<?php
/**
 * Message and destination URL builder.
 *
 * @package AetosQuickOrderChat
 */

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

/**
 * Build transparent product and cart messages without customer data.
 */
final class Aetos_QOC_Message_Builder {

	/**
	 * Sanitized plugin settings.
	 *
	 * @var array<string,mixed>
	 */
	private $settings;

	/**
	 * Store settings for message generation.
	 *
	 * @param array<string,mixed> $settings Sanitized plugin settings.
	 */
	public function __construct( $settings ) {
		$this->settings = $settings;
	}

	/**
	 * Whether a usable international destination number is configured.
	 *
	 * @return bool
	 */
	public function is_ready() {
		return 1 === preg_match( '/^\d{7,15}$/', $this->settings['phone'] );
	}

	/**
	 * Return the destination URL prefix used by product-page JavaScript.
	 *
	 * @return string
	 */
	public function get_base_url() {
		if ( ! $this->is_ready() ) {
			return '';
		}

		return 'https://wa.me/' . $this->settings['phone'] . '?text=';
	}

	/**
	 * Build a complete click URL for a message.
	 *
	 * @param string $message Plain-text message.
	 * @return string
	 */
	public function get_chat_url( $message ) {
		$base_url = $this->get_base_url();

		if ( '' === $base_url || '' === $message ) {
			return '';
		}

		return $base_url . rawurlencode( $message );
	}

	/**
	 * Return display-safe product values used by PHP and browser message builders.
	 *
	 * @param WC_Product $product WooCommerce product.
	 * @return array<string,string>
	 */
	public function get_product_context( $product ) {
		if ( ! $product instanceof WC_Product ) {
			return array();
		}

		$product_url = get_permalink( $product->get_id() );

		return array(
			'name'  => $this->plain_text( $product->get_name() ),
			'sku'   => $this->plain_text( $product->get_sku() ),
			'price' => $this->product_price_text( $product ),
			'url'   => is_string( $product_url ) ? $product_url : '',
		);
	}

	/**
	 * Format the current catalog price without hidden screen-reader duplicates.
	 *
	 * @param WC_Product $product WooCommerce product.
	 * @return string
	 */
	private function product_price_text( $product ) {
		if ( $product->is_type( 'variable' ) ) {
			$minimum = (float) $product->get_variation_price( 'min', true );
			$maximum = (float) $product->get_variation_price( 'max', true );

			if ( $minimum !== $maximum ) {
				return $this->plain_text( wc_price( $minimum ) ) . ' - ' . $this->plain_text( wc_price( $maximum ) );
			}

			return $this->plain_text( wc_price( $minimum ) );
		}

		if ( '' === $product->get_price() ) {
			return '';
		}

		return $this->plain_text( wc_price( wc_get_price_to_display( $product ) ) );
	}

	/**
	 * Build the server-side product fallback message.
	 *
	 * @param WC_Product $product  WooCommerce product.
	 * @param float      $quantity Selected quantity.
	 * @return string
	 */
	public function get_product_message( $product, $quantity = 1 ) {
		$context = $this->get_product_context( $product );

		if ( empty( $context ) ) {
			return '';
		}

		return $this->get_product_message_from_context( $context, $quantity );
	}

	/**
	 * Build a product message from an already-sanitized context.
	 *
	 * @param array<string,string> $context  Product values.
	 * @param float                $quantity Selected quantity.
	 * @param array<int,string>    $options  Selected variation labels.
	 * @return string
	 */
	public function get_product_message_from_context( $context, $quantity = 1, $options = array() ) {
		if ( empty( $context['name'] ) ) {
			return '';
		}

		$lines   = $this->get_message_opening();
		$lines[] = sprintf(
			'%1$s: %2$s',
			__( 'Product', 'aetos-quick-order-chat' ),
			$context['name']
		);
		$lines[] = sprintf(
			'%1$s: %2$s',
			__( 'Quantity', 'aetos-quick-order-chat' ),
			$this->format_quantity( $quantity )
		);

