/*
 * MinIO Go Library for Amazon S3 Compatible Cloud Storage
 * Copyright 2015-2017 MinIO, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package minio

import (
	"bytes"
	"context"
	"encoding/base64"
	"encoding/hex"
	"encoding/xml"
	"fmt"
	"hash/crc32"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"sort"
	"strconv"
	"strings"

	"github.com/google/uuid"
	"github.com/minio/minio-go/v7/pkg/encrypt"
	"github.com/minio/minio-go/v7/pkg/s3utils"
)

func (c *Client) putObjectMultipart(ctx context.Context, bucketName, objectName string, reader io.Reader, size int64,
	opts PutObjectOptions,
) (info UploadInfo, err error) {
	info, err = c.putObjectMultipartNoStream(ctx, bucketName, objectName, reader, opts)
	if err != nil {
		errResp := ToErrorResponse(err)
		// Verify if multipart functionality is not available, if not
		// fall back to single PutObject operation.
		if errResp.Code == "AccessDenied" && strings.Contains(errResp.Message, "Access Denied") {
			// Verify if size of reader is greater than '5GiB'.
			if size > maxSinglePutObjectSize {
				return UploadInfo{}, errEntityTooLarge(size, maxSinglePutObjectSize, bucketName, objectName)
			}
			// Fall back to uploading as single PutObject operation.
			return c.putObject(ctx, bucketName, objectName, reader, size, opts)
		}
	}
	return info, err
}

func (c *Client) putObjectMultipartNoStream(ctx context.Context, bucketName, objectName string, reader io.Reader, opts PutObjectOptions) (info UploadInfo, err error) {
	// Input validation.
	if err = s3utils.CheckValidBucketName(bucketName); err != nil {
		return UploadInfo{}, err
	}
	if err = s3utils.CheckValidObjectName(objectName); err != nil {
		return UploadInfo{}, err
	}

	// Total data read and written to server. should be equal to
	// 'size' at the end of the call.
	var totalUploadedSize int64

	// Complete multipart upload.
	var complMultipartUpload completeMultipartUpload

	// Calculate the optimal parts info for a given size.
	totalPartsCount, partSize, _, err := OptimalPartInfo(-1, opts.PartSize)
	if err != nil {
		return UploadInfo{}, err
	}

	// Choose hash algorithms to be calculated by hashCopyN,
	// avoid sha256 with non-v4 signature request or
	// HTTPS connection.
	hashAlgos, hashSums := c.hashMaterials(opts.SendContentMd5, !opts.DisableContentSha256)
	if len(hashSums) == 0 {
		if opts.UserMetadata == nil {
			opts.UserMetadata = make(map[string]string, 1)
		}
		opts.UserMetadata["X-Amz-Checksum-Algorithm"] = "CRC32C"
	}

	// Initiate a new multipart upload.
	uploadID, err := c.newUploadID(ctx, bucketName, objectName, opts)
	if err != nil {
		return UploadInfo{}, err
	}
	delete(opts.UserMetadata, "X-Amz-Checksum-Algorithm")

	defer func() {
		if err != nil {
			c.abortMultipartUpload(ctx, bucketName, objectName, uploadID)
		}
	}()

	// Part number always starts with '1'.
	partNumber := 1

	// Initialize parts uploaded map.
	partsInfo := make(map[int]ObjectPart)

	// Create a buffer.
	buf := make([]byte, partSize)

	// Create checksums
	// CRC32C is ~50% faster on AMD64 @ 30GB/s
	var crcBytes []byte
	customHeader := make(http.Header)
	crc := crc32.New(crc32.MakeTable(crc32.Castagnoli))
	for partNumber <= totalPartsCount {
		length, rErr := readFull(reader, buf)
		if rErr == io.EOF && partNumber > 1 {
			break
		}

		if rErr != nil && rErr != io.ErrUnexpectedEOF && rErr != io.EOF {
			return UploadInfo{}, rErr
		}

		// Calculates hash sums while copying partSize bytes into cw.
		for k, v := range hashAlgos {
			v.Write(buf[:length])
			hashSums[k] = v.Sum(nil)
			v.Close()
		}

