<?php

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

final class AIEO_SEO_Sitemap_Priority {

	
	const OPTION = 'aieo_seo_sitemap_priority';

	
	const SIGNALS = array(
		'sales'    => 30,
		'search'   => 25,
		'visitors' => 20,
		'fresh'    => 20,
		'unique'   => 15,
		'links'    => 10,
	);

	
	const HALF_LIFE = 180;

	
	const SCALE = 100;

	
	private static $settings = null;

	
	private static $columns = null;

	
	private static $live = array();

	

	
	public static function active() {
		return false !== get_option( self::OPTION, false );
	}

	
	public static function settings() {
		if ( null === self::$settings ) {
			self::$settings = self::sanitize( get_option( self::OPTION, array() ), $ignored, false );
		}
		return self::$settings;
	}

	public static function save( $raw, &$errors = null ) {
		$clean = self::sanitize( $raw, $errors, true );
		update_option( self::OPTION, $clean, false );
		self::$settings = $clean;
		return $clean;
	}

	public static function reset() {
		self::$settings = null;
		self::$columns  = null;
		self::$live     = array();
	}

	
	public static function sanitize( $raw, &$errors = null, $strict = true ) {
		$errors  = array();
		$raw     = is_array( $raw ) ? $raw : array();
		$weights = array();
		foreach ( self::SIGNALS as $key => $default ) {
			$w               = $raw['weights'][ $key ] ?? $default;
			$weights[ $key ] = is_numeric( $w ) ? max( 0, min( 100, (int) round( (float) $w ) ) ) : $default;
		}
		$limits = array();
		foreach ( array_slice( (array) ( $raw['limits'] ?? array() ), 0, 200, true ) as $target => $limit ) {
			if ( ! is_string( $target ) || ! preg_match( '/^(post|term):([^\s:<>"\'&]{1,64})$/u', $target, $m ) || ! is_array( $limit ) ) {
				continue;
			}
			if ( $strict && ! ( 'post' === $m[1] ? post_type_exists( $m[2] ) : taxonomy_exists( $m[2] ) ) ) {
				continue;
			}
			$mode = (string) ( $limit['mode'] ?? '' );
			if ( ! in_array( $mode, array( 'percent', 'count' ), true ) ) {
				continue; 
			}
			$value = class_exists( 'AIEO_SEO_Sitemap_Rules' ) ? AIEO_SEO_Sitemap_Rules::number( is_scalar( $limit['value'] ?? null ) ? (string) $limit['value'] : '' ) : null;
			$max   = 'percent' === $mode ? 100 : 10000000;
			if ( null === $value || $value < 1 || $value > $max || floor( $value ) != $value ) { 
				$name     = ( $strict && class_exists( 'AIEO_SEO_Sitemap_Rules' ) ) ? ( AIEO_SEO_Sitemap_Rules::targets()[ $target ] ?? $target ) : $target;
				$errors[] = 'percent' === $mode
					
					? sprintf( __( '%s: the share to keep is a whole number from 1 to 100.', 'ai-eshop-optimizer' ), $name )
					
					: sprintf( __( '%s: the number to keep is a whole number from 1.', 'ai-eshop-optimizer' ), $name );
				continue;
			}
			$limits[ $target ] = array(
				'mode'  => $mode,
				'value' => (int) $value,
			);
		}
		if ( $limits && ! array_sum( $weights ) ) {
			
			$errors[] = __( 'Give at least one signal a weight: a limit keeps the best-scored items.', 'ai-eshop-optimizer' );
		}
		return array(
			'weights' => $weights,
			'limits'  => $limits,
		);
	}

	

	
	public static function columns_ok() {
		if ( null === self::$columns ) {
			global $wpdb;
			$t              = $wpdb->prefix . 'aieo_seo_posts';
			$prev           = $wpdb->suppress_errors( true );
			self::$columns  = 2 === (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = %s AND COLUMN_NAME IN ('priority_score', 'sitemap_cut')", $t ) );
			$wpdb->suppress_errors( $prev );
		}
		return self::$columns;
	}

