<?php
/**
 * Generates /.well-known/agent-card.json AND /.well-known/agent.json (A2A Protocol v0.3).
 *
 * A2A v0.3 spec uses /.well-known/agent.json as the canonical path.
 * We generate both for backward compatibility.
 *
 * @see https://github.com/a2aproject/A2A
 * @since 2.0.0 (agent-card.json)
 * @since 3.0.0 (agent.json alias, security extensions)
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class AIREWP_Agent_Card {

    public function __construct() {
        // Generation triggered by main plugin
    }

    /**
     * Generate agent-card.json (legacy) + agent.json (A2A v0.3 canonical path).
     */
    public static function generate( array $settings ): void {
        $dir  = AI_Ready_WP::get_well_known_dir();
        $json = wp_json_encode( self::build( $settings ), JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );

        // Write both: agent.json (A2A v0.3 spec) and agent-card.json (backward compat)
        AI_Ready_WP::write_file( $dir . 'agent-card.json', $json );
        AI_Ready_WP::write_file( $dir . 'agent.json', $json );
    }

    /**
     * Serve the agent card straight from memory, without touching the filesystem.
     *
     * Same reasoning as AIREWP_Agents_JSON::serve(): a site that cannot write
     * into .well-known/ still has every value needed to answer the request.
     */
    public static function serve(): void {
        AIREWP_Rewrite::send_json( self::build( AI_Ready_WP::get_settings() ) );
    }

    /**
     * Build the agent card data structure.
     *
     * Shared by the written files and the dynamic response so the three cannot
     * drift apart, filters included.
     */
    public static function build( array $settings ): array {
        $skills = self::build_skills( $settings );

        $agent_card = [
            'name'                  => $settings['company_name'] . ' AI Assistant',
            'description'           => sprintf(
                'AI assistant for %s. %s',
                $settings['company_name'],
                $settings['company_desc']
            ),
            'url'                   => home_url(),
            'version'               => AIREWP_VERSION,
            'protocol_version'      => '0.3.0',
            'capabilities'          => [
                'streaming'         => false,
                'pushNotifications' => false,
                'stateTransitionHistory' => false,
            ],
            'defaultInputModes'     => [ 'text/plain' ],
            'defaultOutputModes'    => [ 'text/plain', 'application/json' ],
            'skills'                => $skills,
            'provider'              => [
                'organization'   => $settings['company_name'],
                'url'            => home_url(),
            ],
            'security'              => [
                'authentication' => 'none',
                'cors'           => true,
            ],
            'extensions'            => self::build_extensions( $settings ),
            'metadata'              => [
                'generated_by'   => 'AI-Ready WP ' . AIREWP_VERSION,
                'generated_at'   => gmdate( 'c' ),
            ],
        ];

        return apply_filters( 'airewp_agent_card', $agent_card, $settings );
    }

    /**
     * Build extensions block with discovery links.
     */
    private static function build_extensions( array $settings ): array {
        // No builtBy/promo block: the agent card is the site owner's public
        // document — tool credits in it read as self-promotion.
        $ext = [];

        // llms.txt reference. On a site where WP_Filesystem cannot connect the
        // global stays null, and calling ->exists() on it was a fatal error.
        $fs = AI_Ready_WP::filesystem();
        if ( null !== $fs && ! empty( $settings['enable_llms_txt'] ) && $fs->exists( AIREWP_ROOT_PATH . 'llms.txt' ) ) {
            $ext['llmsTxt'] = home_url( '/llms.txt' );
        }

        // Industry metadata
        if ( ! empty( $settings['industry'] ) && 'general' !== $settings['industry'] ) {
            $ext['industry'] = $settings['industry'];
        }

        // WordPress platform
        $ext['platform'] = [
            'name'    => 'WordPress',
            'version' => get_bloginfo( 'version' ),
        ];

        return $ext;
    }

    /**
     * Build skills array based on site capabilities.
     */
    private static function build_skills( array $settings ): array {
        $name   = $settings['company_name'];
        $skills = [];

