//go:build !plan9 && !solaris && !js
// +build !plan9,!solaris,!js

// Package oracleobjectstorage provides an interface to the OCI object storage system.
package oracleobjectstorage

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"path"
	"strings"
	"time"

	"github.com/oracle/oci-go-sdk/v65/common"
	"github.com/oracle/oci-go-sdk/v65/objectstorage"
	"github.com/rclone/rclone/fs"
	"github.com/rclone/rclone/fs/config/configmap"
	"github.com/rclone/rclone/fs/config/configstruct"
	"github.com/rclone/rclone/fs/hash"
	"github.com/rclone/rclone/fs/operations"
	"github.com/rclone/rclone/fs/walk"
	"github.com/rclone/rclone/lib/bucket"
	"github.com/rclone/rclone/lib/pacer"
)

// Register with Fs
func init() {
	fs.Register(&fs.RegInfo{
		Name:        "oracleobjectstorage",
		Description: "Oracle Cloud Infrastructure Object Storage",
		Prefix:      "oos",
		NewFs:       NewFs,
		CommandHelp: commandHelp,
		Options:     newOptions(),
	})
}

// Fs represents a remote object storage server
type Fs struct {
	name          string                             // name of this remote
	root          string                             // the path we are working on if any
	opt           Options                            // parsed config options
	ci            *fs.ConfigInfo                     // global config
	features      *fs.Features                       // optional features
	srv           *objectstorage.ObjectStorageClient // the connection to the object storage
	rootBucket    string                             // bucket part of root (if any)
	rootDirectory string                             // directory part of root (if any)
	cache         *bucket.Cache                      // cache for bucket creation status
	pacer         *fs.Pacer                          // To pace the API calls
}

// NewFs Initialize backend
func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, error) {
	// Parse config into Options struct
	opt := new(Options)
	err := configstruct.Set(m, opt)
	if err != nil {
		return nil, err
	}
	ci := fs.GetConfig(ctx)
	objectStorageClient, err := newObjectStorageClient(ctx, opt)
	if err != nil {
		return nil, err
	}
	p := pacer.NewDefault(pacer.MinSleep(minSleep), pacer.MaxSleep(maxSleep), pacer.DecayConstant(decayConstant))
	f := &Fs{
		name:  name,
		opt:   *opt,
		ci:    ci,
		srv:   objectStorageClient,
		cache: bucket.NewCache(),
		pacer: fs.NewPacer(ctx, p),
	}
	f.setRoot(root)
	f.features = (&fs.Features{
		ReadMimeType:      true,
		WriteMimeType:     true,
		BucketBased:       true,
		BucketBasedRootOK: true,
		SetTier:           true,
		GetTier:           true,
		SlowModTime:       true,
	}).Fill(ctx, f)
	if f.rootBucket != "" && f.rootDirectory != "" && !strings.HasSuffix(root, "/") {
		// Check to see if the (bucket,directory) is actually an existing file
		oldRoot := f.root
		newRoot, leaf := path.Split(oldRoot)
		f.setRoot(newRoot)
		_, err := f.NewObject(ctx, leaf)
		if err != nil {
			// File doesn't exist or is a directory so return old f
			f.setRoot(oldRoot)
			return f, nil
		}
		// return an error with fs which points to the parent
		return f, fs.ErrorIsFile
	}
	return f, err
}

func checkUploadChunkSize(cs fs.SizeSuffix) error {
	if cs < minChunkSize {
		return fmt.Errorf("%s is less than %s", cs, minChunkSize)
	}
	return nil
}

func (f *Fs) setUploadChunkSize(cs fs.SizeSuffix) (old fs.SizeSuffix, err error) {
	err = checkUploadChunkSize(cs)
	if err == nil {
		old, f.opt.ChunkSize = f.opt.ChunkSize, cs
	}
	return
}

func checkUploadCutoff(cs fs.SizeSuffix) error {
	if cs > maxUploadCutoff {
		return fmt.Errorf("%s is greater than %s", cs, maxUploadCutoff)
	}
	return nil
}

func (f *Fs) setUploadCutoff(cs fs.SizeSuffix) (old fs.SizeSuffix, err error) {
	err = checkUploadCutoff(cs)
	if err == nil {
		old, f.opt.UploadCutoff = f.opt.UploadCutoff, cs
	}
	return
}

