// commandShouldRunOnDaemon determines, from commmand details, whether a
// command ought to be executed on an IPFS daemon.
//
// It returns a client if the command should be executed on a daemon and nil if
// it should be executed on a client. It returns an error if the command must
// NOT be executed on either.
func commandShouldRunOnDaemon(details cmdDetails, req cmds.Request, root *cmds.Command) (cmdsHttp.Client, error) {
	path := req.Path()
	// root command.
	if len(path) < 1 {
		return nil, nil
	}

	if details.cannotRunOnClient && details.cannotRunOnDaemon {
		return nil, fmt.Errorf("command disabled: %s", path[0])
	}

	if details.doesNotUseRepo && details.canRunOnClient() {
		return nil, nil
	}

	// at this point need to know whether api is running. we defer
	// to this point so that we dont check unnecessarily

	// did user specify an api to use for this command?
	apiAddrStr, _, err := req.Option(coreCmds.ApiOption).String()
	if err != nil {
		return nil, err
	}

	client, err := getApiClient(req.InvocContext().ConfigRoot, apiAddrStr)
	if err == repo.ErrApiNotRunning {
		if apiAddrStr != "" && req.Command() != daemonCmd {
			// if user SPECIFIED an api, and this cmd is not daemon
			// we MUST use it. so error out.
			return nil, err
		}

		// ok for api not to be running
	} else if err != nil { // some other api error
		return nil, err
	}

	if client != nil { // daemon is running
		if details.cannotRunOnDaemon {
			e := "cannot use API with this command."

			// check if daemon locked. legacy error text, for now.
			daemonLocked, _ := fsrepo.LockedByOtherProcess(req.InvocContext().ConfigRoot)
			if daemonLocked {
				e = "ipfs daemon is running. please stop it to run this command"
			}

			return nil, cmds.ClientError(e)
		}

		return client, nil
	}

	if details.cannotRunOnClient {
		return nil, cmds.ClientError("must run on the ipfs daemon")
	}

	return nil, nil
}

func getCompressOptions(req cmds.Request) (int, error) {
	cmprs, _, _ := req.Option("compress").Bool()
	cmplvl, cmplvlFound, _ := req.Option("compression-level").Int()
	switch {
	case !cmprs:
		return gzip.NoCompression, nil
	case cmprs && !cmplvlFound:
		return gzip.DefaultCompression, nil
	case cmprs && cmplvlFound && (cmplvl < 1 || cmplvl > 9):
		return gzip.NoCompression, ErrInvalidCompressionLevel
	}
	return cmplvl, nil
}

//collects options and opens the fuse mountpoint
func mountFuse(req cmds.Request) error {
	cfg, err := req.InvocContext().GetConfig()
	if err != nil {
		return fmt.Errorf("mountFuse: GetConfig() failed: %s", err)
	}

	fsdir, found, err := req.Option(ipfsMountKwd).String()
	if err != nil {
		return fmt.Errorf("mountFuse: req.Option(%s) failed: %s", ipfsMountKwd, err)
	}
	if !found {
		fsdir = cfg.Mounts.IPFS
	}

	nsdir, found, err := req.Option(ipnsMountKwd).String()
	if err != nil {
		return fmt.Errorf("mountFuse: req.Option(%s) failed: %s", ipnsMountKwd, err)
	}
	if !found {
		nsdir = cfg.Mounts.IPNS
	}

	node, err := req.InvocContext().ConstructNode()
	if err != nil {
		return fmt.Errorf("mountFuse: ConstructNode() failed: %s", err)
	}

	err = commands.Mount(node, fsdir, nsdir)
	if err != nil {
		return err
	}
	fmt.Printf("IPFS mounted at: %s\n", fsdir)
	fmt.Printf("IPNS mounted at: %s\n", nsdir)
	return nil
}

func callCommand(ctx context.Context, req cmds.Request, root *cmds.Command, cmd *cmds.Command) (cmds.Response, error) {
	log.Info(config.EnvDir, " ", req.InvocContext().ConfigRoot)
	var res cmds.Response

	err := req.SetRootContext(ctx)
	if err != nil {
		return nil, err
	}

	details, err := commandDetails(req.Path(), root)
	if err != nil {
		return nil, err
	}

	client, err := commandShouldRunOnDaemon(*details, req, root)
	if err != nil {
		return nil, err
	}

	err = callPreCommandHooks(ctx, *details, req, root)
	if err != nil {
		return nil, err
	}

	if cmd.PreRun != nil {
		err = cmd.PreRun(req)
		if err != nil {
			return nil, err
		}
	}

	if client != nil {
		log.Debug("Executing command via API")
		res, err = client.Send(req)
		if err != nil {
			if isConnRefused(err) {
				err = repo.ErrApiNotRunning
			}
			return nil, err
		}

