<?php

namespace SilverStripe\CMS\Forms;

use SilverStripe\CMS\Model\SiteTree;
use SilverStripe\Control\Controller;
use SilverStripe\Control\HTTPRequest;
use SilverStripe\Core\Convert;
use SilverStripe\Forms\TextField;
use SilverStripe\View\Requirements;

/**
 * Used to edit the SiteTree->URLSegment property, and suggest input based on the serverside rules
 * defined through {@link SiteTree->generateURLSegment()} and {@link URLSegmentFilter}.
 *
 * Note: The actual conversion for saving the value takes place in the model layer.
 */
class SiteTreeURLSegmentField extends TextField
{

    /**
     * @var string
     */
    protected $helpText;

    /**
     * @var string
     */
    protected $urlPrefix;

    /**
     * @var string
     */
    protected $urlSuffix;

    /**
     * @var string
     */
    protected $defaultUrl;

    private static $allowed_actions = [
        'suggest'
    ];

    public function Value()
    {
        return rawurldecode($this->value ?? '');
    }

    public function getAttributes()
    {
        return array_merge(
            parent::getAttributes(),
            [
                'data-prefix' => $this->getURLPrefix(),
                'data-suffix' => $this->getURLSuffix(),
                'data-default-url' => $this->getDefaultURL()
            ]
        );
    }

    public function Field($properties = [])
    {
        return parent::Field($properties);
    }

    /**
     * @param HTTPRequest $request
     * @return string
     */
    public function suggest($request)
    {
        if (!$request->getVar('value')) {
            return $this->httpError(
                405,
                _t('SilverStripe\\CMS\\Forms\\SiteTreeURLSegmentField.EMPTY', 'Please enter a URL segment or click cancel')
            );
        }
        $page = $this->getPage();

        // Same logic as SiteTree->onBeforeWrite
        $page->URLSegment = $page->generateURLSegment($request->getVar('value'));
        $count = 2;
        while (!$page->validURLSegment()) {
            $page->URLSegment = preg_replace('/-[0-9]+$/', '', $page->URLSegment ?? '') . '-' . $count;
            $count++;
        }

        Controller::curr()->getResponse()->addHeader('Content-Type', 'application/json');
        return json_encode(['value' => $page->URLSegment]);
    }

    /**
     * @return SiteTree
     */
    public function getPage()
    {
        $idField = $this->getForm()->Fields()->dataFieldByName('ID');
        return ($idField && $idField->Value())
            ? SiteTree::get()->byID($idField->Value())
            : SiteTree::singleton();
    }

    /**
     * @param string $string The secondary text to show
     * @return $this
     */
    public function setHelpText($string)
    {
        $this->helpText = $string;
        return $this;
    }

    /**
     * @return string the secondary text to show in the template
     */
    public function getHelpText()
    {
        return $this->helpText;
    }

    /**
     * @param string $url the url that prefixes the page url segment field
     * @return $this
     */
    public function setURLPrefix($url)
    {
        $this->urlPrefix = $url;
        return $this;
    }

    /**
     * @return string the url prefixes the page url segment field to show in template
     */
    public function getURLPrefix()
    {
        return $this->urlPrefix;
    }

    public function getURLSuffix()
    {
        return $this->urlSuffix;
    }

    /**
     * @return string Indicator for UI to respond to changes accurately,
     * and auto-update the field value if changes to the default occur.
     * Does not set the field default value.
     */
    public function getDefaultURL()
    {
        return $this->defaultUrl;
    }

    public function setDefaultURL($url)
    {
        $this->defaultUrl = $url;
        return $this;
    }

    public function setURLSuffix($suffix)
    {
        $this->urlSuffix = $suffix;
        return $this;
    }

    public function Type()
    {
        return 'text urlsegment';
    }

    public function getURL()
    {
        return Controller::join_links($this->getURLPrefix(), $this->Value(), $this->getURLSuffix());
    }

    public function performReadonlyTransformation()
    {
        $newInst = parent::performReadonlyTransformation();
        $newInst->helpText = $this->helpText;
        $newInst->urlPrefix = $this->urlPrefix;
        $newInst->urlSuffix = $this->urlSuffix;
        $newInst->defaultUrl = $this->defaultUrl;
        return $newInst;
    }
}