Refactor: Define FSM state constants inside the public package

1 files changed, 237 insertions, 0 deletions

diff --git a/fsm.go b/fsm.go
new file mode 100644
index 0000000..31ed30b
--- /dev/null
+++ b/fsm.go
@@ -0,0 +1,237 @@
+package eduvpn
+
+import (
+	"errors"
+	"fmt"
+        "github.com/jwijenbergh/eduvpn-common/internal/fsm"
+        "github.com/jwijenbergh/eduvpn-common/internal/types"
+)
+
+type FSMStateID = fsm.FSMStateID
+type FSMStates = fsm.FSMStates
+type FSMState = fsm.FSMState
+type FSMTransition = fsm.FSMTransition
+
+const (
+	// Deregistered means the app is not registered with the wrapper
+	STATE_DEREGISTERED FSMStateID = iota
+
+	// No Server means the user has not chosen a server yet
+	STATE_NO_SERVER
+
+	// The user selected a Secure Internet server but needs to choose a location
+	STATE_ASK_LOCATION
+
+	// The user is currently selecting a server in the UI
+	STATE_SEARCH_SERVER
+
+	// We are loading the server details
+	STATE_LOADING_SERVER
+
+	// Chosen Server means the user has chosen a server to connect to
+	STATE_CHOSEN_SERVER
+
+	// OAuth Started means the OAuth process has started
+	STATE_OAUTH_STARTED
+
+	// Authorized means the OAuth process has finished and the user is now authorized with the server
+	STATE_AUTHORIZED
+
+	// Requested config means the user has requested a config for connecting
+	STATE_REQUEST_CONFIG
+
+	// Ask profile means the go code is asking for a profile selection from the UI
+	STATE_ASK_PROFILE
+
+	// Disconnected means the user has gotten a config for a server but is not connected yet
+	STATE_DISCONNECTED
+
+	// Disconnecting means the OS is disconnecting and the Go code is doing the /disconnect
+	STATE_DISCONNECTING
+
+	// Connecting means the OS is establishing a connection to the server
+	STATE_CONNECTING
+
+	// Connected means the user has been connected to the server
+	STATE_CONNECTED
+)
+
+func GetStateName(s FSMStateID) string {
+	switch s {
+	case STATE_DEREGISTERED:
+		return "Deregistered"
+	case STATE_NO_SERVER:
+		return "No_Server"
+	case STATE_ASK_LOCATION:
+		return "Ask_Location"
+	case STATE_SEARCH_SERVER:
+		return "Search_Server"
+	case STATE_LOADING_SERVER:
+		return "Loading_Server"
+	case STATE_CHOSEN_SERVER:
+		return "Chosen_Server"
+	case STATE_OAUTH_STARTED:
+		return "OAuth_Started"
+	case STATE_DISCONNECTED:
+		return "Disconnected"
+	case STATE_REQUEST_CONFIG:
+		return "Request_Config"
+	case STATE_ASK_PROFILE:
+		return "Ask_Profile"
+	case STATE_AUTHORIZED:
+		return "Authorized"
+	case STATE_DISCONNECTING:
+		return "Disconnecting"
+	case STATE_CONNECTING:
+		return "Connecting"
+	case STATE_CONNECTED:
+		return "Connected"
+	default:
+		panic("unknown conversion of state to string")
+	}
+}
+
+func newFSM(name string, callback func(FSMStateID, FSMStateID, interface{}), directory string, debug bool) fsm.FSM {
+	states := FSMStates{
+		STATE_DEREGISTERED: FSMState{Transitions: []FSMTransition{{STATE_NO_SERVER, "Client registers"}}},
+		STATE_NO_SERVER: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_NO_SERVER, "Reload list"},
+				{STATE_CHOSEN_SERVER, "User chooses a server"},
+				{STATE_SEARCH_SERVER, "The user is trying to choose a Server in the UI"},
+				{STATE_CONNECTED, "The user is already connected"},
+				{STATE_ASK_LOCATION, "Change the location in the main screen"},
+			},
+		},
+		STATE_SEARCH_SERVER: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_LOADING_SERVER, "User clicks a server in the UI"},
+				{STATE_NO_SERVER, "Cancel or Error"},
+			},
+			BackState: STATE_NO_SERVER,
+		},
+		STATE_ASK_LOCATION: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_CHOSEN_SERVER, "Location chosen"},