	

	
	public static function types() {
		global $wpdb;
		$t   = $wpdb->prefix . 'aieo_seo_posts';
		$out = array();
		
		foreach ( (array) $wpdb->get_results( "SELECT object_type, COUNT(*) AS n FROM `{$t}` WHERE indexable = 1 AND canonical_url <> '' GROUP BY object_type ORDER BY object_type", ARRAY_A ) as $r ) {
			$out[ (string) $r['object_type'] ] = (int) $r['n'];
		}
		return $out;
	}

	
	public static function run_all() {
		if ( ! self::columns_ok() ) {
			return array();
		}
		if ( ! self::active() ) {
			self::clear_cuts();
			return array();
		}
		$out = array();
		foreach ( array_keys( self::types() ) as $type ) {
			$out[ $type ] = self::run_type( $type );
		}
		self::clear_cuts( array_keys( $out ) );
		return $out;
	}

	
	public static function run_type( $type ) {
		if ( ! self::columns_ok() ) {
			return array( 'scored' => 0, 'listed' => 0, 'cut' => 0 );
		}
		$scored = self::score_type( (string) $type );
		$cut    = self::cut_type( (string) $type );
		return array( 'scored' => $scored ) + $cut;
	}

	
	public static function clear_cuts( array $except = array() ) {
		global $wpdb;
		$t = $wpdb->prefix . 'aieo_seo_posts';
		if ( ! self::columns_ok() ) {
			return;
		}
		$not = $except ? ' AND object_type NOT IN (' . implode( ',', array_fill( 0, count( $except ), '%s' ) ) . ')' : '';
		$sql = "UPDATE `{$t}` SET sitemap_cut = 0 WHERE sitemap_cut <> 0{$not}";
		
		$wpdb->query( $except ? $wpdb->prepare( $sql, $except ) : $sql );
	}

	
	public static function score_type( $type ) {
		global $wpdb;
		$t    = $wpdb->prefix . 'aieo_seo_posts';
		$rows = array(); 
		
		foreach ( (array) $wpdb->get_results( $wpdb->prepare( "SELECT id, object_id FROM `{$t}` WHERE object_type = %s AND indexable = 1 AND canonical_url <> ''", $type ), ARRAY_A ) as $r ) {
			$rows[ (int) $r['object_id'] ] = (int) $r['id'];
		}
		$wpdb->flush(); 
		if ( ! $rows ) {
			return 0;
		}
		$kind    = class_exists( 'AIEO_SEO_Sitemap_Rules' ) ? AIEO_SEO_Sitemap_Rules::kind( $type ) : '';
		$weights = self::settings()['weights'];
		$signals = self::signals( $type, $kind, array_keys( $rows ) );
		$scores  = array();
		foreach ( $rows as $object_id => $row_id ) {
			$sum   = 0.0;
			$total = 0;
			foreach ( $signals as $key => $values ) {
				if ( empty( $weights[ $key ] ) || ! isset( $values[ $object_id ] ) ) {
					continue;
				}
				$sum   += $weights[ $key ] * $values[ $object_id ];
				$total += $weights[ $key ];
			}
			$scores[ $row_id ] = $total ? (int) round( $sum / $total * self::SCALE ) : 0;
		}
		self::write_scores( $scores );
		return count( $scores );
	}

	
	public static function cut_type( $type ) {
		global $wpdb;
		$t      = $wpdb->prefix . 'aieo_seo_posts';
		$kind   = class_exists( 'AIEO_SEO_Sitemap_Rules' ) ? AIEO_SEO_Sitemap_Rules::kind( $type ) : '';
		$limit  = self::settings()['limits'][ $kind . ':' . $type ] ?? null;
		
		$rows   = (array) $wpdb->get_results( $wpdb->prepare( "SELECT id, sitemap FROM `{$t}` WHERE object_type = %s AND indexable = 1 AND canonical_url <> '' AND sitemap > 0 ORDER BY priority_score DESC, id DESC", $type ), ARRAY_A );
		$wpdb->flush(); 
		$n      = count( $rows );
		$keep   = $n;
		if ( is_array( $limit ) ) {
			$keep = 'percent' === $limit['mode'] ? (int) ceil( $n * $limit['value'] / 100 ) : min( $n, (int) $limit['value'] );
		}
		$always = 0;
		foreach ( $rows as $r ) {
			$always += 2 === (int) $r['sitemap'] ? 1 : 0;
		}
		$room = max( 0, $keep - $always );
		$cut  = array();
		foreach ( $rows as $r ) {
			if ( 2 === (int) $r['sitemap'] ) {
				continue;
			}
			if ( $room > 0 ) {
				--$room;
				continue;
			}
			$cut[] = (int) $r['id'];
		}
		
