<?php

declare( strict_types=1 );

namespace PulseViews\Analytics;

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

use PulseViews\Database\ViewsRepository;

final class ViewTracker {

    private ViewsRepository $repo;
    private BotFilter       $bot_filter;
    private SessionManager  $sessions;

    public function __construct() {
        $this->repo       = new ViewsRepository();
        $this->bot_filter = new BotFilter();
        $this->sessions   = new SessionManager();
    }

    public function init(): void {
        $mode = $this->get_tracking_mode();

        match ( $mode ) {
            'php'  => add_action( 'template_redirect', [ $this, 'maybe_track_php' ], 20 ),
            'js'   => add_action( 'wp_enqueue_scripts', [ $this, 'enqueue_js_tracker' ] ),
            'both' => ( function () {
                add_action( 'template_redirect', [ $this, 'maybe_track_php' ], 20 );
                add_action( 'wp_enqueue_scripts', [ $this, 'enqueue_js_tracker' ] );
            } )(),
            default => null,
        };
    }

    public function maybe_track_php(): void {
        if ( ! $this->should_track() ) {
            return;
        }

        $post_id = get_queried_object_id();
        if ( ! $post_id ) {
            return;
        }

        $this->record_view( $post_id );
    }

    public function record_view( int $post_id, array $context = [] ): bool {
        if ( ! $this->is_trackable_post( $post_id ) ) {
            return false;
        }

        $interval_minutes = (int) $this->get_setting( 'session_interval', 30 );
        $interval_seconds = $interval_minutes * MINUTE_IN_SECONDS;

        $ip_hash     = $this->hash_ip( $this->get_real_ip() );
        $session_key = $this->sessions->get_or_create( $interval_seconds );
        $user_agent  = sanitize_text_field( sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ?? '' ) ) );
        $referrer    = sanitize_url( wp_get_referer() ?: '' );

        $is_bot = $this->bot_filter->is_bot( $user_agent );

        $should = apply_filters( 'pulseviews/should_track', true, $post_id, $context );
        if ( ! $should ) {
            return false;
        }

        // If interval is greater than 0, check duplicate records. If 0, bypass duplicate check.
        if ( $interval_seconds > 0 && $this->repo->is_duplicate( $post_id, $session_key, $ip_hash, $interval_seconds ) ) {
            return false;
        }

        if ( $this->is_excluded( $ip_hash ) ) {
            return false;
        }

        $real_ip      = $this->get_real_ip();
        $country_code = $context['country_code'] ?? $this->resolve_country( $real_ip );

        $view_id = $this->repo->insert_view( [
            'post_id'      => $post_id,
            'ip_hash'      => $ip_hash,
            'session_key'  => $session_key,
            'user_agent'   => $user_agent,
            'is_bot'       => $is_bot,
            'country_code' => $country_code,
            'referrer'     => $referrer,
        ] );

        if ( $view_id > 0 ) {
            wp_cache_delete( "pulseviews_totals_{$post_id}_total", 'pulseviews' );
            wp_cache_delete( "pulseviews_totals_{$post_id}_today", 'pulseviews' );
            wp_cache_delete( 'pulseviews_site_totals', 'pulseviews' );

            do_action( 'pulseviews/view_recorded', $view_id, $post_id, $context );

            return true;
        }

        return false;
    }

    public function enqueue_js_tracker(): void {
        if ( ! is_singular() ) {
            return;
        }

        wp_enqueue_script(
            'pulseviews-tracker',
            PULSEVIEWS_URL . 'assets/frontend/tracker.js',
            [],
            PULSEVIEWS_VERSION,
            [ 'strategy' => 'defer', 'in_footer' => true ]
        );

        wp_localize_script( 'pulseviews-tracker', 'pulseviewsTracker', [
            'endpoint' => rest_url( 'pulseviews/v1/track' ),
            'nonce'    => wp_create_nonce( 'wp_rest' ),
            'postId'   => get_queried_object_id(),
            'mode'     => $this->get_tracking_mode(),
        ] );
    }

    private function should_track(): bool {
        if ( ! is_singular() ) {
            return false;
        }

        if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
            return false;
        }
        if ( wp_doing_ajax() || wp_doing_cron() || is_admin() ) {
            return false;
        }

        if ( $this->get_setting( 'exclude_logged_in', false ) && is_user_logged_in() ) {
            return false;
        }

        $excluded_roles = (array) $this->get_setting( 'exclude_roles', [ 'administrator', 'editor' ] );
        if ( is_user_logged_in() && $this->current_user_has_role( $excluded_roles ) ) {
            return false;
        }

        return true;
    }

    private function is_trackable_post( int $post_id ): bool {
        $post = get_post( $post_id );
        if ( ! $post || 'publish' !== $post->post_status ) {
            return false;
        }

