<?php
/**
 * Network-level database operations for the cross-site mirror index.
 *
 * @package MediaRightsAudit\Core
 */

namespace MediaRightsAudit\Core;

use MediaRightsAudit\External\HostnameFilter;

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

/**
 * Manages {base_prefix}mra_network_index, a denormalized mirror of each site's
 * mra_media_index that enables fast cross-site queries in the network admin.
 *
 * Detailed data (top_domains JSON, raw_response) stays in per-site tables and
 * is loaded on demand via switch_to_blog(). This table holds only the fields
 * needed for list display, filtering, and aggregated stats.
 *
 * All sync methods must be called while the target site's context is active
 * (switch_to_blog already called), so $wpdb->prefix resolves to per-site tables
 * while $wpdb->base_prefix always resolves to the network-wide prefix.
 */
class NetworkDatabase {

	/**
	 * Returns the fully-qualified network mirror table name.
	 *
	 * Uses base_prefix so it lives in the main site's DB regardless of active blog.
	 *
	 * @return string
	 */
	public static function table_name(): string {
		global $wpdb;
		return $wpdb->base_prefix . 'mra_network_index';
	}

	/**
	 * Creates the network mirror table using dbDelta (idempotent).
	 *
	 * @return void
	 */
	public static function create_network_table(): void {
		global $wpdb;

		$charset_collate = $wpdb->get_charset_collate();
		$table           = self::table_name();

		require_once ABSPATH . 'wp-admin/includes/upgrade.php';

		dbDelta(
			"CREATE TABLE {$table} (
  site_id bigint(20) unsigned NOT NULL,
  attachment_id bigint(20) unsigned NOT NULL,
  site_url varchar(255) NOT NULL DEFAULT '',
  file_name varchar(255) NOT NULL DEFAULT '',
  file_url text NOT NULL,
  mime_type varchar(100) NOT NULL DEFAULT '',
  file_size bigint(20) unsigned NOT NULL DEFAULT 0,
  external_status enum('pending','queued','scanned','matches','error') NOT NULL DEFAULT 'pending',
  internal_scanned_at datetime DEFAULT NULL,
  external_scanned_at datetime DEFAULT NULL,
  has_alert tinyint(1) NOT NULL DEFAULT 0,
  is_dismissed tinyint(1) NOT NULL DEFAULT 0,
  updated_at datetime NOT NULL,
  PRIMARY KEY  (site_id, attachment_id),
  KEY external_status (external_status),
  KEY has_alert (has_alert)
) {$charset_collate};"
		);
	}

	/**
	 * Drops the network mirror table. Used only during full network uninstall.
	 *
	 * @return void
	 */
	public static function drop_network_table(): void {
		global $wpdb;
		$table = self::table_name();
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$wpdb->query( "DROP TABLE IF EXISTS `{$table}`" );
	}

	/**
	 * Removes all mirror rows for a given site.
	 *
	 * Called when a site resets all its plugin data (truncate_all).
	 *
	 * @param int $site_id WordPress blog ID.
	 *
	 * @return void
	 */
	public static function clear_site( int $site_id ): void {
		global $wpdb;

		$wpdb->delete( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			self::table_name(),
			array( 'site_id' => $site_id ),
			array( '%d' )
		);
	}

	/**
	 * Syncs the mirror table for the currently active site.
	 *
	 * Reads mra_media_index, mra_external_results (for has_alert), and
	 * mra_dismissed_alerts (for is_dismissed) from the current site's tables,
	 * then replaces all mirror rows for this site.
	 *
	 * Must be called while switch_to_blog($site_id) is active.
	 *
	 * @param int $site_id WordPress blog ID (must match the currently active blog).
	 *
	 * @return void
	 */
	public static function sync_site( int $site_id ): void {
		global $wpdb;

		$site_url = get_site_url( $site_id );
		$table    = self::table_name();

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		$rows = $wpdb->get_results(
			"SELECT attachment_id, file_name, file_url, mime_type, file_size,
			        external_status, internal_scanned_at, external_scanned_at
			 FROM {$wpdb->prefix}mra_media_index",
			ARRAY_A
		);

		self::clear_site( $site_id );

		if ( empty( $rows ) || ! is_array( $rows ) ) {
			return;
		}

		$ids          = array_map( 'intval', array_column( $rows, 'attachment_id' ) );
		$placeholders = implode( ',', array_fill( 0, count( $ids ), '%d' ) );

