transport: make Endpoint an interface, fixes #362

* add internal *url.URL implementation for regular URLs.
* add internal implementation for SCP-like URLs.

10 files changed, 199 insertions, 60 deletions

diff --git a/plumbing/transport/client/client.go b/plumbing/transport/client/client.go
index a398a74..76c1469 100644
--- a/plumbing/transport/client/client.go
+++ b/plumbing/transport/client/client.go
@@ -35,13 +35,13 @@ func InstallProtocol(scheme string, c transport.Transport) {
 // http://, https://, ssh:// and file://.
 // See `InstallProtocol` to add or modify protocols.
 func NewClient(endpoint transport.Endpoint) (transport.Transport, error) {
-	f, ok := Protocols[endpoint.Scheme]
+	f, ok := Protocols[endpoint.Protocol()]
 	if !ok {
-		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Scheme)
+		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Protocol())
 	}
 
 	if f == nil {
-		return nil, fmt.Errorf("malformed client for scheme %q, client is defined as nil", endpoint.Scheme)
+		return nil, fmt.Errorf("malformed client for scheme %q, client is defined as nil", endpoint.Protocol())
 	}
 
 	return f, nil
diff --git a/plumbing/transport/common.go b/plumbing/transport/common.go
index d3cfe21..0ff9e89 100644
--- a/plumbing/transport/common.go
+++ b/plumbing/transport/common.go
@@ -18,6 +18,7 @@ import (
 	"io"
 	"net/url"
 	"regexp"
+	"strconv"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
@@ -28,7 +29,7 @@ var (
 	ErrRepositoryNotFound     = errors.New("repository not found")
 	ErrEmptyRemoteRepository  = errors.New("remote repository is empty")
 	ErrAuthenticationRequired = errors.New("authentication required")
-	ErrAuthorizationFailed	  = errors.New("authorization failed")
+	ErrAuthorizationFailed    = errors.New("authorization failed")
 	ErrEmptyUploadPackRequest = errors.New("empty git-upload-pack given")
 	ErrInvalidAuthMethod      = errors.New("invalid auth method")
 	ErrAlreadyConnected       = errors.New("session already established")
@@ -88,42 +89,134 @@ type ReceivePackSession interface {
 	ReceivePack(*packp.ReferenceUpdateRequest) (*packp.ReportStatus, error)
 }
 
-type Endpoint url.URL
-
-var (
-	isSchemeRegExp   = regexp.MustCompile("^[^:]+://")
-	scpLikeUrlRegExp = regexp.MustCompile("^(?P<user>[^@]+@)?(?P<host>[^:]+):/?(?P<path>.+)$")
-)
+// Endpoint represents a Git URL in any supported protocol.
+type Endpoint interface {
+	// Protocol returns the protocol (e.g. git, https, file). It should never
+	// return the empty string.
+	Protocol() string
+	// User returns the user or an empty string if none is given.
+	User() string
+	// Password returns the password or an empty string if none is given.
+	Password() string
+	// Host returns the host or an empty string if none is given.
+	Host() string
+	// Port returns the port or 0 if there is no port or a default should be
+	// used.
+	Port() int
+	// Path returns the repository path.
+	Path() string
+	// String returns a string representation of the Git URL.
+	String() string
+}
 
 func NewEndpoint(endpoint string) (Endpoint, error) {
-	endpoint = transformSCPLikeIfNeeded(endpoint)
+	if e, ok := parseSCPLike(endpoint); ok {
+		return e, nil
+	}
 
 	u, err := url.Parse(endpoint)
 	if err != nil {
-		return Endpoint{}, plumbing.NewPermanentError(err)
+		return nil, plumbing.NewPermanentError(err)
 	}
 
 	if !u.IsAbs() {
-		return Endpoint{}, plumbing.NewPermanentError(fmt.Errorf(
+		return nil, plumbing.NewPermanentError(fmt.Errorf(
 			"invalid endpoint: %s", endpoint,
 		))
 	}
 
