package redisclient

import (
	"app/commons/core"
	"errors"
	"fmt"
	"github.com/go-redsync/redsync/v4"
	"time"
)

// Lock 获取分布式锁 -- 指定超时时间

func LockWithTime(lockKey string, expSecond int32) (*redsync.Mutex, error) {
	opts := LockOptions{
		Expiration: expSecond,       // 锁的过期时间（秒）
		MaxRetries: int(expSecond),  // 最大重试次数
		RetryDelay: 1 * time.Second, // 重试间隔
	}

	// 默认值
	if opts.Expiration <= 0 {
		opts.Expiration = DefaultLockOptions.Expiration
	}
	if opts.MaxRetries <= 0 {
		opts.MaxRetries = DefaultLockOptions.MaxRetries
	}
	if opts.RetryDelay <= 0 {
		opts.RetryDelay = DefaultLockOptions.RetryDelay
	}

	return LockWithOptions(lockKey, opts)
}

// Lock 获取分布式锁
func Lock(lockKey string) (*redsync.Mutex, error) {
	opts := LockOptions{
		Expiration: int32(3),               // 锁的过期时间（秒）
		MaxRetries: 8,                      // 最大重试次数
		RetryDelay: 300 * time.Millisecond, // 重试间隔
	}

	// 默认值
	if opts.Expiration <= 0 {
		opts.Expiration = DefaultLockOptions.Expiration
	}
	if opts.MaxRetries <= 0 {
		opts.MaxRetries = DefaultLockOptions.MaxRetries
	}
	if opts.RetryDelay <= 0 {
		opts.RetryDelay = DefaultLockOptions.RetryDelay
	}

	return LockWithOptions(lockKey, opts)
}

// LockWithOptions 使用指定的选项获取分布式锁
// 返回锁定的 mutex，失败时返回错误
// 使用完后需调用 Unlock() 释放锁
// 获取锁
func LockWithOptions(lockKey string, opts LockOptions) (*redsync.Mutex, error) {
	if opts.Expiration <= 0 || opts.MaxRetries < 1 || opts.RetryDelay < 0 {
		return nil, errors.New("invalid lock options")
	}

	mutex := redisSync().NewMutex(
		lockKey,
		redsync.WithExpiry(time.Duration(opts.Expiration)*time.Second),
		redsync.WithTries(opts.MaxRetries),
		redsync.WithRetryDelay(opts.RetryDelay),
	)

	if err := mutex.Lock(); err != nil {
		return nil, fmt.Errorf("failed to acquire lock: %w", err)
	}

	return mutex, nil
}

// 解锁

func UnlockSafe(mutex *redsync.Mutex) error {
	if _, err := mutex.Unlock(); err != nil {
		if errors.Is(err, redsync.ErrLockAlreadyExpired) {
			core.Log.Debug("Lock already expired, ignore error")
			return nil
		}
		return err
	}
	return nil
}