        // Core skills always present
        $skills[] = [
            'id'          => 'business-info',
            'name'        => 'Business Information',
            'description' => "Provide information about {$name} — who we are, what we do, and how to reach us.",
            'tags'        => [ 'info', 'contact', 'about' ],
            'examples'    => [
                "What does {$name} do?",
                "How can I contact {$name}?",
                "What services does {$name} offer?",
            ],
        ];

        $skills[] = [
            'id'          => 'content-search',
            'name'        => 'Content Search',
            'description' => "Search and retrieve content from the {$name} website.",
            'tags'        => [ 'search', 'content', 'pages' ],
            'examples'    => [
                'Find articles about web design',
                'What pages are available?',
            ],
        ];

        // Services skill
        if ( ! empty( $settings['services'] ) ) {
            $services_list = implode( ', ', array_map( 'trim', explode( ',', $settings['services'] ) ) );
            $skills[]      = [
                'id'          => 'service-info',
                'name'        => 'Service Information',
                'description' => "Provide details about services offered by {$name}: {$services_list}.",
                'tags'        => [ 'services', 'pricing', 'offerings' ],
                'examples'    => [
                    "What services does {$name} offer?",
                    'Tell me about your pricing',
                    'Do you offer consulting?',
                ],
            ];
        }

        // Contact skill
        $skills[] = [
            'id'          => 'contact',
            'name'        => 'Contact & Inquiries',
            'description' => "Handle contact requests and inquiries for {$name}.",
            'tags'        => [ 'contact', 'inquiry', 'support' ],
            'examples'    => [
                'I want to get in touch',
                'How do I request a quote?',
                'Schedule a consultation',
            ],
        ];

        // WooCommerce skills
        if ( class_exists( 'WooCommerce' ) ) {
            $skills[] = [
                'id'          => 'product-catalog',
                'name'        => 'Product Catalog',
                'description' => "Browse and search products available at {$name}.",
                'tags'        => [ 'products', 'shop', 'catalog', 'ecommerce' ],
                'examples'    => [
                    'Show me your products',
                    'What items do you sell?',
                    'Search for a specific product',
                ],
            ];
        }

        // Industry-specific skills
        $industry_skills = self::get_industry_skills( $settings['industry'], $name );
        $skills          = array_merge( $skills, $industry_skills );

        return $skills;
    }

    /**
     * Get industry-specific skills.
     */
    private static function get_industry_skills( string $industry, string $name ): array {
        $skills = [];

        switch ( $industry ) {
            case 'restaurant':
                $skills[] = [
                    'id'          => 'menu',
                    'name'        => 'Menu & Reservations',
                    'description' => "View the menu and make reservations at {$name}.",
                    'tags'        => [ 'menu', 'reservation', 'food', 'dining' ],
                    'examples'    => [ 'Show me the menu', 'Make a reservation' ],
                ];
                break;

            case 'real-estate':
                $skills[] = [
                    'id'          => 'properties',
                    'name'        => 'Property Listings',
                    'description' => "Browse property listings from {$name}.",
                    'tags'        => [ 'properties', 'listings', 'real-estate' ],
                    'examples'    => [ 'Show available properties', 'Search for apartments' ],
                ];
                break;

            case 'hotel':
                $skills[] = [
                    'id'          => 'rooms',
                    'name'        => 'Room Availability',
                    'description' => "Check room availability and rates at {$name}.",
                    'tags'        => [ 'rooms', 'booking', 'availability' ],
                    'examples'    => [ 'Check room availability', 'What rooms are available?' ],
                ];
                break;

            case 'medical':
                $skills[] = [
                    'id'          => 'appointments',
                    'name'        => 'Appointment Scheduling',
                    'description' => "Schedule appointments at {$name}.",
                    'tags'        => [ 'appointment', 'schedule', 'health' ],
                    'examples'    => [ 'Book an appointment', 'What services are available?' ],
                ];
                break;

            case 'legal':
                $skills[] = [
                    'id'          => 'consultation',
                    'name'        => 'Legal Consultation',
                    'description' => "Request a legal consultation from {$name}.",
                    'tags'        => [ 'consultation', 'legal', 'lawyer' ],
                    'examples'    => [ 'Schedule a consultation', 'What areas of law do you practice?' ],
                ];
                break;
        }

        return $skills;
    }
}