<?php
/**
 * Creates the vector store selected in the settings.
 *
 * @package AI House
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class MYBOT_Vector_Factory
 */
class MYBOT_Vector_Factory {

	/**
	 * List of supported stores.
	 *
	 * @return array
	 */
	public static function options() {
		return array(
			'none'     => __( 'None (quick chat only)', 'aihouse' ),
			'supabase' => 'Supabase (pgvector)',
			'pinecone' => 'Pinecone',
			'qdrant'   => 'Qdrant',
		);
	}

	/**
	 * Creates the vector store from the settings.
	 *
	 * @param MYBOT_Settings $settings Settings.
	 * @return MYBOT_Vector_Store|WP_Error
	 */
	public static function make( $settings ) {
		$store = sanitize_key( (string) $settings->get( 'vector_store', 'none' ) );

		if ( 'none' === $store ) {
			return new WP_Error( 'mybot_vector_disabled', __( 'The vector store is not enabled.', 'aihouse' ) );
		}

		$url       = (string) $settings->get( 'vector_url', '' );
		$key       = $settings->secret( 'vector_key' );
		$namespace = (string) $settings->get( 'vector_namespace', 'mybot' );

		switch ( $store ) {
			case 'supabase':
				return new MYBOT_Vector_Supabase( $url, $key );

			case 'pinecone':
				return new MYBOT_Vector_Pinecone( $url, $key, $namespace );

			case 'qdrant':
				return new MYBOT_Vector_Qdrant( $url, $key, $namespace );
		}

		return new WP_Error(
			'mybot_unknown_vector_store',
			/* translators: %s: vector store slug */
			sprintf( __( 'Unsupported vector store: %s', 'aihouse' ), $store )
		);
	}

	/**
	 * Checks the connection, used by the "Test" button in the admin.
	 *
	 * @param MYBOT_Settings $settings Settings.
	 * @return true|WP_Error
	 */
	public static function test_connection( $settings ) {
		$store = self::make( $settings );

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

		if ( ! $store->is_configured() ) {
			return new WP_Error( 'mybot_vector_unconfigured', __( 'The vector store URL or API key is missing.', 'aihouse' ) );
		}

		$embedder = MYBOT_LLM_Factory::embedding_provider( $settings );

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

		$vectors = $embedder->embed( array( 'connection test' ), $settings->embedding_model() );

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

		// One text was sent, so the first vector is the answer whichever key it came back under.
		$vector = is_array( $vectors ) ? reset( $vectors ) : null;

		if ( empty( $vector ) || ! is_array( $vector ) ) {
			return new WP_Error( 'mybot_embedding_empty', __( 'Could not generate a test vector.', 'aihouse' ) );
		}

		$result = $store->query( $vector, 1, 0.0 );

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

		/*
		 * A search alone cannot prove the key may write. With Supabase, row level security is
		 * on and no policy exists, so an "anon" key gets an empty list and HTTP 200 from the
		 * search function — while every real write during indexing fails with "new row
		 * violates row-level security policy". Writing one probe row and deleting it is what
		 * tells the two keys apart, and it fails here instead of after a wasted indexing run.
		 */
		$probe_id = '__mybot_connection_probe__';

		$probe = $store->upsert(
			array(
				array(
					'id'       => $probe_id,
					'content'  => 'mybot connection test',
					'metadata' => array( 'probe' => 1 ),
					'values'   => $vector,
				),
			)
		);

		if ( is_wp_error( $probe ) ) {
			return new WP_Error(
				'mybot_vector_write_denied',
				sprintf(
					/* translators: %s: error message returned by the vector store */
					__( 'The vector store accepted a search but refused a test write, so indexing will fail: %s — with Supabase this usually means the key is the public "anon" key; use the "service_role" key instead.', 'aihouse' ),
					$probe->get_error_message()
				)
			);
		}

		// Best effort: a probe row left behind is harmless, but it should not linger.
		$store->delete( array( $probe_id ) );

		return true;
	}
}