys($this->attributes));
+
+        $diff = [];
+
+        foreach ($this->attributes as $name => $value) {
+            $original = $this->original[$name];
+
+            if ($original != $value) {
+                $diff[$name] = $value;
+            }
+        }
+
+        return $diff;
+    }
+
+    public static function generateColumnsWithBinding(array $columns): string
+    {
+        array_walk($columns, function(&$value, $key) {
+            $value = Utils::backtick($value) . '=?';
+        });
+
+        return implode(',', $columns);
+    }
+
+    private function generateKey(): string
+    {
+        return substr(hash('sha256', serialize($this->attributes) . random_bytes(10) . microtime()), 0, 7);
+    }
+}

src/Database/Query/Select.php

@@ -0,0 +1,402 @@
+<?php namespace MapGuesser\Database\Query;
+
+use Closure;
+use MapGuesser\Interfaces\Database\IConnection;
+use MapGuesser\Interfaces\Database\IResultSet;
+use MapGuesser\Database\RawExpression;
+use MapGuesser\Database\Utils;
+
+class Select
+{
+    const CONDITION_WHERE = 0;
+
+    const CONDITION_HAVING = 1;
+
+    private IConnection $connection;
+
+    private string $table;
+
+    private string $idName = 'id';
+
+    private array $tableAliases = [];
+
+    private array $joins = [];
+
+    private array $columns = [];
+
+    private array $conditions = [self::CONDITION_WHERE => [], self::CONDITION_HAVING => []];
+
+    private array $groups = [];
+
+    private array $orders = [];
+
+    private array $limit;
+
+    public function __construct(IConnection $connection, string $table)
+    {
+        $this->connection = $connection;
+        $this->table = $table;
+    }
+
+    public function setIdName(string $idName): Select
+    {
+        $this->idName = $idName;
+
+        return $this;
+    }
+
+    public function setTableAliases(array $tableAliases): Select
+    {
+        $this->tableAliases = array_merge($this->tableAliases, $tableAliases);
+
+        return $this;
+    }
+
+    public function columns(array $columns): Select
+    {
+        $this->columns = array_merge($this->columns, $columns);
+
+        return $this;
+    }
+
+    public function innerJoin($table, $column1, string $relation, $column2): Select
+    {
+        $this->addJoin('INNER', $table, $column1, $relation, $column2);
+
+        return $this;
+    }
+
+    public function leftJoin($table, $column1, string $relation, $column2): Select
+    {
+        $this->addJoin('LEFT', $table, $column1, $relation, $column2);
+
+        return $this;
+    }
+
+    public function whereId($value): Select
+    {
+        $this->addWhereCondition('AND', $this->idName, '=', $value);
+
+        return $this;
+    }
+
+    public function where($column, string $relation = null, $value = null): Select
+    {
+        $this->addWhereCondition('AND', $column, $relation, $value);
+
+        return $this;
+    }
+
+    public function orWhere($column, string $relation = null, $value = null): Select
+    {
+        $this->addWhereCondition('OR', $column, $relation, $value);
+
+        return $this;
+    }
+
+    public function having($column, string $relation = null, $value = null): Select
+    {
+        $this->addHavingCondition('AND', $column, $relation, $value);
+
+        return $this;
+    }
+
+    public function orHaving($column, string $relation = null, $value = null): Select
+    {
+        $this->addHavingCondition('OR', $column, $relation, $value);
+
+        return $this;
+    }
+
+    public function groupBy($column): Select
+    {
+        $this->groups[] = $column;
+
+        return $this;
+    }
+
+    public function orderBy($column, string $type = 'asc'): Select
+    {
+        $this->orders[] = [$column, $type];
+
+        return $this;
+    }
+
+    public function limit(int $limit, int $offset = 0): Select
+    {
+        $this->limit = [$limit, $offset];
+
+        return $this;
+    }
+
+    public function resetLimit(): void
+    {
+        $this->limit = null;
+    }
+
+    public function paginate(int $page, int $itemsPerPage)
