<?php
declare(strict_types=1);
// Exit if accessed directly
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Tracks wp-admin activity for Live Sessions "Active" / "Idle" status.
 *
 * @package    ActivityLogPro
 * @since      1.1.0
 */
class ACTLOGPRO_Live_Sessions_Activity {

    /** User meta key storing last admin activity unix timestamp. */
    public const USER_META_KEY = 'actlogpro_last_admin_activity';

    /** Option key for minutes threshold to count as Active. */
    public const THRESHOLD_OPTION = 'actlogpro_live_sessions_active_minutes';

    /** Default active threshold in minutes. */
    public const DEFAULT_THRESHOLD_MINUTES = 10;

    /** Minimum seconds between DB writes per user. */
    private const THROTTLE_SECONDS = 60;

    /** Allowed threshold values (minutes). */
    private const ALLOWED_THRESHOLDS = [ 5, 10, 15 ];

    /**
     * Register hooks for recording admin activity.
     */
    public static function init(): void {
        add_action( 'admin_init', [ __CLASS__, 'maybe_record_activity' ], 20 );
        add_filter( 'heartbeat_received', [ __CLASS__, 'on_heartbeat_received' ], 10, 2 );
    }

    /**
     * Record activity on admin page loads (throttled).
     */
    public static function maybe_record_activity(): void {
        if ( ! is_user_logged_in() || ! is_admin() ) {
            return;
        }

        self::record_activity_for_user( get_current_user_id() );
    }

    /**
     * Record activity when WordPress Heartbeat fires in wp-admin.
     *
     * @param array<string,mixed> $response Heartbeat response.
     * @param array<string,mixed> $data     Heartbeat request data.
     * @return array<string,mixed>
     */
    public static function on_heartbeat_received( array $response, array $data ): array {
        if ( is_user_logged_in() && is_admin() ) {
            self::record_activity_for_user( get_current_user_id() );
        }

        return $response;
    }

    /**
     * Update last admin activity for a user if throttle allows.
     *
     * @param int $user_id User ID.
     */
    private static function record_activity_for_user( int $user_id ): void {
        if ( $user_id <= 0 ) {
            return;
        }

        $throttle_key = 'actlogpro_admin_act_' . $user_id;
        if ( get_transient( $throttle_key ) ) {
            return;
        }

        update_user_meta( $user_id, self::USER_META_KEY, time() );
        set_transient( $throttle_key, 1, self::THROTTLE_SECONDS );
    }

    /**
     * Get configured active threshold in minutes.
     */
    public static function get_threshold_minutes(): int {
        $minutes = (int) get_option( self::THRESHOLD_OPTION, self::DEFAULT_THRESHOLD_MINUTES );
        if ( ! in_array( $minutes, self::ALLOWED_THRESHOLDS, true ) ) {
            $minutes = self::DEFAULT_THRESHOLD_MINUTES;
        }
        return $minutes;
    }

    /**
     * Sanitize and validate a threshold value for saving.
     *
     * @param int $minutes Raw minutes value.
     * @return int
     */
    public static function sanitize_threshold_minutes( int $minutes ): int {
        return in_array( $minutes, self::ALLOWED_THRESHOLDS, true )
            ? $minutes
            : self::DEFAULT_THRESHOLD_MINUTES;
    }

    /**
     * Get activity status for display in Live Sessions.
     *
     * @param int $user_id User ID.
     * @return array{status: string, label: string, last_activity: int, tooltip: string}
     */
    public static function get_status_for_user( int $user_id ): array {
        $threshold = self::get_threshold_minutes() * MINUTE_IN_SECONDS;
        $last      = (int) get_user_meta( $user_id, self::USER_META_KEY, true );
        $now       = time();
        $is_active = $last > 0 && ( $now - $last ) <= $threshold;

        if ( $is_active ) {
            $mins_ago = max( 0, (int) floor( ( $now - $last ) / 60 ) );
            $tooltip  = $mins_ago < 1
                ? __( 'Active in dashboard · just now', 'activity-log-pro' )
                : sprintf(
                    /* translators: %d: minutes ago */
                    __( 'Active in dashboard · %d min ago', 'activity-log-pro' ),
                    $mins_ago
                );

            return [
                'status'        => 'active',
                'label'         => __( 'Active', 'activity-log-pro' ),
                'last_activity' => $last,
                'tooltip'       => $tooltip,
            ];
        }

        if ( $last > 0 ) {
            $tooltip = sprintf(
                /* translators: %s: human-readable time difference */
                __( 'Logged in · last seen in dashboard %s ago', 'activity-log-pro' ),
                human_time_diff( $last, $now )
            );
        } else {
            $tooltip = __( 'Logged in · no recent dashboard activity recorded', 'activity-log-pro' );
        }

        return [
            'status'        => 'idle',
            'label'         => __( 'Idle', 'activity-log-pro' ),
            'last_activity' => $last,
            'tooltip'       => $tooltip,
        ];
    }
}