	} else {
		log.Debug("Executing command locally")

		err := req.SetRootContext(ctx)
		if err != nil {
			return nil, err
		}

		// Okay!!!!! NOW we can call the command.
		res = root.Call(req)

	}

	if cmd.PostRun != nil {
		cmd.PostRun(req, res)
	}

	return res, nil
}

func getRepoPath(req cmds.Request) (string, error) {
	repoOpt, found, err := req.Option("config").String()
	if err != nil {
		return "", err
	}
	if found && repoOpt != "" {
		return repoOpt, nil
	}

	repoPath, err := fsrepo.BestKnownPath()
	if err != nil {
		return "", err
	}
	return repoPath, nil
}

// serveHTTPGateway collects options, creates listener, prints status message and starts serving requests
func serveHTTPGateway(req cmds.Request) (error, <-chan error) {
	cfg, err := req.InvocContext().GetConfig()
	if err != nil {
		return fmt.Errorf("serveHTTPGateway: GetConfig() failed: %s", err), nil
	}

	gatewayMaddr, err := ma.NewMultiaddr(cfg.Addresses.Gateway)
	if err != nil {
		return fmt.Errorf("serveHTTPGateway: invalid gateway address: %q (err: %s)", cfg.Addresses.Gateway, err), nil
	}

	writable, writableOptionFound, err := req.Option(writableKwd).Bool()
	if err != nil {
		return fmt.Errorf("serveHTTPGateway: req.Option(%s) failed: %s", writableKwd, err), nil
	}
	if !writableOptionFound {
		writable = cfg.Gateway.Writable
	}

	gwLis, err := manet.Listen(gatewayMaddr)
	if err != nil {
		return fmt.Errorf("serveHTTPGateway: manet.Listen(%s) failed: %s", gatewayMaddr, err), nil
	}
	// we might have listened to /tcp/0 - lets see what we are listing on
	gatewayMaddr = gwLis.Multiaddr()

	if writable {
		fmt.Printf("Gateway (writable) server listening on %s\n", gatewayMaddr)
	} else {
		fmt.Printf("Gateway (readonly) server listening on %s\n", gatewayMaddr)
	}

	var opts = []corehttp.ServeOption{
		corehttp.CommandsROOption(*req.InvocContext()),
		corehttp.VersionOption(),
		corehttp.IPNSHostnameOption(),
		corehttp.GatewayOption(writable),
	}

	if len(cfg.Gateway.RootRedirect) > 0 {
		opts = append(opts, corehttp.RedirectOption("", cfg.Gateway.RootRedirect))
	}

	node, err := req.InvocContext().ConstructNode()
	if err != nil {
		return fmt.Errorf("serveHTTPGateway: ConstructNode() failed: %s", err), nil
	}

	errc := make(chan error)
	go func() {
		errc <- corehttp.Serve(node, gwLis.NetListener(), opts...)
		close(errc)
	}()
	return nil, errc
}

func tourRunFunc(req cmds.Request, res cmds.Response) {

	cfg, err := req.InvocContext().GetConfig()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	id := tour.TopicID(cfg.Tour.Last)
	if len(req.Arguments()) > 0 {
		id = tour.TopicID(req.Arguments()[0])
	}

	w := new(bytes.Buffer)
	t, err := tourGet(id)
	if err != nil {

		// If no topic exists for this id, we handle this error right here.
		// To help the user achieve the task, we construct a response
		// comprised of...
		// 1) a simple error message
		// 2) the full list of topics

		fmt.Fprintln(w, "ERROR")
		fmt.Fprintln(w, err)
		fmt.Fprintln(w, "")
		fprintTourList(w, tour.TopicID(cfg.Tour.Last))
		res.SetOutput(w)

		return
	}

	fprintTourShow(w, t)
	res.SetOutput(w)
}

func getQuery(req cmds.Request) (string, error) {
	query := url.Values{}
	for k, v := range req.Options() {
		str := fmt.Sprintf("%v", v)
		query.Set(k, str)
	}

