<?php
/**
 * Public Agent REST Controller
 *
 * Serves the Public Agent settings page: the global widget values, the fixed
 * widget schema, and one entry per active integration panel.
 *
 * @package Aisentic\PublicAgent
 */

declare(strict_types=1);

namespace Aisentic\PublicAgent;

use Aisentic\Abstract\Base_Rest_Controller;
use Aisentic\Api\Models\Settings;
use WP_REST_Request;

defined( 'ABSPATH' ) || exit;

/**
 * Public agent controller class
 */
class Public_Agent_Controller extends Base_Rest_Controller {

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

	/**
	 * Register routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		register_rest_route(
			$this->namespace,
			'/public-agent',
			[
				[
					'methods'             => \WP_REST_Server::READABLE,
					'callback'            => [ $this, 'get_settings' ],
					'permission_callback' => [ $this, 'permission_check' ],
				],
				[
					'methods'             => \WP_REST_Server::CREATABLE,
					'callback'            => [ $this, 'save_settings' ],
					'permission_callback' => [ $this, 'permission_check' ],
				],
			]
		);
	}

	/**
	 * Only a site administrator may read or change these settings.
	 *
	 * @return bool
	 */
	public function permission_check(): bool {
		return current_user_can( 'manage_options' );
	}

	/**
	 * Return the whole Public Agent payload.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return \WP_HTTP_Response
	 */
	public function get_settings( WP_REST_Request $request ) {
		unset( $request );

		return $this->response( $this->build_payload( new Settings() ) );
	}

	/**
	 * Clean and store the submitted Public Agent settings.
	 *
	 * Only keys declared in a schema are written, so the client cannot push
	 * free-form data into the settings option. A panel missing from the request
	 * keeps whatever it had, which is what lets a deactivated integration hold
	 * its configuration.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return \WP_HTTP_Response
	 */
	public function save_settings( WP_REST_Request $request ) {
		$body = $request->get_json_params();

		if ( ! is_array( $body ) ) {
			$body = [];
		}

		$public_chat = [];

		$widget = $this->clean_widget(
			isset( $body['widget'] ) && is_array( $body['widget'] ) ? $body['widget'] : []
		);

		if ( $widget ) {
			$public_chat['widget'] = $widget;
		}

		$integrations = $this->clean_integrations(
			isset( $body['integrations'] ) && is_array( $body['integrations'] ) ? $body['integrations'] : []
		);

		if ( $integrations ) {
			$public_chat['integrations'] = $integrations;
		}

		if ( $public_chat ) {
			( new Settings() )->merge_and_save( [ 'publicChat' => $public_chat ] );
		}

		return $this->response(
			$this->build_payload( new Settings() ),
			__( 'Public agent settings saved', 'aisentic' )
		);
	}

	/**
	 * Clean the global widget half of the request body.
	 *
	 * @param array $input Raw widget values.
	 * @return array
	 */
	private function clean_widget( array $input ): array {
		$clean = [];

		foreach ( Panel_Registry::get_widget_schema() as $key => $field ) {
			if ( ! array_key_exists( $key, $input ) ) {
				continue;
			}

			$value = Field_Sanitizer::sanitize( $field, $input[ $key ] );

			if ( null !== $value ) {
				$clean[ $key ] = $value;
			}
		}

		return $clean;
	}

	/**
	 * Clean the per-integration half of the request body.
	 *
	 * @param array $input Raw values, keyed by panel id.
	 * @return array
	 */
	private function clean_integrations( array $input ): array {
		$clean = [];

		foreach ( $input as $id => $values ) {
			$id    = (string) $id;
			$panel = Panel_Registry::get_panel( $id );

			if ( null === $panel || ! is_array( $values ) ) {
				continue;
			}

			$panel_clean = [];

			foreach ( $panel['fields'] as $key => $field ) {
				if ( ! array_key_exists( $key, $values ) ) {
					continue;
				}

				$value = Field_Sanitizer::sanitize( $field, $values[ $key ] );

				if ( null !== $value ) {
					$panel_clean[ $key ] = $value;
				}
			}

			if ( $panel_clean ) {
				$clean[ $id ] = $panel_clean;
			}
		}

		return $clean;
	}

	/**
	 * Build the payload the admin page renders from.
	 *
	 * @param Settings $settings Settings instance.
	 * @return array
	 */
	private function build_payload( Settings $settings ): array {
		$agent         = new Public_Agent_Settings( $settings );
		$widget_schema = Panel_Registry::get_widget_schema();
		$widget        = [];

		foreach ( array_keys( $widget_schema ) as $key ) {
			$widget[ $key ] = $agent->widget( (string) $key );
		}

		$panels = [];

		foreach ( Panel_Registry::get_active_panels() as $id => $panel ) {
			$values = [];

			foreach ( array_keys( $panel['fields'] ) as $key ) {
				$values[ $key ] = $agent->integration( (string) $id, (string) $key );
			}

			$panels[] = [
				'id'     => $panel['id'],
				'label'  => $panel['label'],
				'icon'   => $panel['icon'],
				'slot'   => $panel['slot'],
				'docs'   => $panel['docs'],
				'fields' => self::json_safe_fields( $panel['fields'] ),
				'values' => $values,
			];
		}

		return [
			'widget'       => $widget,
			'widgetSchema' => self::json_safe_fields( $widget_schema ),
			'panels'       => $panels,
		];
	}

	/**
	 * Drop anything in a field that cannot survive json_encode.
	 *
	 * A panel author may put a closure or an object in a field by mistake; the
	 * admin page only needs plain data.
	 *
	 * @param array $fields Normalized fields.
	 * @return array
	 */
	private static function json_safe_fields( array $fields ): array {
		foreach ( $fields as $key => $field ) {
			if ( ! is_array( $field ) ) {
				unset( $fields[ $key ] );
				continue;
			}

			foreach ( $field as $field_key => $field_value ) {
				if ( is_object( $field_value ) || is_resource( $field_value ) ) {
					unset( $fields[ $key ][ $field_key ] );
				}
			}
		}

		return $fields;
	}
}