<?php
/**
 * Passende Drogentests automatisch in Blog-Beiträgen einblenden.
 *
 * - Backend-Meta-Box je Beitrag (aktivieren + optional feste Produkt-IDs)
 * - Wenn aktiv: thematisch passende Produkte werden zentral in the_content eingefügt
 * - Automatisches Matching anhand von Substanz-Stichwörtern im Beitrag
 *
 * @package dgt-affiliate
 */

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

/* =========================================================================
   Matching: passende Produkte zu einem Beitrag finden
   ========================================================================= */
function dgt_aff_match_products( $post_id, $limit = 3 ) {
	// Manuelle Auswahl hat Vorrang.
	$manual = trim( (string) get_post_meta( $post_id, '_dgt_product_ids', true ) );
	if ( '' !== $manual ) {
		$ids = array_filter( array_map( 'absint', preg_split( '/[\s,]+/', $manual ) ) );
		if ( $ids ) {
			return array_slice( $ids, 0, $limit );
		}
	}

	$text = strtolower( get_the_title( $post_id ) . ' ' . wp_strip_all_tags( strip_shortcodes( get_post_field( 'post_content', $post_id ) ) ) );

	// Substanz-Signale im Beitrag erkennen.
	$keywords = array(
		'thc'  => array( 'cannabis', 'marihuana', 'thc', 'gras', 'weed', 'joint', 'kiff', 'hanf', 'haschisch', 'tetrahydro' ),
		'coc'  => array( 'kokain', 'koks', 'cocaine' ),
		'amp'  => array( 'amphetamin', 'speed', 'crystal', 'methamphetamin', 'pep' ),
		'mdma' => array( 'mdma', 'ecstasy', 'xtc' ),
		'opi'  => array( 'opiat', 'heroin', 'morphin', 'opioid', 'codein' ),
	);
	$signals = array();
	foreach ( $keywords as $code => $list ) {
		foreach ( $list as $k ) {
			if ( false !== strpos( $text, $k ) ) {
				$signals[ $code ] = true;
				break;
			}
		}
	}

	$products = get_posts(
		array(
			'post_type'   => DGT_AFF_CPT,
			'post_status' => 'publish',
			'numberposts' => -1,
		)
	);

	$scored = array();
	foreach ( $products as $p ) {
		$t       = strtolower( $p->post_title );
		$is_multi = ( false !== strpos( $t, 'multi' ) || false !== strpos( $t, 'parameter' ) || false !== strpos( $t, 'dip 6' ) );
		$score   = 0;

		if ( ! empty( $signals['thc'] ) && ( strpos( $t, 'thc' ) !== false || strpos( $t, 'cannabis' ) !== false || strpos( $t, 'marihuana' ) !== false || strpos( $t, 'tetrahydro' ) !== false ) ) {
			$score += 5;
		}
		if ( ! empty( $signals['coc'] ) && ( strpos( $t, 'coc' ) !== false || strpos( $t, 'kokain' ) !== false ) ) {
			$score += 5;
		}
		if ( ! empty( $signals['amp'] ) && ( strpos( $t, 'amp' ) !== false || strpos( $t, 'amphetamin' ) !== false ) ) {
			$score += 5;
		}
		if ( ! empty( $signals['mdma'] ) && strpos( $t, 'mdma' ) !== false ) {
			$score += 4;
		}
		if ( ! empty( $signals['opi'] ) && ( strpos( $t, 'mor' ) !== false || strpos( $t, 'opi' ) !== false || $is_multi ) ) {
			$score += 3;
		}
		// Multi-Tests passen breit.
		if ( $is_multi ) {
			$score += $signals ? 2 : 3;
		}
		if ( $score > 0 ) {
			$scored[ $p->ID ] = $score;
		}
	}

	arsort( $scored );
	$ids = array_slice( array_keys( $scored ), 0, $limit );

	// Fallback: keine Treffer → zufällige (Multi-)Tests.
	if ( empty( $ids ) ) {
		$ids = wp_list_pluck(
			get_posts(
				array(
					'post_type'   => DGT_AFF_CPT,
					'post_status' => 'publish',
					'numberposts' => $limit,
					'orderby'     => 'rand',
				)
			),
			'ID'
		);
	}
	return $ids;
}