	args := req.Arguments()
	argDefs := req.Command().Arguments

	argDefIndex := 0

	for _, arg := range args {
		argDef := argDefs[argDefIndex]
		// skip ArgFiles
		for argDef.Type == cmds.ArgFile {
			argDefIndex++
			argDef = argDefs[argDefIndex]
		}

		query.Add("arg", arg)

		if len(argDefs) > argDefIndex+1 {
			argDefIndex++
		}
	}

	return query.Encode(), nil
}

// read json objects off of the given stream, and write the objects out to
// the 'out' channel
func readStreamedJson(req cmds.Request, rr io.Reader, out chan<- interface{}) {
	defer close(out)
	dec := json.NewDecoder(rr)
	outputType := reflect.TypeOf(req.Command().Type)

	ctx := req.Context()

	for {
		v, err := decodeTypedVal(outputType, dec)
		if err != nil {
			if err != io.EOF {
				log.Error(err)
			}
			return
		}

		select {
		case <-ctx.Done():
			return
		case out <- v:
		}
	}
}

func getBlockForKey(req cmds.Request, skey string) (*blocks.Block, error) {
	n, err := req.InvocContext().GetNode()
	if err != nil {
		return nil, err
	}

	if !u.IsValidHash(skey) {
		return nil, errors.New("Not a valid hash")
	}

	h, err := mh.FromB58String(skey)
	if err != nil {
		return nil, err
	}

	k := key.Key(h)
	b, err := n.Blocks.GetBlock(req.Context(), k)
	if err != nil {
		return nil, err
	}

	log.Debugf("ipfs block: got block with key: %q", b.Key())
	return b, nil
}

func rmLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 3 {
		return "", fmt.Errorf("not enough arguments for rm-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]

	e := dagutils.NewDagEditor(nd.DAG, root)

	err = e.RmLink(req.Context(), path)
	if err != nil {
		return "", err
	}

	nnode := e.GetNode()

	return nnode.Key()
}

func setDataCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 3 {
		return "", fmt.Errorf("not enough arguments for set-data")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	root.Data = []byte(req.Arguments()[2])

	newkey, err := nd.DAG.Add(root)
	if err != nil {
		return "", err
	}

	return newkey, nil
}

func (c *client) Send(req cmds.Request) (cmds.Response, error) {

	if req.Context() == nil {
		log.Warningf("no context set in request")
		if err := req.SetRootContext(context.TODO()); err != nil {
			return nil, err
		}
	}

	// save user-provided encoding
	previousUserProvidedEncoding, found, err := req.Option(cmds.EncShort).String()
	if err != nil {
		return nil, err
	}

	// override with json to send to server
	req.SetOption(cmds.EncShort, cmds.JSON)

	// stream channel output
	req.SetOption(cmds.ChanOpt, "true")

	query, err := getQuery(req)
	if err != nil {
		return nil, err
	}

	var fileReader *MultiFileReader
	var reader io.Reader

	if req.Files() != nil {
		fileReader = NewMultiFileReader(req.Files(), true)
		reader = fileReader
	} else {
		// if we have no file data, use an empty Reader
		// (http.NewRequest panics when a nil Reader is used)
		reader = strings.NewReader("")
	}

	path := strings.Join(req.Path(), "/")
	url := fmt.Sprintf(ApiUrlFormat, c.serverAddress, ApiPath, path, query)

	httpReq, err := http.NewRequest("POST", url, reader)
	if err != nil {
		return nil, err
	}

	// TODO extract string consts?
	if fileReader != nil {
		httpReq.Header.Set(contentTypeHeader, "multipart/form-data; boundary="+fileReader.Boundary())
		httpReq.Header.Set(contentDispHeader, "form-data: name=\"files\"")
	} else {
		httpReq.Header.Set(contentTypeHeader, applicationOctetStream)
	}
	version := config.CurrentVersionNumber
	httpReq.Header.Set(uaHeader, fmt.Sprintf("/go-ipfs/%s/", version))

	ec := make(chan error, 1)
	rc := make(chan cmds.Response, 1)
	dc := req.Context().Done()

	go func() {
		httpRes, err := c.httpClient.Do(httpReq)
		if err != nil {
			ec <- err
			return
		}

