package sharememory

import (
	"fmt"
	"unsafe"

	"modelRT/orm"

	"golang.org/x/sys/unix"
)

// CreateShareMemory defines a function to create a shared memory
func CreateShareMemory(key uintptr, structSize uintptr) (uintptr, error) {
	// logger := logger.GetLoggerInstance()
	// create shared memory
	shmID, _, err := unix.Syscall(unix.SYS_SHMGET, key, structSize, unix.IPC_CREAT|0o666)
	if err != 0 {
		// logger.Error(fmt.Sprintf("create shared memory by key %v failed:", key), zap.Error(err))
		return 0, fmt.Errorf("create shared memory failed:%w", err)
	}

	// attach shared memory
	shmAddr, _, err := unix.Syscall(unix.SYS_SHMAT, shmID, 0, 0)
	if err != 0 {
		// logger.Error(fmt.Sprintf("attach shared memory by shmID %v failed:", shmID), zap.Error(err))
		return 0, fmt.Errorf("attach shared memory failed:%w", err)
	}
	return shmAddr, nil
}

// ReadComponentFromShareMemory defines a function to read component value from shared memory
func ReadComponentFromShareMemory(key uintptr, componentInfo *orm.Component) error {
	structSize := unsafe.Sizeof(orm.Component{})
	shmID, _, err := unix.Syscall(unix.SYS_SHMGET, key, uintptr(int(structSize)), 0o666)
	if err != 0 {
		return fmt.Errorf("get shared memory failed:%w", err)
	}

	shmAddr, _, err := unix.Syscall(unix.SYS_SHMAT, shmID, 0, 0)
	if err != 0 {
		return fmt.Errorf("attach shared memory failed:%w", err)
	}

	// 读取共享内存中的数据
	componentInfo = (*orm.Component)(unsafe.Pointer(shmAddr + structSize))

	// Detach shared memory
	unix.Syscall(unix.SYS_SHMDT, shmAddr, 0, 0)
	return nil
}

func WriteComponentInShareMemory(key uintptr, componentInfo *orm.Component) error {
	structSize := unsafe.Sizeof(orm.Component{})
	shmID, _, err := unix.Syscall(unix.SYS_SHMGET, key, uintptr(int(structSize)), 0o666)
	if err != 0 {
		return fmt.Errorf("get shared memory failed:%w", err)
	}

	shmAddr, _, err := unix.Syscall(unix.SYS_SHMAT, shmID, 0, 0)
	if err != 0 {
		return fmt.Errorf("attach shared memory failed:%w", err)
	}

	obj := (*orm.Component)(unsafe.Pointer(shmAddr + unsafe.Sizeof(structSize)))
	fmt.Println(obj)
	obj.ComponentType = componentInfo.ComponentType

	// id integer NOT NULL DEFAULT nextval('component_id_seq'::regclass),
	// global_uuid uuid NOT NULL DEFAULT gen_random_uuid(),
	// nspath character varying(32) COLLATE pg_catalog."default",
	// tag character varying(32) COLLATE pg_catalog."default" NOT NULL,
	// name character varying(64) COLLATE pg_catalog."default" NOT NULL,
	// description character varying(512) COLLATE pg_catalog."default" NOT NULL DEFAULT ''::character varying,
	// grid character varying(64) COLLATE pg_catalog."default" NOT NULL,
	// zone character varying(64) COLLATE pg_catalog."default" NOT NULL,
	// station character varying(64) COLLATE pg_catalog."default" NOT NULL,
	// type integer NOT NULL,
	// in_service boolean DEFAULT false,
	// state integer NOT NULL DEFAULT 0,
	// connected_bus jsonb NOT NULL DEFAULT '{}'::jsonb,
	// label jsonb NOT NULL DEFAULT '{}'::jsonb,
	// context jsonb NOT NULL DEFAULT '{}'::jsonb,
	// page_id integer NOT NULL,
	// op integer NOT NULL DEFAULT '-1'::integer,
	// ts timestamp with time zone NOT NULL DEFAULT CURRENT_TIMESTAMP,

	unix.Syscall(unix.SYS_SHMDT, shmAddr, 0, 0)
	return nil
}

// DeleteShareMemory defines a function to delete shared memory
func DeleteShareMemory(key uintptr) error {
	_, _, err := unix.Syscall(unix.SYS_SHM_UNLINK, key, 0, 0o666)
	if err != 0 {
		return fmt.Errorf("get shared memory failed:%w", err)
	}
	return nil
}