<?php

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

class AdGhost_Key_Values {

    const OPTION = 'adghost_key_values';

    const AUTO = [
        'post_id'   => 'post_id',
        'page_type' => 'page_type',
        'category'  => 'category',
        'tag'       => 'tag',
        'author'    => 'author',
    ];

    const RESERVED = ['adghost', 'adghost-refresh', 'agh-ivt', 'agh_tq'];

    const MAX_VALUES = 10;

    const MAX_PAIRS = 20;

    public static function settings() {
        $saved = get_option(self::OPTION, []);
        $saved = is_array($saved) ? $saved : [];
        $auto  = [];
        foreach ((array) ($saved['auto'] ?? []) as $item => $key) {
            $key = self::sanitize_key_name($key);
            if (isset(self::AUTO[$item]) && $key !== '') {
                $auto[$item] = $key;
            }
        }
        return [
            'auto'   => $auto,
            'custom' => self::sanitize_pairs($saved['custom'] ?? []),
        ];
    }

    public static function save(array $data, callable $has) {
        $saved = get_option(self::OPTION, []);
        $saved = is_array($saved) ? $saved : [];
        $auto  = (array) ($saved['auto'] ?? []);
        foreach (self::AUTO as $item => $default) {
            if ($has('kv_' . $item)) {
                $on  = in_array((string) $data['kv_' . $item], ['1', 'true'], true) || $data['kv_' . $item] === true || $data['kv_' . $item] === 1;
                $key = $has('kv_' . $item . '_key') ? self::sanitize_key_name($data['kv_' . $item . '_key']) : ($auto[$item] ?? '');
                if ($on) {
                    $auto[$item] = $key !== '' ? $key : $default;
                } else {
                    unset($auto[$item]);
                }
            }
        }
        $saved['auto'] = $auto;
        if ($has('kv_custom')) {
            $saved['custom'] = self::sanitize_pairs((string) $data['kv_custom']);
        }
        update_option(self::OPTION, $saved);
    }

    public static function page_values() {
        $settings = self::settings();
        $out      = [];
        foreach ($settings['auto'] as $item => $key) {
            $values = self::clean_values(self::auto_value($item));
            if ($values) {
                $out[$key] = $values;
            }
        }
        foreach ($settings['custom'] as $key => $values) {
            $out[$key] = $values;
        }
        return $out;
    }

    private static function auto_value($item) {
        $singular = function_exists('is_singular') && is_singular();
        $id       = $singular ? (int) get_queried_object_id() : 0;
        switch ($item) {
            case 'post_id':
                return $id ? [(string) $id] : [];
            case 'page_type':
                return [AdGhost_Targeting::page_type()];
            case 'category':
            case 'tag':
                $taxonomy = $item === 'category' ? 'category' : 'post_tag';
                if ($id) {
                    $terms = get_the_terms($id, $taxonomy);
                    return is_array($terms) ? wp_list_pluck($terms, 'slug') : [];
                }

                $object = function_exists('get_queried_object') ? get_queried_object() : null;
                return ($object instanceof WP_Term && $object->taxonomy === $taxonomy) ? [$object->slug] : [];
            case 'author':
                if ($id) {
                    $user = get_userdata((int) get_post_field('post_author', $id));
                    return $user ? [$user->user_nicename] : [];
                }
                $object = function_exists('get_queried_object') ? get_queried_object() : null;
                return ($object instanceof WP_User) ? [$object->user_nicename] : [];
        }
        return [];
    }

    public static function sanitize_key_name($key) {
        $key = strtolower(trim((string) $key));
        $key = preg_replace('/\s+/', '_', $key);
        $key = substr(preg_replace('/[^a-z0-9_-]/', '', $key), 0, 20);
        return preg_match('/^[a-z]/', $key) ? $key : '';
    }

    public static function sanitize_value($value) {
        $value = preg_replace('/["\'=!+#*~;^()<>\[\],&\\\\]|[\x00-\x1f]/u', '', (string) $value);
        return trim(function_exists('mb_substr') ? mb_substr(trim($value), 0, 40) : substr(trim($value), 0, 40));
    }

    private static function clean_values(array $values) {
        $out = [];
        foreach ($values as $value) {
            $value = self::sanitize_value($value);
            if ($value !== '' && !in_array($value, $out, true)) {
                $out[] = $value;
            }
        }
        return array_slice($out, 0, self::MAX_VALUES);
    }

    public static function sanitize_pairs($input) {
        $pairs = [];
        if (is_array($input)) {
            foreach ($input as $key => $values) {
                $pairs[] = [$key, is_array($values) ? $values : explode(',', (string) $values)];
            }
        } else {
            foreach (preg_split('/[\r\n;]+/', (string) $input) as $line) {
                if (strpos($line, '=') === false) {
                    continue;
                }
                [$key, $values] = explode('=', $line, 2);
                $pairs[] = [$key, explode(',', $values)];
            }
        }

        $out = [];
        foreach ($pairs as [$key, $values]) {
            $key = self::sanitize_key_name($key);
            if ($key === '' || in_array($key, self::RESERVED, true) || strpos($key, 'hb_') === 0) {
                continue;
            }
            $values = self::clean_values((array) $values);
            if ($values) {
                $out[$key] = $values;
            }
            if (count($out) >= self::MAX_PAIRS) {
                break;
            }
        }
        return $out;
    }

    public static function to_text(array $pairs, $glue = "\n") {
        $lines = [];
        foreach ($pairs as $key => $values) {
            $lines[] = $key . '=' . implode(', ', (array) $values);
        }
        return implode($glue, $lines);
    }

    public static function page_script() {
        $values = self::page_values();
        if (!$values) {
            return '';
        }
        return '(function(c){c.pageTargeting=Object.assign(c.pageTargeting||{},' . wp_json_encode($values, JSON_HEX_TAG | JSON_HEX_AMP) . ');})'
            . '(window.AdGhostConfig=window.AdGhostConfig||{});';
    }

    public static function amp_json() {
        $values = self::page_values();
        return $values ? wp_json_encode(['targeting' => $values]) : null;
    }
}