package oss_tool

import (
	"context"
	"errors"
	"fmt"
	cf "git.ssgfgtfy.com/public/ssgf_utils/common_fun"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
	"image"
	"image/jpeg"
	"image/png"
	"io"
	"os"
	"time"
)

type ALiYunOSSClient struct {
	AccessKeyID     string
	AccessKeySecret string
	Region          string
	ossClient       *oss.Client
}

// NewAliYunOSS 创建阿里云OSS客户端
func (c *ALiYunOSSClient) NewAliYunOSS() (err error) {
	if c.AccessKeyID == "" || c.AccessKeySecret == "" {
		return errors.New("请配置 oss accessKeyID accessKeySecret")
	}
	if c.Region == "" {
		return errors.New("请配置 oss region")
	}
	provider := credentials.NewStaticCredentialsProvider(c.AccessKeyID, c.AccessKeySecret)
	cfg := oss.LoadDefaultConfig().WithSignatureVersion(oss.SignatureVersionV4).WithCredentialsProvider(provider).WithRegion(c.Region)
	c.ossClient = oss.NewClient(cfg)
	return nil
}

// BuildPutSignUrl 获取上传签名
func (c *ALiYunOSSClient) BuildPutSignUrl(bucket string, key string, expires time.Duration) (result *oss.PresignResult, err error) {
	// 生成PutObject的预签名URL
	result, err = c.ossClient.Presign(
		context.Background(),
		&oss.PutObjectRequest{
			Bucket: oss.Ptr(bucket),
			Key:    oss.Ptr(key),
		},
		oss.PresignExpires(expires),
	)
	if err != nil {
		return nil, err
	}
	return
}

// BuildPutSignUrlByPutObjectRequest 根据PutObjectRequest生成PutObject的预签名URL
func (c *ALiYunOSSClient) BuildPutSignUrlByPutObjectRequest(req *oss.PutObjectRequest, expires time.Duration) (result *oss.PresignResult, err error) {
	// 生成PutObject的预签名URL
	result, err = c.ossClient.Presign(
		context.Background(),
		req,
		oss.PresignExpires(expires),
	)
	if err != nil {
		return nil, err
	}
	return
}

// BuildSignUrlByGetObjectRequest 根据GetObjectRequest生成GetObject的预签名URL
func (c *ALiYunOSSClient) BuildSignUrlByGetObjectRequest(req *oss.GetObjectRequest) (result *oss.PresignResult, err error) {
	// 生成PutObject的预签名URL
	result, err = c.ossClient.Presign(
		context.Background(),
		req,
	)
	if err != nil {
		return nil, err
	}
	return
}

// PutForLocalFile 上传本地文件
func (c *ALiYunOSSClient) PutForLocalFile(bucket, key, path string) (result *oss.PutObjectResult, err error) {
	// 创建上传对象的请求
	putRequest := &oss.PutObjectRequest{
		Bucket:       oss.Ptr(bucket),          // 存储空间名称
		Key:          oss.Ptr(key),             // 对象名称
		StorageClass: oss.StorageClassStandard, // 指定对象的存储类型为标准存储
		ContentType:  oss.Ptr("application/octet-stream"),
	}
	// 执行上传对象的请求
	result, err = c.ossClient.PutObjectFromFile(context.Background(), putRequest, path)
	if err != nil {
		return nil, err
	}
	return
}

// GetObject 下载文件,返回的是一个*oss.GetObjectResult （不推荐使用，如果使用的话，需要手动调用object.Body.Close()手动关闭资源）
func (c *ALiYunOSSClient) GetObject(bucket string, key string) (object *oss.GetObjectResult, body io.ReadCloser, err error) {
	getRequest := &oss.GetObjectRequest{
		Bucket: oss.Ptr(bucket), // 存储空间名称
		Key:    oss.Ptr(key),    // 对象名称
	}
	// 执行获取对象的操作并处理结果
	result, err := c.ossClient.GetObject(context.TODO(), getRequest)
	if err != nil {
		return nil, nil, err
	}
	//defer func() {
	//	_ = result.Body.Close() // 确保在函数结束时关闭响应体
	//}()
	return result, result.Body, nil
}

// GetObjectToFile 获取对象并保存到本地
func (c *ALiYunOSSClient) GetObjectToFile(bucket string, key string, path string) (err error) {
	getRequest := &oss.GetObjectRequest{
		Bucket: oss.Ptr(bucket), // 存储空间名称
		Key:    oss.Ptr(key),    // 对象名称
	}
	// 执行获取对象的操作并处理结果
	result, err := c.ossClient.GetObject(context.TODO(), getRequest)
	if err != nil {
		return err
	}
	defer func() {
		_ = result.Body.Close() // 确保在函数结束时关闭响应体
	}()
	// 确保文件目录存在
	err = cf.EnsureParentDirExists(path)
	if err != nil {
		return err
	}
	// 创建目标文件
	file, err := os.Create(path)
	if err != nil {
		return err
	}
	defer file.Close()

	// 将 reader 中的内容复制到文件中
	_, err = io.Copy(file, result.Body)
	return nil
}

// GetObjectToImage 获取对象并保存为图片对象
func (c *ALiYunOSSClient) GetObjectToImage(bucket string, key string) (img image.Image, err error) {
	getRequest := &oss.GetObjectRequest{
		Bucket: oss.Ptr(bucket), // 存储空间名称
		Key:    oss.Ptr(key),    // 对象名称
	}
	// 执行获取对象的操作并处理结果
	result, err := c.ossClient.GetObject(context.TODO(), getRequest)
	if err != nil {
		return nil, err
	}
	defer func() {
		_ = result.Body.Close() // 确保在函数结束时关闭响应体
	}()
	img, _, err = image.Decode(result.Body)
	if err != nil {
		// 尝试 JPEG 解码
		img, err = jpeg.Decode(result.Body)
		if err != nil {
			// 尝试 PNG 解码
			img, err = png.Decode(result.Body)
			if err != nil {
				return nil, fmt.Errorf("图片解码失败（支持的格式：JPEG/PNG）: %v", err)
			}
		}
	}
	return img, nil
}

// DelObject 删除对象
func (c *ALiYunOSSClient) DelObject(bucket string, key string) (result *oss.DeleteObjectResult, err error) {
	// 创建删除对象的请求
	request := &oss.DeleteObjectRequest{
		Bucket: oss.Ptr(bucket), // 存储空间名称
		Key:    oss.Ptr(key),    // 对象名称
	}
	// 执行删除对象的操作并处理结果
	result, err = c.ossClient.DeleteObject(context.TODO(), request)
	if err != nil {
		return nil, err
	}
	return result, err
}