<?php
/**
 * REST API controller for AI request logs.
 *
 * @package WordPress\AI\Logging
 */

declare( strict_types=1 );

namespace WordPress\AI\Logging\REST;

use WP_Error;
use WP_REST_Controller;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;
use WordPress\AI\Logging\AI_Request_Log_Manager;

defined( 'ABSPATH' ) || exit;

/**
 * Provides `/ai/v1/logs` routes for the AI Request Logs admin UI.
 *
 * @since 1.0.0
 */
class AI_Request_Log_Controller extends WP_REST_Controller {

	/**
	 * Log manager instance.
	 */
	private AI_Request_Log_Manager $manager;

	/**
	 * Constructor.
	 *
	 * @param \WordPress\AI\Logging\AI_Request_Log_Manager $manager Log manager.
	 */
	public function __construct( AI_Request_Log_Manager $manager ) {
		$this->namespace = 'ai/v1';
		$this->rest_base = 'logs';
		$this->manager   = $manager;
	}

	/**
	 * Registers REST routes.
	 */
	public function register_routes(): void {
		// GET /ai/v1/logs - List logs with filtering.
		// DELETE /ai/v1/logs - Purge all logs.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base,
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_logs' ),
					'permission_callback' => array( $this, 'permissions_check' ),
					'args'                => $this->get_collection_params(),
				),
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'purge_logs' ),
					'permission_callback' => array( $this, 'permissions_check' ),
				),
			)
		);

		// GET /ai/v1/logs/summary - Get aggregate statistics.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/summary',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_summary' ),
					'permission_callback' => array( $this, 'permissions_check' ),
					'args'                => array(
						'period' => array(
							'type'    => 'string',
							'enum'    => array( 'minute', 'hour', 'day', 'week', 'month', 'all' ),
							'default' => 'day',
						),
					),
				),
			)
		);

		// GET /ai/v1/logs/filters - Get filter options.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/filters',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_filters' ),
					'permission_callback' => array( $this, 'permissions_check' ),
				),
			)
		);

		// GET /ai/v1/logs/{id} - Get single log entry.
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/(?P<id>[a-f0-9\-]+)',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_log' ),
					'permission_callback' => array( $this, 'permissions_check' ),
					'args'                => array(
						'id' => array(
							'type'              => 'string',
							'required'          => true,
							'validate_callback' => static function ( $value ): bool {
								return wp_is_uuid( $value );
							},
						),
					),
				),
			)
		);
	}

	/**
	 * Permission check - restricted to administrators.
	 */
	public function permissions_check(): bool {
		return current_user_can( 'manage_options' );
	}

	/**
	 * Retrieves logs with filtering and pagination.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function get_logs( WP_REST_Request $request ): WP_REST_Response {
		$args = array(
			'type'             => $request->get_param( 'type' ) ?? '',
			'status'           => $request->get_param( 'status' ) ?? '',
			'provider'         => $request->get_param( 'provider' ) ?? '',
			'operation'        => $request->get_param( 'operation' ) ?? '',
			'tokens_filter'    => $request->get_param( 'tokens_filter' ) ?? '',
			'user_id'          => $request->get_param( 'user_id' ) ?? 0,
			'date_from'        => $request->get_param( 'date_from' ) ?? '',
			'date_to'          => $request->get_param( 'date_to' ) ?? '',
			'search'           => $request->get_param( 'search' ) ?? '',
			'page'             => $request->get_param( 'page' ) ?? 1,
			'per_page'         => $request->get_param( 'per_page' ) ?? 25,
			'orderby'          => $request->get_param( 'orderby' ) ?? 'timestamp',
			'order'            => $request->get_param( 'order' ) ?? 'DESC',
			'cursor_id'        => $request->get_param( 'cursor_id' ),
			'cursor_timestamp' => $request->get_param( 'cursor_timestamp' ),
		);

		$result = $this->manager->get_logs( $args );

		$response = rest_ensure_response( $result['items'] );
		$response->header( 'X-WP-Total', (string) $result['total'] );
		$response->header( 'X-WP-TotalPages', (string) $result['pages'] );

