// Package drime provides an interface to the Drime
// object storage system.
package drime

/*
Return results give

  X-Ratelimit-Limit: 2000
  X-Ratelimit-Remaining: 1999

The rate limit headers indicate the number of allowed API requests per
minute. The limit is two thousand requests per minute, and rclone
should stay under that.
*/

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"path"
	"strconv"
	"strings"
	"time"

	"github.com/rclone/rclone/backend/drime/api"
	"github.com/rclone/rclone/fs"
	"github.com/rclone/rclone/fs/config"
	"github.com/rclone/rclone/fs/config/configmap"
	"github.com/rclone/rclone/fs/config/configstruct"
	"github.com/rclone/rclone/fs/fserrors"
	"github.com/rclone/rclone/fs/fshttp"
	"github.com/rclone/rclone/fs/hash"
	"github.com/rclone/rclone/lib/dircache"
	"github.com/rclone/rclone/lib/encoder"
	"github.com/rclone/rclone/lib/pacer"
	"github.com/rclone/rclone/lib/random"
	"github.com/rclone/rclone/lib/rest"
)

const (
	minSleep       = 10 * time.Millisecond
	maxSleep       = 20 * time.Second
	decayConstant  = 1 // bigger for slower decay, exponential
	baseURL        = "https://app.drime.cloud/"
	rootURL        = baseURL + "api/v1"
	rateLimitSleep = 5 * time.Second // penalise a goroutine by this long for making a rate limit error
	maxDepth       = 4               // in ListR recursive list this deep (maximum is 16)
)

// Register with Fs
func init() {
	fs.Register(&fs.RegInfo{
		Name:        "drime",
		Description: "Drime",
		NewFs:       NewFs,
		Options: []fs.Option{{
			Name: "access_token",
			Help: `API Access token

You can get this from the web control panel.`,
			Sensitive: true,
		}, {
			Name: "root_folder_id",
			Help: `ID of the root folder

Leave this blank normally, rclone will fill it in automatically.

If you want rclone to be restricted to a particular folder you can
fill it in - see the docs for more info.
`,
			Default:   "",
			Advanced:  true,
			Sensitive: true,
		}, {
			Name: "workspace_id",
			Help: `Account ID

Leave this blank normally, rclone will fill it in automatically.
`,
			Default:   "",
			Advanced:  true,
			Sensitive: true,
		}, {
			Name:     "list_chunk",
			Help:     `Number of items to list in each call`,
			Default:  1000,
			Advanced: true,
		}, {
			Name:     config.ConfigEncoding,
			Help:     config.ConfigEncodingHelp,
			Advanced: true,
			Default: (encoder.Display | // Slash Control Delete Dot
				encoder.EncodeDoubleQuote |
				encoder.EncodeAsterisk |
				encoder.EncodeColon |
				encoder.EncodeLtGt |
				encoder.EncodeQuestion |
				encoder.EncodeLeftSpace |
				encoder.EncodeBackSlash |
				encoder.EncodePipe |
				encoder.EncodeExclamation |
				encoder.EncodeLeftPeriod |
				encoder.EncodeRightPeriod |
				encoder.EncodeInvalidUtf8),
		}},
	})
}

// Options defines the configuration for this backend
type Options struct {
	AccessToken  string               `config:"access_token"`
	RootFolderID string               `config:"root_folder_id"`
	WorkspaceID  string               `config:"workspace_id"`
	ListChunk    int                  `config:"list_chunk"`
	Enc          encoder.MultiEncoder `config:"encoding"`
}

// Fs represents a remote drime
type Fs struct {
	name     string             // name of this remote
	root     string             // the path we are working on
	opt      Options            // parsed options
	features *fs.Features       // optional features
	srv      *rest.Client       // the connection to the server
	dirCache *dircache.DirCache // Map of directory path to directory id
	pacer    *fs.Pacer          // pacer for API calls
}

// Object describes a drime object
//
// The full set of metadata will always be present
type Object struct {
	fs       *Fs       // what this object is part of
	remote   string    // The remote path
	size     int64     // size of the object
	modTime  time.Time // modification time of the object
	id       string    // ID of the object
	dirID    string    // ID of the object's directory
	mimeType string    // mime type of the object
	url      string    // where to download this object
}

// ------------------------------------------------------------

// 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 {
	return fmt.Sprintf("drime root '%s'", f.root)
}

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

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

// retryErrorCodes is a slice of error codes that we will retry
var retryErrorCodes = []int{
	429, // Too Many Requests.
	500, // Internal Server Error
	502, // Bad Gateway
	503, // Service Unavailable
	504, // Gateway Timeout
	509, // Bandwidth Limit Exceeded
}

// Return true if the api error has the status given
func isAPIErr(err error, status string) bool {
	var apiErr api.Error
	if errors.As(err, &apiErr) {
		return apiErr.Status == status
	}
	return false
}

// shouldRetry returns a boolean as to whether this resp and err
// deserve to be retried.  It returns the err as a convenience
func shouldRetry(ctx context.Context, resp *http.Response, err error) (bool, error) {
	if fserrors.ContextError(ctx, &err) {
		return false, err
	}
	if isAPIErr(err, "error-rateLimit") {
		// Give an immediate penalty to rate limits
		fs.Debugf(nil, "Rate limited, sleep for %v", rateLimitSleep)
		time.Sleep(rateLimitSleep)
		//return true, pacer.RetryAfterError(err, 2*time.Second)
		return true, err
	}
	return fserrors.ShouldRetry(err) || fserrors.ShouldRetryHTTP(resp, retryErrorCodes), err
}