		// using the overridden JSON encoding in request
		res, err := getResponse(httpRes, req)
		if err != nil {
			ec <- err
			return
		}

		rc <- res
	}()

	for {
		select {
		case <-dc:
			log.Debug("Context cancelled, cancelling HTTP request...")
			tr := http.DefaultTransport.(*http.Transport)
			tr.CancelRequest(httpReq)
			dc = nil // Wait for ec or rc
		case err := <-ec:
			return nil, err
		case res := <-rc:
			if found && len(previousUserProvidedEncoding) > 0 {
				// reset to user provided encoding after sending request
				// NB: if user has provided an encoding but it is the empty string,
				// still leave it as JSON.
				req.SetOption(cmds.EncShort, previousUserProvidedEncoding)
			}
			return res, nil
		}
	}
}

// getResponse decodes a http.Response to create a cmds.Response
func getResponse(httpRes *http.Response, req cmds.Request) (cmds.Response, error) {
	var err error
	res := cmds.NewResponse(req)

	contentType := httpRes.Header.Get(contentTypeHeader)
	contentType = strings.Split(contentType, ";")[0]

	lengthHeader := httpRes.Header.Get(contentLengthHeader)
	if len(lengthHeader) > 0 {
		length, err := strconv.ParseUint(lengthHeader, 10, 64)
		if err != nil {
			return nil, err
		}
		res.SetLength(length)
	}

	rr := &httpResponseReader{httpRes}
	res.SetCloser(rr)

	if contentType != applicationJson {
		// for all non json output types, just stream back the output
		res.SetOutput(rr)
		return res, nil

	} else if len(httpRes.Header.Get(channelHeader)) > 0 {
		// if output is coming from a channel, decode each chunk
		outChan := make(chan interface{})

		go readStreamedJson(req, rr, outChan)

		res.SetOutput((<-chan interface{})(outChan))
		return res, nil
	}

	dec := json.NewDecoder(rr)

	// If we ran into an error
	if httpRes.StatusCode >= http.StatusBadRequest {
		e := cmds.Error{}

		switch {
		case httpRes.StatusCode == http.StatusNotFound:
			// handle 404s
			e.Message = "Command not found."
			e.Code = cmds.ErrClient

		case contentType == plainText:
			// handle non-marshalled errors
			mes, err := ioutil.ReadAll(rr)
			if err != nil {
				return nil, err
			}
			e.Message = string(mes)
			e.Code = cmds.ErrNormal

		default:
			// handle marshalled errors
			err = dec.Decode(&e)
			if err != nil {
				return nil, err
			}
		}

		res.SetError(e, e.Code)

		return res, nil
	}

	outputType := reflect.TypeOf(req.Command().Type)
	v, err := decodeTypedVal(outputType, dec)
	if err != nil && err != io.EOF {
		return nil, err
	}

	res.SetOutput(v)

	return res, nil
}

func addLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 4 {
		return "", fmt.Errorf("not enough arguments for add-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]
	childk := key.B58KeyDecode(req.Arguments()[3])

	create, _, err := req.Option("create").Bool()
	if err != nil {
		return "", err
	}

	var createfunc func() *dag.Node
	if create {
		createfunc = func() *dag.Node {
			return &dag.Node{Data: ft.FolderPBData()}
		}
	}

	e := dagutils.NewDagEditor(nd.DAG, root)

	childnd, err := nd.DAG.Get(req.Context(), childk)
	if err != nil {
		return "", err
	}

	err = e.InsertNodeAtPath(req.Context(), path, childnd, createfunc)
	if err != nil {
		return "", err
	}

	nnode := e.GetNode()

	return nnode.Key()
}

func daemonFunc(req cmds.Request, res cmds.Response) {
	// let the user know we're going.
	fmt.Printf("Initializing daemon...\n")

	ctx := req.InvocContext()

	go func() {
		select {
		case <-req.Context().Done():
			fmt.Println("Received interrupt signal, shutting down...")
		}
	}()

	// check transport encryption flag.
	unencrypted, _, _ := req.Option(unencryptTransportKwd).Bool()
	if unencrypted {
		log.Warningf(`Running with --%s: All connections are UNENCRYPTED.
		You will not be able to connect to regular encrypted networks.`, unencryptTransportKwd)
		conn.EncryptConnections = false
	}

	// first, whether user has provided the initialization flag. we may be
	// running in an uninitialized state.
	initialize, _, err := req.Option(initOptionKwd).Bool()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	if initialize {

		// now, FileExists is our best method of detecting whether IPFS is
		// configured. Consider moving this into a config helper method
		// `IsInitialized` where the quality of the signal can be improved over
		// time, and many call-sites can benefit.
		if !util.FileExists(req.InvocContext().ConfigRoot) {
			err := initWithDefaults(os.Stdout, req.InvocContext().ConfigRoot)
			if err != nil {
				res.SetError(err, cmds.ErrNormal)
				return
			}
		}
	}

