<?php
/**
 * Listing stats integration for Zone B view counting.
 *
 * @package WP_Data_Optimizer
 */

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

/**
 * Zone B/D integration — Listing Statistics & Archival.
 *
 * Zone B (Warm): Tracks per-listing page view counts with a 24-hour TTL.
 *   - Reads from wpdo_warm first; falls back to postmeta if no warm entry.
 *   - Increments on each front-end singular hp_listing page load (non-admin, non-bot).
 *   - Keeps postmeta clean by flushing accumulated counts via cron (wpdo_flush_views).
 *
 * Zone D (Archive): Archives hot-zone fields for expired listings.
 *   - Triggered by the existing wpdo_archive_sweep cron (daily).
 *   - Finds listings where hp_expired_time < now and expired > TMDO_ARCHIVE_DAYS ago.
 *   - Archives hp_price, hp_featured, hp_verified, hp_expired_time with gzip compression.
 */
class TMDO_Listing_Stats {

	/** Meta key used for the warm-zone view counter. */
	const VIEW_KEY = 'wpdo_views';

	/** TTL for warm-zone view entries (24 hours). */
	const VIEW_TTL = DAY_IN_SECONDS;

	/** How many days after expiry before archiving hot fields. */
	const ARCHIVE_DAYS = 30;

	/** Hot-zone meta keys to archive for expired listings. */
	const ARCHIVE_KEYS = array( 'hp_price', 'hp_featured', 'hp_verified', 'hp_expired_time' );

	/**
	 * Register all hooks.
	 */
	public static function register_hooks(): void {
		// Zone B: increment view count on front-end singular listing pages.
		add_action( 'wp', array( __CLASS__, 'maybe_increment_view' ) );

		// Zone B: flush accumulated warm-zone counts to postmeta (hourly).
		add_action( 'wpdo_flush_views', array( __CLASS__, 'flush_views_to_postmeta' ) );

		// Zone D: archive expired listing fields (daily cron via wpdo_archive_sweep).
		add_action( 'wpdo_archive_sweep', array( __CLASS__, 'archive_expired_listings' ), 20 );
	}

	/**
	 * Schedule the flush cron if not already registered.
	 *
	 * Called from TMDO_Core::schedule_cron().
	 */
	public static function schedule_cron(): void {
		if ( ! wp_next_scheduled( 'wpdo_flush_views' ) ) {
			wp_schedule_event( time(), 'hourly', 'wpdo_flush_views' );
		}
	}

	// ── Zone B: View Counter ─────────────────────────────────────────────────

	/**
	 * Increment the warm-zone view counter for the current listing page.
	 *
	 * Only fires on front-end, singular hp_listing pages, for non-bot requests.
	 */
	public static function maybe_increment_view(): void {
		if ( is_admin() || ! is_singular( 'hp_listing' ) ) {
			return;
		}

		// Skip common bots by checking for empty or known bot user-agents.
		$ua = sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ?? '' ) );
		if ( empty( $ua ) || preg_match( '/bot|crawl|slurp|spider|mediapartners/i', $ua ) ) {
			return;
		}

		$post_id = (int) get_the_ID();
		if ( $post_id <= 0 ) {
			return;
		}

		self::increment_view( $post_id );
	}

	/**
	 * Increment the warm-zone view count for a listing.
	 *
	 * @param int $post_id Listing post ID.
	 */
	public static function increment_view( int $post_id ): void {
		$current = (int) TMDO_Zone_Warm::get( $post_id, self::VIEW_KEY );
		TMDO_Zone_Warm::set( $post_id, self::VIEW_KEY, (string) ( $current + 1 ), self::VIEW_TTL );
	}

	/**
	 * Read the view count for a listing.
	 *
	 * Returns warm-zone value if available; falls back to postmeta hp_view_count.
	 *
	 * @param int $post_id Listing post ID.
	 * @return int
	 */
	public static function get_view_count( int $post_id ): int {
		$warm = TMDO_Zone_Warm::get( $post_id, self::VIEW_KEY );
		if ( null !== $warm ) {
			return (int) $warm;
		}
		return (int) get_post_meta( $post_id, 'hp_view_count', true );
	}

	/**
	 * Flush all warm-zone view counts to postmeta and reset warm entries.
	 *
	 * Called hourly by wpdo_flush_views cron.
	 *
	 * @return int Number of listings flushed.
	 */
	public static function flush_views_to_postmeta(): int {
		global $wpdb;