		
		
		$was   = array_map( 'intval', (array) $wpdb->get_col( $wpdb->prepare( "SELECT id FROM `{$t}` WHERE object_type = %s AND sitemap_cut = 1", $type ) ) );
		$was   = array_flip( $was );
		$now   = array_flip( $cut );
		$set   = array_keys( array_diff_key( $now, $was ) );
		$clear = array_keys( array_diff_key( $was, $now ) );
		foreach ( array( 1 => $set, 0 => $clear ) as $flag => $ids ) {
			foreach ( array_chunk( $ids, 1000 ) as $chunk ) {
				
				$wpdb->query( "UPDATE `{$t}` SET sitemap_cut = " . (int) $flag . ' WHERE id IN (' . implode( ',', array_map( 'intval', $chunk ) ) . ')' );
			}
		}
		return array(
			'listed' => $n - count( $cut ),
			'cut'    => count( $cut ),
		);
	}

	
	private static function write_scores( array $scores ) {
		global $wpdb;
		$t    = $wpdb->prefix . 'aieo_seo_posts';
		$tmp  = $wpdb->prefix . 'aieo_sitemap_scores_tmp';
		
		
		$prev = $wpdb->suppress_errors( true );
		$made = false !== $wpdb->query( "CREATE TEMPORARY TABLE IF NOT EXISTS `{$tmp}` ( id BIGINT UNSIGNED NOT NULL PRIMARY KEY, s SMALLINT UNSIGNED NOT NULL )" ); 
		$whole = $made && false !== $wpdb->query( "DELETE FROM `{$tmp}`" ); 
		foreach ( $whole ? array_chunk( $scores, 1000, true ) : array() as $chunk ) {
			$values = array();
			foreach ( $chunk as $id => $s ) {
				$values[] = '(' . (int) $id . ',' . max( 0, min( 65535, (int) $s ) ) . ')';
			}
			if ( false === $wpdb->query( "INSERT INTO `{$tmp}` (id, s) VALUES " . implode( ',', $values ) ) ) { 
				$whole = false;
				break;
			}
		}
		
		$whole = $whole && false !== $wpdb->query( "UPDATE `{$t}` sp JOIN `{$tmp}` x ON x.id = sp.id SET sp.priority_score = x.s WHERE sp.priority_score <> x.s" );
		if ( $made ) {
			$wpdb->query( "DROP TEMPORARY TABLE IF EXISTS `{$tmp}`" ); 
		}
		$wpdb->suppress_errors( $prev );
		if ( $whole ) {
			return;
		}
		foreach ( array_chunk( $scores, 500, true ) as $chunk ) {
			$case = '';
			foreach ( $chunk as $id => $s ) {
				$case .= ' WHEN ' . (int) $id . ' THEN ' . max( 0, min( 65535, (int) $s ) );
			}
			
			$wpdb->query( "UPDATE `{$t}` SET priority_score = CASE id{$case} END WHERE id IN (" . implode( ',', array_map( 'intval', array_keys( $chunk ) ) ) . ')' );
		}
	}

	

	
	public static function signals( $type, $kind, array $ids ) {
		$want = array_flip( array_map( 'intval', $ids ) );
		$out  = array();
		foreach ( array_keys( self::SIGNALS ) as $key ) {
			$raw = self::raw( $key, $type, $kind );
			if ( null === $raw ) {
				continue;
			}
			list( $values, $missing_is_zero ) = $raw;
			$values = array_intersect_key( $values, $want );
			if ( $missing_is_zero ) {
				$values += array_fill_keys( array_keys( array_diff_key( $want, $values ) ), 0.0 );
			}
			if ( ! $values ) {
				continue;
			}
			if ( 'fresh' === $key ) {
				$out[ $key ] = $values; 
			} elseif ( 'unique' === $key ) {
				$out[ $key ] = array_map( static fn ( $p ) => 100.0 - $p, self::percentiles( $values ) );
			} else {
				$out[ $key ] = self::percentiles( $values );
			}
		}
		return $out;
	}

	
	private static function raw( $key, $type, $kind ) {
		global $wpdb;
		$values = array();
		switch ( $key ) {
			case 'sales':
				if ( 'product' === $type ) {
					$t = $wpdb->prefix . 'aieo_seo_posts';
					
