<?php
/**
 * Quick replies.
 *
 * @package Dealroot
 */

namespace Dealroot;

defined( 'ABSPATH' ) || exit;

/**
 * Short answers to an enquiry, written once and sent from the lead with one click by email or
 * WhatsApp, with the name of the person and the form filled in.
 */
class Replies {

	/**
	 * Most replies kept.
	 */
	const MAX = 6;

	/**
	 * Placeholders with what they stand for.
	 *
	 * @return array<string, string>
	 */
	public static function placeholders() {
		return array(
			'{first_name}' => __( 'first name of the person', 'dealroot' ),
			'{name}'       => __( 'full name', 'dealroot' ),
			'{form}'       => __( 'name of the form', 'dealroot' ),
			'{site}'       => __( 'name of your website', 'dealroot' ),
			'{my_name}'    => __( 'your name', 'dealroot' ),
		);
	}

	/**
	 * Replies to start with, in the language loaded.
	 *
	 * @return array[]
	 */
	public static function defaults() {
		return array(
			array(
				'title'   => __( 'Thanks, we will call', 'dealroot' ),
				'subject' => __( 'Your enquiry', 'dealroot' ),
				'body'    => __( "Hello {first_name},\n\nthank you for your enquiry. We will call you back today.\n\nBest regards\n{my_name}\n{site}", 'dealroot' ),
			),
			array(
				'title'   => __( 'Ask for a time', 'dealroot' ),
				'subject' => __( 'Your enquiry', 'dealroot' ),
				'body'    => __( "Hello {first_name},\n\nthank you for your message. When is a good time to call you?\n\nBest regards\n{my_name}\n{site}", 'dealroot' ),
			),
			array(
				'title'   => __( 'Ask for details', 'dealroot' ),
				'subject' => __( 'A question about your enquiry', 'dealroot' ),
				'body'    => __( "Hello {first_name},\n\nthank you for your enquiry. So that we can make you a fitting offer, could you tell us a little more about what you need and by when?\n\nBest regards\n{my_name}\n{site}", 'dealroot' ),
			),
		);
	}

	/**
	 * The replies of the site. The ones to start with are in the language of the enquiry, so a
	 * customer is not answered in the language of the screen of the team.
	 *
	 * @param object|null $lead Lead the reply is for.
	 * @return array[]
	 */
	public static function all( $lead = null ) {
		$saved = Settings::get( 'replies' );

		$locale = Ai::customer_locale( $lead );

		if ( ! is_array( $saved ) || ! $saved ) {
			return Ai::in_locale( $locale, array( self::class, 'defaults' ) );
		}

		// Saved replies keep what was written, but the parts still as they came, e.g. the subject
		// "Your enquiry", are taken in the language of the enquiry.
		$rows  = self::sanitize( $saved );
		$known = self::known_texts();
		$own   = null;

		foreach ( $rows as $i => $row ) {
			foreach ( array( 'title', 'subject', 'body' ) as $part ) {
				$key = $part . '|' . self::normalize( $row[ $part ] );

				if ( isset( $known[ $key ] ) ) {
					$own = null !== $own ? $own : Ai::in_locale( $locale, array( self::class, 'defaults' ) );

					$rows[ $i ][ $part ] = $own[ $known[ $key ] ][ $part ] ?? $row[ $part ];
				}
			}
		}

		return $rows;
	}

	/**
	 * The texts of the replies to start with, in the languages the replies were likely saved in:
	 * English, the language of the site, of the screen and of the team.
	 *
	 * @return array<string, int> "part|text" => position of the reply.
	 */
	private static function known_texts() {
		static $known = null;

		if ( null !== $known ) {
			return $known;
		}

		$known = array();

		foreach ( array_unique( array( 'en_US', get_locale(), get_user_locale(), Ai::team_locale() ) ) as $locale ) {
			foreach ( (array) Ai::in_locale( $locale, array( self::class, 'defaults' ) ) as $i => $reply ) {
				foreach ( array( 'title', 'subject', 'body' ) as $part ) {
					$known[ $part . '|' . self::normalize( $reply[ $part ] ) ] = $i;
				}
			}
		}

		return $known;
	}

	/**
	 * A text compared without regard to line endings and spaces at its ends.
	 *
	 * @param string $text Text.
	 * @return string
	 */
	private static function normalize( $text ) {
		return trim( str_replace( "\r\n", "\n", (string) $text ) );
	}

	/**
	 * Replies from the settings form: rows without a text are dropped.
	 *
	 * @param mixed $rows Raw rows.
	 * @return array[]
	 */
	public static function sanitize( $rows ) {
		$clean = array();

		foreach ( is_array( $rows ) ? $rows : array() as $row ) {
			if ( ! is_array( $row ) ) {
				continue;
			}

			$body = trim( mb_substr( sanitize_textarea_field( (string) ( $row['body'] ?? '' ) ), 0, 2000 ) );

			if ( '' === $body ) {
				continue;
			}

			$clean[] = array(
				'title'   => mb_substr( sanitize_text_field( (string) ( $row['title'] ?? '' ) ), 0, 60 ),
				'subject' => mb_substr( sanitize_text_field( (string) ( $row['subject'] ?? '' ) ), 0, 150 ),
				'body'    => $body,
			);

			if ( count( $clean ) >= self::MAX ) {
				break;
			}
		}

		return $clean;
	}

	/**
	 * A text with the details of a lead in place of the placeholders.
	 *
	 * @param string $text Text.
	 * @param object $lead Lead.
	 * @return string
	 */
	public static function fill( $text, $lead ) {
		$name  = trim( (string) $lead->name );
		$first = '' !== $name ? (string) strtok( $name, ' ' ) : '';
		$user  = wp_get_current_user();

		$text = strtr(
			(string) $text,
			array(
				'{first_name}' => $first,
				'{name}'       => $name,
				'{form}'       => (string) $lead->form_name,
				'{site}'       => wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ),
				'{my_name}'    => $user && $user->exists() ? $user->display_name : '',
			)
		);

		// "Hello ," when the name is not known.
		$text = (string) preg_replace( '/[ \t]+([,.!?])/u', '$1', $text );

		return trim( (string) preg_replace( "/\n{3,}/", "\n\n", $text ) );
	}
}