// readMetaDataForPath reads the metadata from the path
func (f *Fs) readMetaDataForPath(ctx context.Context, path string) (info *api.Item, err error) {
	// defer log.Trace(f, "path=%q", path)("info=%+v, err=%v", &info, &err)
	leaf, directoryID, err := f.dirCache.FindPath(ctx, path, false)
	if err != nil {
		if err == fs.ErrorDirNotFound {
			return nil, fs.ErrorObjectNotFound
		}
		return nil, err
	}

	found, err := f.listAll(ctx, directoryID, false, true, leaf, func(item *api.Item) bool {
		if item.Name == leaf {
			info = item
			return true
		}
		return false
	})
	if err != nil {
		return nil, err
	}
	if !found {
		return nil, fs.ErrorObjectNotFound
	}
	return info, nil
}

// getItem reads item for ID given
func (f *Fs) getItem(ctx context.Context, id string, dirID string, leaf string) (info *api.Item, err error) {
	found, err := f.listAll(ctx, dirID, false, true, leaf, func(item *api.Item) bool {
		if item.ID.String() == id {
			info = item
			return true
		}
		return false
	})
	if !found {
		return nil, fs.ErrorObjectNotFound
	}
	return info, err
}

// errorHandler parses a non 2xx error response into an error
func errorHandler(resp *http.Response) error {
	body, err := rest.ReadBody(resp)
	if err != nil {
		fs.Debugf(nil, "Couldn't read error out of body: %v", err)
		body = nil
	}
	// Decode error response if there was one - they can be blank
	var errResponse api.Error
	if len(body) > 0 {
		err = json.Unmarshal(body, &errResponse)
		if err != nil {
			fs.Debugf(nil, "Couldn't decode error response: %v", err)
		}
	}
	if errResponse.Status == "" {
		errResponse.Status = fmt.Sprintf("%s (%d): %s", resp.Status, resp.StatusCode, string(body))
	}
	return errResponse
}

// NewFs constructs an Fs from the path, container:path
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
	}

	root = parsePath(root)

	client := fshttp.NewClient(ctx)

	f := &Fs{
		name:  name,
		root:  root,
		opt:   *opt,
		srv:   rest.NewClient(client).SetRoot(rootURL),
		pacer: fs.NewPacer(ctx, pacer.NewDefault(pacer.MinSleep(minSleep), pacer.MaxSleep(maxSleep), pacer.DecayConstant(decayConstant))),
	}
	f.features = (&fs.Features{
		// FIXME
		// CaseInsensitive:          false,
		// CanHaveEmptyDirectories:  true,
		// DuplicateFiles:           true,
		ReadMimeType:  true,
		WriteMimeType: true,
		// WriteDirSetModTime:       true,
		// DirModTimeUpdatesOnWrite: true,
	}).Fill(ctx, f)
	f.srv.SetErrorHandler(errorHandler)
	f.srv.SetHeader("Authorization", "Bearer "+f.opt.AccessToken)
	f.srv.SetHeader("Accept", "application/json")

	// Read account ID if not present
	// err = f.readWorkspaceID(ctx, m)
	// if err != nil {
	// 	return nil, err
	// }

	// Read Root Folder ID if not present
	// err = f.readRootFolderID(ctx, m)
	// if err != nil {
	// 	return nil, err
	// }

	// Get rootFolderID
	rootID := f.opt.RootFolderID
	f.dirCache = dircache.New(root, rootID, f)

	// Find the current root
	err = f.dirCache.FindRoot(ctx, false)
	if err != nil {
		// Assume it is a file
		newRoot, remote := dircache.SplitPath(root)
		tempF := *f
		tempF.dirCache = dircache.New(newRoot, rootID, &tempF)
		tempF.root = newRoot
		// Make new Fs which is the parent
		err = tempF.dirCache.FindRoot(ctx, false)
		if err != nil {
			// No root so return old f
			return f, nil
		}
		_, err := tempF.newObjectWithInfo(ctx, remote, nil)
		if err != nil {
			if err == fs.ErrorObjectNotFound {
				// File doesn't exist so return old f
				return f, nil
			}
			return nil, err
		}
		f.features.Fill(ctx, &tempF)
		// XXX: update the old f here instead of returning tempF, since
		// `features` were already filled with functions having *f as a receiver.
		// See https://github.com/rclone/rclone/issues/2182
		f.dirCache = tempF.dirCache
		f.root = tempF.root
		// return an error with an fs which points to the parent
		return f, fs.ErrorIsFile
	}
	return f, nil
}

// Read the WorkspaceID into f.opt if not set and cache in the config file as workspace_id
// func (f *Fs) readWorkspaceID(ctx context.Context, m configmap.Mapper) (err error) {
// 	if f.opt.WorkspaceID != "" {
// 		return nil
// 	}
// 	opts := rest.Opts{
// 		Method: "GET",
// 		Path:   "/accounts/getid",
// 	}
// 	var result api.AccountsGetID
// 	var resp *http.Response
// 	err = f.pacer.Call(func() (bool, error) {
// 		resp, err = f.srv.CallJSON(ctx, &opts, nil, &result)
// 		return shouldRetry(ctx, resp, err)
// 	})
// 	if err != nil {
// 		return fmt.Errorf("failed to read account ID: %w", err)
// 	}
// 	f.opt.WorkspaceID = result.Data.ID
// 	m.Set("workspace_id", f.opt.WorkspaceID)
// 	return nil
// }

// Read the Accounts info
// func (f *Fs) getAccounts(ctx context.Context) (result *api.AccountsGet, err error) {
// 	opts := rest.Opts{
// 		Method: "GET",
// 		Path:   "/accounts/" + f.opt.WorkspaceID,
// 	}
// 	result = new(api.AccountsGet)
// 	var resp *http.Response
// 	err = f.pacer.Call(func() (bool, error) {
// 		resp, err = f.srv.CallJSON(ctx, &opts, nil, &result)
// 		return shouldRetry(ctx, resp, err)
// 	})
// 	if err != nil {
// 		return nil, fmt.Errorf("failed to read accountd info: %w", err)
// 	}
// 	return result, nil
// }