		// Update progress reader appropriately to the latest offset
		// as we read from the source.
		rd := newHook(bytes.NewReader(buf[:length]), opts.Progress)

		// Checksums..
		var (
			md5Base64 string
			sha256Hex string
		)

		if hashSums["md5"] != nil {
			md5Base64 = base64.StdEncoding.EncodeToString(hashSums["md5"])
		}
		if hashSums["sha256"] != nil {
			sha256Hex = hex.EncodeToString(hashSums["sha256"])
		}
		if len(hashSums) == 0 {
			crc.Reset()
			crc.Write(buf[:length])
			cSum := crc.Sum(nil)
			customHeader.Set("x-amz-checksum-crc32c", base64.StdEncoding.EncodeToString(cSum))
			crcBytes = append(crcBytes, cSum...)
		}

		p := uploadPartParams{bucketName: bucketName, objectName: objectName, uploadID: uploadID, reader: rd, partNumber: partNumber, md5Base64: md5Base64, sha256Hex: sha256Hex, size: int64(length), sse: opts.ServerSideEncryption, streamSha256: !opts.DisableContentSha256, customHeader: customHeader}
		// Proceed to upload the part.
		objPart, uerr := c.uploadPart(ctx, p)
		if uerr != nil {
			return UploadInfo{}, uerr
		}

		// Save successfully uploaded part metadata.
		partsInfo[partNumber] = objPart

		// Save successfully uploaded size.
		totalUploadedSize += int64(length)

		// Increment part number.
		partNumber++

		// For unknown size, Read EOF we break away.
		// We do not have to upload till totalPartsCount.
		if rErr == io.EOF {
			break
		}
	}

	// Loop over total uploaded parts to save them in
	// Parts array before completing the multipart request.
	for i := 1; i < partNumber; i++ {
		part, ok := partsInfo[i]
		if !ok {
			return UploadInfo{}, errInvalidArgument(fmt.Sprintf("Missing part number %d", i))
		}
		complMultipartUpload.Parts = append(complMultipartUpload.Parts, CompletePart{
			ETag:           part.ETag,
			PartNumber:     part.PartNumber,
			ChecksumCRC32:  part.ChecksumCRC32,
			ChecksumCRC32C: part.ChecksumCRC32C,
			ChecksumSHA1:   part.ChecksumSHA1,
			ChecksumSHA256: part.ChecksumSHA256,
		})
	}

	// Sort all completed parts.
	sort.Sort(completedParts(complMultipartUpload.Parts))
	opts = PutObjectOptions{}
	if len(crcBytes) > 0 {
		// Add hash of hashes.
		crc.Reset()
		crc.Write(crcBytes)
		opts.UserMetadata = map[string]string{"X-Amz-Checksum-Crc32c": base64.StdEncoding.EncodeToString(crc.Sum(nil))}
	}
	uploadInfo, err := c.completeMultipartUpload(ctx, bucketName, objectName, uploadID, complMultipartUpload, opts)
	if err != nil {
		return UploadInfo{}, err
	}

	uploadInfo.Size = totalUploadedSize
	return uploadInfo, nil
}

// initiateMultipartUpload - Initiates a multipart upload and returns an upload ID.
func (c *Client) initiateMultipartUpload(ctx context.Context, bucketName, objectName string, opts PutObjectOptions) (initiateMultipartUploadResult, error) {
	// Input validation.
	if err := s3utils.CheckValidBucketName(bucketName); err != nil {
		return initiateMultipartUploadResult{}, err
	}
	if err := s3utils.CheckValidObjectName(objectName); err != nil {
		return initiateMultipartUploadResult{}, err
	}

	// Initialize url queries.
	urlValues := make(url.Values)
	urlValues.Set("uploads", "")

	if opts.Internal.SourceVersionID != "" {
		if opts.Internal.SourceVersionID != nullVersionID {
			if _, err := uuid.Parse(opts.Internal.SourceVersionID); err != nil {
				return initiateMultipartUploadResult{}, errInvalidArgument(err.Error())
			}
		}
		urlValues.Set("versionId", opts.Internal.SourceVersionID)
	}

