// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
//go:build plus

package oss

import (
	"bytes"
	"errors"
	"github.com/TeaOSLab/EdgeCommon/pkg/serverconfigs/ossconfigs"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/request"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/iwind/TeaGo/types"
	"io"
	"net/http"
	"strings"
	"time"
)

type AmazonS3Provider struct {
	bucketName string

	client *s3.S3
}

func NewAmazonS3Provider() ProviderInterface {
	return &AmazonS3Provider{}
}

func (this *AmazonS3Provider) Init(options ossconfigs.OSSOptions, bucketName string) error {
	realOptions, ok := options.(*ossconfigs.AmazonS3ProviderOptions)
	if !ok {
		return errors.New("invalid options for 'AmazonS3Provider'")
	}

	this.bucketName = bucketName

	var config = &aws.Config{
		Credentials: credentials.NewCredentials(NewAmazonS3CredentialProvider(realOptions.AccessKeyId, realOptions.AccessKeySecret)),
		Region:      aws.String(realOptions.Region),
	}
	if len(realOptions.Endpoint) > 0 {
		config.Endpoint = aws.String(realOptions.Endpoint)
	}

	switch realOptions.BucketAddressStyle {
	case ossconfigs.AmazonS3BucketAddressStylePath, "":
		config.S3ForcePathStyle = aws.Bool(true)
	case ossconfigs.AmazonS3BucketAddressStyleDomain:
		// do nothing
	}

	sess, err := session.NewSession(config)
	if err != nil {
		return err
	}
	this.client = s3.New(sess)

	return nil
}

func (this *AmazonS3Provider) Head(key string) (httpResponse *http.Response, nativeErrCode string, err error) {
	var input = &s3.HeadObjectInput{
		Bucket: aws.String(this.bucketName),
		Key:    aws.String(key),
	}

	resp, respErr := this.client.HeadObject(input)
	if respErr != nil {
		nativeErrCode, err = this.parseErr(respErr)
		return
	}

	var statusCode = http.StatusOK

	httpResponse = &http.Response{
		StatusCode:    statusCode,
		ContentLength: aws.Int64Value(resp.ContentLength),
		Body:          io.NopCloser(bytes.NewReader(nil)),
	}

	if httpResponse.Header == nil {
		httpResponse.Header = http.Header{}
	}

	// response headers
	// TODO 可以设置是否显示x-amz-*报头
	// TODO 考虑是否将 resp.Metadata 加入到Header
	// TODO 考虑将 *bool, *int64 等类型也加入到Header
	for _, header := range []*AmazonS3Header{
		{"Accept-Ranges", resp.AcceptRanges},
		{"Cache-Control", resp.CacheControl},
		{"x-amz-checksum-crc32", resp.ChecksumCRC32},
		{"x-amz-checksum-crc32c", resp.ChecksumCRC32C},
		{"x-amz-checksum-sha1", resp.ChecksumSHA1},
		{"x-amz-checksum-sha256", resp.ChecksumSHA256},
		{"Content-Disposition", resp.ContentDisposition},
		{"Content-Encoding", resp.ContentEncoding},
		{"Content-Language", resp.ContentLanguage},
		{"Content-Length", resp.ContentLength},
		{"Content-Type", resp.ContentType},
		{"ETag", resp.ETag},
		{"x-amz-expiration", resp.Expiration},
		{"Expires", resp.Expires},
		{"x-amz-object-lock-legal-hold", resp.ObjectLockLegalHoldStatus},
		{"x-amz-object-lock-mode", resp.ObjectLockMode},
		{"Last-Modified", resp.LastModified},
		{"x-amz-object-lock-retain-until-date", resp.ObjectLockRetainUntilDate},
		{"x-amz-replication-status", resp.ReplicationStatus},
		{"x-amz-request-charged", resp.RequestCharged},
		{"x-amz-restore", resp.Restore},
		{"x-amz-server-side-encryption-customer-algorithm", resp.SSECustomerAlgorithm},
		{"x-amz-server-side-encryption-customer-key-MD5", resp.SSECustomerKeyMD5},
		{"x-amz-server-side-encryption-aws-kms-key-id", resp.SSEKMSKeyId},
		{"x-amz-server-side-encryption", resp.ServerSideEncryption},
		{"x-amz-storage-class", resp.StorageClass},
		{"x-amz-version-id", resp.VersionId},
		{"x-amz-website-redirect-location", resp.WebsiteRedirectLocation},
		{"x-amz-mp-parts-count", resp.PartsCount},
	} {
		if header.Value != nil {
			switch value := header.Value.(type) {
			case *string:
				var stringValue = aws.StringValue(value)
				if len(stringValue) > 0 {
					httpResponse.Header[header.Name] = []string{stringValue}
				}
			case *int64:
				var int64Value = aws.Int64Value(value)
				if int64Value >= 0 {
					if !strings.HasPrefix(header.Name, "x-") || int64Value > 0 {
						httpResponse.Header[header.Name] = []string{types.String(int64Value)}
					}
				}
			case *time.Time:
				var t = aws.TimeValue(value)
				if t.Year() > 1000 {
					httpResponse.Header[header.Name] = []string{t.Format("Mon, 02 Jan 2006 15:04:05") + " GMT"}
				}
			}
		}
	}

	return
}

func (this *AmazonS3Provider) Get(key string) (httpResponse *http.Response, nativeErrCode string, err error) {
	return this.GetRange(key, "")
}

