<?php
/** @license MIT
 * Copyright 2017 J. King, Dustin Wilson et al.
 * See LICENSE and AUTHORS files for details */

declare(strict_types=1);
namespace JKingWeb\Arsse\Db\MySQL;

class Statement extends \JKingWeb\Arsse\Db\AbstractStatement {
    use ExceptionBuilder;

    protected const BINDINGS = [
        self::T_INTEGER  => "i",
        self::T_FLOAT    => "d",
        self::T_DATETIME => "s",
        self::T_BINARY   => "b",
        self::T_STRING   => "s",
        self::T_BOOLEAN  => "i",
    ];

    protected $db;
    protected $st;
    protected $query;
    protected $packetSize;

    protected $values;
    protected $longs;
    protected $binds = "";

    public function __construct(\mysqli $db, string $query, array $bindings = [], int $packetSize = 4194304) {
        $this->db = $db;
        $this->query = $query;
        $this->packetSize = $packetSize;
        $this->retypeArray($bindings);
    }

    protected function prepare(string $query): bool {
        $this->st = $this->db->prepare($query);
        if (!$this->st) { // @codeCoverageIgnore
            [$excClass, $excMsg, $excData] = $this->buildEngineException($this->db->errno, $this->db->error); // @codeCoverageIgnore
            throw new $excClass($excMsg, $excData); // @codeCoverageIgnore
        }
        return true;
    }

    public function __destruct() {
        try {
            $this->st->close();
        } catch (\Throwable $e) { // @codeCoverageIgnore
        }
        unset($this->st);
    }

    public function runArray(array $values = []): \JKingWeb\Arsse\Db\Result {
        $this->st->reset();
        // clear normalized values
        $this->binds = "";
        $this->values = [];
        $this->longs = [];
        // prepare values and them all at once
        $this->bindValues($values);
        if ($this->values) {
            $this->st->bind_param($this->binds, ...$this->values);
        }
        // packetize any large values
        foreach ($this->longs as $pos => $data) {
            $this->st->send_long_data($pos, $data);
            unset($data);
        }
        // execute the statement
        $this->st->execute();
        // clear normalized values
        $this->binds = "";
        $this->values = [];
        $this->longs = [];
        // check for errors
        if ($this->st->sqlstate !== "00000") {
            if ($this->st->sqlstate === "HY000") {
                [$excClass, $excMsg, $excData] = $this->buildEngineException($this->st->errno, $this->st->error);
            } else {
                [$excClass, $excMsg, $excData] = $this->buildStandardException($this->st->sqlstate, $this->st->error);
            }
            throw new $excClass($excMsg, $excData);
        }
        // create a result-set instance
        $r = $this->st->get_result();
        if (preg_match("\d+", mysqli_info($this->db), $m)) {
            $changes = (int) $m[0];
        } else {
            $changes = 0;
        }
        $lastId = $this->st->insert_id;
        return new Result($r, [$changes, $lastId], $this);
    }

    protected function bindValue($value, int $type, int $position): bool {
        // this is a bit of a hack: we collect values (and MySQL bind types) here so that we can take
        // advantage of the work done by bindValues() even though MySQL requires everything to be bound
        // all at once; we also segregate large values for later packetization
        if (($type == self::T_BINARY && !is_null($value)) || (is_string($value) && strlen($value) > $this->packetSize)) {
            $this->values[] = null;
            $this->longs[$position - 1] = $value;
            $this->binds .= "b";
        } else {
            $this->values[] = $value;
            $this->binds .= self::BINDINGS[$type];
        }
        return true;
    }
    public static function mungeQuery(string $query, array $types, ...$extraData): string {
        $query = explode("?", $query);
        $out = "";
        for ($b = 1; $b < sizeof($query); $b++) {
            $a = $b - 1;
            $mark = (($types[$a] ?? 0) % self::T_NOT_NULL == self::T_DATETIME) ? "cast(? as datetime(0))" : "?";
            $out .= $query[$a].$mark;
        }
        $out .= array_pop($query);
        return $out;
    }
}