<?php
/**
 * Eventin AI REST controller.
 *
 * @package Aisentic\Integrations\Eventin_Ai
 */

namespace Aisentic\Integrations\Eventin_Ai;

defined( 'ABSPATH' ) || exit;

use Aisentic\Abstract\Base_Rest_Controller;
use Aisentic\Agent\Providers\Llm_Provider_Factory;
use Aisentic\Api\Models\Settings;
use Aisentic\Public\Policy;
use Aisentic\Util\Ai_Error_Message;
use Aisentic\Util\Log;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

/**
 * Routes used by the Eventin AI windows:
 *
 *   POST aisentic/v1/eventin-ai/generate    { type, prompt } -> { status, data }
 *   GET  aisentic/v1/eventin-ai/connection                   -> { is_connected, token_form_url }
 *
 * Banner images (type "image") are out of scope for now: one AI image costs
 * hundreds of credits. The old Eventin AI plugin made them with DALL-E.
 *
 * The answers have the same shape as the old eventin-ai/v1 routes, so the copied React code works unchanged.
 */
class Eventin_Ai_Controller extends Base_Rest_Controller {

	/**
	 * Namespace.
	 *
	 * @var string
	 */
	protected $namespace = 'aisentic/v1';

	/**
	 * Base.
	 *
	 * @var string
	 */
	protected $rest_base = 'eventin-ai';

	/**
	 * Makes the text generator.
	 *
	 * @var callable
	 */
	private $text_factory;

	/**
	 * Constructor. The factories are for tests; production uses the defaults.
	 *
	 * @param callable|null $text_factory Returns an Eventin_Ai_Text_Generator.
	 */
	public function __construct( ?callable $text_factory = null ) {
		$this->text_factory = $text_factory ?? static fn() => Eventin_Ai_Text_Generator::from_settings( new Settings() );
	}

	/**
	 * Register routes. Only when Eventin is active.
	 *
	 * @return void
	 */
	public function register_routes() {
		if ( ! class_exists( 'Wpeventin' ) ) {
			return;
		}

		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/generate',
			[
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => [ $this, 'generate' ],
				'permission_callback' => [ $this, 'can_manage_events' ],
			]
		);

		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/connection',
			[
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => [ $this, 'connection' ],
				'permission_callback' => [ $this, 'can_manage_options' ],
			]
		);
	}

	/**
	 * Same rule as the old plugin.
	 *
	 * @return bool
	 */
	public function can_manage_events(): bool {
		return current_user_can( 'etn_manage_event' );
	}

	/**
	 * Same rule as the old plugin.
	 *
	 * @return bool
	 */
	public function can_manage_options(): bool {
		return current_user_can( 'manage_options' );
	}

	/**
	 * Make event text.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function generate( WP_REST_Request $request ) {
		$input  = json_decode( $request->get_body(), true );
		$input  = is_array( $input ) ? $input : [];
		$type   = sanitize_text_field( (string) ( $input['type'] ?? '' ) );
		$prompt = sanitize_textarea_field( (string) ( $input['prompt'] ?? '' ) );

		if ( '' === $type ) {
			return $this->invalid( __( 'Please provide prompt type.', 'aisentic' ) );
		}

		if ( '' === $prompt ) {
			return $this->invalid( __( 'Please provide prompt.', 'aisentic' ) );
		}

		if ( 'image' === $type ) {
			return $this->invalid( __( 'Banner images with AI are not available yet.', 'aisentic' ) );
		}

		if ( ! in_array( $type, Eventin_Ai_Text_Generator::TYPES, true ) ) {
			return $this->invalid( __( 'Unknown prompt type.', 'aisentic' ) );
		}

		$policy     = new Policy();
		$rate_limit = (int) ( new Settings() )->get( 'general.rateLimitPerMinute', 20 );

		if ( $policy->isRateLimited( 'eventin_ai_' . $policy->getRequestIdentifier(), $rate_limit ) ) {
			return new WP_Error( 'aisentic_rate_limited', __( 'Too many requests. Please wait a minute and try again.', 'aisentic' ), [ 'status' => 429 ] );
		}

		try {
			$data = ( $this->text_factory )()->generate( $type, $prompt );

			return new WP_REST_Response(
				[
					'status' => 'success',
					'data'   => $data,
				],
				200
			);
		} catch ( Eventin_Ai_Exception $e ) {
			return new WP_Error( 'aisentic_eventin_ai_failed', $e->getMessage(), [ 'status' => 502 ] );
		} catch ( \Throwable $e ) {
			Log::error(
                'Eventin AI generation failed',
                [
					'type'    => $type,
					'message' => $e->getMessage(),
				]
            );

			return new WP_Error(
				'aisentic_eventin_ai_failed',
				Ai_Error_Message::from_throwable( $e, __( 'The AI request failed. Please try again.', 'aisentic' ) ),
				[ 'status' => 502 ]
			);
		}
	}

	/**
	 * Is the selected provider ready?
	 *
	 * @return WP_REST_Response
	 */
	public function connection(): WP_REST_Response {
		return new WP_REST_Response(
			[
				'is_connected'   => Llm_Provider_Factory::has_credentials( new Settings() ),
				'token_form_url' => admin_url( 'admin.php?page=aisentic#/settings/ai-configuration' ),
			],
			200
		);
	}

	/**
	 * 422 error.
	 *
	 * @param string $message Message.
	 * @return WP_Error
	 */
	private function invalid( string $message ): WP_Error {
		return new WP_Error( 'aisentic_eventin_ai_invalid', $message, [ 'status' => 422 ] );
	}
}