<?php /* Copyright (c) 2024 Freya Murphy */

function __nullify(mixed $val): mixed {
	if (!$val) {
		return NULL;
	} else {
		return $val;
	}
}

class DatabaseQuery {

	private \PDO $conn;
	private string $query;

	private bool $where;
	private bool $set;

	private array $param;

	function __construct(\PDO $conn) {
		$this->conn = $conn;
		$this->query = '';

		$this->set = FALSE;
		$this->where = FALSE;
		$this->param = array();
	}

	///
	/// ARBITRARY QUERY
	///

	public function query(string $query): DatabaseQuery {
		$this->query .= $query;
		return $this;
	}

	///
	/// SELECT
	///

	public function select(string $select): DatabaseQuery {
		$this->query .= "SELECT $select\n";
		return $this;
	}

	public function from(string $from): DatabaseQuery {
		$this->query .= "FROM $from\n";
		return $this;
	}

	///
	/// INSERT
	///

	public function insert_into(string $insert, string ...$columns): DatabaseQuery {
		$this->query .= "INSERT INTO $insert\n (";
		foreach ($columns as $idx => $column) {
			if ($idx !== 0) {
				$this->query .= ",";
			}
			$this->query .= $column;
		}
		$this->query .= ")\n";
		return $this;
	}

	public function values(mixed ...$values): DatabaseQuery {
		$this->query .= "VALUES (";
		foreach ($values as $idx => $value) {
			if ($idx !== 0) {
				$this->query .= ",";
			}
			$this->query .= "?";
			array_push($this->param, $value);
		}
		$this->query .= ")\n";
		return $this;
	}

	///
	/// WHERE
	///

	public function where(string $cond): DatabaseQuery {
		if (!$this->where) {
			$this->where = TRUE;
			$this->query .= "WHERE ";
		} else {
			$this->query .= "AND ";
		}
		$this->query .= "$cond ";
		return $this;
	}

	/**
	 * @param array<mixed> $array
	 */
	public function where_in(string $column, array $array): DatabaseQuery {
		if (!$this->where) {
			$this->where = TRUE;
			$this->query .= "WHERE ";
		} else {
			$this->query .= "AND ";
		}
		if (empty($array)) {
			$this->query .= "FALSE\n";
			return $this;
		}
		$in = $this->in($array);
		$this->query .= "$column $in\n";
		return $this;
	}

	/**
	 * @param array<mixed> $array
	 */
	private function in(array $array): DatabaseQuery {
		$in = 'IN (';
		foreach ($array as $idx => $item) {
			if ($idx != 0) {
				$in .= ",";
			}
			$in .= "?";
			array_push($this->param, $item);
		}
		$in .= ")";
		return $in;
	}

	///
	/// OPERATORS
	///

	public function like(mixed $item): DatabaseQuery {
		$this->query .= "LIKE ?\n";
		array_push($this->param, $item);
		return $this;
	}

	public function eq(mixed $item): DatabaseQuery {
		$this->query .= "= ?\n";
		array_push($this->param, $item);
		return $this;
	}

	public function ne(mixed $item): DatabaseQuery {
		$this->query .= "<> ?\n";
		array_push($this->param, $item);
		return $this;
	}

	public function lt(mixed $item): DatabaseQuery {
		$this->query .= "< ?\n";
		array_push($this->param, $item);
		return $this;
	}

	public function le(mixed $item): DatabaseQuery {
		$this->query .= "<= ?\n";
		array_push($this->param, $item);
		return $this;
	}

	///
	/// JOINS
	///

	public function join(string $table, string $on, string $type = 'LEFT'): DatabaseQuery {
		$this->query .= "$type JOIN $table ON $on\n";
		return $this;
	}

	///
	/// LIMIT, OFFSET, ORDER
	///

	public function limit(int $limit): DatabaseQuery {
		$this->query .= "LIMIT ?\n";
		array_push($this->param, $limit);
		return $this;
	}

	public function offset(int $offset): DatabaseQuery {
		$this->query .= "OFFSET ?\n";
		array_push($this->param, $offset);
		return $this;
	}

	public function order_by(string $column, string $order = 'ASC'): DatabaseQuery {
		$this->query .= "ORDER BY " . $column . ' ' . $order . ' ';
		return $this;
	}

	///
	/// COLLECT
	///

	public function rows(mixed ...$params): ?array {
		$args = $this->param;
		foreach ($params as $param) {
			array_push($args, $param);
		}
		$stmt = $this->conn->prepare($this->query);
		try {
			$stmt->execute($args);
		} catch (Exception $ex) {
			echo $ex;
			echo '<br> >> caused by <<<br>';
			echo str_replace("\n", "<br>", $this->query);
		}
		return __nullify($stmt->fetchAll(PDO::FETCH_ASSOC));
	}

	public function row(mixed ...$params): ?array {
		$args = $this->param;
		foreach ($params as $param) {
			array_push($args, $param);
		}
		$stmt = $this->conn->prepare($this->query);
		$stmt->execute($args);
		return __nullify($stmt->fetch(PDO::FETCH_ASSOC));
	}

	public function execute(mixed ...$params): bool {
		$args = $this->param;
		foreach ($params as $param) {
			array_push($args, $param);
		}
		$stmt = $this->conn->prepare($this->query);
		try {
			$stmt->execute($args);
			return TRUE;
		} catch (Exception $_e) {
			echo $_e;
			echo '<br> >> caused by <<<br>';
			echo str_replace("\n", "<br>", $this->query);
			return FALSE;
		}
	}
}

/**
 * DatabaseHelper
 * allows queries on the
 * postgres database
 */
class DatabaseHelper {

	private ?\PDO $conn;

	function __construct() {
		$this->conn = NULL;
	}

	private function connect(): \PDO {
		if ($this->conn === NULL) {
			$user = getenv("POSTGRES_USER");
			$pass = getenv("POSTGRES_PASSWORD");
			$db	  = getenv("POSTGRES_DB");
			$host = 'db';
			$port = '5432';

			$conn_str = sprintf("pgsql:host=%s;port=%d;dbname=%s;user=%s;password=%s",
                $host,
                $port,
                $db,
                $user,
				$pass
			);
			$this->conn = new \PDO($conn_str);
			$this->conn->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
		}
		return $this->conn;
	}

	public function select(string $select): DatabaseQuery {
		$conn = $this->connect();
		$query = new DatabaseQuery($conn);
		return $query->select($select);
	}

	public function insert_into(string $insert, string ...$columns): DatabaseQuery {
		$conn = $this->connect();
		$query = new DatabaseQuery($conn);
		return $query->insert_into($insert, ...$columns);
	}

	public function query(string $query_str): DatabaseQuery {
		$conn = $this->connect();
		$query = new DatabaseQuery($conn);
		return $query->query($query_str);
	}
}