func (this *AmazonS3Provider) GetRange(key string, bytesRange string) (httpResponse *http.Response, nativeErrCode string, err error) {
	var input = &s3.GetObjectInput{
		Bucket: aws.String(this.bucketName),
		Key:    aws.String(key),
	}
	if len(bytesRange) > 0 {
		input.Range = aws.String(bytesRange)
	}

	resp, respErr := this.client.GetObject(input)
	if respErr != nil {
		nativeErrCode, err = this.parseErr(respErr)
		return
	}

	var statusCode = http.StatusOK
	if resp.ContentRange != nil && len(aws.StringValue(resp.ContentRange)) > 0 {
		statusCode = http.StatusPartialContent
	}

	httpResponse = &http.Response{
		StatusCode:    statusCode,
		ContentLength: aws.Int64Value(resp.ContentLength),
		Body:          resp.Body,
	}

	if httpResponse.Header == nil {
		httpResponse.Header = http.Header{}
	}

	// response headers
	// TODO 可以设置是否显示x-amz-*报头
	// TODO 考虑是否将 resp.Metadata 加入到Header
	// TODO 考虑将 *bool, *int64 等类型也加入到Header
	for _, header := range []*AmazonS3Header{
		{"Accept-Ranges", resp.AcceptRanges},
		{"Cache-Control", resp.CacheControl},
		{"x-amz-checksum-crc32", resp.ChecksumCRC32},
		{"x-amz-checksum-crc32c", resp.ChecksumCRC32C},
		{"x-amz-checksum-sha1", resp.ChecksumSHA1},
		{"x-amz-checksum-sha256", resp.ChecksumSHA256},
		{"Content-Disposition", resp.ContentDisposition},
		{"Content-Encoding", resp.ContentEncoding},
		{"Content-Language", resp.ContentLanguage},
		{"Content-Length", resp.ContentLength},
		{"Content-Range", resp.ContentRange},
		{"Content-Type", resp.ContentType},
		{"ETag", resp.ETag},
		{"x-amz-expiration", resp.Expiration},
		{"Expires", resp.Expires},
		{"x-amz-object-lock-legal-hold", resp.ObjectLockLegalHoldStatus},
		{"x-amz-object-lock-mode", resp.ObjectLockMode},
		{"Last-Modified", resp.LastModified},
		{"x-amz-object-lock-retain-until-date", resp.ObjectLockRetainUntilDate},
		{"x-amz-replication-status", resp.ReplicationStatus},
		{"x-amz-request-charged", resp.RequestCharged},
		{"x-amz-restore", resp.Restore},
		{"x-amz-server-side-encryption-customer-algorithm", resp.SSECustomerAlgorithm},
		{"x-amz-server-side-encryption-customer-key-MD5", resp.SSECustomerKeyMD5},
		{"x-amz-server-side-encryption-aws-kms-key-id", resp.SSEKMSKeyId},
		{"x-amz-server-side-encryption", resp.ServerSideEncryption},
		{"x-amz-storage-class", resp.StorageClass},
		{"x-amz-version-id", resp.VersionId},
		{"x-amz-website-redirect-location", resp.WebsiteRedirectLocation},
		{"x-amz-mp-parts-count", resp.PartsCount},
		{"x-amz-tagging-count", resp.TagCount},
	} {
		if header.Value != nil {
			switch value := header.Value.(type) {
			case *string:
				var stringValue = aws.StringValue(value)
				if len(stringValue) > 0 {
					httpResponse.Header[header.Name] = []string{stringValue}
				}
			case *int64:
				var int64Value = aws.Int64Value(value)
				if int64Value >= 0 {
					if !strings.HasPrefix(header.Name, "x-") || int64Value > 0 {
						httpResponse.Header[header.Name] = []string{types.String(int64Value)}
					}
				}
			case *time.Time:
				var t = aws.TimeValue(value)
				if t.Year() > 1000 {
					httpResponse.Header[header.Name] = []string{t.Format("Mon, 02 Jan 2006 15:04:05") + " GMT"}
				}
			}
		}
	}

	return
}

func (this *AmazonS3Provider) parseErr(err error) (errCode string, resultErr error) {
	if err == nil {
		return
	}

	resultErr = err

	respErr, ok := err.(awserr.Error)
	if ok {
		errCode = respErr.Code()
	}

	// 特殊错误
	if errCode == s3.ErrCodeNoSuchBucket {
		resultErr = errNoBucket
		return
	}

	if errCode == s3.ErrCodeNoSuchKey {
		resultErr = errNotFound
		return
	}

	if errCode == request.ErrCodeResponseTimeout {
		resultErr = errRequestTimeout
		return
	}

	return
}

// AmazonS3CredentialProvider 认证服务
type AmazonS3CredentialProvider struct {
	accessKeyId     string
	secretAccessKey string
}

func NewAmazonS3CredentialProvider(accessKeyId string, secretAccessKey string) *AmazonS3CredentialProvider {
	return &AmazonS3CredentialProvider{
		accessKeyId:     accessKeyId,
		secretAccessKey: secretAccessKey,
	}
}

func (this *AmazonS3CredentialProvider) Retrieve() (credentials.Value, error) {
	return credentials.Value{
		AccessKeyID:     this.accessKeyId,
		SecretAccessKey: this.secretAccessKey,
		SessionToken:    "",
		ProviderName:    "",
	}, nil
}

func (this *AmazonS3CredentialProvider) IsExpired() bool {
	return false
}

// AmazonS3Header Header组合
type AmazonS3Header struct {
	Name  string
	Value any
}