+    {
+        $this->limit($itemsPerPage, ($page - 1) * $itemsPerPage);
+
+        return $this;
+    }
+
+    public function execute(): IResultSet
+    {
+        list($query, $params) = $this->generateQuery();
+
+        return $this->connection->prepare($query)->execute($params);
+    }
+
+    public function count(): int
+    {
+        if (count($this->groups) > 0 || count($this->conditions[self::CONDITION_HAVING]) > 0) {
+            $orders = $this->orders;
+
+            $this->orders = [];
+
+            list($query, $params) = $this->generateQuery();
+
+            $result = $this->connection->prepare('SELECT COUNT(*) num_rows FROM (' . $query . ') x')
+                ->execute($params)
+                ->fetch(IResultSet::FETCH_NUM);
+
+            $this->orders = $orders;
+
+            return $result[0];
+        } else {
+            $columns = $this->columns;
+            $orders = $this->orders;
+
+            $this->columns = [new RawExpression('COUNT(*) num_rows')];
+            $this->orders = [];
+
+            list($query, $params) = $this->generateQuery();
+
+            $result = $this->connection->prepare($query)
+                ->execute($params)
+                ->fetch(IResultSet::FETCH_NUM);
+
+            $this->columns = $columns;
+            $this->orders = $orders;
+
+            return $result[0];
+        }
+    }
+
+    private function addJoin(string $type, $table, $column1, string $relation, $column2): void
+    {
+        $this->joins[] = [$type, $table, $column1, $relation, $column2];
+    }
+
+    private function addWhereCondition(string $logic, $column, string $relation, $value): void
+    {
+        $this->conditions[self::CONDITION_WHERE][] = [$logic, $column, $relation, $value];
+    }
+
+    private function addHavingCondition(string $logic, $column, string $relation, $value): void
+    {
+        $this->conditions[self::CONDITION_HAVING][] = [$logic, $column, $relation, $value];
+    }
+
+    private function generateQuery(): array
+    {
+        $queryString = 'SELECT ' . $this->generateColumns() . ' FROM ' . $this->generateTable($this->table, true);
+
+        if (count($this->joins) > 0) {
+            $queryString .= ' ' . $this->generateJoins();
+        }
+
+        if (count($this->conditions[self::CONDITION_WHERE]) > 0) {
+            list($wheres, $whereParams) = $this->generateConditions(self::CONDITION_WHERE);
+
+            $queryString .= ' WHERE ' .  $wheres;
+        } else {
+            $whereParams = [];
+        }
+
+        if (count($this->groups) > 0) {
+            $queryString .= ' GROUP BY ' . $this->generateGroupBy();
+        }
+
+        if (count($this->conditions[self::CONDITION_HAVING]) > 0) {
+            list($havings, $havingParams) = $this->generateConditions(self::CONDITION_HAVING);
+
+            $queryString .= ' HAVING ' .  $havings;
+        } else {
+            $havingParams = [];
+        }
+
+        if (count($this->orders) > 0) {
+            $queryString .= ' ORDER BY ' . $this->generateOrderBy();
+        }
+
+        if (isset($this->limit)) {
+            $queryString .= ' LIMIT ' . $this->limit[1] . ', ' . $this->limit[0];
+        }
+
+        return [$queryString, array_merge($whereParams, $havingParams)];
+    }
+
+    private function generateTable($table, bool $defineAlias = false): string
+    {
+        if ($table instanceof RawExpression) {
+            return (string) $table;
+        }
+
+        if (isset($this->tableAliases[$table])) {
+            return ($defineAlias ? Utils::backtick($this->tableAliases[$table]) . ' ' . Utils::backtick($table) : Utils::backtick($table));
+        }
+
+        return Utils::backtick($table);
+    }
+
+    private function generateColumn($column): string
+    {
+        if ($column instanceof RawExpression) {
+            return (string) $column;
+        }
+
+        if (is_array($column)) {
+            $out = '';
+
+            if ($column[0]) {
+                $out .= $this->generateTable($column[0]) . '.';
+            }