		// Load top_domains per attachment to compute has_alert.
		// phpcs:disable WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
		$domain_rows = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT attachment_id, top_domains
				 FROM {$wpdb->prefix}mra_external_results
				 WHERE attachment_id IN ({$placeholders})",
				...$ids
			),
			ARRAY_A
		);
		// phpcs:enable WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare

		// Build merged domain map: attachment_id → domain → count.
		$domains_by_id = array();
		if ( is_array( $domain_rows ) ) {
			foreach ( $domain_rows as $dr ) {
				if ( ! is_array( $dr ) ) {
					continue;
				}
				$aid = is_numeric( $dr['attachment_id'] ?? null ) ? (int) $dr['attachment_id'] : 0;
				$td  = is_string( $dr['top_domains'] ?? null ) ? json_decode( $dr['top_domains'], true ) : null;
				if ( $aid <= 0 || ! is_array( $td ) ) {
					continue;
				}
				if ( ! isset( $domains_by_id[ $aid ] ) ) {
					$domains_by_id[ $aid ] = array();
				}
				foreach ( $td as $domain => $count ) {
					if ( is_string( $domain ) ) {
						$domains_by_id[ $aid ][ $domain ] = ( $domains_by_id[ $aid ][ $domain ] ?? 0 ) + ( is_numeric( $count ) ? (int) $count : 0 );
					}
				}
			}
		}

		// Load dismissed attachment IDs.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		$dismissed_col = $wpdb->get_col( "SELECT attachment_id FROM {$wpdb->prefix}mra_dismissed_alerts" );
		$dismissed_ids = array();
		if ( is_array( $dismissed_col ) ) {
			foreach ( $dismissed_col as $did ) {
				if ( is_numeric( $did ) ) {
					$dismissed_ids[ (int) $did ] = true;
				}
			}
		}

		$now = current_time( 'mysql', true );

		foreach ( $rows as $row ) {
			if ( ! is_array( $row ) ) {
				continue;
			}
			$aid = is_numeric( $row['attachment_id'] ?? null ) ? (int) $row['attachment_id'] : 0;
			if ( $aid <= 0 ) {
				continue;
			}

			$has_alert    = HostnameFilter::has_alert_domains( $domains_by_id[ $aid ] ?? array() ) ? 1 : 0;
			$is_dismissed = isset( $dismissed_ids[ $aid ] ) ? 1 : 0;

			// phpcs:disable WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared
			$wpdb->query(
				$wpdb->prepare(
					"REPLACE INTO `{$table}`
					 (site_id, attachment_id, site_url, file_name, file_url, mime_type,
					  file_size, external_status, internal_scanned_at, external_scanned_at,
					  has_alert, is_dismissed, updated_at)
					 VALUES (%d, %d, %s, %s, %s, %s, %d, %s, %s, %s, %d, %d, %s)",
					$site_id,
					$aid,
					$site_url,
					is_string( $row['file_name'] ?? null ) ? $row['file_name'] : '',
					is_string( $row['file_url'] ?? null ) ? $row['file_url'] : '',
					is_string( $row['mime_type'] ?? null ) ? $row['mime_type'] : '',
					is_numeric( $row['file_size'] ?? null ) ? (int) $row['file_size'] : 0,
					is_string( $row['external_status'] ?? null ) ? $row['external_status'] : 'pending',
					is_string( $row['internal_scanned_at'] ?? null ) && '' !== $row['internal_scanned_at'] ? $row['internal_scanned_at'] : null,
					is_string( $row['external_scanned_at'] ?? null ) && '' !== $row['external_scanned_at'] ? $row['external_scanned_at'] : null,
					$has_alert,
					$is_dismissed,
					$now
				)
			);
			// phpcs:enable WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		}
	}

	/**
	 * Updates the dismissal flag for a single attachment in the mirror.
	 *
	 * Lighter alternative to sync_site() when only dismissal status changes.
	 *
	 * @param int  $site_id       WordPress blog ID.
	 * @param int  $attachment_id WordPress attachment ID.
	 * @param bool $is_dismissed  Whether the alert is dismissed.
	 *
	 * @return void
	 */
	public static function update_dismissal_flag( int $site_id, int $attachment_id, bool $is_dismissed ): void {
		global $wpdb;

		$wpdb->update( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			self::table_name(),
			array(
				'is_dismissed' => $is_dismissed ? 1 : 0,
				'updated_at'   => current_time( 'mysql', true ),
			),
			array(
				'site_id'       => $site_id,
				'attachment_id' => $attachment_id,
			),
			array( '%d', '%s' ),
			array( '%d', '%d' )
		);
	}
}