// Read the RootFolderID into f.opt if not set and cache in the config file as root_folder_id
// func (f *Fs) readRootFolderID(ctx context.Context, m configmap.Mapper) (err error) {
// 	if f.opt.RootFolderID != "" {
// 		return nil
// 	}
// 	result, err := f.getAccounts(ctx)
// 	if err != nil {
// 		return err
// 	}
// 	f.opt.RootFolderID = result.Data.RootFolder
// 	m.Set("root_folder_id", f.opt.RootFolderID)
// 	return nil
// }

// rootSlash returns root with a slash on if it is empty, otherwise empty string
func (f *Fs) rootSlash() string {
	if f.root == "" {
		return f.root
	}
	return f.root + "/"
}

// 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 *api.Item) (fs.Object, error) {
	o := &Object{
		fs:     f,
		remote: remote,
	}
	var err error
	if info != nil {
		// Set info
		err = o.setMetaData(info)
	} else {
		err = o.readMetaData(ctx) // reads info and meta, 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)
}

// FindLeaf finds a directory of name leaf in the folder with ID pathID
func (f *Fs) FindLeaf(ctx context.Context, pathID, leaf string) (pathIDOut string, found bool, err error) {
	// Find the leaf in pathID
	found, err = f.listAll(ctx, pathID, true, false, leaf, func(item *api.Item) bool {
		if item.Name == leaf {
			pathIDOut = item.ID.String()
			return true
		}
		return false
	})
	return pathIDOut, found, err
}

// createDir makes a directory with pathID as parent and name leaf and modTime
func (f *Fs) createDir(ctx context.Context, pathID, leaf string, modTime time.Time) (item *api.Item, err error) {
	var resp *http.Response
	var result api.CreateFolderResponse
	opts := rest.Opts{
		Method: "POST",
		Path:   "/folders",
	}
	mkdir := api.CreateFolderRequest{
		Name:     f.opt.Enc.FromStandardName(leaf),
		ParentID: json.Number(pathID),
	}
	err = f.pacer.Call(func() (bool, error) {
		resp, err = f.srv.CallJSON(ctx, &opts, &mkdir, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return nil, fmt.Errorf("failed to create folder: %w", err)
	}
	return &result.Folder, nil
}

// CreateDir makes a directory with pathID as parent and name leaf
func (f *Fs) CreateDir(ctx context.Context, pathID, leaf string) (newID string, err error) {
	// fs.Debugf(f, "CreateDir(%q, %q)\n", pathID, leaf)
	item, err := f.createDir(ctx, pathID, leaf, time.Now())
	if err != nil {
		return "", err
	}
	return item.ID.String(), nil
}

// list the objects into the function supplied
//
// If directories is set it only sends directories
// User function to process a File item from listAll
//
// Should return true to finish processing
type listAllFn func(*api.Item) bool

// Lists the directory required calling the user function on each item found
//
// If name is set then the server will limit the returned items to those
// with that name.
//
// If the user fn ever returns true then it early exits with found = true
func (f *Fs) listAll(ctx context.Context, dirID string, directoriesOnly bool, filesOnly bool, name string, fn listAllFn) (found bool, err error) {
	opts := rest.Opts{
		Method:     "GET",
		Path:       "/drive/file-entries",
		Parameters: url.Values{},
	}
	if dirID != "" {
		opts.Parameters.Add("parentIds", dirID)
	}
	if name != "" {
		// FIXME causes 500 server error
		//opts.Parameters.Add("query", f.opt.Enc.FromStandardName(name))
	}
	if directoriesOnly {
		opts.Parameters.Add("type", api.ItemTypeFolder)
	}
	opts.Parameters.Set("perPage", strconv.Itoa(f.opt.ListChunk))
	page := 1
OUTER:
	for {
		opts.Parameters.Set("page", strconv.Itoa(page))
		var result api.Listing
		var resp *http.Response
		err = f.pacer.Call(func() (bool, error) {
			resp, err = f.srv.CallJSON(ctx, &opts, nil, &result)
			return shouldRetry(ctx, resp, err)
		})
		if err != nil {
			return found, fmt.Errorf("couldn't list files: %w", err)
		}
		for _, item := range result.Data {
			if item.Type == api.ItemTypeFolder {
				if filesOnly {
					continue
				}
			} else {
				if directoriesOnly {
					continue
				}
			}
			item.Name = f.opt.Enc.ToStandardName(item.Name)
			if fn(&item) {
				found = true
				break OUTER
			}
		}
		if result.NextPage == 0 {
			break
		}
		page = result.NextPage
	}
	return found, err
}

// Convert a list item into a DirEntry
func (f *Fs) itemToDirEntry(ctx context.Context, remote string, info *api.Item) (entry fs.DirEntry, err error) {
	if info.Type == api.ItemTypeFolder {
		// cache the directory ID for later lookups
		f.dirCache.Put(remote, info.ID.String())
		entry = fs.NewDir(remote, info.UpdatedAt).
			SetSize(info.FileSize).
			SetID(info.ID.String()).
			SetParentID(info.ParentID.String())
	} else {
		entry, err = f.newObjectWithInfo(ctx, remote, info)
		if err != nil {
			return nil, err
		}
	}
	return entry, nil
}

