<?php

namespace ctiso\Database;

use ctiso\Database\StatementIterator,
    ctiso\Tools\StringUtil,
    PDO;
use TheSeer\Tokenizer\Exception;

/**
 * @implements \IteratorAggregate<int, array>
 */
class PDOStatement extends \PDOStatement implements \IteratorAggregate
{
    /** @var int */
    protected $cursorPos = 0;
    /** @var array<int, mixed> */
    public $cache = [];
    /** @var ?array */
    public $fields;

    function getIterator(): \Iterator {
        return new StatementIterator($this);
    }

    protected function __construct() {
    }

    function rewind(): void {
        $this->cursorPos = 0;
    }

    /**
     * @param int $rownum
     * @return bool
     */
    public function seek($rownum): bool {
        if ($rownum < 0) {
            return false;
        }

        // PostgreSQL rows start w/ 0, but this works, because we are
        // looking to move the position _before_ the next desired position
        $this->cursorPos = $rownum;
        return true;
    }

    function valid(): bool {
        return true;
    }

    /**
     * @return bool
     */
    public function first() {
        if ($this->cursorPos !== 0) { $this->seek(0); }
        return $this->next();
    }

    function next(): bool{
        if ($this->getRecordCount() > $this->cursorPos) {
            if (!isset($this->cache[$this->cursorPos])) {
                $this->cache[$this->cursorPos] = $this->fetch(PDO::FETCH_ASSOC);
            }
            $this->fields = $this->cache[$this->cursorPos];

            $this->cursorPos++;
            return true;
        } else {
            $this->fields = null;
            return false;
        }
    }

    function key(): int {
        return $this->cursorPos;
    }

    /**
     * @return mixed
     */
    function current() {
       return $this->cache[$this->cursorPos];
    }

    /**
     * @return array|null
     */
    function getRow() {
        return $this->fields;
    }

    /**
     * @param string $name
     * @return int
     */
    function getInt($name): int {
        if (!$this->fields) {
            throw new \Exception('no fields');
        }
        return (int)$this->fields[$name];
    }

    /**
     * @param string $name
     * @return string
     */
    function getBlob($name) {
        return $this->fields[$name];
    }

    /**
     * @param string $name
     * @return string
     */
    function getString($name) {
        return $this->fields[$name] ?? null;
    }

    /**
     * @param string $name
     * @return bool
     */
    function getBoolean($name) {
        return (bool)$this->fields[$name];
    }

    /**
     * @param string $name
     * @return mixed
     */
    function get($name) {
        return $this->fields[$name];
    }

    /**
     * @param string $name
     * @return array
     */
    function getArray($name) {
        return StringUtil::strToArray($this->fields[$name]);
    }

    /**
     * @return int
     */
    function getRecordCount() {
        return count($this->cache);
    }

    /**
     * @param array $args
     * @return bool
     */
    function execute($args = null): bool {
        $result = parent::execute($args);
        return $result;
    }

}