<?php
/**
 * Adcaver Ad Helper Frontend
 *
 * Handles frontend tasks like outputting the verification meta tag,
 * enqueuing scripts, and rendering ad zone shortcodes/auto-placements.
 *
 * @package    Adcaver_Ad_Helper
 * @subpackage Adcaver_Ad_Helper/includes
 * @author     Edu Brazeal, Adcaver Team <https://edubrazeal.com>
 */

// Prevent direct access via ABSPATH check
if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

class Adcaver_Helper_Frontend {

	/**
	 * Stores the Site ID for use in the script tag filter and shortcodes.
	 * @var int
	 */
	private $site_id = 0;

	/**
	 * Flag to check if the main ad server script has been enqueued.
	 * @var bool
	 */
	private $ad_server_script_enqueued = false;

	/**
	 * Stores the plugin options to avoid multiple get_option calls.
	 * @var array
	 */
	private $options = array();

	/**
	 * Constructor: Stores options.
	 * @since 1.0.1
	 */
	public function __construct() {
		$this->options = get_option( ADCAVER_HELPER_OPTION_NAME, array() );
		$this->site_id = isset( $this->options['site_id'] ) ? absint( $this->options['site_id'] ) : 0;
	}

	/**
	 * Outputs the Adcaver verification meta tag in the <head> if a code is saved.
	 *
	 * Only outputs on the front page (homepage).
	 *
	 * @since    1.0.0
	 */
	public function output_verification_meta_tag() {
		if ( ! is_front_page() || ! is_singular() ) {
			return;
		}

		$verification_code = isset( $this->options['verification_code'] ) ? trim( $this->options['verification_code'] ) : '';

		if ( ! empty( $verification_code ) && strlen( $verification_code ) > 10 ) {
			$sanitized_code = sanitize_text_field( $verification_code );
			echo '<meta name="zeal-ad-verification" content="' . esc_attr( $sanitized_code ) . '" />' . "\n";
		}
	}

	/**
	 * Conditionally enqueues overlay ad scripts and the main ad server script.
	 *
	 * @since    1.0.0
	 */
	public function enqueue_frontend_scripts() {
		if ( is_admin() || is_customize_preview() ) {
			return;
		}

		if ( empty( $this->site_id ) ) {
			return;
		}

		$adcaver_server_url = rtrim( ADCAVER_SERVER_URL, '/' ) . '/';
        $script_base_url    = $adcaver_server_url . 'wp-content/plugins/zeal-ad-manager/public/';

		$overlay_scripts_enqueued = false;

		if ( ! empty( $this->options['enable_vignette'] ) ) {
			$script_url = $script_base_url . 'zealup-vignette.js';
			wp_enqueue_script( 'adcaver-vignette', $script_url, array(), ADCAVER_HELPER_VERSION, true );
			$overlay_scripts_enqueued = true;
		}

		if ( ! empty( $this->options['enable_anchor'] ) ) {
			$script_url = $script_base_url . 'zealup-anchor.js';
			wp_enqueue_script( 'adcaver-anchor', $script_url, array(), ADCAVER_HELPER_VERSION, true );
			$overlay_scripts_enqueued = true;
		}

		if ( ! empty( $this->options['enable_sticky_bar'] ) ) {
			$script_url = $script_base_url . 'zealup-sticky-bar.js';
			wp_enqueue_script( 'adcaver-sticky-bar', $script_url, array(), ADCAVER_HELPER_VERSION, true );
			$overlay_scripts_enqueued = true;
		}

        if ( $overlay_scripts_enqueued ) {
            add_filter( 'script_loader_tag', array( $this, 'add_script_attributes' ), 10, 3 );
        }

		$auto_placements_enabled = $this->check_if_auto_placements_enabled();

		if ( $overlay_scripts_enqueued || $auto_placements_enabled ) {
			$this->maybe_enqueue_ad_server_script();
		}
	}