		$table = TMDO_Zone_Warm::table();
		$rows  = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT post_id, meta_value FROM `{$table}` WHERE meta_key = %s", // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				self::VIEW_KEY
			),
			ARRAY_A
		);

		if ( ! $rows ) {
			return 0;
		}

		// Batch-fetch existing hp_view_count for all post IDs in one query.
		$post_ids      = array_map( 'intval', array_column( $rows, 'post_id' ) );
		$placeholders  = implode( ',', array_fill( 0, count( $post_ids ), '%d' ) );
		$existing_rows = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT post_id, meta_value FROM {$wpdb->postmeta} WHERE meta_key = 'hp_view_count' AND post_id IN ({$placeholders})", // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare -- $wpdb->postmeta is core. phpcs:ignore WPDO.AntiEAV.no-direct-postmeta-select -- Listing Stats: Zone B → postmeta view-count sync path.
				...$post_ids
			),
			ARRAY_A
		);
		$existing_map  = array();
		foreach ( $existing_rows as $er ) {
			$existing_map[ (int) $er['post_id'] ] = (int) $er['meta_value'];
		}

		$flushed = 0;
		foreach ( $rows as $row ) {
			$post_id   = (int) $row['post_id'];
			$new_views = (int) $row['meta_value'];

			// Add to existing postmeta total.
			$existing = $existing_map[ $post_id ] ?? 0;
			update_post_meta( $post_id, 'hp_view_count', $existing + $new_views );

			// Remove the warm entry after flush.
			TMDO_Zone_Warm::delete( $post_id, self::VIEW_KEY );
			++$flushed;
		}

		return $flushed;
	}

	// ── Zone D: Expired Listing Archival ─────────────────────────────────────

	/**
	 * Archive hot-zone fields for listings that expired ARCHIVE_DAYS ago.
	 *
	 * Reads hp_expired_time from postmeta (or hot zone via Sync Bridge).
	 * Archives ARCHIVE_KEYS with gzip compression into wpdo_archive.
	 *
	 * @param int $limit Max listings to process per run.
	 * @return int Number of listing fields archived.
	 */
	public static function archive_expired_listings( int $limit = 200 ): int {
		global $wpdb;

		$cutoff = (int) ( time() - self::ARCHIVE_DAYS * DAY_IN_SECONDS );

		// Find published listings with hp_expired_time before cutoff.
		$listings = $wpdb->get_col(
			$wpdb->prepare(
				"SELECT DISTINCT pm.post_id
				 FROM {$wpdb->postmeta} pm
				 INNER JOIN {$wpdb->posts} p ON p.ID = pm.post_id
				 WHERE pm.meta_key = 'hp_expired_time'
				   AND pm.meta_value > '0'
				   AND CAST(pm.meta_value AS UNSIGNED) < %d
				   AND p.post_type = 'hp_listing'
				   AND p.post_status IN ('publish','private')
				 LIMIT %d",
				$cutoff,
				$limit
			)
		);

		if ( ! $listings ) {
			return 0;
		}

		$listing_ids = array_map( 'intval', $listings );
		$id_list     = implode( ',', $listing_ids );
		$key_list    = implode( ',', array_fill( 0, count( self::ARCHIVE_KEYS ), '%s' ) );

		// Batch-fetch all relevant postmeta rows in one query.
		$meta_rows = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT meta_id, post_id, meta_key, meta_value FROM {$wpdb->postmeta} WHERE post_id IN ({$id_list}) AND meta_key IN ({$key_list})", // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare -- $wpdb->postmeta is core. phpcs:ignore WPDO.AntiEAV.no-direct-postmeta-select -- Archive sweep: must read postmeta to migrate to Zone D.
				...self::ARCHIVE_KEYS
			),
			ARRAY_A
		);

		// Build lookup: $meta_map[ post_id ][ meta_key ] = [ meta_id, meta_value ].
		$meta_map = array();
		foreach ( $meta_rows as $mr ) {
			$meta_map[ (int) $mr['post_id'] ][ $mr['meta_key'] ] = array(
				'meta_id'    => (int) $mr['meta_id'],
				'meta_value' => $mr['meta_value'],
			);
		}

		$archived = 0;
		foreach ( $listing_ids as $post_id ) {
			foreach ( self::ARCHIVE_KEYS as $meta_key ) {
				if ( ! isset( $meta_map[ $post_id ][ $meta_key ] ) ) {
					continue;
				}
				$entry      = $meta_map[ $post_id ][ $meta_key ];
				$meta_value = $entry['meta_value'];
				if ( '' === $meta_value || false === $meta_value ) {
					continue;
				}
				TMDO_Zone_Archive::archive(
					$post_id,
					'hp_listing',
					$meta_key,
					(string) $meta_value,
					$entry['meta_id'],
					true // compress.
				);
				++$archived;
			}
		}

		return $archived;
	}

	/**
	 * Get archive statistics for expired listings.
	 *
	 * @return array{total_rows: int, compressed_rows: int, post_types: array}
	 */
	public static function stats(): array {
		return TMDO_Zone_Archive::stats();
	}
}