<?php
namespace Zadex\Loop;

defined('ABSPATH') || exit;

/**
 * Reusable control groups (`widgets/_common/<group>.json`, e.g. `query.json`).
 *
 * A manifest lists them with `"controlGroups": ["query"]` or
 * `[{"group": "query", "defaults": {"query_post_type": "product"}, "exclude": ["query_source"]}]`.
 * The group's sections are inserted before the manifest's first style-tab section and its controls are appended
 * (ids the manifest already defines win). The editor does the same in `src/editor/core/controlGroups.ts`, so
 * PHP (defaults, sanitizer) and JS (panel, CSS) see the same control list. Expansion is idempotent.
 */
final class ControlGroups
{
    /** @var array<string, array|null> */
    private static array $cache = [];

    /** @return array{sections: array, controls: array}|null */
    public static function group(string $name, string $base_path): ?array
    {
        $name = preg_replace('/[^a-z0-9_-]/', '', strtolower($name)) ?? '';
        if ($name === '' || $name === 'controls') {
            return null;
        }
        $file = rtrim($base_path, '/\\') . '/_common/' . $name . '.json';
        if (!array_key_exists($file, self::$cache)) {
            $decoded = is_readable($file) ? wp_json_file_decode($file, ['associative' => true]) : null;
            self::$cache[$file] = is_array($decoded) ? [
                'sections' => is_array($decoded['sections'] ?? null) ? $decoded['sections'] : [],
                'controls' => is_array($decoded['controls'] ?? null) ? $decoded['controls'] : [],
            ] : null;
        }
        return self::$cache[$file];
    }

    public static function expand(array $manifest, string $base_path): array
    {
        $groups = $manifest['controlGroups'] ?? null;
        if (!is_array($groups) || !$groups) {
            return $manifest;
        }
        $sections = is_array($manifest['sections'] ?? null) ? $manifest['sections'] : [];
        $controls = is_array($manifest['controls'] ?? null) ? $manifest['controls'] : [];
        $section_ids = array_column($sections, 'id');
        $control_ids = array_column($controls, 'id');
        foreach ($groups as $entry) {
            $spec = is_string($entry) ? ['group' => $entry] : (is_array($entry) ? $entry : []);
            $group = self::group((string) ($spec['group'] ?? ''), $base_path);
            if ($group === null) {
                continue;
            }
            $defaults = is_array($spec['defaults'] ?? null) ? $spec['defaults'] : [];
            $exclude = is_array($spec['exclude'] ?? null) ? $spec['exclude'] : [];
            $new_sections = [];
            foreach ($group['sections'] as $section) {
                if (is_array($section) && isset($section['id']) && !in_array($section['id'], $section_ids, true)) {
                    $new_sections[] = $section;
                    $section_ids[] = $section['id'];
                }
            }
            if ($new_sections) {
                $at = count($sections);
                foreach ($sections as $i => $section) {
                    if (($section['tab'] ?? 'content') === 'style') {
                        $at = $i;
                        break;
                    }
                }
                array_splice($sections, $at, 0, $new_sections);
            }
            foreach ($group['controls'] as $control) {
                if (!is_array($control) || !isset($control['id']) || in_array($control['id'], $control_ids, true) || in_array($control['id'], $exclude, true)) {
                    continue;
                }
                if (array_key_exists($control['id'], $defaults)) {
                    $control['default'] = $defaults[$control['id']];
                }
                $controls[] = $control;
                $control_ids[] = $control['id'];
            }
        }
        $manifest['sections'] = $sections;
        $manifest['controls'] = $controls;
        return $manifest;
    }
}