<?php
/**
 * Shared helpers.
 *
 * @package MM_Post_Grid
 */

namespace MM_Post_Grid;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Small, dependency free utilities used across the plugin.
 *
 * @since 0.1
 */
final class Helpers {

	/**
	 * Casts a shortcode style value to a boolean.
	 *
	 * Accepts the values authors actually type: yes/no, true/false, on/off, 1/0.
	 *
	 * @since 0.1
	 *
	 * @param mixed $value Raw value.
	 * @return bool
	 */
	public static function to_bool( $value ) {
		if ( is_bool( $value ) ) {
			return $value;
		}

		if ( is_numeric( $value ) ) {
			return (bool) $value;
		}

		if ( ! is_string( $value ) ) {
			return false;
		}

		return in_array( strtolower( trim( $value ) ), array( 'yes', 'true', 'on', '1' ), true );
	}

	/**
	 * Turns a comma separated string (or array) into a clean list of strings.
	 *
	 * @since 0.1
	 *
	 * @param mixed $value Raw value.
	 * @return string[]
	 */
	public static function to_list( $value ) {
		if ( ! is_array( $value ) ) {
			$value = explode( ',', (string) $value );
		}

		$list = array();

		foreach ( $value as $item ) {
			if ( ! is_scalar( $item ) ) {
				continue;
			}

			$item = trim( (string) $item );

			if ( '' !== $item ) {
				$list[] = $item;
			}
		}

		return array_values( array_unique( $list ) );
	}

	/**
	 * Turns a comma separated string (or array) into a list of positive integers.
	 *
	 * @since 0.1
	 *
	 * @param mixed $value Raw value.
	 * @return int[]
	 */
	public static function to_id_list( $value ) {
		$ids = array();

		foreach ( self::to_list( $value ) as $item ) {
			if ( ! is_numeric( $item ) ) {
				continue;
			}

			$id = (int) $item;

			// Anything that is not a positive ID is dropped rather than folded
			// into one: absint() would turn "-2" into post 2, which the author
			// never asked for.
			if ( $id > 0 ) {
				$ids[] = $id;
			}
		}

		return array_values( array_unique( $ids ) );
	}

	/**
	 * Sanitizes a space separated list of CSS class names.
	 *
	 * @since 0.1
	 *
	 * @param mixed $value Raw value.
	 * @return string
	 */
	public static function to_class_list( $value ) {
		$classes = preg_split( '/\s+/', (string) $value, -1, PREG_SPLIT_NO_EMPTY );

		if ( ! is_array( $classes ) ) {
			return '';
		}

		$classes = array_filter( array_map( 'sanitize_html_class', $classes ) );

		return implode( ' ', array_unique( $classes ) );
	}

	/**
	 * Clamps an integer between two bounds.
	 *
	 * @since 0.1
	 *
	 * @param mixed    $value    Raw value.
	 * @param int      $min      Lower bound.
	 * @param int      $max      Upper bound.
	 * @param int|null $fallback Value to use when $value is not numeric. Falls
	 *                           back to $min when null.
	 * @return int
	 */
	public static function clamp_int( $value, $min, $max, $fallback = null ) {
		if ( ! is_numeric( $value ) ) {
			// Falling back to $min would turn columns="four" into a one column
			// grid without saying so. The caller's fallback is the honest answer.
			$value = null === $fallback ? $min : $fallback;
		}

		return max( (int) $min, min( (int) $max, (int) $value ) );
	}

	/**
	 * Returns the box-shadow pair for a shadow preset.
	 *
	 * Presets are used instead of free text so that no arbitrary CSS can reach
	 * the front end through the settings.
	 *
	 * @since 0.1
	 *
	 * @param string $preset Preset key.
	 * @return array{shadow:string,hover:string}
	 */
	public static function shadow( $preset ) {
		$presets = array(
			'none'   => array(
				'shadow' => 'none',
				'hover'  => 'none',
			),
			'soft'   => array(
				'shadow' => '0 1px 2px rgba(24, 24, 43, 0.04)',
				'hover'  => '0 12px 28px -12px rgba(24, 24, 43, 0.22)',
			),
			'medium' => array(
				'shadow' => '0 2px 6px rgba(24, 24, 43, 0.08)',
				'hover'  => '0 18px 36px -14px rgba(24, 24, 43, 0.28)',
			),
			'strong' => array(
				'shadow' => '0 6px 16px rgba(24, 24, 43, 0.12)',
				'hover'  => '0 24px 48px -16px rgba(24, 24, 43, 0.34)',
			),
		);

		return isset( $presets[ $preset ] ) ? $presets[ $preset ] : $presets['soft'];
	}

	/**
	 * Converts an aspect ratio preset to a CSS aspect-ratio value.
	 *
	 * @since 0.1
	 *
	 * @param string $preset Preset key, for example `16-9`.
	 * @return string
	 */
	public static function ratio( $preset ) {
		$presets = array(
			'16-9'  => '16 / 9',
			'16-10' => '16 / 10',
			'3-2'   => '3 / 2',
			'4-3'   => '4 / 3',
			'1-1'   => '1 / 1',
			'3-4'   => '3 / 4',
			'auto'  => 'auto',
		);

		return isset( $presets[ $preset ] ) ? $presets[ $preset ] : $presets['16-10'];
	}

	/**
	 * Final guard for values printed inside a CSS declaration.
	 *
	 * Every value already comes from a typed setting, this only makes sure a
	 * third party filter cannot inject declarations or close the style block.
	 *
	 * @since 0.1
	 *
	 * @param string $value CSS value.
	 * @return string
	 */
	public static function css_value( $value ) {
		$value = preg_replace( '/[^a-zA-Z0-9#%(),.\/ _-]/', '', (string) $value );

		return trim( (string) $value );
	}

	/**
	 * Builds the visible page window for numbered pagination.
	 *
	 * Returns page numbers plus `null` placeholders where a gap should be shown.
	 *
	 * @since 0.1
	 *
	 * @param int $current Current page.
	 * @param int $total   Total pages.
	 * @param int $range   How many pages to show on each side of the current one.
	 * @return array<int, int|null>
	 */
	public static function page_window( $current, $total, $range = 2 ) {
		$current = max( 1, (int) $current );
		$total   = max( 1, (int) $total );
		$pages   = array();

		for ( $page = 1; $page <= $total; $page++ ) {
			$is_edge   = 1 === $page || $total === $page;
			$in_window = abs( $current - $page ) <= $range;

			if ( $is_edge || $in_window ) {
				$pages[] = $page;
			} elseif ( ! empty( $pages ) && null !== end( $pages ) ) {
				$pages[] = null;
			}
		}

		return $pages;
	}
}