<?php
declare(strict_types=1);

namespace addon\paycenter\library;

use think\facade\Db;

/**
 * 支付中心表结构自愈。
 *
 * 事实源：addon/paycenter/install.sql（插件自带，随插件分发）。
 * 安装时由 AddonService::importsql() 导入；运行期（下单 / 回调 / 后台流水页）再兜底一次，
 * 保证「插件已启用但表被误删 / 老库缺列」时不炸。
 *
 * 幂等：缺表建表、缺列补列都是 SHOW 探测，重复调用安全，进程内只探测一次。
 */
class Schema
{
    /** 插件私有表（不含表前缀） */
    public const TABLES = ['paycenter_trade'];

    /** 老库补列：[表 => [列 => 列定义]] */
    private const COLUMNS = [
        'paycenter_trade' => [
            'biz'     => '`biz` varchar(30) NOT NULL DEFAULT \'\' COMMENT \'业务标识\'',
            'biz_id'  => '`biz_id` int NOT NULL DEFAULT 0 COMMENT \'业务侧订单主键\'',
            'scene'   => '`scene` varchar(20) NOT NULL DEFAULT \'\' COMMENT \'支付场景\'',
            'attach'  => '`attach` varchar(500) NOT NULL DEFAULT \'\' COMMENT \'业务附加数据\'',
            'notify_at' => '`notify_at` int NOT NULL DEFAULT 0 COMMENT \'回调时间\'',
        ],
    ];

    private static bool $done = false;

    /** install.sql 解析缓存：[不含前缀表名 => CREATE 语句] */
    private static array $ddl = [];

    public static function ensure(): void
    {
        if (self::$done) {
            return;
        }
        self::$done = true;

        $prefix = self::prefix();
        foreach (self::ddl() as $table => $statement) {
            $full = $prefix . $table;
            if (self::tableExists($full)) {
                continue;
            }
            try {
                Db::execute(str_replace('__PREFIX__', $prefix, $statement));
            } catch (\Throwable $e) {
                // 建表失败不阻断业务：后续写库会再暴露真实错误
                trace('[paycenter] 建表失败 ' . $full . '：' . $e->getMessage(), 'error');
            }
        }

        foreach (self::COLUMNS as $table => $columns) {
            $full = $prefix . $table;
            if (!self::tableExists($full)) {
                continue;
            }
            foreach ($columns as $col => $def) {
                try {
                    if (empty(Db::query("SHOW COLUMNS FROM `{$full}` LIKE '{$col}'"))) {
                        Db::execute("ALTER TABLE `{$full}` ADD COLUMN {$def}");
                    }
                } catch (\Throwable) {
                    // 补列失败不阻断
                }
            }
        }
    }

    public static function prefix(): string
    {
        $default = (string) config('database.default', 'mysql');

        return (string) config("database.connections.{$default}.prefix", '');
    }

    private static function tableExists(string $full): bool
    {
        try {
            return !empty(Db::query("SHOW TABLES LIKE '{$full}'"));
        } catch (\Throwable) {
            return false;
        }
    }

    /**
     * 解析插件自带 install.sql，取出建表语句。
     * @return array<string,string>
     */
    private static function ddl(): array
    {
        if (self::$ddl !== []) {
            return self::$ddl;
        }
        $file = dirname(__DIR__) . DIRECTORY_SEPARATOR . 'install.sql';
        if (!is_file($file)) {
            return self::$ddl = [];
        }
        $sql = (string) file_get_contents($file);
        if (preg_match_all('/CREATE\s+TABLE\s+IF\s+NOT\s+EXISTS\s+`?__PREFIX__(\w+)`?\s*\(.*?\)\s*[^;]*;/is', $sql, $m)) {
            foreach ($m[1] as $i => $table) {
                self::$ddl[$table] = $m[0][$i];
            }
        }

        return self::$ddl;
    }
}