<?php

namespace SilverStripe\Forms\HTMLEditor;

use SilverStripe\Assets\File;
use SilverStripe\Forms\ReadonlyField;
use SilverStripe\Forms\TextField;

/**
 * Encapsulation of an image tag, linking to an image either internal or external to the site.
 */
class HTMLEditorField_Image extends HTMLEditorField_File
{

	/**
	 * @var int
	 */
	protected $width;

	/**
	 * @var int
	 */
	protected $height;

	/**
	 * File size details
	 *
	 * @var string
	 */
	protected $size;

	public function __construct($url, File $file = null)
	{
		parent::__construct($url, $file);

		if ($file) {
			return;
		}

		// Get size of remote file
		$size = @filesize($url);
		if ($size) {
			$this->size = $size;
		}

		// Get dimensions of remote file
		$info = @getimagesize($url);
		if ($info) {
			$this->width = $info[0];
			$this->height = $info[1];
		}
	}

	public function getFields()
	{
		$fields = parent::getFields();

		// Alt text
		$fields->insertBefore(
			'CaptionText',
			TextField::create(
				'AltText',
				_t('HTMLEditorField.IMAGEALT', 'Alternative text (alt)'),
				$this->Title,
				80
			)->setDescription(
				_t('HTMLEditorField.IMAGEALTTEXTDESC', 'Shown to screen readers or if image can\'t be displayed')
			)
		);

		// Tooltip
		$fields->insertAfter(
			'AltText',
			TextField::create(
				'Title',
				_t('HTMLEditorField.IMAGETITLETEXT', 'Title text (tooltip)')
			)->setDescription(
				_t('HTMLEditorField.IMAGETITLETEXTDESC', 'For additional information about the image')
			)
		);

		return $fields;
	}

	protected function getDetailFields()
	{
		$fields = parent::getDetailFields();
		$width = $this->getOriginalWidth();
		$height = $this->getOriginalHeight();

		// Show dimensions of original
		if ($width && $height) {
			$fields->insertAfter(
				'ClickableURL',
				ReadonlyField::create(
					"OriginalWidth",
					_t('AssetTableField.WIDTH', 'Width'),
					$width
				)
			);
			$fields->insertAfter(
				'OriginalWidth',
				ReadonlyField::create(
					"OriginalHeight",
					_t('AssetTableField.HEIGHT', 'Height'),
					$height
				)
			);
		}
		return $fields;
	}

	/**
	 * Get width of original, if known
	 *
	 * @return int
	 */
	public function getOriginalWidth()
	{
		if ($this->width) {
			return $this->width;
		}
		if ($this->file) {
			$width = $this->file->getWidth();
			if ($width) {
				return $width;
			}
		}
		return null;
	}

	/**
	 * Get height of original, if known
	 *
	 * @return int
	 */
	public function getOriginalHeight()
	{
		if ($this->height) {
			return $this->height;
		}

		if ($this->file) {
			$height = $this->file->getHeight();
			if ($height) {
				return $height;
			}
		}
		return null;
	}

	public function getWidth()
	{
		if ($this->width) {
			return $this->width;
		}
		return parent::getWidth();
	}

	public function getHeight()
	{
		if ($this->height) {
			return $this->height;
		}
		return parent::getHeight();
	}

	public function getSize()
	{
		if ($this->size) {
			return File::format_size($this->size);
		}
		return parent::getSize();
	}

	/**
	 * Provide an initial width for inserted image, restricted based on $embed_width
	 *
	 * @return int
	 */
	public function getInsertWidth()
	{
		$width = $this->getWidth();
		$maxWidth = $this->config()->insert_width;
		return $width <= $maxWidth
			? $width
			: $maxWidth;
	}

	/**
	 * Provide an initial height for inserted image, scaled proportionally to the initial width
	 *
	 * @return int
	 */
	public function getInsertHeight()
	{
		$width = $this->getWidth();
		$height = $this->getHeight();
		$maxWidth = $this->config()->insert_width;
		return ($width <= $maxWidth) ? $height : round($height * ($maxWidth / $width));
	}

	public function getPreviewURL()
	{
		// Get preview from file
		if ($this->file) {
			return $this->getFilePreviewURL();
		}

		// Embed image directly
		return $this->url;
	}
}