					$values = self::pairs( "SELECT object_id AS k, demand_score AS v FROM `{$t}` WHERE object_type = 'product' AND demand_score IS NOT NULL" );
					return $values ? array( $values, false ) : null;
				}
				$brand = class_exists( 'AIEO_Order_Rules' ) && method_exists( 'AIEO_Order_Rules', 'brand_tax' ) ? (string) AIEO_Order_Rules::brand_tax() : 'product_brand';
				$p     = $wpdb->prefix . 'aieo_core_category_brand_popularity';
				if ( 'term' !== $kind || ! in_array( $type, array( 'product_cat', $brand ), true ) || ! self::has_rows( $p ) ) {
					return null;
				}
				
				$values = 'product_cat' === $type
					? self::pairs( "SELECT category_id AS k, SUM(total_turnover) AS v FROM `{$p}` WHERE brand_id IS NULL AND category_id IS NOT NULL GROUP BY category_id" )
					: self::pairs( "SELECT brand_id AS k, SUM(total_turnover) AS v FROM `{$p}` WHERE brand_id IS NOT NULL AND category_id IS NULL GROUP BY brand_id" );
				
				return array( $values, true );
			case 'search':
				$g = $wpdb->prefix . 'aieo_gsc_daily';
				if ( self::live( 'gsc', static fn () => self::has_rows( $g, "dim_type = 'page'" ) ) ) {
					$cutoff = gmdate( 'Y-m-d', time() - 90 * DAY_IN_SECONDS );
					
					$values = self::pairs( $wpdb->prepare( "SELECT object_id AS k, SUM(clicks) + 0.02 * SUM(impressions) AS v FROM `{$g}` WHERE dim_type = 'page' AND object_type = %s AND object_id > 0 AND `date` >= %s GROUP BY object_id", $type, $cutoff ) );
					return array( $values, true );
				}
				$t = $wpdb->prefix . 'aieo_seo_posts';
				if ( self::live( 'dfs', static fn () => self::has_rows( $t, 'search_demand_score > 0' ) ) ) {
					
					$values = self::pairs( $wpdb->prepare( "SELECT object_id AS k, search_demand_score AS v FROM `{$t}` WHERE object_type = %s", $type ) );
					return array( $values, true );
				}
				return null;
			case 'visitors':
				if ( 'post' !== $kind ) {
					return null;
				}
				if ( 'product' === $type ) {
					$l = $wpdb->prefix . 'aieo_product_lifetime';
					if ( ! self::live( 'lifetime', static fn () => self::has_rows( $l ) ) ) {
						return null;
					}
					
					return array( self::pairs( "SELECT product_id AS k, product_views_30d AS v FROM `{$l}`" ), true );
				}
				$c = $wpdb->prefix . 'aieo_core_content_vitals';
				if ( ! self::live( 'content', static fn () => self::has_rows( $c ) ) ) {
					return null;
				}
				
				return array( self::pairs( $wpdb->prepare( "SELECT content_id AS k, visitors_30d AS v FROM `{$c}` WHERE post_type = %s", $type ) ), true );
			case 'fresh':
				if ( 'post' !== $kind ) {
					return null;
				}
				$t   = $wpdb->prefix . 'aieo_seo_posts';
				$now = time();
				
				foreach ( (array) $wpdb->get_results( $wpdb->prepare( "SELECT p.ID AS k, p.post_modified_gmt AS m FROM `{$wpdb->posts}` p JOIN `{$t}` sp ON sp.object_id = p.ID AND sp.object_type = %s WHERE sp.indexable = 1", $type ), ARRAY_A ) as $r ) {
					$ts = '0000-00-00 00:00:00' === $r['m'] ? 0 : (int) strtotime( $r['m'] . ' UTC' );
					if ( $ts > 0 ) {
						$days                  = max( 0, ( $now - $ts ) / DAY_IN_SECONDS );
						$values[ (int) $r['k'] ] = 100 * pow( 0.5, $days / self::HALF_LIFE );
					}
				}
				return $values ? array( $values, false ) : null;
			case 'unique':
				$s = $wpdb->prefix . 'aieo_sem_pairs';
				if ( ! self::live( 'pairs', static fn () => self::has_rows( $s ) ) ) {
					return null;
				}
				
