<?php
namespace ABILITY;

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

/**
 * Configuration management for ABILITY plugin.
 */
class Config {
    private const FREE_SCAN_LIMIT = 5;
    private const PRO_SCAN_LIMIT  = 999;

    /**
     * Authoritative Basic/Free page limit used for both a single scan and the
     * daily quota. Keeping this in one place prevents UI/runtime drift.
     */
    public static function get_free_scan_limit(): int {
        return self::FREE_SCAN_LIMIT;
    }

    /**
     * Runtime scan ceiling for the active edition.
     */
    public static function get_scan_limit(): int {
        $is_pro = function_exists('ability_is_pro') ? ability_is_pro() : false;
        return $is_pro ? self::PRO_SCAN_LIMIT : self::FREE_SCAN_LIMIT;
    }

    /**
     * Get default settings.
     */
    public static function get_defaults(): array {
        $is_pro = function_exists('ability_is_pro') ? ability_is_pro() : false;
        return [
            'scan_enabled' => true,
            'auto_fix_enabled' => false,
            'widget_enabled' => true,
            'frontend_widget_enabled' => true,
            'widget_position' => 'bottom-right',
            'widget_style' => 'modern',
            'compliance_level' => 'wcag_2_1_aa',
            'scan_schedule' => 'daily',
            'max_files_per_scan' => $is_pro ? self::PRO_SCAN_LIMIT : self::FREE_SCAN_LIMIT,
            'max_sites' => $is_pro ? (function_exists('ability_is_enterprise') && ability_is_enterprise() ? 10 : 3) : 1,
            'exclude_paths' => [],
            'report_email' => get_option('admin_email'),
            'show_branding' => !$is_pro,
            'compliance_reports' => false,
            'api_access' => false,
            'license_key' => '',
            'debug_mode' => false,
            'api_endpoint' => '',
            'experimental_features' => false,
        ];
    }

    /**
     * Sanitize a partial settings payload. Unknown keys are ignored so the
     * generic AJAX endpoint cannot create arbitrary plugin settings.
     */
    public static function sanitize_settings(array $settings): array {
        $defaults = self::get_defaults();
        $allowed  = array_fill_keys(array_keys($defaults), true);
        $clean    = [];

        $boolean_keys = [
            'scan_enabled', 'auto_fix_enabled', 'widget_enabled', 'frontend_widget_enabled',
            'show_branding', 'compliance_reports', 'api_access',
            'debug_mode', 'experimental_features',
        ];
        $integer_keys = ['max_files_per_scan', 'max_sites'];

        foreach ($settings as $key => $value) {
            $safe_key = sanitize_key((string) $key);
            if (!isset($allowed[$safe_key])) {
                continue;
            }

            if (in_array($safe_key, $boolean_keys, true)) {
                $clean[$safe_key] = empty($value) ? 0 : 1;
                continue;
            }

            if (in_array($safe_key, $integer_keys, true)) {
                $clean[$safe_key] = absint($value);
                continue;
            }

            if ('report_email' === $safe_key) {
                $clean[$safe_key] = sanitize_email((string) $value);
                continue;
            }

            if ('api_endpoint' === $safe_key) {
                $clean[$safe_key] = esc_url_raw((string) $value);
                continue;
            }

            if ('exclude_paths' === $safe_key) {
                $raw_paths = is_array($value) ? $value : preg_split('/\r\n|\r|\n/', (string) $value);
                $clean[$safe_key] = array_values(array_filter(array_map(
                    static function ($path) {
                        return sanitize_text_field((string) $path);
                    },
                    is_array($raw_paths) ? $raw_paths : []
                )));
                continue;
            }

            $enum_values = [
                'scan_schedule'    => ['manual', 'daily', 'weekly'],
                'widget_position'  => ['bottom-right', 'bottom-left', 'top-right', 'top-left'],
                'widget_style'     => ['modern', 'classic'],
                'compliance_level' => ['wcag_2_1_a', 'wcag_2_1_aa', 'wcag_2_1_aaa', 'ada', 'section508'],
            ];
            if (isset($enum_values[$safe_key])) {
                $candidate = sanitize_key((string) $value);
                $clean[$safe_key] = in_array($candidate, $enum_values[$safe_key], true)
                    ? $candidate
                    : $defaults[$safe_key];
                continue;
            }

            $clean[$safe_key] = sanitize_text_field((string) $value);
        }

        return $clean;
    }

    /**
     * Enforce edition-owned limits at the server/runtime boundary. UI state is
     * never trusted as the entitlement source.
     */
    private static function enforce_tier_limits(array $settings): array {
        $is_pro = function_exists('ability_is_pro') ? ability_is_pro() : false;

        if (!$is_pro) {
            $requested = isset($settings['max_files_per_scan']) ? absint($settings['max_files_per_scan']) : self::FREE_SCAN_LIMIT;
            $settings['max_files_per_scan'] = max(1, min(self::FREE_SCAN_LIMIT, $requested ?: self::FREE_SCAN_LIMIT));
            $settings['max_sites'] = 1;
            $settings['auto_fix_enabled'] = false;
            $settings['compliance_reports'] = false;
            $settings['api_access'] = false;
            $settings['show_branding'] = true;
        } else {
            $requested = isset($settings['max_files_per_scan']) ? absint($settings['max_files_per_scan']) : self::PRO_SCAN_LIMIT;
            $settings['max_files_per_scan'] = max(1, min(self::PRO_SCAN_LIMIT, $requested ?: self::PRO_SCAN_LIMIT));
        }

        return $settings;
    }

    /**
     * Get settings.
     */
    public static function get_settings(): array {
        $defaults = self::get_defaults();
        $settings = get_option('ability_settings', []);
        if (!is_array($settings)) {
            $settings = [];
        }
        return self::enforce_tier_limits(wp_parse_args($settings, $defaults));
    }

    /**
     * Update settings from a partial payload while preserving unrelated saved
     * values and enforcing the active edition at the server boundary.
     */
    public static function update_settings(array $settings): bool {
        $defaults = self::get_defaults();
        $current  = get_option('ability_settings', []);
        if (!is_array($current)) {
            $current = [];
        }

        $clean  = self::sanitize_settings($settings);
        $merged = array_replace($defaults, $current, $clean);
        $merged = self::enforce_tier_limits($merged);

        return update_option('ability_settings', $merged);
    }
}