"""权限模型公共能力：岗位权限表初始化与历史配置迁移。"""
from services.db import query

_POSITION_PERMISSION_READY = False
SYSTEM_ROLES = ('super_admin', 'admin', 'viewer', '查看者')


def ensure_position_permissions():
    """幂等创建岗位权限表，并复制历史上误存为角色的岗位权限。"""
    global _POSITION_PERMISSION_READY
    if _POSITION_PERMISSION_READY:
        return
    query("""CREATE TABLE IF NOT EXISTS position_operation_permissions (
        id BIGINT AUTO_INCREMENT PRIMARY KEY,
        position_code VARCHAR(80) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
        page VARCHAR(100) NOT NULL,
        operation VARCHAR(100) NOT NULL,
        permission TINYINT NOT NULL DEFAULT 0,
        updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
        UNIQUE KEY uq_position_page_operation (position_code, page, operation),
        KEY idx_position_permission_code (position_code)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci""")
    # 旧版把采购计划、采购跟单、产品开发、运营专员等岗位当成 role 保存。
    # INSERT IGNORE 只做首次迁移，之后管理员修改岗位权限不会被历史数据覆盖。
    query("""INSERT IGNORE INTO position_operation_permissions
             (position_code,page,operation,permission)
             SELECT p.position_code,r.page,r.operation,r.permission
             FROM role_operation_permissions r
             INNER JOIN user_positions p ON BINARY p.position_code=BINARY r.role
             WHERE r.role NOT IN ('super_admin','admin','viewer','查看者')""")
    query("""INSERT IGNORE INTO position_operation_permissions
             (position_code,page,operation,permission)
             SELECT p.position_code,r.page,'view',r.permission
             FROM role_permissions r
             INNER JOIN user_positions p ON BINARY p.position_code=BINARY r.role
             WHERE r.role NOT IN ('super_admin','admin','viewer','查看者')""")
    _POSITION_PERMISSION_READY = True


def user_position_code(user_id):
    rows = query("SELECT position FROM dashboard_users WHERE id=%s LIMIT 1", (user_id,))
    return str(rows[0].get('position') or '').strip() if rows else ''