package models

import (
	"fmt"
	"gorm.io/gorm"
	"time"
	"wms/pkg/mysqlx"
)

type (
	// Lock 分布式锁
	Lock struct {
		LockName string `gorm:"primaryKey"`
		LockedBy string
		LockedAt time.Time
	}

	LockSearch struct {
		Lock
		Orm *gorm.DB
	}
)

func (slf *Lock) TableName() string {
	return "distributed_lock"
}

func NewLockSearch() *LockSearch {
	return &LockSearch{Orm: mysqlx.GetDB()}
}

func (slf *LockSearch) SetOrm(tx *gorm.DB) *LockSearch {
	slf.Orm = tx

	return slf
}

func (slf *LockSearch) SetLockName(lockName string) *LockSearch {
	slf.LockName = lockName
	return slf
}

func (slf *LockSearch) SetLockedBy(lockedBy string) *LockSearch {
	slf.LockedBy = lockedBy
	return slf
}

func (slf *LockSearch) build() *gorm.DB {
	var db = slf.Orm.Model(&Lock{})

	if slf.LockName != "" {
		db = db.Where("lock_name = ?", slf.LockName)
	}

	if slf.LockedBy != "" {
		db = db.Where("locked_by = ?", slf.LockedBy)
	}

	return db
}

// Create 单条插入
func (slf *LockSearch) Create(record *Lock) error {
	var db = slf.build()

	if err := db.Create(record).Error; err != nil {
		return err
	}

	return nil
}

func (slf *LockSearch) Delete() error {
	var db = slf.build()
	return db.Delete(&Lock{}).Error
}

func (slf *LockSearch) First() (*Lock, error) {
	var (
		record = new(Lock)
		db     = slf.build()
	)

	if err := db.First(record).Error; err != nil {
		return record, err
	}

	return record, nil
}

func (slf *LockSearch) AcquireLock(lockName, serviceID string) error {
	err := WithTransaction(func(db *gorm.DB) error {
		lock, err := slf.SetLockName(lockName).SetLockedBy(serviceID).First()
		if err != nil && err != gorm.ErrRecordNotFound {
			return err
		}
		if lock.LockedBy != "" {
			return fmt.Errorf("AcquireLock  failed, lockName: %s, serviceID: %+v", lockName, serviceID)
		}
		return slf.Create(&Lock{
			LockName: lockName,
			LockedBy: serviceID,
			LockedAt: time.Now(),
		})
	})
	return err
}

func (slf *LockSearch) ReleaseLock(lockName, serviceID string) error {
	err := slf.SetLockName(lockName).SetLockedBy(serviceID).Delete()
	if err != nil {
		return fmt.Errorf("AcquireLock  err: %v, lockName: %s, serviceID: %+v", err, lockName, serviceID)
	}
	return nil
}