// 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) {
	directoryID, err := f.dirCache.FindDir(ctx, dir, false)
	if err != nil {
		return nil, err
	}
	var iErr error
	_, err = f.listAll(ctx, directoryID, false, false, "", func(info *api.Item) bool {
		remote := path.Join(dir, info.Name)
		entry, err := f.itemToDirEntry(ctx, remote, info)
		if err != nil {
			iErr = err
			return true
		}
		entries = append(entries, entry)
		return false
	})
	if err != nil {
		return nil, err
	}
	if iErr != nil {
		return nil, iErr
	}
	return entries, nil
}

// implementation of ListR
// func (f *Fs) listR(ctx context.Context, dir string, list *list.Helper) (err error) {
// 	directoryID, err := f.dirCache.FindDir(ctx, dir, false)
// 	if err != nil {
// 		return err
// 	}
// 	opts := rest.Opts{
// 		Method:     "GET",
// 		Path:       "/contents/" + directoryID,
// 		Parameters: url.Values{"maxdepth": {strconv.Itoa(maxDepth)}},
// 	}
// 	page := 1
// 	for {
// 		opts.Parameters.Set("page", strconv.Itoa(page))
// 		opts.Parameters.Set("pageSize", strconv.Itoa(f.opt.ListChunk))
// 		var result api.Contents
// 		var resp *http.Response
// 		err = f.pacer.Call(func() (bool, error) {
// 			resp, err = f.srv.CallJSON(ctx, &opts, nil, &result)
// 			return shouldRetry(ctx, resp, err)
// 		})
// 		if err != nil {
// 			if isAPIErr(err, "error-notFound") {
// 				return fs.ErrorDirNotFound
// 			}
// 			return fmt.Errorf("couldn't recursively list files: %w", err)
// 		}
// 		// Result.Data.Item now contains a recursive listing so we will have to decode recursively
// 		var decode func(string, *api.Item) error
// 		decode = func(dir string, dirItem *api.Item) error {
// 			// If we have ChildrenCount but no Children this means the recursion stopped here
// 			if dirItem.ChildrenCount > 0 && len(dirItem.Children) == 0 {
// 				return f.listR(ctx, dir, list)
// 			}
// 			for _, item := range dirItem.Children {
// 				if item.Type != api.ItemTypeFolder && item.Type != api.ItemTypeFile {
// 					fs.Debugf(f, "Ignoring %q - unknown type %q", item.Name, item.Type)
// 					continue
// 				}
// 				item.Name = f.opt.Enc.ToStandardName(item.Name)
// 				remote := path.Join(dir, item.Name)
// 				entry, err := f.itemToDirEntry(ctx, remote, item)
// 				if err != nil {
// 					return err
// 				}
// 				err = list.Add(entry)
// 				if err != nil {
// 					return err
// 				}
// 				if item.Type == api.ItemTypeFolder {
// 					err := decode(remote, item)
// 					if err != nil {
// 						return err
// 					}
// 				}
// 			}
// 			return nil
// 		}
// 		err = decode(dir, &result.Data.Item)
// 		if err != nil {
// 			return err
// 		}
// 		if !result.Metadata.HasNextPage {
// 			break
// 		}
// 		page += 1
// 	}
// 	return err
// }

// 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 than doing a directory traversal.
// func (f *Fs) ListR(ctx context.Context, dir string, callback fs.ListRCallback) (err error) {
// 	list := list.NewHelper(callback)
// 	err = f.listR(ctx, dir, list)
// 	if err != nil {
// 		return err
// 	}
// 	return list.Flush()
// }

// Creates from the parameters passed in a half finished Object which
// must have setMetaData called on it
//
// Returns the object, leaf, directoryID and error.
//
// Used to create new objects
func (f *Fs) createObject(ctx context.Context, remote string, modTime time.Time, size int64) (o *Object, leaf string, directoryID string, err error) {
	// Create the directory for the object if it doesn't exist
	leaf, directoryID, err = f.dirCache.FindPath(ctx, remote, true)
	if err != nil {
		return
	}
	// Temporary Object under construction
	o = &Object{
		fs:     f,
		remote: remote,
	}
	return o, leaf, directoryID, nil
}

// Put the object
//
// 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) {
	existingObj, err := f.NewObject(ctx, src.Remote())
	switch err {
	case nil:
		return existingObj, existingObj.Update(ctx, in, src, options...)
	case fs.ErrorObjectNotFound:
		// Not found so create it
		return f.PutUnchecked(ctx, in, src, options...)
	default:
		return nil, err
	}
}

// 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...)
}

// PutUnchecked the object into the container
//
// This will produce a duplicate if the object already exists.
//
// 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) PutUnchecked(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
	remote := src.Remote()
	size := src.Size()
	modTime := src.ModTime(ctx)

	o, _, _, err := f.createObject(ctx, remote, modTime, size)
	if err != nil {
		return nil, err
	}
	return o, o.Update(ctx, in, src, options...)
}

// Mkdir creates the container if it doesn't exist
func (f *Fs) Mkdir(ctx context.Context, dir string) error {
	_, err := f.dirCache.FindDir(ctx, dir, true)
	return err
}

// DirSetModTime sets the directory modtime for dir
// func (f *Fs) DirSetModTime(ctx context.Context, dir string, modTime time.Time) error {
// 	dirID, err := f.dirCache.FindDir(ctx, dir, false)
// 	if err != nil {
// 		return err
// 	}
// 	_, err = f.setModTime(ctx, dirID, modTime)
// 	return err
// }

