<?php
/**
 * WP_Query interceptor for hp_listing meta queries.
 *
 * @package WP_Data_Optimizer
 */

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

/**
 * WP_Query interceptor for hp_listing meta queries.
 *
 * The hpct_listing_meta is a key-value table (like wp_postmeta), so each
 * meta_query condition needs its own JOIN alias with a meta_key condition:
 *
 *   LEFT JOIN wp_hpct_listing_meta AS wpdo_lm_0
 *     ON (wp_posts.ID = wpdo_lm_0.listing_id AND wpdo_lm_0.meta_key = 'hp_price')
 *   WHERE wpdo_lm_0.meta_value >= 100
 *
 * All hp_* and _hp_* meta keys are intercepted. Any other meta keys are
 * left in the meta_query to be handled by wp_postmeta as usual.
 */
class TMDO_Listing_Meta_Query extends TMDO_Query_Interceptor_Base {

	/**
	 * Returns the module identifier.
	 *
	 * @return string Module name.
	 */
	protected function get_module(): string {
		return 'listing_meta';
	}

	/**
	 * Returns the post types this interceptor handles.
	 *
	 * @return string[] Post type slugs.
	 */
	protected function get_post_types(): array {
		return array( 'hp_listing' );
	}

	/**
	 * Returns the custom table name.
	 *
	 * @return string Table name without prefix.
	 */
	protected function get_table(): string {
		return 'hpct_listing_meta';
	}

	/**
	 * Returns the join column for this KV table.
	 *
	 * @return string Join column name.
	 */
	protected function get_join_column(): string {
		return 'listing_id';
	}

	/**
	 * Not used — this class overrides pre_get_posts directly.
	 *
	 * @return array Empty array.
	 */
	protected function get_meta_key_map(): array {
		return array();
	}

	// ── Override pre_get_posts for KV-table pattern ───────────────────────

	/**
	 * Intercepts pre_get_posts to handle KV-table meta_query conditions.
	 *
	 * @param \WP_Query $query The WP_Query object.
	 * @return void
	 */
	public function pre_get_posts( \WP_Query $query ): void {
		if ( ! $this->should_intercept( $query ) ) {
			return;
		}

		$raw_meta_query = (array) $query->get( 'meta_query' );
		if ( empty( $raw_meta_query ) ) {
			return;
		}

		$our_clauses = array();
		$remaining   = array();

		foreach ( $raw_meta_query as $k => $clause ) {
			if ( 'relation' === $k || ! is_array( $clause ) || ! isset( $clause['key'] ) ) {
				$remaining[ $k ] = $clause;
				continue;
			}

			if ( $this->is_hp_key( $clause['key'] ) ) {
				$our_clauses[] = array(
					'meta_key' => $clause['key'],
					'value'    => $clause['value'] ?? '',
					'compare'  => strtoupper( trim( $clause['compare'] ?? '=' ) ),
					'type'     => strtoupper( trim( $clause['type'] ?? 'CHAR' ) ),
				);
			} else {
				$remaining[ $k ] = $clause;
			}
		}

		if ( empty( $our_clauses ) ) {
			return;
		}

		if ( isset( $raw_meta_query['relation'] ) && ! isset( $remaining['relation'] ) ) {
			$remaining['relation'] = $raw_meta_query['relation'];
		}

		$query->set( 'meta_query', $remaining );
		$query->set( $this->query_var(), $our_clauses );
	}

	// ── Override posts_join for KV-table: one JOIN alias per condition ─────

	/**
	 * Appends LEFT JOINs for each KV-table meta_query condition.
	 *
	 * @param string    $join  Current JOIN SQL.
	 * @param \WP_Query $query The WP_Query object.
	 * @return string Modified JOIN SQL.
	 */
	public function posts_join( ?string $join, \WP_Query $query ): string {
		$join    = (string) ( $join ?? '' );
		$clauses = $this->get_clauses( $query );
		if ( empty( $clauses ) ) {
			return $join;
		}

		global $wpdb;
		$table    = TMDO_DB::table( $this->get_table() );
		$join_col = esc_sql( $this->get_join_column() );

		foreach ( $clauses as $i => $clause ) {
			$alias    = $this->alias_for( $i );
			$meta_key = $clause['meta_key'];

			if ( false === strpos( $join, "`{$alias}`" ) ) {
				// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $table from TMDO_DB::table(); $alias and $join_col are sanitize_key()-validated.
				$join .= $wpdb->prepare(
					" LEFT JOIN `{$table}` AS `{$alias}`"
					. " ON (`{$wpdb->posts}`.`ID` = `{$alias}`.`{$join_col}`"
					. " AND `{$alias}`.`meta_key` = %s)",
					$meta_key
				);
				// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
			}
		}

		return $join;
	}

	// ── Override posts_where for KV-table ─────────────────────────────────

	/**
	 * Appends WHERE conditions for KV-table meta_value comparisons.
	 *
	 * @param string    $where Current WHERE SQL.
	 * @param \WP_Query $query The WP_Query object.
	 * @return string Modified WHERE SQL.
	 */
	public function posts_where( ?string $where, \WP_Query $query ): string {
		$where   = (string) ( $where ?? '' );
		$clauses = $this->get_clauses( $query );
		if ( empty( $clauses ) ) {
			return $where;
		}

		foreach ( $clauses as $i => $clause ) {
			$alias   = $this->alias_for( $i );
			$col     = "`{$alias}`.`meta_value`";
			$compare = $this->sanitize_compare( $clause['compare'] );
			$type    = $clause['type'];
			$value   = $clause['value'];

			$where .= $this->build_condition( $col, $compare, $type, $value );
		}

		return $where;
	}

	// ── Override posts_groupby ─────────────────────────────────────────────

	/**
	 * Ensures GROUP BY is set when KV-table clauses are active.
	 *
	 * @param string    $groupby Current GROUP BY SQL.
	 * @param \WP_Query $query   The WP_Query object.
	 * @return string Modified GROUP BY SQL.
	 */
	public function posts_groupby( ?string $groupby, \WP_Query $query ): string {
		$groupby = (string) ( $groupby ?? '' );
		$clauses = $this->get_clauses( $query );
		if ( empty( $clauses ) ) {
			return $groupby;
		}

		global $wpdb;
		if ( '' === trim( $groupby ) ) {
			$groupby = "`{$wpdb->posts}`.`ID`";
		}

		return $groupby;
	}

	// ── Helpers ───────────────────────────────────────────────────────────

	/**
	 * Generates a unique SQL alias for a KV-table JOIN at a given index.
	 *
	 * @param int $index Zero-based clause index.
	 * @return string SQL alias string.
	 */
	private function alias_for( int $index ): string {
		return "wpdo_lm_{$index}";
	}

	/**
	 * Checks whether a meta key belongs to HivePress (hp_ or _hp_ prefix).
	 *
	 * @param string $meta_key Meta key to check.
	 * @return bool True if the key is an HP key.
	 */
	private function is_hp_key( string $meta_key ): bool {
		return str_starts_with( $meta_key, 'hp_' ) || str_starts_with( $meta_key, '_hp_' );
	}
}