+				{STATE_NO_SERVER, "Go back or Error"},
+				{STATE_SEARCH_SERVER, "Cancel or Error"},
+			},
+		},
+		STATE_LOADING_SERVER: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_CHOSEN_SERVER, "Server info loaded"},
+				{
+					STATE_ASK_LOCATION,
+					"User chooses a Secure Internet server but no location is configured",
+				},
+				{STATE_NO_SERVER, "Go back or Error"},
+			},
+			BackState: STATE_NO_SERVER,
+		},
+		STATE_CHOSEN_SERVER: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_AUTHORIZED, "Found tokens in config"},
+				{STATE_OAUTH_STARTED, "No tokens found in config"},
+			},
+		},
+		STATE_OAUTH_STARTED: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_AUTHORIZED, "User authorizes with browser"},
+				{STATE_NO_SERVER, "Cancel or Error"},
+				{STATE_SEARCH_SERVER, "Cancel or Error"},
+			},
+			BackState: STATE_NO_SERVER,
+		},
+		STATE_AUTHORIZED: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_OAUTH_STARTED, "Re-authorize with OAuth"},
+				{STATE_REQUEST_CONFIG, "Client requests a config"},
+			},
+		},
+		STATE_REQUEST_CONFIG: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_ASK_PROFILE, "Multiple profiles found and no profile chosen"},
+				{STATE_DISCONNECTED, "Only one profile or profile already chosen"},
+				{STATE_NO_SERVER, "Cancel or Error"},
+				{STATE_OAUTH_STARTED, "Re-authorize"},
+			},
+		},
+		STATE_ASK_PROFILE: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_DISCONNECTED, "User chooses profile"},
+				{STATE_NO_SERVER, "Cancel or Error"},
+				{STATE_SEARCH_SERVER, "Cancel or Error"},
+			},
+		},
+		STATE_DISCONNECTED: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_CONNECTING, "OS reports it is trying to connect"},
+				{STATE_REQUEST_CONFIG, "User reconnects"},
+				{STATE_NO_SERVER, "User wants to choose a new server"},
+				{STATE_OAUTH_STARTED, "Re-authorize with OAuth"},
+			},
+			BackState: STATE_NO_SERVER,
+		},
+		STATE_DISCONNECTING: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_DISCONNECTED, "Cancel or Error"},
+				{STATE_DISCONNECTED, "Done disconnecting"},
+			},
+		},
+		STATE_CONNECTING: FSMState{
+			Transitions: []FSMTransition{
+				{STATE_DISCONNECTED, "Cancel or Error"},
+				{STATE_CONNECTED, "Done connecting"},
+			},
+		},
+		STATE_CONNECTED: FSMState{
+			Transitions: []FSMTransition{{STATE_DISCONNECTING, "App wants to disconnect"}},
+		},
+	}
+	returnedFSM := fsm.FSM{}
+	returnedFSM.Init(name, STATE_DEREGISTERED, states, callback, directory, GetStateName, debug)
+	return returnedFSM
+}
+
+type FSMDeregisteredError struct{}
+
+func (e FSMDeregisteredError) CustomError() *types.WrappedErrorMessage {
+	return &types.WrappedErrorMessage{
+		Message: "Client not registered with the GO library",
+		Err: errors.New(
+			"the current FSM state is deregistered, but the function needs a state that is not deregistered",
+		),
+	}
+}
+
+type FSMWrongStateTransitionError struct {
+	Got  FSMStateID
+	Want FSMStateID
+}
+
+func (e FSMWrongStateTransitionError) CustomError() *types.WrappedErrorMessage {
+	return &types.WrappedErrorMessage{
+		Message: "Wrong FSM transition",
+		Err: errors.New(
+			fmt.Sprintf(
+				"wrong FSM state, got: %s, want: a state with a transition to: %s",
+				GetStateName(e.Got),
+				GetStateName(e.Want),
+			),
+		),
+	}
+}
+
+type FSMWrongStateError struct {
+	Got  FSMStateID
+	Want FSMStateID
+}
+
+func (e FSMWrongStateError) CustomError() *types.WrappedErrorMessage {
+	return &types.WrappedErrorMessage{
+		Message: "Wrong FSM State",
+		Err: errors.New(
+			fmt.Sprintf("wrong FSM state, got: %s, want: %s", GetStateName(e.Got), GetStateName(e.Want)),
+		),
+	}
+}