// deleteObject removes an object by ID
func (f *Fs) deleteObject(ctx context.Context, id string) error {
	opts := rest.Opts{
		Method: "POST",
		Path:   "/file-entries/delete",
	}
	request := api.DeleteRequest{
		EntryIds:      []string{id},
		DeleteForever: false, // FIXME: hard delete?
	}
	var result api.DeleteResponse
	err := f.pacer.Call(func() (bool, error) {
		resp, err := f.srv.CallJSON(ctx, &opts, &request, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return fmt.Errorf("failed to delete item: %w", err)
	}
	// Check the individual result codes also
	for _, err := range result.Data {
		if err.IsError() {
			return fmt.Errorf("failed to delete item: %w", err)
		}
	}
	return nil
}

// purgeCheck removes the root directory, if check is set then it
// refuses to do so if it has anything in
func (f *Fs) purgeCheck(ctx context.Context, dir string, check bool) error {
	root := path.Join(f.root, dir)
	if root == "" {
		return errors.New("can't purge root directory")
	}
	dc := f.dirCache
	rootID, err := dc.FindDir(ctx, dir, false)
	if err != nil {
		return err
	}

	// Check to see if there is contents in the directory
	if check {
		found, err := f.listAll(ctx, rootID, false, false, "", func(item *api.Item) bool {
			return true
		})
		if err != nil {
			return err
		}
		if found {
			return fs.ErrorDirectoryNotEmpty
		}
	}

	// Delete the directory
	err = f.deleteObject(ctx, rootID)
	if err != nil {
		return err
	}

	f.dirCache.FlushDir(dir)
	return nil
}

// Rmdir deletes the root folder
//
// Returns an error if it isn't empty
func (f *Fs) Rmdir(ctx context.Context, dir string) error {
	return f.purgeCheck(ctx, dir, true)
}

// Precision return the precision of this Fs
func (f *Fs) Precision() time.Duration {
	return fs.ModTimeNotSupported
}

// Purge deletes all the files and the container
//
// Optional interface: Only implement this if you have a way of
// deleting all the files quicker than just running Remove() on the
// result of List()
func (f *Fs) Purge(ctx context.Context, dir string) error {
	return f.purgeCheck(ctx, dir, false)
}

// About gets quota information
func (f *Fs) About(ctx context.Context) (usage *fs.Usage, err error) {
	// result, err := f.getAccounts(ctx)
	// if err != nil {
	// 	return nil, err
	// }
	// used := result.Data.StatsCurrent.Storage
	// files := result.Data.StatsCurrent.FileCount
	// total := result.Data.SubscriptionLimitStorage
	// usage = &fs.Usage{
	// 	Used:    fs.NewUsageValue(used),         // bytes in use
	// 	Total:   fs.NewUsageValue(total),        // bytes total
	// 	Free:    fs.NewUsageValue(total - used), // bytes free
	// 	Objects: fs.NewUsageValue(files),        // total objects
	// }
	// FIXME
	return usage, nil
}

// patch an attribute on an object to value
func (f *Fs) patch(ctx context.Context, id, attribute string, value string) (item *api.Item, err error) {
	var resp *http.Response
	var request = api.UpdateItemRequest{
		Name: value,
	}
	var result api.UpdateItemResponse
	opts := rest.Opts{
		Method: "PUT",
		Path:   "/file-entries/" + id,
	}
	err = f.pacer.Call(func() (bool, error) {
		resp, err = f.srv.CallJSON(ctx, &opts, &request, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return nil, fmt.Errorf("failed to patch item %q to %v: %w", attribute, value, err)
	}
	return &result.FileEntry, nil
}

// rename a file or a folder
func (f *Fs) rename(ctx context.Context, id, newLeaf string) (item *api.Item, err error) {
	return f.patch(ctx, id, "name", f.opt.Enc.FromStandardName(newLeaf))
}

// // setModTime sets the modification time of a file or folder
// func (f *Fs) setModTime(ctx context.Context, id string, modTime time.Time) (item *api.Item, err error) {
// 	return f.patch(ctx, id, "modTime", api.ToNativeTime(modTime))
// }

// move a file or a folder to a new directory
// func (f *Fs) move(ctx context.Context, id, newDirID string, dstLeaf string) (item *api.Item, err error) {
func (f *Fs) move(ctx context.Context, id, newDirID string) (err error) {
	var resp *http.Response
	var request = api.MoveRequest{
		EntryIds:      []string{id},
		DestinationID: newDirID,
	}
	var result api.MoveResponse
	opts := rest.Opts{
		Method: "POST",
		Path:   "/file-entries/move",
	}
	err = f.pacer.Call(func() (bool, error) {
		resp, err = f.srv.CallJSON(ctx, &opts, &request, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		// return nil, fmt.Errorf("failed to move item: %w", err)
		return fmt.Errorf("failed to move item: %w", err)
	}
	// itemResult := result.Entries[0] // FIXME: doesn't return entries as specified in docs
	// return &itemResult, nil

	// get result through other means:
	// return f.getItem(ctx, id, newDirID, dstLeaf)

	return nil
}

// move and rename a file or folder to directoryID with leaf
func (f *Fs) moveTo(ctx context.Context, id, srcLeaf, dstLeaf, srcDirectoryID, dstDirectoryID string) (info *api.Item, err error) {
	newLeaf := f.opt.Enc.FromStandardName(dstLeaf)
	oldLeaf := f.opt.Enc.FromStandardName(srcLeaf)
	doRenameLeaf := oldLeaf != newLeaf
	doMove := srcDirectoryID != dstDirectoryID

	// Now rename the leaf to a temporary name if we are moving to
	// another directory to make sure we don't overwrite something
	// in the destination directory by accident
	if doRenameLeaf && doMove {
		tmpLeaf := newLeaf + "." + random.String(8)
		info, err = f.rename(ctx, id, tmpLeaf)
		if err != nil {
			return nil, fmt.Errorf("Move rename leaf: %w", err)
		}
	}