		$options = array_values( array_filter( array_map( array( $this, 'plain_text' ), $options ) ) );
		if ( ! empty( $options ) ) {
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'Options', 'aetos-quick-order-chat' ),
				implode( ', ', $options )
			);
		}

		if ( $this->settings['include_sku'] && ! empty( $context['sku'] ) ) {
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'SKU', 'aetos-quick-order-chat' ),
				$context['sku']
			);
		}

		if ( $this->settings['include_price'] && ! empty( $context['price'] ) ) {
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'Price', 'aetos-quick-order-chat' ),
				$context['price']
			);
		}

		if ( $this->settings['include_link'] && ! empty( $context['url'] ) ) {
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'Link', 'aetos-quick-order-chat' ),
				$context['url']
			);
		}

		return implode( "\n", $lines );
	}

	/**
	 * Build a message from the current WooCommerce cart session.
	 *
	 * @return string
	 */
	public function get_cart_message() {
		if ( ! function_exists( 'WC' ) || ! WC()->cart || WC()->cart->is_empty() ) {
			return '';
		}

		$lines      = $this->get_message_opening();
		$item_index = 0;

		foreach ( WC()->cart->get_cart() as $cart_item ) {
			$product = isset( $cart_item['data'] ) ? $cart_item['data'] : null;

			if ( ! $product instanceof WC_Product || ! $product->exists() ) {
				continue;
			}

			++$item_index;
			$quantity = isset( $cart_item['quantity'] ) ? (float) $cart_item['quantity'] : 1;
			$lines[]  = sprintf(
				'%1$d. %2$s x %3$s',
				$item_index,
				$this->plain_text( $product->get_name() ),
				$this->format_quantity( $quantity )
			);

			if ( $this->settings['include_sku'] && $product->get_sku() ) {
				$lines[] = sprintf(
					'%1$s: %2$s',
					__( 'SKU', 'aetos-quick-order-chat' ),
					$this->plain_text( $product->get_sku() )
				);
			}

			if ( $this->settings['include_price'] ) {
				$lines[] = sprintf(
					'%1$s: %2$s',
					__( 'Line total', 'aetos-quick-order-chat' ),
					$this->plain_text( WC()->cart->get_product_subtotal( $product, $quantity ) )
				);
			}
		}

		if ( 0 === $item_index ) {
			return '';
		}

		if ( $this->settings['include_price'] ) {
			$lines[] = '';
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'Cart total', 'aetos-quick-order-chat' ),
				$this->plain_text( wc_price( (float) WC()->cart->get_total( 'edit' ) ) )
			);
		}

		if ( $this->settings['include_link'] ) {
			$lines[] = sprintf(
				'%1$s: %2$s',
				__( 'Cart link', 'aetos-quick-order-chat' ),
				wc_get_cart_url()
			);
		}

		return implode( "\n", $lines );
	}

	/**
	 * Return the custom introduction followed by one separating line.
	 *
	 * @return array<int,string>
	 */
	private function get_message_opening() {
		return array( $this->settings['intro'], '' );
	}

	/**
	 * Convert an HTML-formatted WooCommerce value to readable plain text.
	 *
	 * @param mixed $value Value to normalize.
	 * @return string
	 */
	public function plain_text( $value ) {
		$charset = get_bloginfo( 'charset' );
		$charset = $charset ? $charset : 'UTF-8';
		$text    = wp_strip_all_tags( (string) $value );

		return trim( html_entity_decode( $text, ENT_QUOTES, $charset ) );
	}

	/**
	 * Format integer or decimal quantities without unnecessary zeroes.
	 *
	 * @param float $quantity Quantity value.
	 * @return string
	 */
	private function format_quantity( $quantity ) {
		$quantity  = max( 0.001, (float) $quantity );
		$formatted = number_format( $quantity, 3, '.', '' );

		return rtrim( rtrim( $formatted, '0' ), '.' );
	}
}