<?php
namespace MazlanHalim\IntelliLanz\REST;

use MazlanHalim\IntelliLanz\Graph\GraphBuilder;
use MazlanHalim\IntelliLanz\Graph\ConnectionsResolver;
use MazlanHalim\IntelliLanz\Graph\SemanticGrouper;

final class GraphController {
    private GraphBuilder $builder;
    private ?SemanticGrouper $grouper;
    private ConnectionsResolver $connections;

    public function __construct( GraphBuilder $builder, ?SemanticGrouper $grouper = null, ?ConnectionsResolver $connections = null ) { $this->builder = $builder; $this->grouper = $grouper; $this->connections = $connections ?? new ConnectionsResolver(); }

    public function registerRoutes(): void {
        register_rest_route( 'intellilanz/v1', '/diagnostics', array(
            'methods' => \WP_REST_Server::READABLE,
            'callback' => array( $this, 'getDiagnostics' ),
            'permission_callback' => array( $this, 'permissionsCheck' ),
        ) );
        register_rest_route( 'intellilanz/v1', '/graph', array(
            'methods' => \WP_REST_Server::READABLE,
            'callback' => array( $this, 'getGraph' ),
            'permission_callback' => array( $this, 'permissionsCheck' ),
        ) );
        register_rest_route( 'intellilanz/v1', '/graph/connections', array(
            'methods' => \WP_REST_Server::READABLE,
            'callback' => array( $this, 'getConnections' ),
            'permission_callback' => array( $this, 'permissionsCheck' ),
        ) );
    }

    public function getConnections( $request ) {
        if ( ! $this->permissionsCheck() ) { return new \WP_Error( 'intellilanz_forbidden', __( 'You cannot access these connections.', 'intellilanz' ), array( 'status' => rest_authorization_required_code() ) ); }
        $node_id = is_object( $request ) && is_callable( array( $request, 'get_param' ) ) ? sanitize_text_field( (string) $request->get_param( 'node_id' ) ) : '';
        if ( $node_id === '' ) { return new \WP_Error( 'intellilanz_invalid_component', __( 'The requested component is invalid.', 'intellilanz' ), array( 'status' => 400 ) ); }
        try {
            $data = $this->connections->resolve( $this->builder->build(), $node_id );
            if ( $data === null ) { return new \WP_Error( 'intellilanz_invalid_component', __( 'The requested component is invalid.', 'intellilanz' ), array( 'status' => 400 ) ); }
            $response = new \WP_REST_Response( $data, 200 );
            $response->header( 'Cache-Control', 'no-store, private' );
            return $response;
        } catch ( \Throwable $error ) {
            return new \WP_Error( 'intellilanz_connections_failed', __( 'Component connections could not be loaded.', 'intellilanz' ), array( 'status' => 500 ) );
        }
    }

    public function permissionsCheck(): bool {
        return current_user_can( 'manage_options' );
    }

    public function getGraph( $request = null ) {
        if ( ! $this->permissionsCheck() ) {
            return new \WP_Error( 'intellilanz_forbidden', __( 'You cannot access this graph.', 'intellilanz' ), array( 'status' => rest_authorization_required_code() ) );
        }
        try {
            $refresh = is_object( $request ) && is_callable( array( $request, 'get_param' ) ) && rest_sanitize_boolean( $request->get_param( 'refresh' ) );
            $graph = $this->builder->build( $refresh );
            $display = $this->grouper !== null && is_object( $request ) && is_callable( array( $request, 'get_param' ) ) && rest_sanitize_boolean( $request->get_param( 'display' ) );
            $response = new \WP_REST_Response( ( $display ? $this->grouper->group( $graph ) : $graph )->jsonSerialize(), 200 );
            $response->header( 'Cache-Control', 'no-store, private' );
            $response->header( 'X-IntelliLanz-Cache', $this->builder->getLastBuildInfo()['cache_hit'] ? 'hit' : 'miss' );
            return $response;
        } catch ( \Throwable $error ) {
            // Never send detector exception messages or configuration details to clients.
            return new \WP_Error( 'intellilanz_build_failed', __( 'The system graph could not be built.', 'intellilanz' ), array( 'status' => 500 ) );
        }
    }

    public function getDiagnostics() {
        if ( ! $this->permissionsCheck() ) {
            return new \WP_Error( 'intellilanz_forbidden', __( 'You cannot access these diagnostics.', 'intellilanz' ), array( 'status' => rest_authorization_required_code() ) );
        }
        try {
            $data = $this->builder->build()->jsonSerialize();
            $statuses = array_fill_keys( array( 'healthy', 'info', 'warning', 'critical', 'inactive', 'unknown' ), 0 );
            foreach ( $data['nodes'] as $node ) { ++$statuses[ $node['status'] ]; }
            $evidence = array_fill_keys( array( 'wordpress_core_structure', 'wordpress_requires_plugins', 'woocommerce_requires_header', 'theme_parent_metadata', 'known_ecosystem_mapping', 'integration_detector' ), 0 );
            foreach ( $data['edges'] as $edge ) {
                $kind = $edge['metadata']['evidence'] ?? null;
                if ( is_string( $kind ) && isset( $evidence[ $kind ] ) ) { ++$evidence[ $kind ]; }
            }
            $evidence = array_filter( $evidence );
            $build = $this->builder->getLastBuildInfo();
            $response = new \WP_REST_Response( array(
                'plugin_version' => \MazlanHalim\IntelliLanz\Plugin::VERSION,
                'generated_at' => $build['generated_at'],
                'cache' => array( 'enabled' => $build['cache_enabled'], 'hit' => $build['cache_hit'] ),
                'counts' => array( 'nodes' => count( $data['nodes'] ), 'edges' => count( $data['edges'] ), 'statuses' => $statuses ),
                'relationship_evidence' => $evidence,
            ), 200 );
            $response->header( 'Cache-Control', 'no-store, private' );
            return $response;
        } catch ( \Throwable $error ) {
            return new \WP_Error( 'intellilanz_diagnostics_failed', __( 'Diagnostics could not be generated.', 'intellilanz' ), array( 'status' => 500 ) );
        }
    }
}