<?php

defined( 'ABSPATH' ) || exit;

if ( ! class_exists( 'AIEO_DataForSEO' ) ) {
	require_once AIEO_DIR . 'includes/seo/class-aieo-dataforseo.php';
}
if ( ! class_exists( 'AIEO_DFS_Rankings' ) ) {
	require_once AIEO_DIR . 'includes/seo/class-aieo-dfs-rankings.php';
}

class AIEO_DFS_Backlinks {

	const SNAP_TABLE    = 'aieo_backlinks';
	const DISAVOW_TABLE = 'aieo_disavow';
	const SUMMARY_OPT   = 'aieo_backlinks_summary'; 
	const LAST_OPT      = 'aieo_backlinks_refreshed_at';
	
	const TOXIC_DEFAULT = 60;

	public static function available() {
		return class_exists( 'AIEO_DataForSEO' ) && AIEO_DataForSEO::is_connected();
	}

	
	public static function target() {
		$host = (string) wp_parse_url( home_url(), PHP_URL_HOST );
		$host = preg_replace( '/^www\./i', '', strtolower( $host ) );
		return (string) apply_filters( 'aieo_backlinks_target', $host );
	}

	
	
	

	public static function snap_table() {
		global $wpdb;
		return $wpdb->prefix . self::SNAP_TABLE;
	}
	public static function disavow_table() {
		global $wpdb;
		return $wpdb->prefix . self::DISAVOW_TABLE;
	}

	
	public static function ensure_tables() {
		global $wpdb;
		$charset = aieo_get_charset_collate();
		$snap    = self::snap_table();
		$dis     = self::disavow_table();

		if ( (string) $wpdb->get_var( "SHOW TABLES LIKE '{$snap}'" ) !== $snap ) {
			
			$wpdb->query( "CREATE TABLE {$snap} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				domain varchar(191) NOT NULL,
				backlinks int unsigned NOT NULL DEFAULT 0,
				spam_score tinyint unsigned NOT NULL DEFAULT 0,
				domain_rank smallint unsigned NOT NULL DEFAULT 0,
				dofollow int unsigned NOT NULL DEFAULT 0,
				first_seen varchar(32) DEFAULT NULL,
				lost tinyint(1) NOT NULL DEFAULT 0,
				fetched_at datetime DEFAULT NULL,
				PRIMARY KEY (id),
				UNIQUE KEY domain (domain),
				KEY spam_score (spam_score),
				KEY domain_rank (domain_rank)
			) {$charset};" );
		}
		if ( (string) $wpdb->get_var( "SHOW TABLES LIKE '{$dis}'" ) !== $dis ) {
			
			$wpdb->query( "CREATE TABLE {$dis} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				domain varchar(191) NOT NULL,
				reason varchar(255) DEFAULT NULL,
				source varchar(20) NOT NULL DEFAULT 'manual',
				spam_score tinyint unsigned DEFAULT NULL,
				added_at datetime DEFAULT NULL,
				PRIMARY KEY (id),
				UNIQUE KEY domain (domain)
			) {$charset};" );
		}
	}

	private static function table_exists( $t ) {
		global $wpdb;
		return (string) $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $t ) ) === $t;
	}

	
	
	

	
	private static function result( $decoded ) {
		if ( is_wp_error( $decoded ) ) {
			return $decoded;
		}
		$task = isset( $decoded['tasks'][0] ) && is_array( $decoded['tasks'][0] ) ? $decoded['tasks'][0] : array();
		if ( isset( $task['cost'] ) && (float) $task['cost'] > 0 && class_exists( 'AIEO_DFS_Rankings' ) ) {
			AIEO_DFS_Rankings::record_spend( (float) $task['cost'] );
		}
		return isset( $task['result'][0] ) && is_array( $task['result'][0] ) ? $task['result'][0] : array();
	}

	private static function budget_ok() {
		return ! class_exists( 'AIEO_DFS_Rankings' )
			|| AIEO_DFS_Rankings::spend_this_month() < AIEO_DFS_Rankings::budget();
	}

