<?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\Misc;

class Query {
    protected $qBody = ""; // main query body
    protected $tBody = []; // main query parameter types
    protected $vBody = []; // main query parameter values
    protected $qWhere = []; // WHERE clause components
    protected $tWhere = []; // WHERE clause type bindings
    protected $vWhere = []; // WHERE clause binding values
    protected $qWhereNot = []; // WHERE NOT clause components
    protected $tWhereNot = []; // WHERE NOT clause type bindings
    protected $vWhereNot = []; // WHERE NOT clause binding values
    protected $group = []; // GROUP BY clause components
    protected $order = []; // ORDER BY clause components
    protected $limit = 0;
    protected $offset = 0;

    public function __construct(string $body = "", $types = null, $values = null) {
        $this->setBody($body, $types, $values);
    }

    public function setBody(string $body = "", $types = null, $values = null): self {
        $this->qBody = $body;
        if (!is_null($types)) {
            $this->tBody[] = $types;
            $this->vBody[] = $values;
        }
        return $this;
    }

    public function setWhere(string $where, $types = null, $values = null): self {
        $this->qWhere[] = $where;
        if (!is_null($types)) {
            $this->tWhere[] = $types;
            $this->vWhere[] = $values;
        }
        return $this;
    }

    public function setWhereNot(string $where, $types = null, $values = null): self {
        $this->qWhereNot[] = $where;
        if (!is_null($types)) {
            $this->tWhereNot[] = $types;
            $this->vWhereNot[] = $values;
        }
        return $this;
    }

    public function setGroup(string ...$column): self {
        foreach ($column as $col) {
            $this->group[] = $col;
        }
        return $this;
    }

    public function setOrder(string ...$order): self {
        foreach ($order as $o) {
            $this->order[] = $o;
        }
        return $this;
    }

    public function setLimit(int $limit, int $offset = 0): self {
        $this->limit = $limit;
        $this->offset = $offset;
        return $this;
    }

    public function __toString(): string {
        return $this->buildQueryBody();
    }

    public function getQuery(): string {
        return $this->__toString();
    }

    public function getTypes(): array {
        return ValueInfo::flatten([$this->tBody, $this->tWhere, $this->tWhereNot]);
    }

    public function getValues(): array {
        return ValueInfo::flatten([$this->vBody, $this->vWhere, $this->vWhereNot]);
    }

    protected function buildQueryBody(): string {
        $out = "";
        // add the body
        $out .= $this->qBody;
        // add any WHERE terms
        if (sizeof($this->qWhere) || sizeof($this->qWhereNot)) {
            $where = implode(" AND ", $this->qWhere);
            $whereNot = implode(" OR ", $this->qWhereNot);
            $whereNot = strlen($whereNot) ? "NOT ($whereNot)" : "";
            $where = implode(" AND ", array_filter([$where, $whereNot]));
            $out .= " WHERE $where";
        }
        // add any GROUP BY terms
        if (sizeof($this->group)) {
            $out .= " GROUP BY ".implode(", ", $this->group);
        }
        // add any ORDER BY terms
        if (sizeof($this->order)) {
            $out .= " ORDER BY ".implode(", ", $this->order);
        }
        // add LIMIT and OFFSET if either is specified
        if ($this->limit > 0 || $this->offset > 0) {
            $out .= " LIMIT ".($this->limit < 1 ? -1 : $this->limit);
            if ($this->offset > 0) {
                $out .= " OFFSET ".$this->offset;
            }
        }
        return $out;
    }
}