-	return Endpoint(*u), nil
+	return urlEndpoint{u}, nil
+}
+
+type urlEndpoint struct {
+	*url.URL
+}
+
+func (e urlEndpoint) Protocol() string { return e.URL.Scheme }
+func (e urlEndpoint) Host() string     { return e.URL.Hostname() }
+
+func (e urlEndpoint) User() string {
+	if e.URL.User == nil {
+		return ""
+	}
+
+	return e.URL.User.Username()
+}
+
+func (e urlEndpoint) Password() string {
+	if e.URL.User == nil {
+		return ""
+	}
+
+	p, _ := e.URL.User.Password()
+	return p
+}
+
+func (e urlEndpoint) Port() int {
+	p := e.URL.Port()
+	if p == "" {
+		return 0
+	}
+
+	i, err := strconv.Atoi(e.URL.Port())
+	if err != nil {
+		return 0
+	}
+
+	return i
 }
 
-func (e *Endpoint) String() string {
-	u := url.URL(*e)
-	return u.String()
+func (e urlEndpoint) Path() string {
+	var res string = e.URL.Path
+	if e.URL.RawQuery != "" {
+		res += "?" + e.URL.RawQuery
+	}
+
+	if e.URL.Fragment != "" {
+		res += "#" + e.URL.Fragment
+	}
+
+	return res
 }
 
-func transformSCPLikeIfNeeded(endpoint string) string {
-	if !isSchemeRegExp.MatchString(endpoint) && scpLikeUrlRegExp.MatchString(endpoint) {
-		m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
-		return fmt.Sprintf("ssh://%s%s/%s", m[1], m[2], m[3])
+type scpEndpoint struct {
+	user string
+	host string
+	path string
+}
+
+func (e *scpEndpoint) Protocol() string { return "ssh" }
+func (e *scpEndpoint) User() string     { return e.user }
+func (e *scpEndpoint) Password() string { return "" }
+func (e *scpEndpoint) Host() string     { return e.host }
+func (e *scpEndpoint) Port() int        { return 22 }
+func (e *scpEndpoint) Path() string     { return e.path }
+
+func (e *scpEndpoint) String() string {
+	var user string
+	if e.user != "" {
+		user = fmt.Sprintf("%s@", e.user)
+	}
+
+	return fmt.Sprintf("%s%s:%s", user, e.host, e.path)
+}
+
+var (
+	isSchemeRegExp   = regexp.MustCompile("^[^:]+://")
+	scpLikeUrlRegExp = regexp.MustCompile("^(?:(?P<user>[^@]+)@)?(?P<host>[^:]+):/?(?P<path>.+)$")
+)
+
+func parseSCPLike(endpoint string) (Endpoint, bool) {
+	if isSchemeRegExp.MatchString(endpoint) || !scpLikeUrlRegExp.MatchString(endpoint) {
+		return nil, false
 	}
 
-	return endpoint
+	m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
+	return &scpEndpoint{
+		user: m[1],
+		host: m[2],
+		path: m[3],
+	}, true
 }
 
 // UnsupportedCapabilities are the capabilities not supported by any client
diff --git a/plumbing/transport/common_test.go b/plumbing/transport/common_test.go
index e9a5efa..ce41045 100644
--- a/plumbing/transport/common_test.go
+++ b/plumbing/transport/common_test.go
@@ -14,22 +14,70 @@ type SuiteCommon struct{}
 
 var _ = Suite(&SuiteCommon{})
 
-func (s *SuiteCommon) TestNewEndpoint(c *C) {
+func (s *SuiteCommon) TestNewEndpointHTTP(c *C) {
+	e, err := NewEndpoint("http://git:pass@github.com/user/repository.git?foo#bar")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "http")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "pass")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git?foo#bar")
+	c.Assert(e.String(), Equals, "http://git:pass@github.com/user/repository.git?foo#bar")
+}
+
+func (s *SuiteCommon) TestNewEndpointSSH(c *C) {
 	e, err := NewEndpoint("ssh://git@github.com/user/repository.git")
 	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
 	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
 }
 