	// Move the object to a new directory (with the existing name)
	// if required
	if doMove {
		err = f.move(ctx, id, dstDirectoryID)
		if err != nil {
			return nil, err
		}
	}

	// Rename the leaf to its final name if required
	if doRenameLeaf {
		info, err = f.rename(ctx, id, newLeaf)
		if err != nil {
			return nil, fmt.Errorf("Move rename leaf: %w", err)
		}
	}

	if info == nil {
		info, err = f.getItem(ctx, id, dstDirectoryID, dstLeaf)
		if err != nil {
			return nil, err
		}
	}

	return info, nil
}

// Move src to this remote using server-side move operations.
//
// This is stored with the remote path given.
//
// It returns the destination Object and a possible error.
//
// Will only be called if src.Fs().Name() == f.Name()
//
// If it isn't possible then return fs.ErrorCantMove
func (f *Fs) Move(ctx context.Context, src fs.Object, remote string) (fs.Object, error) {
	srcObj, ok := src.(*Object)
	if !ok {
		fs.Debugf(src, "Can't move - not same remote type")
		return nil, fs.ErrorCantMove
	}

	// Find existing object
	srcLeaf, srcDirectoryID, err := srcObj.fs.dirCache.FindPath(ctx, srcObj.remote, false)
	if err != nil {
		return nil, err
	}

	// Create temporary object
	dstObj, dstLeaf, dstDirectoryID, err := f.createObject(ctx, remote, srcObj.modTime, srcObj.size)
	if err != nil {
		return nil, err
	}

	// Do the move
	info, err := f.moveTo(ctx, srcObj.id, srcLeaf, dstLeaf, srcDirectoryID, dstDirectoryID)
	if err != nil {
		return nil, err
	}

	err = dstObj.setMetaData(info)
	if err != nil {
		return nil, err
	}
	return dstObj, nil
}

// DirMove moves src, srcRemote to this remote at dstRemote
// using server-side move operations.
//
// Will only be called if src.Fs().Name() == f.Name()
//
// If it isn't possible then return fs.ErrorCantDirMove
//
// If destination exists then return fs.ErrorDirExists
func (f *Fs) DirMove(ctx context.Context, src fs.Fs, srcRemote, dstRemote string) error {
	srcFs, ok := src.(*Fs)
	if !ok {
		fs.Debugf(srcFs, "Can't move directory - not same remote type")
		return fs.ErrorCantDirMove
	}

	srcID, srcDirectoryID, srcLeaf, dstDirectoryID, dstLeaf, err := f.dirCache.DirMove(ctx, srcFs.dirCache, srcFs.root, srcRemote, f.root, dstRemote)
	if err != nil {
		return err
	}

	// Do the move
	_, err = f.moveTo(ctx, srcID, srcLeaf, dstLeaf, srcDirectoryID, dstDirectoryID)
	if err != nil {
		return err
	}
	srcFs.dirCache.FlushDir(srcRemote)
	return nil
}

// copy a file or a folder to a new directory
func (f *Fs) copy(ctx context.Context, id, newDirID string) (item *api.Item, err error) {
	var resp *http.Response
	var request = api.CopyRequest{
		EntryIds:      []string{id},
		DestinationID: newDirID,
	}
	var result api.CopyResponse
	opts := rest.Opts{
		Method: "POST",
		Path:   "/file-entries/duplicate",
	}
	err = f.pacer.Call(func() (bool, error) {
		resp, err = f.srv.CallJSON(ctx, &opts, &request, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return nil, fmt.Errorf("failed to copy item: %w", err)
	}
	itemResult := result.Entries[0]
	return &itemResult, nil
}

// copy and rename a file or folder to directoryID with leaf
func (f *Fs) copyTo(ctx context.Context, srcID, srcLeaf, dstLeaf, dstDirectoryID string) (info *api.Item, err error) {
	// Can have duplicates so don't have to be careful here

	// Copy to dstDirectoryID first
	info, err = f.copy(ctx, srcID, dstDirectoryID)
	if err != nil {
		return nil, err
	}

	// Rename if required
	if srcLeaf != dstLeaf {
		info, err = f.rename(ctx, info.ID.String(), dstLeaf)
		if err != nil {
			return nil, err
		}
	}
	return info, nil
}

// Copy src to this remote using server-side copy operations.
//
// This is stored with the remote path given.
//
// It returns the destination Object and a possible error.
//
// Will only be called if src.Fs().Name() == f.Name()
//
// If it isn't possible then return fs.ErrorCantCopy
func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (dst fs.Object, err error) {
	srcObj, ok := src.(*Object)
	if !ok {
		fs.Debugf(src, "Can't copy - not same remote type")
		return nil, fs.ErrorCantCopy
	}
	srcLeaf := path.Base(srcObj.remote)

	srcPath := srcObj.fs.rootSlash() + srcObj.remote
	dstPath := f.rootSlash() + remote
	if srcPath == dstPath {
		return nil, fmt.Errorf("can't copy %q -> %q as are same name", srcPath, dstPath)
	}

	// Find existing object
	existingObj, err := f.NewObject(ctx, remote)
	if err == nil {
		defer func() {
			// Don't remove existing object if returning an error
			if err != nil {
				return
			}
			fs.Debugf(existingObj, "Server side copy: removing existing object after successful copy")
			err = existingObj.Remove(ctx)
		}()
	}

	// Create temporary object
	dstObj, dstLeaf, dstDirectoryID, err := f.createObject(ctx, remote, srcObj.modTime, srcObj.size)
	if err != nil {
		return nil, err
	}

	// Copy the object
	info, err := f.copyTo(ctx, srcObj.id, srcLeaf, dstLeaf, dstDirectoryID)
	if err != nil {
		return nil, err
	}
	err = dstObj.setMetaData(info)
	if err != nil {
		return nil, err
	}

