<?php
/**
 * ActoSync API Handler
 * 
 * Manages all communication with ActoSync backend services.
 */

if (!defined('ABSPATH')) {
    exit;
}

class ActoSync_API {

    private $api_url = 'https://api.actosync.com/widget/api/chatbot/query/';
    private $suggestions_api_url = 'https://api.actosync.com/widget/api/chatbot/suggestions/';
    private $option_key = 'actosync_chat_settings';
    private $timeout = 50;

    /**
     * Send message to ActoSync API
     * 
     * @param array $payload Message payload
     * @param string $api_token JWT token for authentication
     * @param string $widget_id Widget ID
     * 
     * @return array|WP_Error Response or error
     */
    public function send_message($payload, $api_token, $widget_id) {
        $api_token = trim((string) $api_token);

        if (empty($api_token)) {
            return new WP_Error('no_token', 'API token not configured');
        }

        // Add channel_id to payload (WordPress channel)
        $payload['channel_id'] = 'wordpress';

        $origin = '';
        if (!empty($payload['origin']) && is_string($payload['origin'])) {
            $origin = esc_url_raw($payload['origin']);
        }

        if (empty($origin)) {
            $origin = home_url();
            $payload['origin'] = $origin;
        }

        $referer = '';
        if (!empty($payload['referer']) && is_string($payload['referer'])) {
            $referer = esc_url_raw($payload['referer']);
        }

        if (empty($referer)) {
            $referer = $origin;
        }

        $response = wp_remote_post(
            $this->api_url,
            [
                'method'      => 'POST',
                'headers'     => [
                    'Content-Type'  => 'application/json',
                    'Authorization' => 'Bearer ' . $api_token,
                    'X-Widget-Id'   => $widget_id,
                    'Origin'        => $origin,
                    'Referer'       => $referer,
                    'X-Origin'      => $origin,
                    'Accept'        => 'application/json',
                    'X-Requested-With' => 'XMLHttpRequest'
                ],
                'body'        => wp_json_encode($payload),
                'timeout'     => $this->timeout,
                'sslverify'   => true
            ]
        );

        if (is_wp_error($response)) {
            return $response;
        }

        $status_code = (int) wp_remote_retrieve_response_code($response);
        $body = wp_remote_retrieve_body($response);

        if ($status_code < 200 || $status_code >= 300) {
            $message = $this->extract_error_message_from_body($body);

            if (empty($message)) {
                $message = sprintf('Chat service returned HTTP %d', $status_code);
            }

            return new WP_Error('http_error', $message, ['status_code' => $status_code]);
        }

        if (empty($body)) {
            return new WP_Error('empty_response', 'Chat service returned an empty response');
        }

        $data = json_decode($body, true);

        if (json_last_error() !== JSON_ERROR_NONE || !is_array($data)) {
            return new WP_Error('invalid_response', 'Invalid response from chat service');
        }

        // Support both Shopify format (status: success) and other formats
        if (isset($data['status']) && $data['status'] !== 'success') {
            return new WP_Error('api_status_error', $this->extract_error_message_from_body($body) ?: 'Request failed');
        }

        return $data;
    }

    /**
     * Fetch AI-generated shopping suggestions for the current context.
     *
     * @param array  $payload   Context payload (page, product_id, cart, etc.)
     * @param string $api_token JWT token for authentication
     * @param string $widget_id Widget ID
     *
     * @return array|WP_Error
     */
    public function get_suggestions($payload, $api_token, $widget_id) {
        $api_token = trim((string) $api_token);

        if (empty($api_token)) {
            return new WP_Error('no_token', 'API token not configured');
        }

        $payload['channel_id'] = 'wordpress';

        $origin = '';
        if (!empty($payload['origin']) && is_string($payload['origin'])) {
            $origin = esc_url_raw($payload['origin']);
        }
        if (empty($origin)) {
            $origin = home_url();
            $payload['origin'] = $origin;
        }

        $referer = '';
        if (!empty($payload['referer']) && is_string($payload['referer'])) {
            $referer = esc_url_raw($payload['referer']);
        }
        if (empty($referer)) {
            $referer = $origin;
        }

        $response = wp_remote_post(
            $this->suggestions_api_url,
            [
                'method'    => 'POST',
                'headers'   => [
                    'Content-Type'     => 'application/json',
                    'Authorization'    => 'Bearer ' . $api_token,
                    'X-Widget-Id'      => $widget_id,
                    'Origin'           => $origin,
                    'Referer'          => $referer,
                    'X-Origin'         => $origin,
                    'Accept'           => 'application/json',
                    'X-Requested-With' => 'XMLHttpRequest',
                ],
                'body'      => wp_json_encode($payload),
                'timeout'   => 30,
                'sslverify' => true,
            ]
        );

        if (is_wp_error($response)) {
            return $response;
        }

        $status_code = (int) wp_remote_retrieve_response_code($response);
        $body        = wp_remote_retrieve_body($response);

        if ($status_code < 200 || $status_code >= 300) {
            $message = $this->extract_error_message_from_body($body);
            if (empty($message)) {
                $message = sprintf('Suggestion service returned HTTP %d', $status_code);
            }
            return new WP_Error('http_error', $message, ['status_code' => $status_code]);
        }

        if (empty($body)) {
            return new WP_Error('empty_response', 'Suggestion service returned an empty response');
        }