	
	public static function fetch_summary() {
		if ( ! self::available() ) {
			return new WP_Error( 'aieo_dfs_off', __( 'DataForSEO is not connected (SEO → General).', 'ai-eshop-optimizer' ) );
		}
		if ( ! self::budget_ok() ) {
			return new WP_Error( 'aieo_dfs_budget', __( 'The monthly DataForSEO budget is exhausted.', 'ai-eshop-optimizer' ) );
		}
		$res = self::result( AIEO_DataForSEO::post( '/v3/backlinks/summary/live', array(
			'target'               => self::target(),
			'include_subdomains'   => true,
			'backlinks_status_type' => 'live',
			'rank_scale'           => 'one_hundred',
		) ) );
		if ( is_wp_error( $res ) ) {
			return $res;
		}
		$summary = array(
			'target'             => (string) ( $res['target'] ?? self::target() ),
			'rank'               => (int) ( $res['rank'] ?? 0 ),
			'backlinks'          => (int) ( $res['backlinks'] ?? 0 ),
			'referring_domains'  => (int) ( $res['referring_domains'] ?? 0 ),
			'referring_main_domains' => (int) ( $res['referring_main_domains'] ?? 0 ),
			'broken_backlinks'   => (int) ( $res['broken_backlinks'] ?? 0 ),
			'spam_score'         => (int) ( $res['backlinks_spam_score'] ?? $res['target_spam_score'] ?? 0 ),
			'fetched_at'         => current_time( 'mysql', true ),
		);
		update_option( self::SUMMARY_OPT, $summary, false );
		return $summary;
	}

	public static function cached_summary() {
		$s = get_option( self::SUMMARY_OPT, null );
		return is_array( $s ) ? $s : null;
	}

	
	public static function refresh( $limit = 300 ) {
		if ( ! self::available() ) {
			return new WP_Error( 'aieo_dfs_off', __( 'DataForSEO is not connected (SEO → General).', 'ai-eshop-optimizer' ) );
		}
		if ( ! self::budget_ok() ) {
			return new WP_Error( 'aieo_dfs_budget', __( 'The monthly DataForSEO budget is exhausted.', 'ai-eshop-optimizer' ) );
		}
		self::ensure_tables();
		self::fetch_summary(); 

		$limit = min( 1000, max( 1, (int) $limit ) );
		$res   = self::result( AIEO_DataForSEO::post( '/v3/backlinks/referring_domains/live', array(
			'target'                => self::target(),
			'limit'                 => $limit,
			'order_by'              => array( 'backlinks_spam_score,desc' ),
			'backlinks_status_type' => 'live',
			'include_subdomains'    => true,
			'rank_scale'            => 'one_hundred',
		) ) );
		if ( is_wp_error( $res ) ) {
			return $res;
		}
		$items = isset( $res['items'] ) && is_array( $res['items'] ) ? $res['items'] : array();

		global $wpdb;
		$snap = self::snap_table();
		
		
		
		$wpdb->query( "TRUNCATE TABLE `{$snap}`" );
		$now    = current_time( 'mysql', true );
		$stored = 0;
		foreach ( $items as $it ) {
			$domain = self::normalize_domain( (string) ( $it['domain'] ?? '' ) );
			if ( '' === $domain ) {
				continue;
			}
			$wpdb->insert( $snap, array(
				'domain'      => $domain,
				'backlinks'   => (int) ( $it['backlinks'] ?? 0 ),
				'spam_score'  => min( 100, max( 0, (int) ( $it['backlinks_spam_score'] ?? 0 ) ) ),
				'domain_rank' => min( 65535, max( 0, (int) ( $it['rank'] ?? 0 ) ) ),
				'dofollow'    => (int) ( $it['dofollow'] ?? 0 ),
				'first_seen'  => isset( $it['first_seen'] ) ? substr( (string) $it['first_seen'], 0, 32 ) : null,
				'lost'        => ! empty( $it['is_lost'] ) ? 1 : 0,
				'fetched_at'  => $now,
			), array( '%s', '%d', '%d', '%d', '%d', '%s', '%d', '%s' ) );
			$stored++;
		}
		update_option( self::LAST_OPT, $now, false );
		return array( 'stored' => $stored );
	}