// ------------------------------------------------------------
// Implement backed that represents a remote object storage server
// Fs is the interface a cloud storage system must provide
// ------------------------------------------------------------

// Name of the remote (as passed into NewFs)
func (f *Fs) Name() string {
	return f.name
}

// Root of the remote (as passed into NewFs)
func (f *Fs) Root() string {
	return f.root
}

// String converts this Fs to a string
func (f *Fs) String() string {
	if f.rootBucket == "" {
		return "oss:root"
	}
	if f.rootDirectory == "" {
		return fmt.Sprintf("oss:bucket %s", f.rootBucket)
	}
	return fmt.Sprintf("oss:bucket %s, path %s", f.rootBucket, f.rootDirectory)
}

// Features returns the optional features of this Fs
func (f *Fs) Features() *fs.Features {
	return f.features
}

// Precision of the remote
func (f *Fs) Precision() time.Duration {
	return time.Millisecond
}

// Hashes returns the supported hash sets.
func (f *Fs) Hashes() hash.Set {
	return hash.Set(hash.MD5)
}

// setRoot changes the root of the Fs
func (f *Fs) setRoot(root string) {
	f.root = parsePath(root)
	f.rootBucket, f.rootDirectory = bucket.Split(f.root)
}

// parsePath parses a remote 'url'
func parsePath(path string) (root string) {
	root = strings.Trim(path, "/")
	return
}

// split returns bucket and bucketPath from the rootRelativePath
// relative to f.root
func (f *Fs) split(rootRelativePath string) (bucketName, bucketPath string) {
	bucketName, bucketPath = bucket.Split(path.Join(f.root, rootRelativePath))
	return f.opt.Enc.FromStandardName(bucketName), f.opt.Enc.FromStandardPath(bucketPath)
}

// List the objects and directories in dir into entries.  The
// entries can be returned in any order but should be for a
// complete directory.
//
// dir should be "" to list the root, and should not have
// trailing slashes.
//
// This should return ErrDirNotFound if the directory isn't
// found.
func (f *Fs) List(ctx context.Context, dir string) (entries fs.DirEntries, err error) {
	bucketName, directory := f.split(dir)
	fs.Debugf(f, "listing: bucket : %v, directory: %v", bucketName, dir)
	if bucketName == "" {
		if directory != "" {
			return nil, fs.ErrorListBucketRequired
		}
		return f.listBuckets(ctx)
	}
	return f.listDir(ctx, bucketName, directory, f.rootDirectory, f.rootBucket == "")
}

// listFn is called from list to handle an object.
type listFn func(remote string, object *objectstorage.ObjectSummary, isDirectory bool) error

// list the objects into the function supplied from
// the bucket and root supplied
// (bucket, directory) is the starting directory
// If prefix is set then it is removed from all file names
// If addBucket is set then it adds the bucket to the start of the remotes generated
// If recurse is set the function will recursively list
// If limit is > 0 then it limits to that many files (must be less than 1000)
// If hidden is set then it will list the hidden (deleted) files too.
// if findFile is set it will look for files called (bucket, directory)
func (f *Fs) list(ctx context.Context, bucket, directory, prefix string, addBucket bool, recurse bool, limit int,
	fn listFn) (err error) {
	if prefix != "" {
		prefix += "/"
	}
	if directory != "" {
		directory += "/"
	}