        $data = json_decode($body, true);
        if (json_last_error() !== JSON_ERROR_NONE || !is_array($data)) {
            return new WP_Error('invalid_response', 'Invalid response from suggestion service');
        }

        return $data;
    }

    /**
     * Default smart suggestion settings.
     *
     * @return array
     */
    public function get_default_suggestion_settings() {
        return [
            'enable_smart_suggestions'  => 1,
            'max_suggestion_chips'      => 5,
            'suggest_on_widget_closed'  => 1,
            'auto_refresh_suggestions'  => 1,
            'followup_suggestions'      => 1,
            'product_recommendations'   => 1,
            'cross_sell_suggestions'    => 1,
            'upsell_suggestions'        => 1,
            'personalize_suggestions'   => 1,
            'suggestion_delay_seconds'  => 3,
        ];
    }

    /**
     * Extracts a meaningful error message from API response body.
     *
     * @param string $body
     *
     * @return string
     */
    private function extract_error_message_from_body($body) {
        if (empty($body)) {
            return '';
        }

        $decoded = json_decode($body, true);
        if (!is_array($decoded)) {
            return '';
        }

        foreach (['message', 'error', 'detail', 'response'] as $key) {
            if (!empty($decoded[$key]) && is_string($decoded[$key])) {
                return sanitize_text_field($decoded[$key]);
            }
        }

        if (!empty($decoded['data']) && is_array($decoded['data'])) {
            foreach (['message', 'error', 'detail'] as $nested_key) {
                if (!empty($decoded['data'][$nested_key]) && is_string($decoded['data'][$nested_key])) {
                    return sanitize_text_field($decoded['data'][$nested_key]);
                }
            }
        }

        return '';
    }

    /**
     * Get API configuration
     */
    public function get_config() {
        $opts       = get_option($this->option_key, []);
        $suggestion_defaults = $this->get_default_suggestion_settings();

        return array_merge(
            [
                'api_token'   => $opts['api_token'] ?? '',
                'widget_id'   => $opts['widget_id'] ?? '',
                'agent_id'    => $opts['agent_id'] ?? '',
                'user_id'     => $opts['user_id'] ?? '',
                'agent_name'  => $opts['agent_name'] ?? 'AI Assistant',
                'auto_insert' => $opts['auto_insert'] ?? 0,
            ],
            [
                'enable_smart_suggestions'  => !isset($opts['enable_smart_suggestions']) || !empty($opts['enable_smart_suggestions']) ? 1 : 0,
                'max_suggestion_chips'      => max(3, min(8, (int) ($opts['max_suggestion_chips'] ?? $suggestion_defaults['max_suggestion_chips']))),
                'suggest_on_widget_closed'  => !isset($opts['suggest_on_widget_closed']) || !empty($opts['suggest_on_widget_closed']) ? 1 : 0,
                'auto_refresh_suggestions'  => !isset($opts['auto_refresh_suggestions']) || !empty($opts['auto_refresh_suggestions']) ? 1 : 0,
                'followup_suggestions'      => !isset($opts['followup_suggestions']) || !empty($opts['followup_suggestions']) ? 1 : 0,
                'product_recommendations'   => !isset($opts['product_recommendations']) || !empty($opts['product_recommendations']) ? 1 : 0,
                'cross_sell_suggestions'    => !isset($opts['cross_sell_suggestions']) || !empty($opts['cross_sell_suggestions']) ? 1 : 0,
                'upsell_suggestions'        => !isset($opts['upsell_suggestions']) || !empty($opts['upsell_suggestions']) ? 1 : 0,
                'personalize_suggestions'   => !isset($opts['personalize_suggestions']) || !empty($opts['personalize_suggestions']) ? 1 : 0,
                'suggestion_delay_seconds'  => max(0, min(15, (int) ($opts['suggestion_delay_seconds'] ?? $suggestion_defaults['suggestion_delay_seconds']))),
            ]
        );
    }

    /**
     * Check if plugin is configured
     */
    public function is_configured() {
        $config = $this->get_config();
        return !empty($config['widget_id']) 
            && !empty($config['agent_id']) 
            && !empty($config['user_id']);
    }
}