		// Include cursor info for cursor-based pagination.
		if ( isset( $result['next_cursor'] ) ) {
			$response->header( 'X-WP-NextCursorId', (string) $result['next_cursor']['id'] );
			$response->header( 'X-WP-NextCursorTimestamp', $result['next_cursor']['timestamp'] );
		}

		return $response;
	}

	/**
	 * Retrieves a single log entry.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response|\WP_Error
	 */
	public function get_log( WP_REST_Request $request ) {
		$log_id = $request->get_param( 'id' );
		$log    = $this->manager->get_log( $log_id );

		if ( ! $log ) {
			return new WP_Error(
				'wpai_log_not_found',
				__( 'Log entry not found.', 'ai' ),
				array( 'status' => 404 )
			);
		}

		return rest_ensure_response( $log );
	}

	/**
	 * Retrieves aggregate statistics.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function get_summary( WP_REST_Request $request ): WP_REST_Response {
		$period  = $request->get_param( 'period' ) ?? 'day';
		$summary = $this->manager->get_summary( $period );

		return rest_ensure_response( $summary );
	}

	/**
	 * Retrieves filter options.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function get_filters( WP_REST_Request $request ): WP_REST_Response {
		$filters = $this->manager->get_filter_options();

		return rest_ensure_response( $filters );
	}

	/**
	 * Purges all logs.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function purge_logs( WP_REST_Request $request ): WP_REST_Response {
		$deleted = $this->manager->purge_all_logs();

		return rest_ensure_response(
			array(
				'success' => true,
				'deleted' => $deleted,
				'message' => sprintf(
					/* translators: %d: Number of deleted logs. */
					__( 'Successfully purged %d log entries.', 'ai' ),
					$deleted
				),
			)
		);
	}

	/**
	 * Gets collection parameters for logs list endpoint.
	 *
	 * @return array<string, array<string, mixed>> Parameter definitions.
	 */
	public function get_collection_params(): array {
		return array(
			'type'             => array(
				'description' => __( 'Filter by log type.', 'ai' ),
				'type'        => 'string',
				'enum'        => array( '', 'ai_client', 'mcp_tool', 'ability' ),
				'default'     => '',
			),
			'status'           => array(
				'description' => __( 'Filter by status.', 'ai' ),
				'type'        => 'string',
				'enum'        => array( '', 'success', 'error', 'timeout' ),
				'default'     => '',
			),
			'provider'         => array(
				'description' => __( 'Filter by AI provider.', 'ai' ),
				'type'        => 'string',
				'default'     => '',
			),
			'user_id'          => array(
				'description' => __( 'Filter by user ID.', 'ai' ),
				'type'        => 'integer',
				'default'     => 0,
			),
			'date_from'        => array(
				'description' => __( 'Filter logs from this date (YYYY-MM-DD HH:MM:SS).', 'ai' ),
				'type'        => 'string',
				'format'      => 'date-time',
			),
			'date_to'          => array(
				'description' => __( 'Filter logs until this date (YYYY-MM-DD HH:MM:SS).', 'ai' ),
				'type'        => 'string',
				'format'      => 'date-time',
			),
			'search'           => array(
				'description' => __( 'Search in operations, request previews, response previews, and error messages.', 'ai' ),
				'type'        => 'string',
				'default'     => '',
			),
			'tokens_filter'    => array(
				'description' => __( 'Filter by tokens: "gt:N", "lt:N", or "none".', 'ai' ),
				'type'        => 'string',
				'default'     => '',
			),
			'page'             => array(
				'description' => __( 'Current page of the collection.', 'ai' ),
				'type'        => 'integer',
				'default'     => 1,
				'minimum'     => 1,
			),
			'per_page'         => array(
				'description' => __( 'Maximum number of items per page.', 'ai' ),
				'type'        => 'integer',
				'default'     => 25,
				'minimum'     => 1,
				'maximum'     => 100,
			),
			'orderby'          => array(
				'description' => __( 'Sort collection by attribute.', 'ai' ),
				'type'        => 'string',
				'enum'        => array( 'timestamp', 'type', 'operation', 'duration_ms', 'tokens_total', 'status' ),
				'default'     => 'timestamp',
			),
			'order'            => array(
				'description' => __( 'Order sort attribute ascending or descending.', 'ai' ),
				'type'        => 'string',
				'enum'        => array( 'ASC', 'DESC' ),
				'default'     => 'DESC',
			),
			'cursor_id'        => array(
				'description' => __( 'Cursor ID for cursor-based pagination (use with cursor_timestamp).', 'ai' ),
				'type'        => 'integer',
				'minimum'     => 1,
			),
			'cursor_timestamp' => array(
				'description' => __( 'Cursor timestamp for cursor-based pagination (use with cursor_id).', 'ai' ),
				'type'        => 'string',
				'format'      => 'date-time',
			),
		);
	}
}