	// Reset the modification time as copy does not preserve it
	// err = dstObj.SetModTime(ctx, srcObj.modTime)
	// if err != nil {
	// 	return nil, err
	// }

	return dstObj, nil
}

// unLink a file or directory
// func (f *Fs) unLink(ctx context.Context, remote string, id string, info *api.Item) (err error) {
// 	if info == nil {
// 		info, err = f.readMetaDataForID(ctx, id)
// 		if err != nil {
// 			return err
// 		}
// 	}
// 	for linkID, link := range info.DirectLinks {
// 		fs.Debugf(remote, "Removing direct link %s", link.DirectLink)
// 		opts := rest.Opts{
// 			Method: "DELETE",
// 			Path:   "/contents/" + id + "/directlinks/" + linkID,
// 		}
// 		var result api.Error
// 		err := f.pacer.Call(func() (bool, error) {
// 			resp, err := f.srv.CallJSON(ctx, &opts, nil, &result)
// 			return shouldRetry(ctx, resp, err)
// 		})
// 		if err != nil {
// 			return fmt.Errorf("failed to unlink: %s", link.DirectLink)
// 		}
// 	}
// 	return nil
// }

// PublicLink adds a "readable by anyone with link" permission on the given file or folder.
// func (f *Fs) PublicLink(ctx context.Context, remote string, expire fs.Duration, unlink bool) (string, error) {
// 	id, err := f.dirCache.FindDir(ctx, remote, false)
// 	var info *api.Item
// 	if err == nil {
// 		fs.Debugf(f, "attempting to share directory '%s'", remote)
// 	} else {
// 		fs.Debugf(f, "attempting to share single file '%s'", remote)
// 		info, err = f.readMetaDataForPath(ctx, remote)
// 		if err != nil {
// 			return "", err
// 		}
// 		id = info.ID.String()
// 	}
// 	if unlink {
// 		return "", f.unLink(ctx, remote, id, info)
// 	}
// 	var resp *http.Response
// 	var request api.DirectLinksRequest
// 	var result api.DirectLinksResult
// 	opts := rest.Opts{
// 		Method: "POST",
// 		Path:   "/contents/" + id + "/directlinks",
// 	}
// 	if expire != fs.DurationOff {
// 		when := time.Now().Add(time.Duration(expire))
// 		fs.Debugf(f, "Link expires at %v (duration %v)", when, expire)
// 		request.ExpireTime = api.ToNativeTime(when)
// 	}
// 	err = f.pacer.Call(func() (bool, error) {
// 		resp, err = f.srv.CallJSON(ctx, &opts, &request, &result)
// 		return shouldRetry(ctx, resp, err)
// 	})
// 	if err != nil {
// 		return "", fmt.Errorf("failed to create direct link: %w", err)
// 	}
// 	return result.Data.DirectLink, err
// }

// DirCacheFlush resets the directory cache - used in testing as an
// optional interface
func (f *Fs) DirCacheFlush() {
	f.dirCache.ResetRoot()
}

// Hashes returns the supported hash sets.
func (f *Fs) Hashes() hash.Set {
	return hash.Set(hash.None)
}

// MergeDirs merges the contents of all the directories passed
// in into the first one and rmdirs the other directories.
// func (f *Fs) MergeDirs(ctx context.Context, dirs []fs.Directory) error {
// 	if len(dirs) < 2 {
// 		return nil
// 	}
// 	dstDir := dirs[0]
// 	for _, srcDir := range dirs[1:] {
// 		// list the objects
// 		infos := []*api.Item{}
// 		_, err := f.listAll(ctx, srcDir.ID(), false, false, "", func(info *api.Item) bool {
// 			infos = append(infos, info)
// 			return false
// 		})
// 		if err != nil {
// 			return fmt.Errorf("MergeDirs list failed on %v: %w", srcDir, err)
// 		}
// 		// move them into place
// 		for _, info := range infos {
// 			fs.Infof(srcDir, "merging %q", info.Name)
// 			// Move the file into the destination
// 			_, err = f.move(ctx, info.ID.String(), dstDir.ID())
// 			if err != nil {
// 				return fmt.Errorf("MergeDirs move failed on %q in %v: %w", info.Name, srcDir, err)
// 			}
// 		}
// 		// rmdir the now empty source directory
// 		fs.Infof(srcDir, "removing empty directory")
// 		err = f.deleteObject(ctx, srcDir.ID())
// 		if err != nil {
// 			return fmt.Errorf("MergeDirs move failed to rmdir %q: %w", srcDir, err)
// 		}
// 	}
// 	return nil
// }

// ------------------------------------------------------------

// Fs returns the parent Fs
func (o *Object) Fs() fs.Info {
	return o.fs
}

// Return a string version
func (o *Object) String() string {
	if o == nil {
		return "<nil>"
	}
	return o.remote
}

// Remote returns the remote path
func (o *Object) Remote() string {
	return o.remote
}

// Hash returns the SHA-1 of an object returning a lowercase hex string
func (o *Object) Hash(ctx context.Context, t hash.Type) (string, error) {
	return "", hash.ErrUnsupported
}

// Size returns the size of an object in bytes
func (o *Object) Size() int64 {
	return o.size
}

// setMetaDataAny sets the metadata from info but doesn't check the type
func (o *Object) setMetaDataAny(info *api.Item) {
	o.size = info.FileSize
	o.modTime = info.UpdatedAt
	o.id = info.ID.String()
	o.dirID = info.ParentID.String()
	o.mimeType = info.Mime
	o.url = info.URL
}

