<?php
/**
 * Puts a 404 Emails signup form on the site - the same embed script and
 * options as the "Installation options" snippet in 404 Emails
 * (lib/forms/embed.ts's buildEmbedSnippet()): in the page, as a pop-up, or
 * as a corner button. Used by the editor block, the [404emails] shortcode
 * and "Show on every page".
 *
 * The script is 404 Emails' own /embed.js, loaded from 404 Emails like any
 * other service's widget; the form itself is 404 Emails' hosted form, so
 * consent, double opt-in and the thank-you message work exactly as there.
 *
 * @package Emails404
 */

namespace Emails404;

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

class Embed {

	const MODE_INLINE   = 'inline';
	const MODE_POPUP    = 'popup';
	const MODE_FLOATING = 'floating';

	const TRIGGER_CLICK  = 'click';
	const TRIGGER_DELAY  = 'delay';
	const TRIGGER_SCROLL = 'scroll';
	const TRIGGER_EXIT   = 'exit';

	// The same limits as lib/forms/embed-protocol.ts.
	const DEFAULT_DELAY_SECONDS  = 8;
	const MIN_DELAY_SECONDS      = 1;
	const MAX_DELAY_SECONDS      = 120;
	const DEFAULT_SCROLL_PERCENT = 50;
	const MIN_SCROLL_PERCENT     = 10;
	const MAX_SCROLL_PERCENT     = 90;
	const DEFAULT_FREQUENCY_DAYS = 7;
	const MAX_FREQUENCY_DAYS     = 365;
	const LABEL_MAX_LENGTH       = 60;

	/** A form's public id, as 404 Emails gives it out (never its internal id). */
	public static function is_valid_form_id( $id ) {
		return is_string( $id ) && 1 === preg_match( '/^[A-Za-z0-9_-]{1,64}$/', $id );
	}

	/**
	 * Cleans display options from a block, shortcode or setting - anything
	 * unknown falls back to the default, numbers are kept in range.
	 *
	 * @param array $raw Keys: form, mode, label, position, trigger, delay, scroll, frequency, launcher.
	 * @return array|null Null when there's no valid form.
	 */
	public static function normalize_options( array $raw ) {
		$form = isset( $raw['form'] ) ? trim( (string) $raw['form'] ) : '';
		if ( ! self::is_valid_form_id( $form ) ) {
			return null;
		}

		$mode = isset( $raw['mode'] ) ? (string) $raw['mode'] : self::MODE_INLINE;
		if ( ! in_array( $mode, array( self::MODE_INLINE, self::MODE_POPUP, self::MODE_FLOATING ), true ) ) {
			$mode = self::MODE_INLINE;
		}

		$trigger = isset( $raw['trigger'] ) ? (string) $raw['trigger'] : self::TRIGGER_CLICK;
		if ( ! in_array( $trigger, array( self::TRIGGER_CLICK, self::TRIGGER_DELAY, self::TRIGGER_SCROLL, self::TRIGGER_EXIT ), true ) ) {
			$trigger = self::TRIGGER_CLICK;
		}

		$label = isset( $raw['label'] ) ? trim( wp_strip_all_tags( (string) $raw['label'] ) ) : '';
		if ( function_exists( 'mb_substr' ) ) {
			$label = mb_substr( $label, 0, self::LABEL_MAX_LENGTH );
		} else {
			$label = substr( $label, 0, self::LABEL_MAX_LENGTH );
		}