+func (s *SuiteCommon) TestNewEndpointSSHNoUser(c *C) {
+	e, err := NewEndpoint("ssh://github.com/user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
+	c.Assert(e.String(), Equals, "ssh://github.com/user/repository.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointSSHWithPort(c *C) {
+	e, err := NewEndpoint("ssh://git@github.com:777/user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 777)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
+	c.Assert(e.String(), Equals, "ssh://git@github.com:777/user/repository.git")
+}
+
 func (s *SuiteCommon) TestNewEndpointSCPLike(c *C) {
 	e, err := NewEndpoint("git@github.com:user/repository.git")
 	c.Assert(err, IsNil)
-	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 22)
+	c.Assert(e.Path(), Equals, "user/repository.git")
+	c.Assert(e.String(), Equals, "git@github.com:user/repository.git")
 }
 
 func (s *SuiteCommon) TestNewEndpointWrongForgat(c *C) {
 	e, err := NewEndpoint("foo")
-	c.Assert(err, Not(IsNil))
-	c.Assert(e.Host, Equals, "")
+	c.Assert(err, NotNil)
+	c.Assert(e, IsNil)
 }
 
 func (s *SuiteCommon) TestFilterUnsupportedCapabilities(c *C) {
diff --git a/plumbing/transport/file/client.go b/plumbing/transport/file/client.go
index 58e60db..d2a57d0 100644
--- a/plumbing/transport/file/client.go
+++ b/plumbing/transport/file/client.go
@@ -41,7 +41,7 @@ func (r *runner) Command(cmd string, ep transport.Endpoint, auth transport.AuthM
 		return nil, err
 	}
 
-	return &command{cmd: exec.Command(cmd, ep.Path)}, nil
+	return &command{cmd: exec.Command(cmd, ep.Path())}, nil
 }
 
 type command struct {
diff --git a/plumbing/transport/git/common.go b/plumbing/transport/git/common.go
index 24134c1..753f125 100644
--- a/plumbing/transport/git/common.go
+++ b/plumbing/transport/git/common.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"strings"
 
 	"gopkg.in/src-d/go-git.v4/plumbing/format/pktline"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
@@ -16,6 +15,8 @@ import (
 // DefaultClient is the default git client.
 var DefaultClient = common.NewClient(&runner{})
 
+const DefaultPort = 9418
+
 type runner struct{}
 
 // Command returns a new Command for the given cmd in the given Endpoint
@@ -62,12 +63,13 @@ func (c *command) connect() error {
 }
 
 func (c *command) getHostWithPort() string {
-	host := c.endpoint.Host
-	if strings.Index(c.endpoint.Host, ":") == -1 {
-		host += ":9418"
+	host := c.endpoint.Host()
+	port := c.endpoint.Port()
+	if port <= 0 {
+		port = DefaultPort
 	}
 
-	return host
+	return fmt.Sprintf("%s:%d", host, port)
 }
 
 // StderrPipe git protocol doesn't have any dedicated error channel
@@ -88,7 +90,7 @@ func (c *command) StdoutPipe() (io.Reader, error) {
 }
 
 func endpointToCommand(cmd string, ep transport.Endpoint) string {
-	return fmt.Sprintf("%s %s%chost=%s%c", cmd, ep.Path, 0, ep.Host, 0)
+	return fmt.Sprintf("%s %s%chost=%s%c", cmd, ep.Path(), 0, ep.Host(), 0)
 }
 
 // Wait no-op function, required by the interface
diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go
index 930e8eb..04b6121 100644
--- a/plumbing/transport/http/common.go
+++ b/plumbing/transport/http/common.go
@@ -73,18 +73,12 @@ type AuthMethod interface {
 }
 
 func basicAuthFromEndpoint(ep transport.Endpoint) *BasicAuth {
-	info := ep.User
-	if info == nil {
+	u := ep.User()
+	if u == "" {
 		return nil
 	}
 
-	p, ok := info.Password()
-	if !ok {
-		return nil
-	}
-
-	u := info.Username()
-	return NewBasicAuth(u, p)
+	return NewBasicAuth(u, ep.Password())
 }
 
