<?php
/**
 * 建表语句与结构升级（安装向导与运行时共用同一份）。
 *
 * 五条约定：
 *   1. 全部 IF NOT EXISTS —— 重复执行不破坏已有数据
 *   2. 字符集一律 utf8mb4_unicode_ci，emoji 与人名生僻字都不会乱码
 *   3. 一切业务数据挂在 family_id 下，将来要支持多个家庭也不必改模型
 *   4. 手机号存两份：phone_hash 用于登录查找（确定性哈希），phone_encrypted 用于展示
 *   5. 结构升级走 ensure()，不靠人手动改库 —— 已上线的库也能自己长出新列
 */

declare(strict_types=1);

namespace App;

final class Schema
{
    /** @return string[] */
    public static function statements(): array
    {
        return [
            <<<'SQL'
CREATE TABLE IF NOT EXISTS `families` (
  `id`         INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `name`       VARCHAR(100) NOT NULL COMMENT '家庭名称',
  `motto`      VARCHAR(200) DEFAULT NULL COMMENT '一句话，展示在首页',
  `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='家庭空间（一切数据的根）'
SQL,
            <<<'SQL'
CREATE TABLE IF NOT EXISTS `persons` (
  `id`                INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `family_id`         INT UNSIGNED NOT NULL,
  `kind`              ENUM('member','contact') NOT NULL DEFAULT 'member' COMMENT '家庭成员 / 外部联系人',
  `name`              VARCHAR(50)  NOT NULL COMMENT '姓名',
  `nickname`          VARCHAR(50)  DEFAULT NULL COMMENT '小名',
  `gender`            ENUM('m','f','x') DEFAULT NULL COMMENT '男 / 女 / 未填写',
  `birth_rank`        INT          DEFAULT NULL COMMENT '家中排行（同一对父母的子女里，1=老大），用来算长子/次女',
  `birthday`          DATE         DEFAULT NULL COMMENT '生日（自动生成日历上的生日日程用）',
  `avatar`            VARCHAR(255) DEFAULT NULL COMMENT '头像，相对于 uploads/avatars',
  `phone_hash`        CHAR(64)     DEFAULT NULL COMMENT '手机号 sha256，登录查找用；NULL 不参与唯一约束',
  `phone_encrypted`   VARCHAR(512) DEFAULT NULL COMMENT 'AES 加密的手机号',
  `id_card_encrypted` VARCHAR(512) DEFAULT NULL COMMENT 'AES 加密的身份证号',
  `email`             VARCHAR(120) DEFAULT NULL,
  `address`           VARCHAR(200) DEFAULT NULL,
  `note`              TEXT         DEFAULT NULL COMMENT '备注',
  `is_placeholder`    TINYINT(1) NOT NULL DEFAULT 0 COMMENT '虚拟人物：还没弄清真实身份的占位（如「我的父亲」）',
  `sort_order`        INT NOT NULL DEFAULT 1000 COMMENT '名册排序，小的在前',
  `created_at`        DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at`        DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_phone_hash` (`phone_hash`),
  KEY `idx_family_kind` (`family_id`, `kind`, `sort_order`),
  CONSTRAINT `fk_persons_family` FOREIGN KEY (`family_id`) REFERENCES `families` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='家庭名册'
SQL,
            <<<'SQL'
CREATE TABLE IF NOT EXISTS `accounts` (
  `id`            INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `person_id`     INT UNSIGNED NOT NULL COMMENT '一个人最多一个账号',
  `password_hash` VARCHAR(255) NOT NULL,
  `role`          ENUM('admin','member','guest') NOT NULL DEFAULT 'member' COMMENT '管理员 / 家庭成员 / 访客',
  `status`        ENUM('active','disabled') NOT NULL DEFAULT 'active',
  `last_login_at` DATETIME DEFAULT NULL,
  `created_at`    DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_account_person` (`person_id`),
  CONSTRAINT `fk_accounts_person` FOREIGN KEY (`person_id`) REFERENCES `persons` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='登录账号'
SQL,
            <<<'SQL'
CREATE TABLE IF NOT EXISTS `relations` (
  `id`         INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `family_id`  INT UNSIGNED NOT NULL,
  `from_id`    INT UNSIGNED NOT NULL COMMENT '关系的一端',
  `to_id`      INT UNSIGNED NOT NULL COMMENT '关系的另一端',
  `kind`       ENUM('parent','spouse') NOT NULL COMMENT 'parent: from 是 to 的父/母；spouse: 配偶（对称）',
  `from_role`  ENUM('father','mother') DEFAULT NULL COMMENT 'kind=parent 时必填：from 相对 to 是父亲还是母亲',
  `note`       VARCHAR(200) DEFAULT NULL,
  `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_rel` (`from_id`,`to_id`,`kind`,`from_role`),
  KEY `idx_rel_from` (`from_id`,`kind`),
  KEY `idx_rel_to`   (`to_id`,`kind`),
  CONSTRAINT `fk_rel_family` FOREIGN KEY (`family_id`) REFERENCES `families` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_rel_from`   FOREIGN KEY (`from_id`)   REFERENCES `persons` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_rel_to`     FOREIGN KEY (`to_id`)     REFERENCES `persons` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='亲属关系：只存相邻两代之间的边，其余靠推导'
SQL,
            <<<'SQL'
CREATE TABLE IF NOT EXISTS `settings` (
  `family_id` INT UNSIGNED NOT NULL,
  `k`         VARCHAR(64)  NOT NULL,
  `v`         TEXT         DEFAULT NULL,
  PRIMARY KEY (`family_id`, `k`),
  CONSTRAINT `fk_settings_family` FOREIGN KEY (`family_id`) REFERENCES `families` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='家庭级键值对设置'
SQL,
        ];
    }

