<?php
/**
 * Supabase vector store (Postgres + pgvector through PostgREST).
 *
 * This is the recommended choice for shared hosting because a single service handles
 * all three jobs: storing vectors, storing conversation logs and running edge functions.
 *
 * Run the sql/supabase-schema.sql file in the Supabase SQL Editor first.
 *
 * @package AI House
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class MYBOT_Vector_Supabase
 */
class MYBOT_Vector_Supabase implements MYBOT_Vector_Store {

	/**
	 * Project URL, for example https://abc.supabase.co
	 *
	 * @var string
	 */
	protected $url;

	/**
	 * API key (service_role, or anon with suitable RLS policies).
	 *
	 * @var string
	 */
	protected $key;

	/**
	 * Table name.
	 *
	 * @var string
	 */
	protected $table = 'mybot_documents';

	/**
	 * Constructor.
	 *
	 * @param string $url Project URL.
	 * @param string $key API key.
	 */
	public function __construct( $url, $key ) {
		$this->url = rtrim( (string) $url, '/' );
		$this->key = (string) $key;

		/**
		 * Change the name of the table that stores vectors.
		 *
		 * @param string $table Table name.
		 */
		$this->table = (string) apply_filters( 'mybot_supabase_table', $this->table );
	}

	/**
	 * Store ID.
	 *
	 * @return string
	 */
	public function get_id() {
		return 'supabase';
	}

	/**
	 * Display name.
	 *
	 * @return string
	 */
	public function get_label() {
		return 'Supabase (pgvector)';
	}

	/**
	 * Whether the store is configured.
	 *
	 * @return bool
	 */
	public function is_configured() {
		return '' !== $this->url && '' !== $this->key;
	}

	/**
	 * Authentication headers.
	 *
	 * @param bool $prefer_merge Whether to send the merge-duplicates header.
	 * @return array
	 */
	protected function headers( $prefer_merge = false ) {
		$headers = array(
			'apikey'        => $this->key,
			'Authorization' => 'Bearer ' . $this->key,
		);

		if ( $prefer_merge ) {
			$headers['Prefer'] = 'resolution=merge-duplicates,return=minimal';
		}

		return $headers;
	}

	/**
	 * Writes vectors.
	 *
	 * @param array $records List of records.
	 * @return true|WP_Error
	 */
	public function upsert( $records ) {
		if ( ! $this->is_configured() ) {
			return new WP_Error( 'mybot_vector_unconfigured', __( 'Supabase is not configured.', 'aihouse' ) );
		}

		if ( empty( $records ) ) {
			return true;
		}

		$rows = array();

		foreach ( $records as $record ) {
			$rows[] = array(
				'id'        => (string) $record['id'],
				'content'   => isset( $record['content'] ) ? (string) $record['content'] : '',
				'metadata'  => isset( $record['metadata'] ) ? $record['metadata'] : array(),
				'embedding' => isset( $record['values'] ) ? $record['values'] : array(),
			);
		}

		$response = MYBOT_HTTP::post_json(
			$this->url . '/rest/v1/' . rawurlencode( $this->table ),
			$rows,
			$this->headers( true ),
			20,
			1
		);

		return is_wp_error( $response ) ? $response : true;
	}

	/**
	 * Queries vectors.
	 *
	 * @param array $vector    Query vector.
	 * @param int   $top_k     Number of results.
	 * @param float $min_score Score threshold.
	 * @return array|WP_Error
	 */
	public function query( $vector, $top_k = 4, $min_score = 0.0 ) {
		if ( ! $this->is_configured() ) {
			return new WP_Error( 'mybot_vector_unconfigured', __( 'Supabase is not configured.', 'aihouse' ) );
		}

		$response = MYBOT_HTTP::post_json(
			$this->url . '/rest/v1/rpc/match_mybot_documents',
			array(
				'query_embedding' => $vector,
				'match_count'     => max( 1, (int) $top_k ),
				'min_score'       => (float) $min_score,
			),
			$this->headers(),
			15
		);

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		// PostgREST returns either a bare array or a payload wrapped in 'data', depending on the configuration.
		$rows = isset( $response['data'] ) && is_array( $response['data'] ) ? $response['data'] : $response;

		$results = array();

		foreach ( (array) $rows as $row ) {
			if ( ! is_array( $row ) ) {
				continue;
			}

			$results[] = array(
				'id'       => isset( $row['id'] ) ? (string) $row['id'] : '',
				'score'    => isset( $row['score'] ) ? (float) $row['score'] : 0.0,
				'content'  => isset( $row['content'] ) ? (string) $row['content'] : '',
				'metadata' => isset( $row['metadata'] ) ? $row['metadata'] : array(),
			);
		}

		return $results;
	}

	/**
	 * Deletes by a list of IDs.
	 *
	 * @param array $ids List of IDs.
	 * @return true|WP_Error
	 */
	public function delete( $ids ) {
		if ( ! $this->is_configured() ) {
			return new WP_Error( 'mybot_vector_unconfigured', __( 'Supabase is not configured.', 'aihouse' ) );
		}

		$ids = array_values( array_filter( array_map( 'strval', (array) $ids ), 'strlen' ) );

		if ( empty( $ids ) ) {
			return true;
		}

		$query = '?id=in.(' . implode( ',', array_map( 'rawurlencode', $ids ) ) . ')';

		$response = wp_remote_request(
			$this->url . '/rest/v1/' . rawurlencode( $this->table ) . $query,
			array(
				'method'  => 'DELETE',
				'timeout' => 15,
				'headers' => $this->headers(),
			)
		);

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$code = (int) wp_remote_retrieve_response_code( $response );

		return ( $code >= 200 && $code < 300 )
			? true
			/* translators: %d: the HTTP status code Supabase returned */
			: new WP_Error( 'mybot_vector_delete', sprintf( __( 'Supabase returned status %d.', 'aihouse' ), $code ) );
	}

	/**
	 * Deletes every vector that belongs to a post.
	 *
	 * @param int $source_id Post ID.
	 * @return true|WP_Error
	 */
	public function delete_by_source( $source_id ) {
		if ( ! $this->is_configured() ) {
			return new WP_Error( 'mybot_vector_unconfigured', __( 'Supabase is not configured.', 'aihouse' ) );
		}

		$query = '?metadata->>source_id=eq.' . rawurlencode( (string) absint( $source_id ) );

		$response = wp_remote_request(
			$this->url . '/rest/v1/' . rawurlencode( $this->table ) . $query,
			array(
				'method'  => 'DELETE',
				'timeout' => 15,
				'headers' => $this->headers(),
			)
		);

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$code = (int) wp_remote_retrieve_response_code( $response );

		return ( $code >= 200 && $code < 300 )
			? true
			/* translators: %d: the HTTP status code Supabase returned */
			: new WP_Error( 'mybot_vector_delete', sprintf( __( 'Supabase returned status %d.', 'aihouse' ), $code ) );
	}
}