    /**
     * Adds async and data-site-id attributes to the overlay ad script tags.
     *
     * @since 1.0.1
     * @param string $tag    The HTML script tag.
     * @param string $handle The script handle.
     * @param string $src    The script source URL.
     * @return string Modified HTML script tag.
     */
    public function add_script_attributes( $tag, $handle, $src ) {
        $overlay_handles = array( 'adcaver-vignette', 'adcaver-anchor', 'adcaver-sticky-bar' );

        if ( in_array( $handle, $overlay_handles, true ) && ! empty( $this->site_id ) ) {
            if ( strpos( $tag, ' async' ) === false ) {
                 $tag = str_replace( ' src=', ' async src=', $tag );
            }
            if ( strpos( $tag, ' data-site-id=' ) === false ) {
                 $tag = str_replace( ' src=', ' data-site-id="' . esc_attr( $this->site_id ) . '" src=', $tag );
            }
        }
        return $tag;
    }


    /**
     * Enqueues the main ad server script if it hasn't been already.
     *
     * @since 1.0.1
     */
    private function maybe_enqueue_ad_server_script() {
        if ( ! $this->ad_server_script_enqueued && ! empty( $this->site_id ) ) {
            $adcaver_server_url = rtrim( ADCAVER_SERVER_URL, '/' ) . '/';
            $script_url = $adcaver_server_url . 'wp-content/plugins/zeal-ad-manager/public/zam-ad-server.js';

            wp_enqueue_script(
                'adcaver-ad-server',
                $script_url,
                array(),
                ADCAVER_HELPER_VERSION,
                true
            );
            wp_script_add_data( 'adcaver-ad-server', 'async', true );

            $this->ad_server_script_enqueued = true;
        }
    }

	/**
	 * Checks if any auto-placement settings are enabled.
	 *
	 * @since 1.0.1
	 * @return bool True if any auto-placement is enabled, false otherwise.
	 */
	private function check_if_auto_placements_enabled() {
		$all_placement_keys = array(
			'auto_ad_posts_before_content',
			'auto_ad_posts_after_p1',
			'auto_ad_posts_after_p2',
			'auto_ad_posts_after_p3',
			'auto_ad_posts_mid_content',
			'auto_ad_posts_after_content',
			'auto_ad_pages_before_content',
			'auto_ad_pages_after_content',
			'auto_ad_homepage_before_content',
			'auto_ad_homepage_after_content',
		);

		foreach ( $all_placement_keys as $key ) {
			if ( ! empty( $this->options[ $key ] ) && 'disabled' !== $this->options[ $key ] ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Filters the post content to automatically insert ad placeholders based on settings.
	 *
	 * @since 1.0.1
	 * @param string $content The original post content.
	 * @return string The modified post content with ads inserted.
	 */
	public function auto_insert_ads_in_content( $content ) {
		if ( ! is_singular() || ! is_main_query() || empty( $this->site_id ) ) {
			return $content;
		}

		if ( is_feed() || is_admin() || doing_filter( 'get_the_excerpt' ) ) {
			return $content;
		}

		if ( is_front_page() ) {
			return $this->process_homepage_ads( $content );
		}

		if ( is_page() ) {
			return $this->process_page_ads( $content );
		}

		if ( is_single() ) {
			return $this->process_post_ads( $content );
		}

		return $content;
	}

	/**
	 * Processes ad insertion for homepage content.
	 *
	 * @since 1.0.1
	 * @param string $content The original content.
	 * @return string The modified content with ads inserted.
	 */
	private function process_homepage_ads( $content ) {
		$before_content_type = isset( $this->options['auto_ad_homepage_before_content'] ) ? $this->options['auto_ad_homepage_before_content'] : 'disabled';
		$after_content_type  = isset( $this->options['auto_ad_homepage_after_content'] ) ? $this->options['auto_ad_homepage_after_content'] : 'disabled';

		if ( 'disabled' !== $before_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $before_content_type, $this->site_id );
			if ( $ad_html ) {
				$content = $ad_html . $content;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( 'disabled' !== $after_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $after_content_type, $this->site_id );
			if ( $ad_html ) {
				$content .= $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		return $content;
	}

	/**
	 * Processes ad insertion for page content.
	 *
	 * @since 1.0.1
	 * @param string $content The original content.
	 * @return string The modified content with ads inserted.
	 */
	private function process_page_ads( $content ) {
		$before_content_type = isset( $this->options['auto_ad_pages_before_content'] ) ? $this->options['auto_ad_pages_before_content'] : 'disabled';
		$after_content_type  = isset( $this->options['auto_ad_pages_after_content'] ) ? $this->options['auto_ad_pages_after_content'] : 'disabled';

		if ( 'disabled' !== $before_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $before_content_type, $this->site_id );
			if ( $ad_html ) {
				$content = $ad_html . $content;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( 'disabled' !== $after_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $after_content_type, $this->site_id );
			if ( $ad_html ) {
				$content .= $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		return $content;
	}