        $allowed_types = (array) $this->get_setting( 'post_types', [ 'post', 'page' ] );

        $allowed_types = apply_filters( 'pulseviews/tracked_post_types', $allowed_types, $post_id );

        return in_array( $post->post_type, $allowed_types, true );
    }

    private function is_excluded( string $ip_hash ): bool {
        $exclusions = wp_cache_get( 'pulseviews_exclusions', 'pulseviews' );
        if ( false === $exclusions ) {
            global $wpdb;
            $table      = $wpdb->prefix . 'pulseviews_exclusions';
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
            $exclusions = $wpdb->get_results(
                $wpdb->prepare( 'SELECT type, value FROM %i', $table ),
                ARRAY_A
            );
            wp_cache_set( 'pulseviews_exclusions', $exclusions, 'pulseviews', 300 );
        }

        foreach ( (array) $exclusions as $rule ) {
            if ( 'ip' === $rule['type'] && $rule['value'] === $ip_hash ) {
                return true;
            }
        }

        return false;
    }

    private function resolve_country( string $ip ): string {
        $cf = sanitize_text_field( sanitize_text_field( wp_unslash( $_SERVER['HTTP_CF_IPCOUNTRY'] ?? '' ) ) );
        if ( $cf && 'XX' !== $cf && 2 === strlen( $cf ) ) {
            return strtoupper( $cf );
        }

        foreach ( [ 'HTTP_X_COUNTRY_CODE', 'HTTP_X_GEO_COUNTRY', 'GEOIP_COUNTRY_CODE' ] as $h ) {
            $val = sanitize_text_field( wp_unslash( $_SERVER[ $h ] ?? '' ) );
            if ( $val && 2 === strlen( $val ) ) {
                return strtoupper( $val );
            }
        }

        if ( ! $this->get_setting( 'geo_tracking', false ) ) {
            return '';
        }

        if ( ! filter_var( $ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE ) ) {
            return '';
        }

        $cache_key = 'pulseviews_geo_' . substr( md5( $ip ), 0, 16 );
        $cached    = get_transient( $cache_key );
        if ( false !== $cached ) {
            return (string) $cached;
        }

        $response = wp_remote_get(
            'http://ip-api.com/json/' . rawurlencode( $ip ) . '?fields=countryCode,status',
            [
                'timeout'    => 2,
                'user-agent' => 'PulseViews/' . PULSEVIEWS_VERSION . ' (WordPress)',
            ]
        );

        $country = '';

        if ( ! is_wp_error( $response ) && 200 === wp_remote_retrieve_response_code( $response ) ) {
            $data = json_decode( wp_remote_retrieve_body( $response ), true );
            if ( is_array( $data ) && 'success' === ( $data['status'] ?? '' ) && isset( $data['countryCode'] ) ) {
                $country = strtoupper( sanitize_text_field( $data['countryCode'] ) );
            }
        }

        set_transient( $cache_key, $country, DAY_IN_SECONDS );

        return $country;
    }

    private function get_real_ip(): string {
        $trust_proxy = $this->get_setting( 'trust_proxy_headers', false );

        if ( $trust_proxy ) {
            $headers = [
                'HTTP_CF_CONNECTING_IP',
                'HTTP_X_REAL_IP',
                'HTTP_X_FORWARDED_FOR',
            ];
            foreach ( $headers as $header ) {
                if ( ! empty( $_SERVER[ $header ] ) ) {
                    $ip = trim( explode( ',', sanitize_text_field( wp_unslash( $_SERVER[ $header ] ?? '' ) ) )[0] );
                    if ( filter_var( $ip, FILTER_VALIDATE_IP ) ) {
                        return $ip;
                    }
                }
            }
        }

        return sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ?? '0.0.0.0' ) );
    }

    private function hash_ip( string $ip ): string {
        return hash( 'sha256', $ip . wp_salt( 'auth' ) );
    }

    private function get_tracking_mode(): string {
        return (string) $this->get_setting( 'tracking_mode', 'php' );
    }

    private function current_user_has_role( array $roles ): bool {
        $user = wp_get_current_user();
        return (bool) array_intersect( $roles, (array) $user->roles );
    }

    private function get_setting( string $key, mixed $default = null ): mixed {
        static $settings = null;
        if ( null === $settings ) {
            $settings = get_option( 'pulseviews_settings', [] );
        }
        return $settings[ $key ] ?? $default;
    }
}