	// Set ContentType header.
	customHeader := opts.Header()

	reqMetadata := requestMetadata{
		bucketName:   bucketName,
		objectName:   objectName,
		queryValues:  urlValues,
		customHeader: customHeader,
	}

	// Execute POST on an objectName to initiate multipart upload.
	resp, err := c.executeMethod(ctx, http.MethodPost, reqMetadata)
	defer closeResponse(resp)
	if err != nil {
		return initiateMultipartUploadResult{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return initiateMultipartUploadResult{}, httpRespToErrorResponse(resp, bucketName, objectName)
		}
	}
	// Decode xml for new multipart upload.
	initiateMultipartUploadResult := initiateMultipartUploadResult{}
	err = xmlDecoder(resp.Body, &initiateMultipartUploadResult)
	if err != nil {
		return initiateMultipartUploadResult, err
	}
	return initiateMultipartUploadResult, nil
}

type uploadPartParams struct {
	bucketName   string
	objectName   string
	uploadID     string
	reader       io.Reader
	partNumber   int
	md5Base64    string
	sha256Hex    string
	size         int64
	sse          encrypt.ServerSide
	streamSha256 bool
	customHeader http.Header
	trailer      http.Header
}

// uploadPart - Uploads a part in a multipart upload.
func (c *Client) uploadPart(ctx context.Context, p uploadPartParams) (ObjectPart, error) {
	// Input validation.
	if err := s3utils.CheckValidBucketName(p.bucketName); err != nil {
		return ObjectPart{}, err
	}
	if err := s3utils.CheckValidObjectName(p.objectName); err != nil {
		return ObjectPart{}, err
	}
	if p.size > maxPartSize {
		return ObjectPart{}, errEntityTooLarge(p.size, maxPartSize, p.bucketName, p.objectName)
	}
	if p.size <= -1 {
		return ObjectPart{}, errEntityTooSmall(p.size, p.bucketName, p.objectName)
	}
	if p.partNumber <= 0 {
		return ObjectPart{}, errInvalidArgument("Part number cannot be negative or equal to zero.")
	}
	if p.uploadID == "" {
		return ObjectPart{}, errInvalidArgument("UploadID cannot be empty.")
	}

	// Get resources properly escaped and lined up before using them in http request.
	urlValues := make(url.Values)
	// Set part number.
	urlValues.Set("partNumber", strconv.Itoa(p.partNumber))
	// Set upload id.
	urlValues.Set("uploadId", p.uploadID)

	// Set encryption headers, if any.
	if p.customHeader == nil {
		p.customHeader = make(http.Header)
	}
	// https://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadUploadPart.html
	// Server-side encryption is supported by the S3 Multipart Upload actions.
	// Unless you are using a customer-provided encryption key, you don't need
	// to specify the encryption parameters in each UploadPart request.
	if p.sse != nil && p.sse.Type() == encrypt.SSEC {
		p.sse.Marshal(p.customHeader)
	}

	reqMetadata := requestMetadata{
		bucketName:       p.bucketName,
		objectName:       p.objectName,
		queryValues:      urlValues,
		customHeader:     p.customHeader,
		contentBody:      p.reader,
		contentLength:    p.size,
		contentMD5Base64: p.md5Base64,
		contentSHA256Hex: p.sha256Hex,
		streamSha256:     p.streamSha256,
		trailer:          p.trailer,
	}

	// Execute PUT on each part.
	resp, err := c.executeMethod(ctx, http.MethodPut, reqMetadata)
	defer closeResponse(resp)
	if err != nil {
		return ObjectPart{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return ObjectPart{}, httpRespToErrorResponse(resp, p.bucketName, p.objectName)
		}
	}
	// Once successfully uploaded, return completed part.
	h := resp.Header
	objPart := ObjectPart{
		ChecksumCRC32:  h.Get("x-amz-checksum-crc32"),
		ChecksumCRC32C: h.Get("x-amz-checksum-crc32c"),
		ChecksumSHA1:   h.Get("x-amz-checksum-sha1"),
		ChecksumSHA256: h.Get("x-amz-checksum-sha256"),
	}
	objPart.Size = p.size
	objPart.PartNumber = p.partNumber
	// Trim off the odd double quotes from ETag in the beginning and end.
	objPart.ETag = trimEtag(h.Get("ETag"))
	return objPart, nil
}