	
	
	

	
	public static function referring_domains( $limit = 200, array $args = array() ) {
		global $wpdb;
		$snap = self::snap_table();
		$dis  = self::disavow_table();
		if ( ! self::table_exists( $snap ) ) {
			return array();
		}
		$limit    = min( 1000, max( 1, (int) $limit ) );
		$min_spam = max( 0, (int) ( $args['min_spam'] ?? 0 ) );
		$order    = (string) ( $args['order'] ?? 'spam' );
		$order    = in_array( $order, array( 'spam', 'rank', 'backlinks' ), true ) ? $order : 'spam';
		$order_by = 'spam' === $order ? 's.spam_score DESC, s.backlinks DESC'
			: ( 'rank' === $order ? 's.domain_rank DESC' : 's.backlinks DESC' );

		$dis_join = self::table_exists( $dis ) ? "LEFT JOIN `{$dis}` d ON d.domain = s.domain" : '';
		$dis_col  = self::table_exists( $dis ) ? 'd.domain IS NOT NULL' : '0';
		
		$rows = $wpdb->get_results( $wpdb->prepare(
			"SELECT s.domain, s.backlinks, s.spam_score, s.domain_rank, s.dofollow, s.first_seen, s.lost,
			        ({$dis_col}) AS is_disavowed
			   FROM `{$snap}` s {$dis_join}
			  WHERE s.spam_score >= %d
			  ORDER BY {$order_by}
			  LIMIT %d",
			$min_spam, $limit
		), ARRAY_A );
		return is_array( $rows ) ? array_map( array( __CLASS__, 'cast_row' ), $rows ) : array();
	}

	private static function cast_row( $r ) {
		return array(
			'domain'       => (string) $r['domain'],
			'backlinks'    => (int) $r['backlinks'],
			'spam_score'   => (int) $r['spam_score'],
			'domain_rank'  => (int) $r['domain_rank'],
			'dofollow'     => (int) $r['dofollow'],
			'first_seen'   => (string) $r['first_seen'],
			'lost'         => (bool) (int) $r['lost'],
			'is_disavowed' => (bool) (int) $r['is_disavowed'],
		);
	}

	
	public static function toxic( $threshold = null, $limit = 1000 ) {
		$threshold = null === $threshold ? self::toxic_threshold() : (int) $threshold;
		return self::referring_domains( $limit, array( 'min_spam' => $threshold, 'order' => 'spam' ) );
	}

	public static function toxic_threshold() {
		$t = class_exists( 'AIEO_DMM_Settings' ) ? AIEO_DMM_Settings::get( 'seo.disavow_spam_threshold', self::TOXIC_DEFAULT ) : self::TOXIC_DEFAULT;
		return min( 100, max( 1, (int) $t ) );
	}

	
	
	

	public static function is_disavowed( $domain ) {
		global $wpdb;
		$dis = self::disavow_table();
		if ( ! self::table_exists( $dis ) ) {
			return false;
		}
		$domain = self::normalize_domain( $domain );
		
		return (bool) $wpdb->get_var( $wpdb->prepare( "SELECT 1 FROM `{$dis}` WHERE domain = %s", $domain ) );
	}

	public static function disavow_add( $domain, $reason = '', $source = 'manual' ) {
		global $wpdb;
		self::ensure_tables();
		$domain = self::normalize_domain( $domain );
		if ( '' === $domain ) {
			return false;
		}
		
		$snap  = self::snap_table();
		$spam  = self::table_exists( $snap )
			
			? $wpdb->get_var( $wpdb->prepare( "SELECT spam_score FROM `{$snap}` WHERE domain = %s", $domain ) )
			: null;
		$dis = self::disavow_table();
		
