client.go

package http

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"

	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
	manet "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr/net"

	cmds "github.com/jbenet/go-ipfs/commands"
)

const ApiPath = "/api/v0" // TODO: make configurable

func Send(req cmds.Request) (cmds.Response, error) {
	addr, err := ma.NewMultiaddr(req.Context().Config.Addresses.API)
	if err != nil {
		return nil, err
	}

	_, host, err := manet.DialArgs(addr)
	if err != nil {
		return nil, err
	}

	url := "http://" + host + ApiPath
	url += "/" + strings.Join(req.Path(), "/")

	var userEncoding string
	if enc, found := req.Option(cmds.EncShort); found {
		userEncoding = enc.(string)
		req.SetOption(cmds.EncShort, cmds.JSON)
	} else {
		enc, _ := req.Option(cmds.EncLong)
		userEncoding = enc.(string)
		req.SetOption(cmds.EncLong, cmds.JSON)
	}

	// TODO: handle multiple files with multipart
	var in io.Reader

	query := "?"
	for k, v := range req.Options() {
		query += "&" + k + "=" + v.(string)
	}

	args := req.Arguments()
	for i, arg := range args {
		if req.Command().Arguments[i].Type == cmds.ArgString {
			query += "&arg=" + arg.(string)

		} else {
			// TODO: multipart
			if in != nil {
				return nil, fmt.Errorf("Currently, only one file stream is possible per request")
			}
			in, err = os.Open(arg.(string))
			if err != nil {
				return nil, err
			}
			args[i] = in
		}
	}

	httpRes, err := http.Post(url+query, "application/octet-stream", in)
	if err != nil {
		return nil, err
	}

	res := cmds.NewResponse(req)

	contentType := httpRes.Header["Content-Type"][0]
	contentType = strings.Split(contentType, ";")[0]

	if contentType == "application/octet-stream" {
		res.SetValue(httpRes.Body)
		return res, nil
	}

	dec := json.NewDecoder(httpRes.Body)

	if httpRes.StatusCode >= http.StatusBadRequest {
		e := cmds.Error{}

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

		} else if contentType == "text/plain" {
			// handle non-marshalled errors
			buf := bytes.NewBuffer(nil)
			io.Copy(buf, httpRes.Body)
			e.Message = string(buf.Bytes())
			e.Code = cmds.ErrNormal

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

		res.SetError(e, e.Code)

	} else {
		v := req.Command().Type
		err = dec.Decode(&v)
		if err != nil {
			fmt.Println(err)
			return nil, err
		}

		res.SetValue(v)
	}

	if len(userEncoding) > 0 {
		req.SetOption(cmds.EncShort, userEncoding)
		req.SetOption(cmds.EncLong, userEncoding)
	}

	return res, nil
}