	delimiter := ""
	if !recurse {
		delimiter = "/"
	}
	chunkSize := 1000
	if limit > 0 {
		chunkSize = limit
	}
	var request = objectstorage.ListObjectsRequest{
		NamespaceName: common.String(f.opt.Namespace),
		BucketName:    common.String(bucket),
		Prefix:        common.String(directory),
		Limit:         common.Int(chunkSize),
		Fields:        common.String("name,size,etag,timeCreated,md5,timeModified,storageTier,archivalState"),
	}
	if delimiter != "" {
		request.Delimiter = common.String(delimiter)
	}

	for {
		var resp objectstorage.ListObjectsResponse
		err = f.pacer.Call(func() (bool, error) {
			var err error
			resp, err = f.srv.ListObjects(ctx, request)
			return shouldRetry(ctx, resp.HTTPResponse(), err)
		})
		if err != nil {
			if ociError, ok := err.(common.ServiceError); ok {
				// If it is a timeout then we want to retry that
				if ociError.GetHTTPStatusCode() == http.StatusNotFound {
					err = fs.ErrorDirNotFound
				}
			}
			if f.rootBucket == "" {
				// if listing from the root ignore wrong region requests returning
				// empty directory
				if reqErr, ok := err.(common.ServiceError); ok {
					// 301 if wrong region for bucket
					if reqErr.GetHTTPStatusCode() == http.StatusMovedPermanently {
						fs.Errorf(f, "Can't change region for bucket %q with no bucket specified", bucket)
						return nil
					}
				}
			}
			return err
		}
		if !recurse {
			for _, commonPrefix := range resp.ListObjects.Prefixes {
				if commonPrefix == "" {
					fs.Logf(f, "Nil common prefix received")
					continue
				}
				remote := commonPrefix
				remote = f.opt.Enc.ToStandardPath(remote)
				if !strings.HasPrefix(remote, prefix) {
					fs.Logf(f, "Odd name received %q", remote)
					continue
				}
				remote = remote[len(prefix):]
				if addBucket {
					remote = path.Join(bucket, remote)
				}
				remote = strings.TrimSuffix(remote, "/")
				err = fn(remote, &objectstorage.ObjectSummary{Name: &remote}, true)
				if err != nil {
					return err
				}
			}
		}
		for i := range resp.Objects {
			object := &resp.Objects[i]
			// Finish if file name no longer has prefix
			//if prefix != "" && !strings.HasPrefix(file.Name, prefix) {
			//	return nil
			//}
			remote := *object.Name
			remote = f.opt.Enc.ToStandardPath(remote)
			if !strings.HasPrefix(remote, prefix) {
				// fs.Debugf(f, "Odd name received %v", object.Name)
				continue
			}
			remote = remote[len(prefix):]
			// Check for directory
			isDirectory := remote == "" || strings.HasSuffix(remote, "/")
			if addBucket {
				remote = path.Join(bucket, remote)
			}
			// is this a directory marker?
			if isDirectory && object.Size != nil && *object.Size == 0 {
				continue // skip directory marker
			}
			if isDirectory && len(remote) > 1 {
				remote = remote[:len(remote)-1]
			}
			err = fn(remote, object, isDirectory)
			if err != nil {
				return err
			}
		}
		// end if no NextFileName
		if resp.NextStartWith == nil {
			break
		}
		request.Start = resp.NextStartWith
	}
	return nil
}

// Convert a list item into a DirEntry
func (f *Fs) itemToDirEntry(ctx context.Context, remote string, object *objectstorage.ObjectSummary, isDirectory bool) (fs.DirEntry, error) {
	if isDirectory {
		size := int64(0)
		if object.Size != nil {
			size = *object.Size
		}
		d := fs.NewDir(remote, time.Time{}).SetSize(size)
		return d, nil
	}
	o, err := f.newObjectWithInfo(ctx, remote, object)
	if err != nil {
		return nil, err
	}
	return o, nil
}