		
		
		
		$spam_sql = ( null === $spam ) ? 'NULL' : (int) $spam;
		
		$wpdb->query( $wpdb->prepare(
			"INSERT INTO `{$dis}` (domain, reason, source, spam_score, added_at)
			 VALUES (%s, %s, %s, {$spam_sql}, %s)
			 ON DUPLICATE KEY UPDATE reason = VALUES(reason), source = VALUES(source), spam_score = COALESCE(VALUES(spam_score), spam_score)",
			$domain,
			mb_substr( (string) $reason, 0, 255 ),
			in_array( $source, array( 'manual', 'auto' ), true ) ? $source : 'manual',
			current_time( 'mysql', true )
		) );
		return true;
	}

	public static function disavow_remove( $domain ) {
		global $wpdb;
		$dis = self::disavow_table();
		if ( ! self::table_exists( $dis ) ) {
			return false;
		}
		$domain = self::normalize_domain( $domain );
		
		return (bool) $wpdb->query( $wpdb->prepare( "DELETE FROM `{$dis}` WHERE domain = %s", $domain ) );
	}

	
	public static function disavow_list() {
		global $wpdb;
		$dis = self::disavow_table();
		if ( ! self::table_exists( $dis ) ) {
			return array();
		}
		
		$rows = $wpdb->get_results( "SELECT domain, reason, source, spam_score, added_at FROM `{$dis}` ORDER BY spam_score DESC, domain ASC", ARRAY_A );
		return is_array( $rows ) ? $rows : array();
	}

	public static function disavow_count() {
		global $wpdb;
		$dis = self::disavow_table();
		if ( ! self::table_exists( $dis ) ) {
			return 0;
		}
		
		return (int) $wpdb->get_var( "SELECT COUNT(*) FROM `{$dis}`" );
	}

	
	public static function disavow_all_toxic( $threshold = null ) {
		$n = 0;
		foreach ( self::toxic( $threshold ) as $d ) {
			if ( self::disavow_add( $d['domain'], sprintf( 'spam_score %d', $d['spam_score'] ), 'auto' ) ) {
				$n++;
			}
		}
		return $n;
	}

	
	public static function disavow_file() {
		$lines   = array();
		$lines[] = '# Disavow file generated by Rooster One';
		$lines[] = '# Site: ' . self::target();
		$lines[] = '# Generated: ' . current_time( 'mysql', true ) . ' UTC';
		$lines[] = '# Upload at: ' . self::disavow_tool_url();
		$lines[] = '';
		$seen = array();
		foreach ( self::disavow_list() as $row ) {
			$domain = self::normalize_domain( (string) $row['domain'] );
			if ( '' === $domain || isset( $seen[ $domain ] ) ) {
				continue;
			}
			$seen[ $domain ] = true;
			$note = trim( (string) ( $row['reason'] ?? '' ) );
			if ( '' !== $note ) {
				$lines[] = '# ' . preg_replace( '/[\r\n]+/', ' ', $note );
			}
			$lines[] = 'domain:' . $domain;
		}
		
		return implode( "\n", $lines ) . "\n";
	}

	
	public static function disavow_tool_url() {
		return 'https://search.google.com/search-console/disavow-links';
	}

	
	public static function normalize_domain( $raw ) {
		$raw = trim( strtolower( (string) $raw ) );
		if ( '' === $raw ) {
			return '';
		}
		if ( false !== strpos( $raw, '/' ) || false !== strpos( $raw, ':' ) ) {
			$host = (string) wp_parse_url( ( false === strpos( $raw, '://' ) ? 'http://' . $raw : $raw ), PHP_URL_HOST );
			if ( '' !== $host ) {
				$raw = $host;
			}
		}
		$raw = preg_replace( '/^www\./', '', $raw );
		
		return preg_match( '/^[a-z0-9.-]+\.[a-z]{2,}$/', $raw ) ? $raw : '';
	}
}