<?php
if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

/**
 * Handles the frontend content processing for link injection.
 *
 * @since      1.0
 * @package    AILinkMaster
 * @subpackage AILinkMaster/includes
 */
class AILM_Content_Processor {

    /**
     * @var AILM_Link_Builder
     */
    private $link_builder;

    /**
     * Constructor.
     * @param AILM_Link_Builder $link_builder
     */
    public function __construct( $link_builder ) {
        $this->link_builder = $link_builder;
    }

    /**
     * The main entry point for modifying content.
     *
     * Hooks into `the_content` and applies the internal linking logic.
     *
     * @since 1.0
     * @param string $content The original post content.
     * @return string The modified post content.
     */
    public function process_content( $content ) {
        if ( ! is_singular() && ! is_page() && ! is_home() && ! is_front_page() ) {
            return $content;
        }

        if ( is_admin() || empty( $content ) ) {
            return $content;
        }

        global $post;
        if ( ! $post ) {
            return $content;
        }

        // URL exclusion check
        $exclude_raw = get_option( 'ailm_exclude_urls', '' );
        if ( ! empty( $exclude_raw ) ) {
            $patterns = array_map( 'trim', explode( ',', $exclude_raw ) );
            $request_uri = isset( $_SERVER['REQUEST_URI'] ) ? esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
            $normalized_uri = '/' . trim( $request_uri, '/' ) . '/';
            foreach ( $patterns as $pat ) {
                if ( empty( $pat ) ) {
                    continue;
                }
                if ( $pat === '*' && ( is_front_page() || is_home() ) ) {
                    return $content;
                }
                if ( $pat !== '*' && strpos( $normalized_uri, '/' . trim( $pat, '/' ) . '/' ) !== false ) {
                    return $content;
                }
            }
        }

        // Content length check
        $min_chars = get_option( 'ailm_min_chars', 2000 );
        if ( mb_strlen( wp_strip_all_tags( $content ), 'UTF-8' ) < $min_chars ) {
            return $content;
        }
        
        // Call the Link Builder class to process the content
        return $this->link_builder->build_links( $content, $post );
    }
}