// setMetaData sets the metadata from info
func (o *Object) setMetaData(info *api.Item) (err error) {
	if info.Type == api.ItemTypeFolder {
		return fs.ErrorIsDir
	}
	if info.ID == "" {
		return fmt.Errorf("ID not found in response")
	}
	o.setMetaDataAny(info)
	return nil
}

// readMetaData gets the metadata unconditionally as we expect Object
// to always have the full set of metadata
func (o *Object) readMetaData(ctx context.Context) (err error) {
	var info *api.Item
	info, err = o.fs.readMetaDataForPath(ctx, o.remote)
	if err != nil {
		if isAPIErr(err, "error-notFound") {
			return fs.ErrorObjectNotFound
		}
		return err
	}
	return o.setMetaData(info)
}

// ModTime returns the modification time of the object
//
// It attempts to read the objects mtime and if that isn't present the
// LastModified returned in the http headers
func (o *Object) ModTime(ctx context.Context) time.Time {
	return o.modTime
}

// SetModTime sets the modification time of the local fs object
func (o *Object) SetModTime(ctx context.Context, modTime time.Time) error {
	// info, err := o.fs.setModTime(ctx, o.id, modTime)
	// if err != nil {
	// 	return err
	// }
	// return o.setMetaData(info)
	return fs.ErrorCantSetModTime
}

// Storable returns a boolean showing whether this object storable
func (o *Object) Storable() bool {
	return true
}

// Open an object for read
func (o *Object) Open(ctx context.Context, options ...fs.OpenOption) (in io.ReadCloser, err error) {
	if o.id == "" {
		return nil, errors.New("can't download - no id")
	}
	if o.url == "" {
		// On upload an Object is returned with no url, so fetch it here if needed
		err = o.readMetaData(ctx)
		if err != nil {
			return nil, fmt.Errorf("read metadata: %w", err)
		}
	}
	fs.FixRangeOption(options, o.size)
	var resp *http.Response
	opts := rest.Opts{
		Method:  "GET",
		RootURL: baseURL + o.url,
		Options: options,
		// Workaround for bug in content servers - no longer needed
		// ExtraHeaders: map[string]string{
		// 	"Cookie": "accountToken=" + o.fs.opt.AccessToken,
		// },
	}

	err = o.fs.pacer.Call(func() (bool, error) {
		resp, err = o.fs.srv.Call(ctx, &opts)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return nil, err
	}
	return resp.Body, err
}

// Update the object with the contents of the io.Reader, modTime and size
//
// If existing is set then it updates the object rather than creating a new one.
//
// The new object may have been created if an error is returned.
func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (err error) {
	remote := o.Remote()
	//modTime := src.ModTime(ctx)

	// Create the directory for the object if it doesn't exist
	leaf, directoryID, err := o.fs.dirCache.FindPath(ctx, remote, true)
	if err != nil {
		return err
	}

	// If the file exists, delete it after a successful upload
	if o.id != "" {
		id := o.id
		o.id = ""
		defer func() {
			if err != nil {
				return
			}
			fs.Debugf(o, "Removing old object on successful upload")
			deleteErr := o.fs.deleteObject(ctx, id)
			if deleteErr != nil {
				err = fmt.Errorf("failed to delete existing object: %w", deleteErr)
			}
		}()
	}

	// Do the upload
	var resp *http.Response
	var result api.UploadResponse
	var encodedLeaf = o.fs.opt.Enc.FromStandardName(leaf)
	opts := rest.Opts{
		Method: "POST",
		Body:   in,
		MultipartParams: url.Values{
			"parentId":     {directoryID},
			"relativePath": {encodedLeaf},
			// FIXME "modTime":  {strconv.FormatInt(modTime.Unix(), 10)},
		},
		MultipartContentName: "file",
		MultipartFileName:    encodedLeaf,
		MultipartContentType: fs.MimeType(ctx, src),
		Path:                 "/uploads",
		Options:              options,
	}
	err = o.fs.pacer.CallNoRetry(func() (bool, error) {
		resp, err = o.fs.srv.CallJSON(ctx, &opts, nil, &result)
		return shouldRetry(ctx, resp, err)
	})
	if err != nil {
		return fmt.Errorf("failed to upload file: %w", err)
	}
	return o.setMetaData(&result.FileEntry)
}

// Remove an object
func (o *Object) Remove(ctx context.Context) error {
	return o.fs.deleteObject(ctx, o.id)
}

// ID returns the ID of the Object if known, or "" if not
func (o *Object) ID() string {
	return o.id
}

// MimeType returns the content type of the Object if known, or "" if not
func (o *Object) MimeType(ctx context.Context) string {
	return o.mimeType
}

// ParentID returns the ID of the Object parent if known, or "" if not
func (o *Object) ParentID() string {
	return o.dirID
}

// Check the interfaces are satisfied
var (
	_ fs.Fs              = (*Fs)(nil)
	_ fs.Purger          = (*Fs)(nil)
	_ fs.PutStreamer     = (*Fs)(nil)
	_ fs.Copier          = (*Fs)(nil)
	_ fs.Abouter         = (*Fs)(nil)
	_ fs.Mover           = (*Fs)(nil)
	_ fs.DirMover        = (*Fs)(nil)
	_ fs.DirCacheFlusher = (*Fs)(nil)
	//_ fs.PublicLinker    = (*Fs)(nil)
	//_ fs.MergeDirser    = (*Fs)(nil)
	// _ fs.DirSetModTimer = (*Fs)(nil)
	//	_ fs.ListRer         = (*Fs)(nil)
	_ fs.Object    = (*Object)(nil)
	_ fs.IDer      = (*Object)(nil)
	_ fs.MimeTyper = (*Object)(nil)
)