// listDir lists a single directory
func (f *Fs) listDir(ctx context.Context, bucket, directory, prefix string, addBucket bool) (entries fs.DirEntries, err error) {
	fn := func(remote string, object *objectstorage.ObjectSummary, isDirectory bool) error {
		entry, err := f.itemToDirEntry(ctx, remote, object, isDirectory)
		if err != nil {
			return err
		}
		if entry != nil {
			entries = append(entries, entry)
		}
		return nil
	}
	err = f.list(ctx, bucket, directory, prefix, addBucket, false, 0, fn)
	if err != nil {
		return nil, err
	}
	// bucket must be present if listing succeeded
	f.cache.MarkOK(bucket)
	return entries, nil
}

// listBuckets returns all the buckets to out
func (f *Fs) listBuckets(ctx context.Context) (entries fs.DirEntries, err error) {
	if f.opt.Provider == noAuth {
		return nil, fmt.Errorf("can't list buckets with %v provider, use a valid auth provider in config file", noAuth)
	}
	var request = objectstorage.ListBucketsRequest{
		NamespaceName: common.String(f.opt.Namespace),
		CompartmentId: common.String(f.opt.Compartment),
	}
	var resp objectstorage.ListBucketsResponse
	for {
		err = f.pacer.Call(func() (bool, error) {
			resp, err = f.srv.ListBuckets(ctx, request)
			return shouldRetry(ctx, resp.HTTPResponse(), err)
		})
		if err != nil {
			return nil, err
		}
		for _, item := range resp.Items {
			bucketName := f.opt.Enc.ToStandardName(*item.Name)
			f.cache.MarkOK(bucketName)
			d := fs.NewDir(bucketName, item.TimeCreated.Time)
			entries = append(entries, d)
		}
		if resp.OpcNextPage == nil {
			break
		}
		request.Page = resp.OpcNextPage
	}
	return entries, nil
}

// Return an Object from a path
// If it can't be found it returns the error fs.ErrorObjectNotFound.
func (f *Fs) newObjectWithInfo(ctx context.Context, remote string, info *objectstorage.ObjectSummary) (fs.Object, error) {
	o := &Object{
		fs:     f,
		remote: remote,
	}
	if info != nil {
		// Set info but not meta
		if info.TimeModified == nil {
			fs.Logf(o, "Failed to read last modified")
			o.lastModified = time.Now()
		} else {
			o.lastModified = info.TimeModified.Time
		}
		if info.Md5 != nil {
			md5, err := o.base64ToMd5(*info.Md5)
			if err != nil {
				o.md5 = md5
			}
		}
		o.bytes = *info.Size
		o.storageTier = storageTierMap[strings.ToLower(string(info.StorageTier))]
	} else {
		err := o.readMetaData(ctx) // reads info and headers, returning an error
		if err != nil {
			return nil, err
		}
	}
	return o, nil
}

// NewObject finds the Object at remote.  If it can't be found
// it returns the error fs.ErrorObjectNotFound.
func (f *Fs) NewObject(ctx context.Context, remote string) (fs.Object, error) {
	return f.newObjectWithInfo(ctx, remote, nil)
}

// Put the object into the bucket
// Copy the reader in to the new object which is returned
// The new object may have been created if an error is returned
func (f *Fs) Put(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
	// Temporary Object under construction
	o := &Object{
		fs:     f,
		remote: src.Remote(),
	}
	return o, o.Update(ctx, in, src, options...)
}

// PutStream uploads to the remote path with the modTime given of indeterminate size
func (f *Fs) PutStream(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
	return f.Put(ctx, in, src, options...)
}

// Mkdir creates the bucket if it doesn't exist
func (f *Fs) Mkdir(ctx context.Context, dir string) error {
	bucketName, _ := f.split(dir)
	return f.makeBucket(ctx, bucketName)
}