// completeMultipartUpload - Completes a multipart upload by assembling previously uploaded parts.
func (c *Client) completeMultipartUpload(ctx context.Context, bucketName, objectName, uploadID string,
	complete completeMultipartUpload, opts PutObjectOptions,
) (UploadInfo, error) {
	// Input validation.
	if err := s3utils.CheckValidBucketName(bucketName); err != nil {
		return UploadInfo{}, err
	}
	if err := s3utils.CheckValidObjectName(objectName); err != nil {
		return UploadInfo{}, err
	}

	// Initialize url queries.
	urlValues := make(url.Values)
	urlValues.Set("uploadId", uploadID)
	// Marshal complete multipart body.
	completeMultipartUploadBytes, err := xml.Marshal(complete)
	if err != nil {
		return UploadInfo{}, err
	}

	// Instantiate all the complete multipart buffer.
	completeMultipartUploadBuffer := bytes.NewReader(completeMultipartUploadBytes)
	reqMetadata := requestMetadata{
		bucketName:       bucketName,
		objectName:       objectName,
		queryValues:      urlValues,
		contentBody:      completeMultipartUploadBuffer,
		contentLength:    int64(len(completeMultipartUploadBytes)),
		contentSHA256Hex: sum256Hex(completeMultipartUploadBytes),
		customHeader:     opts.Header(),
	}

	// Execute POST to complete multipart upload for an objectName.
	resp, err := c.executeMethod(ctx, http.MethodPost, reqMetadata)
	defer closeResponse(resp)
	if err != nil {
		return UploadInfo{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return UploadInfo{}, httpRespToErrorResponse(resp, bucketName, objectName)
		}
	}

	// Read resp.Body into a []bytes to parse for Error response inside the body
	var b []byte
	b, err = ioutil.ReadAll(resp.Body)
	if err != nil {
		return UploadInfo{}, err
	}
	// Decode completed multipart upload response on success.
	completeMultipartUploadResult := completeMultipartUploadResult{}
	err = xmlDecoder(bytes.NewReader(b), &completeMultipartUploadResult)
	if err != nil {
		// xml parsing failure due to presence an ill-formed xml fragment
		return UploadInfo{}, err
	} else if completeMultipartUploadResult.Bucket == "" {
		// xml's Decode method ignores well-formed xml that don't apply to the type of value supplied.
		// In this case, it would leave completeMultipartUploadResult with the corresponding zero-values
		// of the members.

		// Decode completed multipart upload response on failure
		completeMultipartUploadErr := ErrorResponse{}
		err = xmlDecoder(bytes.NewReader(b), &completeMultipartUploadErr)
		if err != nil {
			// xml parsing failure due to presence an ill-formed xml fragment
			return UploadInfo{}, err
		}
		return UploadInfo{}, completeMultipartUploadErr
	}

	// extract lifecycle expiry date and rule ID
	expTime, ruleID := amzExpirationToExpiryDateRuleID(resp.Header.Get(amzExpiration))

	return UploadInfo{
		Bucket:           completeMultipartUploadResult.Bucket,
		Key:              completeMultipartUploadResult.Key,
		ETag:             trimEtag(completeMultipartUploadResult.ETag),
		VersionID:        resp.Header.Get(amzVersionID),
		Location:         completeMultipartUploadResult.Location,
		Expiration:       expTime,
		ExpirationRuleID: ruleID,

		ChecksumSHA256: completeMultipartUploadResult.ChecksumSHA256,
		ChecksumSHA1:   completeMultipartUploadResult.ChecksumSHA1,
		ChecksumCRC32:  completeMultipartUploadResult.ChecksumCRC32,
		ChecksumCRC32C: completeMultipartUploadResult.ChecksumCRC32C,
	}, nil
}