	/**
	 * Processes ad insertion for post content.
	 *
	 * @since 1.0.1
	 * @param string $content The original content.
	 * @return string The modified content with ads inserted.
	 */
	private function process_post_ads( $content ) {
		$before_content_type = isset( $this->options['auto_ad_posts_before_content'] ) ? $this->options['auto_ad_posts_before_content'] : 'disabled';
		$after_p1_type       = isset( $this->options['auto_ad_posts_after_p1'] ) ? $this->options['auto_ad_posts_after_p1'] : 'disabled';
		$after_p2_type       = isset( $this->options['auto_ad_posts_after_p2'] ) ? $this->options['auto_ad_posts_after_p2'] : 'disabled';
		$after_p3_type       = isset( $this->options['auto_ad_posts_after_p3'] ) ? $this->options['auto_ad_posts_after_p3'] : 'disabled';
		$mid_content_type    = isset( $this->options['auto_ad_posts_mid_content'] ) ? $this->options['auto_ad_posts_mid_content'] : 'disabled';
		$after_content_type  = isset( $this->options['auto_ad_posts_after_content'] ) ? $this->options['auto_ad_posts_after_content'] : 'disabled';

		if ( 'disabled' !== $before_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $before_content_type, $this->site_id );
			if ( $ad_html ) {
				$content = $ad_html . $content;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		$closing_p = '</p>';
		$paragraphs = explode( $closing_p, $content );
		$paragraph_count = count( $paragraphs );

		$ads_to_insert = array();

		if ( 'disabled' !== $after_p1_type && $paragraph_count > 1 ) {
			$ad_html = $this->get_ad_html_for_type( $after_p1_type, $this->site_id );
			if ( $ad_html ) {
				$ads_to_insert[0] = $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( 'disabled' !== $after_p2_type && $paragraph_count > 2 ) {
			$ad_html = $this->get_ad_html_for_type( $after_p2_type, $this->site_id );
			if ( $ad_html ) {
				$ads_to_insert[1] = $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( 'disabled' !== $after_p3_type && $paragraph_count > 3 ) {
			$ad_html = $this->get_ad_html_for_type( $after_p3_type, $this->site_id );
			if ( $ad_html ) {
				$ads_to_insert[2] = $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( 'disabled' !== $mid_content_type && $paragraph_count > 4 ) {
			$mid_point = floor( $paragraph_count / 2 );
			$ad_html = $this->get_ad_html_for_type( $mid_content_type, $this->site_id );
			if ( $ad_html ) {
				$ads_to_insert[$mid_point - 1] = $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		if ( ! empty( $ads_to_insert ) ) {
			krsort( $ads_to_insert );
			foreach ( $ads_to_insert as $position => $ad_html ) {
				if ( isset( $paragraphs[$position] ) ) {
					$paragraphs[$position] .= $closing_p . $ad_html;
				}
			}
			$content = implode( $closing_p, $paragraphs );
		}

		if ( 'disabled' !== $after_content_type ) {
			$ad_html = $this->get_ad_html_for_type( $after_content_type, $this->site_id );
			if ( $ad_html ) {
				$content .= $ad_html;
				$this->maybe_enqueue_ad_server_script();
			}
		}

		return $content;
	}

	/**
	 * Helper function to generate the ad unit HTML based on ad type.
	 *
	 * @since 1.0.1
	 * @param string $type    Ad type ('spotlight', 'banner', 'story').
	 * @param int    $site_id Publisher Site ID.
	 * @return string|false Ad unit HTML or false if type is invalid.
	 */
	private function get_ad_html_for_type( $type, $site_id ) {
		$template = '';
		switch ( $type ) {
			case 'spotlight':
				$template = 'spotlight';
				break;
			case 'banner':
				$template = 'banner';
				break;
			case 'story':
				$template = 'story';
				break;
			default:
				return false;
		}

		if ( empty( $site_id ) ) {
			return false;
		}

		return sprintf(
			'<div class="zeal-ad-unit" data-site-id="%d" data-template="%s"></div>',
			esc_attr( $site_id ),
			esc_attr( $template )
		);
	}
}