+
+            $out .= Utils::backtick($column[1]);
+
+            if (!empty($column[2])) {
+                $out .= ' ' . Utils::backtick($column[2]);
+            }
+
+            return $out;
+        } else {
+            return Utils::backtick($column);
+        }
+    }
+
+    private function generateColumns(): string
+    {
+        $columns = $this->columns;
+
+        array_walk($columns, function (&$value, $key) {
+            $value = $this->generateColumn($value);
+        });
+
+        return implode(',', $columns);
+    }
+
+    private function generateJoins(): string
+    {
+        $joins = $this->joins;
+
+        array_walk($joins, function (&$value, $key) {
+            $value = $value[0] . ' JOIN ' . $this->generateTable($value[1], true) . ' ON ' . $this->generateColumn($value[2]) . ' ' . $value[3] . ' ' . $this->generateColumn($value[4]);
+        });
+
+        return implode(' ', $joins);
+    }
+
+    private function generateConditions(string $type): array
+    {
+        $conditions = '';
+        $params = [];
+
+        foreach ($this->conditions[$type] as $condition) {
+            list($logic, $column, $relation, $value) = $condition;
+
+            if ($column instanceof Closure) {
+                list($conditionsStringFragment, $paramsFragment) = $this->generateComplexConditionFragment($type, $column);
+            } else {
+                list($conditionsStringFragment, $paramsFragment) = $this->generateConditionFragment($condition);
+            }
+
+            if ($conditions !== '') {
+                $conditions .= ' ' . $logic . ' ';
+            }
+
+            $conditions .= $conditionsStringFragment;
+            $params = array_merge($params, $paramsFragment);
+        }
+
+        return [$conditions, $params];
+    }
+
+    private function generateConditionFragment(array $condition): array
+    {
+        list($logic, $column, $relation, $value) = $condition;
+
+        if ($column instanceof RawExpression) {
+            return [(string) $column, []];
+        }
+
+        $conditionsString = $this->generateColumn($column) . ' ';
+
+        if ($value === null) {
+            return [$conditionsString . ($relation == '=' ? 'IS NULL' : 'IS NOT NULL'), []];
+        }
+
+        $conditionsString .= strtoupper($relation) . ' ';;
+
+        switch ($relation = strtolower($relation)) {
+            case 'between':
+                $params = [$value[0], $value[1]];
+
+                $conditionsString .= '? AND ?';
+                break;
+
+            case 'in':
+            case 'not in':
+                $params = $value;
+
+                if (count($value) > 0) {
+                    $conditionsString .= '(' . implode(', ', array_fill(0, count($value), '?')) . ')';
+                } else {
+                    $conditionsString = $relation == 'in' ? '0' : '1';
+                }
+                break;
+
+            default:
+                $params = [$value];
+
+                $conditionsString .= '?';
+        }
+
+        return [$conditionsString, $params];
+    }
+
+    private function generateComplexConditionFragment(string $type, Closure $conditionCallback): array
+    {
+        $instance = new static($this->connection, $this->table);
+        $instance->tableAliases = $this->tableAliases;
+
+        $conditionCallback($instance);
+
+        list($conditions, $params) = $instance->generateConditions($type);
+
+        return ['(' . $conditions . ')', $params];
+    }
+
+    private function generateGroupBy(): string
+    {
+        $groups = $this->groups;
+
+        array_walk($groups, function (&$value, $key) {
+            $value = $this->generateColumn($value);
+        });
+
+        return implode(',', $groups);
+    }
+
+    private function generateOrderBy(): string
+    {
+        $orders = $this->orders;
+
+        array_walk($orders, function (&$value, $key) {
+            $value = $this->generateColumn($value[0]) . ' ' . $value[1];
+        });
+
+        return implode(',', $orders);
+    }
+}