 // BasicAuth represent a HTTP basic auth
diff --git a/plumbing/transport/http/upload_pack.go b/plumbing/transport/http/upload_pack.go
index 8f73789..2d1ea45 100644
--- a/plumbing/transport/http/upload_pack.go
+++ b/plumbing/transport/http/upload_pack.go
@@ -150,7 +150,7 @@ func (s *upSession) doRequest(method, url string, content *bytes.Buffer) (*http.
 // it requires a bytes.Buffer, because we need to know the length
 func (s *upSession) applyHeadersToRequest(req *http.Request, content *bytes.Buffer) {
 	req.Header.Add("User-Agent", "git/1.0")
-	req.Header.Add("Host", s.endpoint.Host)
+	req.Header.Add("Host", s.endpoint.Host()) // host:port
 
 	if content == nil {
 		req.Header.Add("Accept", "*/*")
diff --git a/plumbing/transport/server/loader.go b/plumbing/transport/server/loader.go
index cfe9f04..b51a795 100644
--- a/plumbing/transport/server/loader.go
+++ b/plumbing/transport/server/loader.go
@@ -34,7 +34,7 @@ func NewFilesystemLoader(base billy.Filesystem) Loader {
 // storer for it. Returns transport.ErrRepositoryNotFound if a repository does
 // not exist in the given path.
 func (l *fsLoader) Load(ep transport.Endpoint) (storer.Storer, error) {
-	fs := l.base.Dir(ep.Path)
+	fs := l.base.Dir(ep.Path())
 	if _, err := fs.Stat("config"); err != nil {
 		return nil, transport.ErrRepositoryNotFound
 	}
diff --git a/plumbing/transport/ssh/auth_method.go b/plumbing/transport/ssh/auth_method.go
index a3e1ad1..84dfe14 100644
--- a/plumbing/transport/ssh/auth_method.go
+++ b/plumbing/transport/ssh/auth_method.go
@@ -179,9 +179,14 @@ type PublicKeysCallback struct {
 // NewSSHAgentAuth returns a PublicKeysCallback based on a SSH agent, it opens
 // a pipe with the SSH agent and uses the pipe as the implementer of the public
 // key callback function.
-func NewSSHAgentAuth(user string) (AuthMethod, error) {
-	if user == "" {
-		user = DefaultUsername
+func NewSSHAgentAuth(u string) (AuthMethod, error) {
+	if u == "" {
+		usr, err := user.Current()
+		if err != nil {
+			return nil, fmt.Errorf("error getting current user: %q", err)
+		}
+
+		u = usr.Username
 	}
 
 	sshAgentAddr := os.Getenv("SSH_AUTH_SOCK")
@@ -195,7 +200,7 @@ func NewSSHAgentAuth(user string) (AuthMethod, error) {
 	}
 
 	return &PublicKeysCallback{
-		User:     user,
+		User:     u,
 		Callback: agent.NewClient(pipe).Signers,
 	}, nil
 }
diff --git a/plumbing/transport/ssh/common.go b/plumbing/transport/ssh/common.go
index 7b44a91..d53fc12 100644
--- a/plumbing/transport/ssh/common.go
+++ b/plumbing/transport/ssh/common.go
@@ -3,7 +3,6 @@ package ssh
 
 import (
 	"fmt"
-	"strings"
 
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport/internal/common"
@@ -20,6 +19,8 @@ var DefaultAuthBuilder = func(user string) (AuthMethod, error) {
 	return NewSSHAgentAuth(user)
 }
 
+const DefaultPort = 22
+
 type runner struct{}
 
 func (r *runner) Command(cmd string, ep transport.Endpoint, auth transport.AuthMethod) (common.Command, error) {
@@ -110,25 +111,21 @@ func (c *command) connect() error {
 }
 
 func (c *command) getHostWithPort() string {
-	host := c.endpoint.Host
-	if strings.Index(c.endpoint.Host, ":") == -1 {
-		host += ":22"
+	host := c.endpoint.Host()
+	port := c.endpoint.Port()
+	if port <= 0 {
+		port = DefaultPort
 	}
 
-	return host
+	return fmt.Sprintf("%s:%d", host, port)
 }
 
 func (c *command) setAuthFromEndpoint() error {
-	var u string
-	if info := c.endpoint.User; info != nil {
-		u = info.Username()
-	}
-
 	var err error
-	c.auth, err = DefaultAuthBuilder(u)
+	c.auth, err = DefaultAuthBuilder(c.endpoint.User())
 	return err
 }
 
 func endpointToCommand(cmd string, ep transport.Endpoint) string {
-	return fmt.Sprintf("%s '%s'", cmd, ep.Path)
+	return fmt.Sprintf("%s '%s'", cmd, ep.Path())
 }