		return array(
			'form'      => $form,
			'mode'      => $mode,
			'label'     => $label,
			'position'  => ( isset( $raw['position'] ) && 'bottom-left' === $raw['position'] ) ? 'bottom-left' : 'bottom-right',
			'trigger'   => $trigger,
			'delay'     => self::clamp( isset( $raw['delay'] ) ? $raw['delay'] : null, self::DEFAULT_DELAY_SECONDS, self::MIN_DELAY_SECONDS, self::MAX_DELAY_SECONDS ),
			'scroll'    => self::clamp( isset( $raw['scroll'] ) ? $raw['scroll'] : null, self::DEFAULT_SCROLL_PERCENT, self::MIN_SCROLL_PERCENT, self::MAX_SCROLL_PERCENT ),
			'frequency' => self::clamp( isset( $raw['frequency'] ) ? $raw['frequency'] : null, self::DEFAULT_FREQUENCY_DAYS, 0, self::MAX_FREQUENCY_DAYS ),
			'launcher'  => ! ( isset( $raw['launcher'] ) && in_array( $raw['launcher'], array( false, 0, '0', 'false', 'none', 'no' ), true ) ),
		);
	}

	/**
	 * The embed script's attributes - only what differs from the defaults,
	 * exactly like buildEmbedSnippet(), so a page carries the same snippet
	 * 404 Emails' own Installation options would give.
	 *
	 * @param array  $options      Output of normalize_options().
	 * @param string $platform_url The 404 Emails app address.
	 * @return array<string,string>
	 */
	public static function script_attributes( array $options, $platform_url ) {
		$attributes = array(
			'src'       => untrailingslashit( $platform_url ) . '/embed.js',
			'data-form' => $options['form'],
		);
		$mode = $options['mode'];

		if ( self::MODE_INLINE !== $mode ) {
			$attributes['data-mode'] = $mode;
			if ( '' !== $options['label'] ) {
				$attributes['data-label'] = $options['label'];
			}
		}
		if ( self::MODE_FLOATING === $mode && 'bottom-left' === $options['position'] ) {
			$attributes['data-position'] = 'bottom-left';
		}
		if ( self::MODE_POPUP === $mode && self::TRIGGER_CLICK !== $options['trigger'] ) {
			$attributes['data-trigger'] = $options['trigger'];
			if ( self::TRIGGER_DELAY === $options['trigger'] && self::DEFAULT_DELAY_SECONDS !== $options['delay'] ) {
				$attributes['data-delay'] = (string) $options['delay'];
			}
			if ( self::TRIGGER_SCROLL === $options['trigger'] && self::DEFAULT_SCROLL_PERCENT !== $options['scroll'] ) {
				$attributes['data-scroll'] = (string) $options['scroll'];
			}
			if ( self::DEFAULT_FREQUENCY_DAYS !== $options['frequency'] ) {
				$attributes['data-frequency'] = (string) $options['frequency'];
			}
			if ( ! $options['launcher'] ) {
				$attributes['data-launcher'] = 'none';
			}
		}
		return $attributes;
	}

	/**
	 * The script tag for a form, or '' when the site isn't connected or the
	 * form id isn't valid (a page never breaks because of a bad shortcode).
	 *
	 * @param array $raw Display options, see normalize_options().
	 * @return string
	 */
	public static function render( array $raw ) {
		$options      = self::normalize_options( $raw );
		$platform_url = Settings::get_platform_url();
		if ( null === $options || '' === $platform_url ) {
			return '';
		}
		return wp_get_script_tag( self::script_attributes( $options, $platform_url ) );
	}

	/** The hosted form's address - the editor block's preview. */
	public static function preview_url( $form_id, $mode = self::MODE_INLINE ) {
		$platform_url = Settings::get_platform_url();
		if ( '' === $platform_url || ! self::is_valid_form_id( $form_id ) ) {
			return '';
		}
		return untrailingslashit( $platform_url ) . '/forms/' . rawurlencode( $form_id ) . '?embed=1&instance=wp-editor&mode=' . rawurlencode( $mode );
	}

	private static function clamp( $value, $fallback, $min, $max ) {
		if ( null === $value || '' === $value || ! is_numeric( $value ) ) {
			return $fallback;
		}
		return (int) max( $min, min( $max, (int) round( (float) $value ) ) );
	}
}