	// acquire the repo lock _before_ constructing a node. we need to make
	// sure we are permitted to access the resources (datastore, etc.)
	repo, err := fsrepo.Open(req.InvocContext().ConfigRoot)
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	cfg, err := ctx.GetConfig()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	// Start assembling node config
	ncfg := &core.BuildCfg{
		Online: true,
		Repo:   repo,
	}

	routingOption, _, err := req.Option(routingOptionKwd).String()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}
	if routingOption == routingOptionSupernodeKwd {
		servers, err := cfg.SupernodeRouting.ServerIPFSAddrs()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			repo.Close() // because ownership hasn't been transferred to the node
			return
		}
		var infos []peer.PeerInfo
		for _, addr := range servers {
			infos = append(infos, peer.PeerInfo{
				ID:    addr.ID(),
				Addrs: []ma.Multiaddr{addr.Transport()},
			})
		}

		ncfg.Routing = corerouting.SupernodeClient(infos...)
	}

	node, err := core.NewNode(req.Context(), ncfg)
	if err != nil {
		log.Error("error from node construction: ", err)
		res.SetError(err, cmds.ErrNormal)
		return
	}

	printSwarmAddrs(node)

	defer func() {
		// We wait for the node to close first, as the node has children
		// that it will wait for before closing, such as the API server.
		node.Close()
//.........这里部分代码省略.........

// serveHTTPApi collects options, creates listener, prints status message and starts serving requests
func serveHTTPApi(req cmds.Request) (error, <-chan error) {
	cfg, err := req.InvocContext().GetConfig()
	if err != nil {
		return fmt.Errorf("serveHTTPApi: GetConfig() failed: %s", err), nil
	}

	apiAddr, _, err := req.Option(commands.ApiOption).String()
	if err != nil {
		return fmt.Errorf("serveHTTPApi: %s", err), nil
	}
	if apiAddr == "" {
		apiAddr = cfg.Addresses.API
	}
	apiMaddr, err := ma.NewMultiaddr(apiAddr)
	if err != nil {
		return fmt.Errorf("serveHTTPApi: invalid API address: %q (err: %s)", apiAddr, err), nil
	}

	apiLis, err := manet.Listen(apiMaddr)
	if err != nil {
		return fmt.Errorf("serveHTTPApi: manet.Listen(%s) failed: %s", apiMaddr, err), nil
	}
	// we might have listened to /tcp/0 - lets see what we are listing on
	apiMaddr = apiLis.Multiaddr()
	fmt.Printf("API server listening on %s\n", apiMaddr)

	unrestricted, _, err := req.Option(unrestrictedApiAccessKwd).Bool()
	if err != nil {
		return fmt.Errorf("serveHTTPApi: Option(%s) failed: %s", unrestrictedApiAccessKwd, err), nil
	}

	apiGw := corehttp.NewGateway(corehttp.GatewayConfig{
		Writable: true,
		BlockList: &corehttp.BlockList{
			Decider: func(s string) bool {
				if unrestricted {
					return true
				}
				// for now, only allow paths in the WebUI path
				for _, webuipath := range corehttp.WebUIPaths {
					if strings.HasPrefix(s, webuipath) {
						return true
					}
				}
				return false
			},
		},
	})
	var opts = []corehttp.ServeOption{
		corehttp.CommandsOption(*req.InvocContext()),
		corehttp.WebUIOption,
		apiGw.ServeOption(),
		corehttp.VersionOption(),
		defaultMux("/debug/vars"),
		defaultMux("/debug/pprof/"),
		corehttp.LogOption(),
		corehttp.PrometheusOption("/debug/metrics/prometheus"),
	}

	if len(cfg.Gateway.RootRedirect) > 0 {
		opts = append(opts, corehttp.RedirectOption("", cfg.Gateway.RootRedirect))
	}

	node, err := req.InvocContext().ConstructNode()
	if err != nil {
		return fmt.Errorf("serveHTTPApi: ConstructNode() failed: %s", err), nil
	}

	if err := node.Repo.SetAPIAddr(apiMaddr.String()); err != nil {
		return fmt.Errorf("serveHTTPApi: SetAPIAddr() failed: %s", err), nil
	}

	errc := make(chan error)
	go func() {
		errc <- corehttp.Serve(node, apiLis.NetListener(), opts...)
		close(errc)
	}()
	return nil, errc
}