// makeBucket creates the bucket if it doesn't exist
func (f *Fs) makeBucket(ctx context.Context, bucketName string) error {
	return f.cache.Create(bucketName, func() error {
		details := objectstorage.CreateBucketDetails{
			Name:             common.String(bucketName),
			CompartmentId:    common.String(f.opt.Compartment),
			PublicAccessType: objectstorage.CreateBucketDetailsPublicAccessTypeNopublicaccess,
		}
		req := objectstorage.CreateBucketRequest{
			NamespaceName:       common.String(f.opt.Namespace),
			CreateBucketDetails: details,
		}
		err := f.pacer.Call(func() (bool, error) {
			resp, err := f.srv.CreateBucket(ctx, req)
			return shouldRetry(ctx, resp.HTTPResponse(), err)
		})
		if err == nil {
			fs.Infof(f, "Bucket %q created with accessType %q", bucketName,
				objectstorage.CreateBucketDetailsPublicAccessTypeNopublicaccess)
		}
		if svcErr, ok := err.(common.ServiceError); ok {
			if code := svcErr.GetCode(); code == "BucketAlreadyOwnedByYou" || code == "BucketAlreadyExists" {
				err = nil
			}
		}
		return err
	}, func() (bool, error) {
		return f.bucketExists(ctx, bucketName)
	})
}

// Check if the bucket exists
//
// NB this can return incorrect results if called immediately after bucket deletion
func (f *Fs) bucketExists(ctx context.Context, bucketName string) (bool, error) {
	req := objectstorage.HeadBucketRequest{
		NamespaceName: common.String(f.opt.Namespace),
		BucketName:    common.String(bucketName),
	}
	err := f.pacer.Call(func() (bool, error) {
		resp, err := f.srv.HeadBucket(ctx, req)
		return shouldRetry(ctx, resp.HTTPResponse(), err)
	})
	if err == nil {
		return true, nil
	}
	if err, ok := err.(common.ServiceError); ok {
		if err.GetHTTPStatusCode() == http.StatusNotFound {
			return false, nil
		}
	}
	return false, err
}

// Rmdir delete an empty bucket. if bucket is not empty this is will fail with appropriate error
func (f *Fs) Rmdir(ctx context.Context, dir string) error {
	bucketName, directory := f.split(dir)
	if bucketName == "" || directory != "" {
		return nil
	}
	return f.cache.Remove(bucketName, func() error {
		req := objectstorage.DeleteBucketRequest{
			NamespaceName: common.String(f.opt.Namespace),
			BucketName:    common.String(bucketName),
		}
		err := f.pacer.Call(func() (bool, error) {
			resp, err := f.srv.DeleteBucket(ctx, req)
			return shouldRetry(ctx, resp.HTTPResponse(), err)
		})
		if err == nil {
			fs.Infof(f, "Bucket %q deleted", bucketName)
		}
		return err
	})
}

func (f *Fs) abortMultiPartUpload(ctx context.Context, bucketName, bucketPath, uploadID string) (err error) {
	if uploadID == "" {
		return nil
	}
	request := objectstorage.AbortMultipartUploadRequest{
		NamespaceName: common.String(f.opt.Namespace),
		BucketName:    common.String(bucketName),
		ObjectName:    common.String(bucketPath),
		UploadId:      common.String(uploadID),
	}
	err = f.pacer.Call(func() (bool, error) {
		resp, err := f.srv.AbortMultipartUpload(ctx, request)
		return shouldRetry(ctx, resp.HTTPResponse(), err)
	})
	return err
}

