<?php

namespace App\Support;

use Illuminate\Support\Facades\Validator;
use Illuminate\Validation\ValidationException;

final class LocalizedContent
{
    public const LANGUAGES = ['zh' => '中文', 'en' => '英文', 'vi' => '越南语'];

    public static function parse($input, int $titleLimit, int $contentLimit, bool $subtitle = false): array
    {
        if (!is_array($input) || array_diff(array_keys($input), array_keys(self::LANGUAGES))) {
            self::invalid('translations', '请按zh/en/vi提交多语言内容');
        }
        $result = [];
        foreach (self::LANGUAGES as $language => $_) {
            if (!array_key_exists($language, $input)) continue;
            $block = $input[$language];
            if (!is_array($block)) self::invalid('translations.' . $language, '语言内容必须为对象');
            $data = Validator::make($block, [
                'title' => ['nullable', 'string', 'max:' . $titleLimit],
                'content' => ['nullable', 'string', 'max:' . $contentLimit],
                'subtitle' => ['nullable', 'string', 'max:500'],
            ])->validate();
            if (trim((string) ($data['content'] ?? '')) === '') continue;
            if (trim((string) ($data['title'] ?? '')) === '') self::invalid('translations.' . $language . '.title', '已填写正文的语言必须填写标题');
            $result[$language] = ['title' => trim($data['title']), 'content' => $data['content']];
            if ($subtitle) $result[$language]['subtitle'] = (string) ($data['subtitle'] ?? '');
        }
        if (!$result) self::invalid('translations', '至少填写一个语言的标题和正文');
        return $result;
    }

    public static function invalid(string $field, string $message): void
    {
        throw ValidationException::withMessages([$field => $message]);
    }
}