    /**
     * 幂等结构升级：建表 + 补齐后加的列/枚举值。
     *
     * ⚠️ CREATE TABLE IF NOT EXISTS 对**已存在的表**什么都不做 ——
     *    所以给老库加列必须显式 ALTER，而且要先查 information_schema 再改，
     *    否则第二次执行会报 Duplicate column。这就是「部署即可升级」的全部秘密。
     */
    public static function ensure(): void
    {
        $db = Database::get();
        foreach (self::statements() as $sql) {
            $db->exec($sql);
        }
        self::addColumn($db, 'persons', 'birth_rank',
            "ADD COLUMN `birth_rank` INT DEFAULT NULL COMMENT '家中排行（同一对父母的子女里，1=老大），用来算长子/次女' AFTER `gender`");
        self::addColumn($db, 'persons', 'is_placeholder',
            "ADD COLUMN `is_placeholder` TINYINT(1) NOT NULL DEFAULT 0 COMMENT '虚拟人物：还没弄清真实身份的占位（如「我的父亲」）' AFTER `note`");
        self::widenRoleEnum($db);
    }

    /** 列不存在才加 */
    private static function addColumn(\PDO $db, string $table, string $column, string $alter): void
    {
        $st = $db->prepare(
            'SELECT COUNT(*) FROM information_schema.COLUMNS
             WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = ? AND COLUMN_NAME = ?'
        );
        $st->execute([$table, $column]);
        if ((int)$st->fetchColumn() === 0) {
            $db->exec("ALTER TABLE `{$table}` {$alter}");
        }
    }

    /** accounts.role 原本只有 admin/member，升级时要把 guest 加进枚举 */
    private static function widenRoleEnum(\PDO $db): void
    {
        $st = $db->prepare(
            "SELECT COLUMN_TYPE FROM information_schema.COLUMNS
             WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'accounts' AND COLUMN_NAME = 'role'"
        );
        $st->execute();
        $type = (string)$st->fetchColumn();
        if ($type !== '' && strpos($type, 'guest') === false) {
            $db->exec(
                "ALTER TABLE `accounts` MODIFY COLUMN `role`
                 ENUM('admin','member','guest') NOT NULL DEFAULT 'member'
                 COMMENT '管理员 / 家庭成员 / 访客'"
            );
        }
    }
}