-- M8 基础设施：对象存储文件管理
-- 元数据行落 PostgreSQL，文件体存 MinIO（S3 兼容）。对象键即桶内路径，body 永不经数据库。

-- file_objects：文件元数据索引 + 访问控制
-- scope='personal' 绑定 portal 用户（个人文件仓）；scope='system' 为平台文件（admin 文件管理）。
CREATE TABLE IF NOT EXISTS gateway.file_objects (
    id uuid PRIMARY KEY,
    object_key text NOT NULL UNIQUE,
    original_name text NOT NULL CHECK (length(original_name) BETWEEN 1 AND 255),
    content_type text NOT NULL DEFAULT 'application/octet-stream',
    size_bytes bigint NOT NULL DEFAULT 0 CHECK (size_bytes BETWEEN 0 AND 536870912),
    content_sha256 char(64) NOT NULL,
    scope text NOT NULL CHECK (scope IN ('personal', 'system')),
    owner_user_id uuid REFERENCES gateway.portal_users(id) ON DELETE CASCADE,
    created_by uuid NOT NULL,
    created_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    updated_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    CONSTRAINT file_objects_personal_owner CHECK (
        (scope = 'personal' AND owner_user_id IS NOT NULL)
        OR (scope = 'system' AND owner_user_id IS NULL)
    )
);

-- 部分索引：个人文件按用户倒序，系统文件按时间倒序，sha256 去重查找
CREATE INDEX IF NOT EXISTS file_objects_personal_idx
    ON gateway.file_objects (owner_user_id, created_at DESC)
    WHERE scope = 'personal';
CREATE INDEX IF NOT EXISTS file_objects_system_idx
    ON gateway.file_objects (created_at DESC)
    WHERE scope = 'system';
CREATE INDEX IF NOT EXISTS file_objects_sha256_idx
    ON gateway.file_objects (content_sha256);