				$values = self::pairs( $wpdb->prepare( "SELECT source_id AS k, MAX(score) AS v FROM `{$s}` WHERE source_type = %s GROUP BY source_id", $type ) );
				return $values ? array( $values, false ) : null;
			case 'links':
				$k = $wpdb->prefix . 'aieo_sem_links';
				if ( ! self::live( 'links', static fn () => self::has_rows( $k, "status = 'approved'" ) ) ) {
					return null;
				}
				
				return array( self::pairs( $wpdb->prepare( "SELECT target_id AS k, COUNT(*) AS v FROM `{$k}` WHERE status = 'approved' AND target_type = %s GROUP BY target_id", $type ) ), true );
		}
		return null;
	}

	
	public static function available() {
		global $wpdb;
		$p = $wpdb->prefix;
		return array(
			'sales'    => self::has_rows( $p . 'aieo_seo_posts', "object_type = 'product' AND demand_score IS NOT NULL" ) || self::has_rows( $p . 'aieo_core_category_brand_popularity' ),
			'search'   => self::has_rows( $p . 'aieo_gsc_daily', "dim_type = 'page'" ) || self::has_rows( $p . 'aieo_seo_posts', 'search_demand_score > 0' ),
			'visitors' => self::has_rows( $p . 'aieo_core_content_vitals' ) || self::has_rows( $p . 'aieo_product_lifetime' ),
			'fresh'    => true,
			'unique'   => self::has_rows( $p . 'aieo_sem_pairs' ),
			'links'    => self::has_rows( $p . 'aieo_sem_links', "status = 'approved'" ),
		);
	}

	
	public static function percentiles( array $values ) {
		$n = count( $values );
		if ( $n < 2 ) {
			return array_map( static fn () => 50.0, $values );
		}
		asort( $values, SORT_NUMERIC );
		$keys = array_keys( $values );
		$vals = array_values( $values );
		$out  = array();
		for ( $i = 0; $i < $n; $i = $j + 1 ) {
			$j = $i;
			while ( $j + 1 < $n && (float) $vals[ $j + 1 ] === (float) $vals[ $i ] ) {
				++$j;
			}
			$p = (float) ( ( $i + $j ) / 2 / ( $n - 1 ) * 100 );
			for ( $k = $i; $k <= $j; $k++ ) {
				$out[ $keys[ $k ] ] = $p;
			}
		}
		return $out;
	}

	
	private static function pairs( $sql ) {
		global $wpdb;
		$out = array();
		
		foreach ( (array) $wpdb->get_results( $sql, ARRAY_A ) as $r ) {
			$out[ (int) $r['k'] ] = (float) $r['v'];
		}
		$wpdb->flush(); 
		return $out;
	}

	
	private static function has_rows( $table, $where = '1=1' ) {
		global $wpdb;
		$prev = $wpdb->suppress_errors( true );
		
		$hit = $table === $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) ) && null !== $wpdb->get_var( "SELECT 1 FROM `{$table}` WHERE {$where} LIMIT 1" );
		$wpdb->suppress_errors( $prev );
		return $hit;
	}

	
	private static function live( $name, callable $probe ) {
		if ( ! array_key_exists( $name, self::$live ) ) {
			self::$live[ $name ] = (bool) $probe();
		}
		return self::$live[ $name ];
	}

	
	public static function labels() {
		return array(
			'sales'    => __( 'Sales performance', 'ai-eshop-optimizer' ),
			'search'   => __( 'Search demand', 'ai-eshop-optimizer' ),
			'visitors' => __( 'Visitors', 'ai-eshop-optimizer' ),
			'fresh'    => __( 'Content freshness', 'ai-eshop-optimizer' ),
			'unique'   => __( 'Content uniqueness', 'ai-eshop-optimizer' ),
			'links'    => __( 'Internal link importance', 'ai-eshop-optimizer' ),
		);
	}
}