// cleanUpBucket removes all pending multipart uploads for a given bucket over the age of maxAge
func (f *Fs) cleanUpBucket(ctx context.Context, bucket string, maxAge time.Duration,
	uploads []*objectstorage.MultipartUpload) (err error) {
	fs.Infof(f, "cleaning bucket %q of pending multipart uploads older than %v", bucket, maxAge)
	for _, upload := range uploads {
		if upload.TimeCreated != nil && upload.Object != nil && upload.UploadId != nil {
			age := time.Since(upload.TimeCreated.Time)
			what := fmt.Sprintf("pending multipart upload for bucket %q key %q dated %v (%v ago)", bucket, *upload.Object,
				upload.TimeCreated, age)
			if age > maxAge {
				fs.Infof(f, "removing %s", what)
				if operations.SkipDestructive(ctx, what, "remove pending upload") {
					continue
				}
				ignoreErr := f.abortMultiPartUpload(ctx, *upload.Bucket, *upload.Object, *upload.UploadId)
				if ignoreErr != nil {
					// fs.Debugf(f, "ignoring error %s", ignoreErr)
				}
			} else {
				// fs.Debugf(f, "ignoring %s", what)
			}
		} else {
			fs.Infof(f, "MultipartUpload doesn't have sufficient details to abort.")
		}
	}
	return err
}

// CleanUp removes all pending multipart uploads
func (f *Fs) cleanUp(ctx context.Context, maxAge time.Duration) (err error) {
	uploadsMap, err := f.listMultipartUploadsAll(ctx)
	if err != nil {
		return err
	}
	for bucketName, uploads := range uploadsMap {
		cleanErr := f.cleanUpBucket(ctx, bucketName, maxAge, uploads)
		if err != nil {
			fs.Errorf(f, "Failed to cleanup bucket %q: %v", bucketName, cleanErr)
			err = cleanErr
		}
	}
	return err
}

// CleanUp removes all pending multipart uploads older than 24 hours
func (f *Fs) CleanUp(ctx context.Context) (err error) {
	return f.cleanUp(ctx, 24*time.Hour)
}

// ------------------------------------------------------------
// Implement ListRer is an optional interfaces for Fs
//------------------------------------------------------------

/*
ListR lists the objects and directories of the Fs starting
from dir recursively into out.

dir should be "" to start from the root, and should not
have trailing slashes.

This should return ErrDirNotFound if the directory isn't
found.

It should call callback for each tranche of entries read.
These need not be returned in any particular order.  If
callback returns an error then the listing will stop
immediately.

Don't implement this unless you have a more efficient way
of listing recursively that doing a directory traversal.
*/
func (f *Fs) ListR(ctx context.Context, dir string, callback fs.ListRCallback) (err error) {
	bucketName, directory := f.split(dir)
	list := walk.NewListRHelper(callback)
	listR := func(bucket, directory, prefix string, addBucket bool) error {
		return f.list(ctx, bucket, directory, prefix, addBucket, true, 0, func(remote string, object *objectstorage.ObjectSummary, isDirectory bool) error {
			entry, err := f.itemToDirEntry(ctx, remote, object, isDirectory)
			if err != nil {
				return err
			}
			return list.Add(entry)
		})
	}
	if bucketName == "" {
		entries, err := f.listBuckets(ctx)
		if err != nil {
			return err
		}
		for _, entry := range entries {
			err = list.Add(entry)
			if err != nil {
				return err
			}
			bucketName := entry.Remote()
			err = listR(bucketName, "", f.rootDirectory, true)
			if err != nil {
				return err
			}
			// bucket must be present if listing succeeded
			f.cache.MarkOK(bucketName)
		}
	} else {
		err = listR(bucketName, directory, f.rootDirectory, f.rootBucket == "")
		if err != nil {
			return err
		}
		// bucket must be present if listing succeeded
		f.cache.MarkOK(bucketName)
	}
	return list.Flush()
}

// Check the interfaces are satisfied
var (
	_ fs.Fs          = &Fs{}
	_ fs.Copier      = &Fs{}
	_ fs.PutStreamer = &Fs{}
	_ fs.ListRer     = &Fs{}
	_ fs.Commander   = &Fs{}

	_ fs.Object    = &Object{}
	_ fs.MimeTyper = &Object{}
	_ fs.GetTierer = &Object{}
	_ fs.SetTierer = &Object{}
)