/* =========================================================================
   Einfügen in the_content (zentral)
   ========================================================================= */
function dgt_aff_inject_products( $content ) {
	if ( is_admin() || ! is_singular( 'post' ) || ! in_the_loop() || ! is_main_query() || is_feed() ) {
		return $content;
	}
	$post_id = get_the_ID();
	if ( ! get_post_meta( $post_id, '_dgt_show_products', true ) ) {
		return $content;
	}

	$ids = dgt_aff_match_products( $post_id, 2 );
	if ( empty( $ids ) ) {
		return $content;
	}

	$block = dgt_aff_products(
		array(
			'ids'     => implode( ',', $ids ),
			'limit'   => count( $ids ),
			'columns' => 2,
			'layout'  => 'list',
			'title'   => 'Passende Drogentests',
		)
	);
	if ( '' === $block ) {
		return $content;
	}
	$block = '<div class="dgt-aff-incontent">' . $block . '</div>';

	// Zentral einfügen: nach dem mittleren Absatz.
	$parts = preg_split( '#(</p>)#i', $content, -1, PREG_SPLIT_DELIM_CAPTURE );
	$paras = array();
	$buf   = '';
	foreach ( $parts as $seg ) {
		$buf .= $seg;
		if ( '</p>' === strtolower( $seg ) ) {
			$paras[] = $buf;
			$buf     = '';
		}
	}
	if ( '' !== $buf ) {
		$paras[] = $buf;
	}

	$n = count( $paras );
	if ( $n < 3 ) {
		return $content . $block;
	}
	$pos = max( 1, (int) round( $n / 2 ) );
	array_splice( $paras, $pos, 0, $block );
	return implode( '', $paras );
}
add_filter( 'the_content', 'dgt_aff_inject_products', 20 );

/* =========================================================================
   Backend: Meta-Box
   ========================================================================= */
function dgt_aff_incontent_metabox() {
	add_meta_box( 'dgt_aff_incontent', 'Drogentests im Beitrag', 'dgt_aff_incontent_html', 'post', 'side', 'default' );
}
add_action( 'add_meta_boxes', 'dgt_aff_incontent_metabox' );

function dgt_aff_incontent_html( $post ) {
	wp_nonce_field( 'dgt_aff_incontent', 'dgt_aff_incontent_nonce' );
	$on  = get_post_meta( $post->ID, '_dgt_show_products', true );
	$ids = get_post_meta( $post->ID, '_dgt_product_ids', true );
	?>
	<p>
		<label>
			<input type="checkbox" name="dgt_show_products" value="1" <?php checked( $on, '1' ); ?>>
			<strong>Passende Drogentests einblenden</strong>
		</label>
	</p>
	<p class="description" style="margin:0 0 10px;">Wenn aktiv, werden thematisch passende Produkte automatisch zentral im Beitrag angezeigt.</p>
	<p>
		<label for="dgt_product_ids">Feste Produkt-IDs (optional)</label>
		<input type="text" id="dgt_product_ids" name="dgt_product_ids" value="<?php echo esc_attr( $ids ); ?>" class="widefat" placeholder="z. B. 991, 983">
		<span class="description">Leer = automatische Auswahl nach Thema.</span>
	</p>
	<?php
	if ( $on ) {
		$match = dgt_aff_match_products( $post->ID, 2 );
		if ( $match ) {
			echo '<p class="description" style="margin-top:8px;"><strong>Aktuelle Auswahl:</strong><br>';
			foreach ( $match as $mid ) {
				echo esc_html( get_the_title( $mid ) ) . '<br>';
			}
			echo '</p>';
		}
	}
}

function dgt_aff_incontent_save( $post_id ) {
	if ( ! isset( $_POST['dgt_aff_incontent_nonce'] ) || ! wp_verify_nonce( sanitize_text_field( wp_unslash( $_POST['dgt_aff_incontent_nonce'] ) ), 'dgt_aff_incontent' ) ) {
		return;
	}
	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
		return;
	}
	if ( ! current_user_can( 'edit_post', $post_id ) ) {
		return;
	}
	update_post_meta( $post_id, '_dgt_show_products', empty( $_POST['dgt_show_products'] ) ? '' : '1' );
	$ids = isset( $_POST['dgt_product_ids'] ) ? sanitize_text_field( wp_unslash( $_POST['dgt_product_ids'] ) ) : '';
	if ( '' === $ids ) {
		delete_post_meta( $post_id, '_dgt_product_ids' );
	} else {
		update_post_meta( $post_id, '_dgt_product_ids', $ids );
	}
}
add_action( 'save_post_post', 'dgt_aff_incontent_save' );