src/Database/RawExpression.php

@@ -0,0 +1,16 @@
+<?php namespace MapGuesser\Database;
+
+class RawExpression
+{
+    private string $expression;
+
+    public function __construct(string $expression)
+    {
+        $this->expression = $expression;
+    }
+
+    public function __toString(): string
+    {
+        return $this->expression;
+    }
+}

src/Database/Utils.php

@@ -0,0 +1,7 @@
+<?php namespace MapGuesser\Database;
+
+class Utils {
+    public static function backtick(string $name) {
+        return '`' . $name . '`';
+    }
+}

src/Http/Request.php

@@ -0,0 +1,93 @@
+<?php namespace MapGuesser\Http;
+
+class Request
+{
+    const HTTP_GET = 0;
+
+    const HTTP_POST = 1;
+
+    private string $url;
+
+    private int $method;
+
+    private string $query = '';
+
+    private array $headers = [];
+
+    public function __construct(string $url, int $method = self::HTTP_GET)
+    {
+        $this->url = $url;
+        $this->method = $method;
+    }
+
+    public function setQuery($query)
+    {
+        if (is_string($query)) {
+            $this->query = $query;
+        } else {
+            $this->query = http_build_query($query);
+        }
+    }
+
+    public function setHeaders(array $headers)
+    {
+        $this->headers = array_merge($this->headers, $headers);
+    }
+
+    public function send(): Response
+    {
+        $ch = curl_init();
+
+        if ($this->method === self::HTTP_GET) {
+            $url = $this->url . '?' . $this->query;
+        } elseif ($this->method === self::HTTP_POST) {
+            $url  = $this->url;
+
+            curl_setopt($ch, CURLOPT_POST, 1);
+            curl_setopt($ch, CURLOPT_POSTFIELDS, $this->query);
+        }
+
+        curl_setopt($ch, CURLOPT_URL, $url);
+        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
+        curl_setopt($ch, CURLOPT_TIMEOUT, 20);
+        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
+        curl_setopt($ch, CURLOPT_USERAGENT, 'MapGuesser cURL/1.0');
+
+        if (count($this->headers) > 0) {
+            curl_setopt($ch, CURLOPT_HTTPHEADER, $this->headers);
+        }
+
+        $responseHeaders = [];
+        curl_setopt(
+            $ch,
+            CURLOPT_HEADERFUNCTION,
+            function ($ch, $header) use (&$responseHeaders) {
+                $len = strlen($header);
+                $header = explode(':', $header, 2);
+
+                if (count($header) < 2) {
+                    return $len;
+                }
+
+                $responseHeaders[strtolower(trim($header[0]))][] = trim($header[1]);
+
+                return $len;
+            }
+        );
+
+        $responseBody = curl_exec($ch);
+
+        if ($responseBody === false) {
+            $error = curl_error($ch);
+
+            curl_close($ch);
+
+            throw new \Exception($error);
+        }
+
+        curl_close($ch);
+
+        return new Response($responseBody, $responseHeaders);
+    }
+}

src/Http/Response.php

@@ -0,0 +1,24 @@
+<?php namespace MapGuesser\Http;
+
+class Response
+{
+    private string $body;
+
+    private array $headers;
+
+    public function __construct(string $body, array $headers)
+    {
+        $this->body = $body;
+        $this->headers = $headers;
+    }
+
+    public function getBody()
+    {
+        return $this->body;
+    }
+
+    public function getHeaders()
+    {
+        return $this->headers;
+    }
+}

src/Interfaces/Controller/IController.php

@@ -0,0 +1,8 @@
+<?php namespace MapGuesser\Interfaces\Controller;
+
+use MapGuesser\Interfaces\View\IView;
+
+interface IController
+{
+    public function run(): IView;
+}

src/Interfaces/Database/IConnection.php

@@ -0,0 +1,20 @@
+<?php namespace MapGuesser\Interfaces\Database;
+
+interface IConnection
+{
+    public function startTransaction(): void;
+
+    public function commit(): void;
+
+    public function rollback(): void;
+
+    public function query(string $query): ?IResultSet;
+
+    public function multiQuery(string $query): array;
+
+    public function prepare(string $query): IStatement;
+
+    public function lastId(): int;
+
+    public function getAffectedRows(): int;
+}

src/Interfaces/Database/IResultSet.php

@@ -0,0 +1,16 @@
+<?php namespace MapGuesser\Interfaces\Database;
+
+interface IResultSet
+{
+    const FETCH_ASSOC = 0;
+
+    const FETCH_NUM = 1;
+
+    const FETCH_BOTH = 2;
+
+    public function fetch(int $type);
+
+    public function fetchAll(int $type);
+
+    public function fetchOneColumn(string $valueName, string $keyName);
+}

src/Interfaces/Database/IStatement.php

@@ -0,0 +1,8 @@
+<?php namespace MapGuesser\Interfaces\Database;
+
+interface IStatement
+{
+    public function execute(array $params): ?IResultSet;
+
+    public function getAffectedRows(): int;
+}

src/Interfaces/View/IView.php

@@ -0,0 +1,10 @@
+<?php namespace MapGuesser\Interfaces\View;
+
+interface IView
+{
+    public function &getData(): array;
+
+    public function &render(): string;
+
+    public function getContentType(): string;
+}

src/View/ViewBase.php

@@ -1,6 +1,8 @@
 <?php namespace MapGuesser\View;
 
-abstract class ViewBase
+use MapGuesser\Interfaces\View\IView;
+
+abstract class ViewBase implements IView
 {
     protected array $data;