<?php
/**
 * Plugin settings.
 *
 * @package FlipWebP
 */

namespace FlipWebP;

defined( 'ABSPATH' ) || exit;

/**
 * Reads and sanitizes the single plugin option.
 */
class Settings {

	const OPTION = 'flipwebp_settings';

	/**
	 * Default values.
	 *
	 * @return array<string, int>
	 */
	public static function defaults() {
		return array(
			'quality'           => 82,
			'max_dimension'     => 0,
			'delete_originals'  => 1,
			'create_backups'    => 0,
			'convert_on_upload' => 0,
		);
	}

	/**
	 * Create the option on activation when it does not exist yet.
	 *
	 * @return void
	 */
	public static function install() {
		if ( false === get_option( self::OPTION, false ) ) {
			add_option( self::OPTION, self::defaults(), '', true );
		}
	}

	/**
	 * Register the setting with WordPress.
	 *
	 * @return void
	 */
	public static function register() {
		add_action( 'admin_init', array( self::class, 'register_setting' ) );
	}

	/**
	 * Register the option and its sanitizer.
	 *
	 * @return void
	 */
	public static function register_setting() {
		register_setting(
			'flipwebp_settings_group',
			self::OPTION,
			array(
				'type'              => 'array',
				'sanitize_callback' => array( self::class, 'sanitize' ),
				'default'           => self::defaults(),
				'show_in_rest'      => false,
			)
		);
	}

	/**
	 * Saved settings merged onto defaults.
	 *
	 * @return array<string, int>
	 */
	public static function all() {
		$saved = get_option( self::OPTION, array() );
		if ( ! is_array( $saved ) ) {
			$saved = array();
		}

		$settings = wp_parse_args( $saved, self::defaults() );

		return self::normalize( $settings );
	}

	/**
	 * One boolean setting.
	 *
	 * @param string $key Setting key.
	 * @return bool
	 */
	public static function enabled( $key ) {
		$all = self::all();

		return ! empty( $all[ $key ] );
	}

	/**
	 * Quality value used for encoding, after the developer filter.
	 *
	 * @param int $attachment_id Attachment ID.
	 * @return int
	 */
	public static function quality( $attachment_id = 0 ) {
		$quality = (int) self::all()['quality'];

		/**
		 * Filters the WebP quality for one conversion.
		 *
		 * Values are clamped to 40–100.
		 *
		 * @param int $quality       Quality from 40 to 100.
		 * @param int $attachment_id Attachment ID.
		 */
		$quality = (int) apply_filters( 'flipwebp_quality', $quality, (int) $attachment_id );

		return min( 100, max( 40, $quality ) );
	}

	/**
	 * Longest-side resize limit. Zero keeps the current pixel size.
	 *
	 * @param int $attachment_id Attachment ID.
	 * @return int
	 */
	public static function max_dimension( $attachment_id = 0 ) {
		$max = (int) self::all()['max_dimension'];

		/**
		 * Filters the maximum width or height in pixels.
		 *
		 * Zero disables resizing. Positive values are clamped to 320–12000.
		 *
		 * @param int $max           Maximum dimension.
		 * @param int $attachment_id Attachment ID.
		 */
		$max = (int) apply_filters( 'flipwebp_max_dimension', $max, (int) $attachment_id );

		if ( $max < 1 ) {
			return 0;
		}

		return min( 12000, max( 320, $max ) );
	}

	/**
	 * Sanitize the settings form.
	 *
	 * The Settings API unslashes this value before the callback runs.
	 *
	 * @param mixed $input Raw setting value.
	 * @return array<string, int>
	 */
	public static function sanitize( $input ) {
		$output = self::defaults();
		if ( ! is_array( $input ) ) {
			return $output;
		}

		$output['quality']           = isset( $input['quality'] ) ? absint( $input['quality'] ) : $output['quality'];
		$output['max_dimension']     = isset( $input['max_dimension'] ) ? absint( $input['max_dimension'] ) : 0;
		$output['delete_originals']  = empty( $input['delete_originals'] ) ? 0 : 1;
		$output['create_backups']    = empty( $input['create_backups'] ) ? 0 : 1;
		$output['convert_on_upload'] = empty( $input['convert_on_upload'] ) ? 0 : 1;

		return self::normalize( $output );
	}

	/**
	 * Clamp a settings array to the allowed ranges.
	 *
	 * @param array<string, mixed> $settings Settings to clamp.
	 * @return array<string, int>
	 */
	private static function normalize( $settings ) {
		$quality = isset( $settings['quality'] ) ? absint( $settings['quality'] ) : 82;
		$max     = isset( $settings['max_dimension'] ) ? absint( $settings['max_dimension'] ) : 0;

		if ( $quality < 40 ) {
			$quality = 40;
		} elseif ( $quality > 100 ) {
			$quality = 100;
		}

		if ( $max > 0 && $max < 320 ) {
			$max = 320;
		} elseif ( $max > 12000 ) {
			$max = 12000;
		}

		return array(
			'quality'           => $quality,
			'max_dimension'     => $max,
			'delete_originals'  => empty( $settings['delete_originals'] ) ? 0 : 1,
			'create_backups'    => empty( $settings['create_backups'] ) ? 0 : 1,
			'convert_on_upload' => empty( $settings['convert_on_upload'] ) ? 0 : 1,
		);
	}
}