feat: add support for deleting status columns

Add support for deleting status columns. If a column is not empty then
it will not be deleted and the user will see an error message in the
status bar.

Part of apollo/pelican#24

internal/board/board.go

@@ -160,11 +160,11 @@ type UpdateStatusArgs struct {
 	StatusArgs
 }
 
-// UpdateStatus modifies an existing status in the db.
+// UpdateStatus modifies an existing status in the database.
 func (b *Board) UpdateStatus(args UpdateStatusArgs) error {
 	status, err := b.Status(args.StatusID)
 	if err != nil {
-		return fmt.Errorf("unable to retrieve the status from the db. %w", err)
+		return fmt.Errorf("unable to retrieve the status from the database. %w", err)
 	}
 
 	if len(args.Name) > 0 {
@@ -182,10 +182,53 @@ func (b *Board) UpdateStatus(args UpdateStatusArgs) error {
 	return nil
 }
 
-// TODO: Finish implementation.
-// func (b *Board) DeleteStatus() error {
-// 	return nil
-// }
+// DeleteStatus deletes a status from the database.
+// A status can only be deleted if it does not contain any cards.
+func (b *Board) DeleteStatus(statusID int) error {
+	status, err := b.Status(statusID)
+	if err != nil {
+		return fmt.Errorf("unable to retrieve the status from the database; %w", err)
+	}
+
+	if len(status.CardIds) > 0 {
+		return StatusNotEmptyError{ID: statusID}
+	}
+
+	if err := db.Delete(b.db, db.StatusBucket, statusID); err != nil {
+		return fmt.Errorf("unable to delete the status from the database; %w", err)
+	}
+
+	if err := b.normaliseStatusesPositionValues(); err != nil {
+		return fmt.Errorf("unable to normalise the statuses position values; %w", err)
+	}
+
+	return nil
+}
+
+// normaliseStatusesPositionValues retrieves the ordered list of statuses from the database and sets
+// each status' positional value based on its position in the list.
+func (b *Board) normaliseStatusesPositionValues() error {
+	statuses, err := b.StatusList()
+	if err != nil {
+		return fmt.Errorf("unable to get the list of statuses; %w", err)
+	}
+
+	for i, status := range statuses {
+		updateArgs := UpdateStatusArgs{
+			StatusID: status.ID,
+			StatusArgs: StatusArgs{
+				Name:     "",
+				Position: i + 1,
+			},
+		}
+
+		if err := b.UpdateStatus(updateArgs); err != nil {
+			return fmt.Errorf("unable to update the status %q; %w", status.Name, err)
+		}
+	}
+
+	return nil
+}
 
 type MoveToStatusArgs struct {
 	CardID          int
@@ -346,18 +389,18 @@ type DeleteCardArgs struct {
 // DeleteCard deletes a card from the database.
 func (b *Board) DeleteCard(args DeleteCardArgs) error {
 	if err := db.Delete(b.db, db.CardBucket, args.CardID); err != nil {
-		return fmt.Errorf("unable to delete the card from the database, %w", err)
+		return fmt.Errorf("unable to delete the card from the database; %w", err)
 	}
 
 	status, err := b.Status(args.StatusID)
 	if err != nil {
-		return fmt.Errorf("unable to read Status '%d' from the database, %w", args.StatusID, err)
+		return fmt.Errorf("unable to read Status '%d' from the database; %w", args.StatusID, err)
 	}
 
 	status.RemoveCardID(args.CardID)
 
 	if _, err := db.Write(b.db, db.StatusBucket, &status); err != nil {
-		return fmt.Errorf("unable to update the status in the database, %w", err)
+		return fmt.Errorf("unable to update the status in the database; %w", err)
 	}
 
 	return nil

internal/board/status.go

@@ -19,6 +19,14 @@ func (e StatusNotExistError) Error() string {
 	return fmt.Sprintf("status ID '%d' does not exist in the database", e.ID)
 }
 
+type StatusNotEmptyError struct {
+	ID int
+}
+
+func (e StatusNotEmptyError) Error() string {
+	return fmt.Sprintf("status ID '%d' must contain no cards before deletion", e.ID)
+}
+
 // Status represents the status of the Kanban board.
 type Status struct {
 	ID       int

internal/board/status_lifecycle_test.go

@@ -1,6 +1,7 @@
 package board_test
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -50,13 +51,28 @@ func TestStatusLifecycle(t *testing.T) {
 	t.Run("Test Read Status (Next)", testReadStatus(kanban, statusNextExpectedID, statusNextName, statusNextExpectedBoardPosition))
 
 	t.Logf("Let us now update the names of two of our statuses...")
-	t.Run("Test Status Update (In Progress)", testUpdateStatus(kanban, 2, 2, "In Progress"))
-	t.Run("Test Status Update (Backlog)", testUpdateStatus(kanban, 1, 1, "Backlog"))
+	t.Run("Test Status Update (Doing to In Progress)", testUpdateStatus(kanban, 2, 2, "In Progress"))
+	t.Run("Test Status Update (To Do to Backlog)", testUpdateStatus(kanban, 1, 1, "Backlog"))
 
-	// (TODO: Rearranging statuses still needs to be implemented) Rearrange the board so the order is To Do, On Hold, In Progress, Done
+	// (TODO: Rearranging statuses still needs to be implemented)
+	// Rearrange the board so the order is: Backlog, Next, In Progress, On Hold, Done
 
 	t.Logf("Let us now try moving a card from one status to another...")
 	t.Run("Test Move Card To Status", testMoveCardToStatus(kanban))
+
+	// TODO: This needs to be updated when we re-arrange the board.
+	expectedPositions := map[int]string{
+		1: "Backlog",
+		2: "In Progress",
+		3: "Done",
+		4: "Next",
+	}
+
+	t.Logf("Let us now delete the 'On Hold' status from the database...")
+	t.Run("Test Delete Status (On Hold)", testDeleteEmptyStatus(kanban, statusOnHoldExpectedID, expectedPositions))
+
+	t.Logf("Additionally, let us try to delete a status that contains a card...")
+	t.Run("Test Delete a non-empty status", testDeleteNonEmptyStatus(kanban, 3))
 }
 
 func testCreateStatus(kanban board.Board, name string, position int) func(t *testing.T) {
@@ -202,3 +218,47 @@ func testMoveCardToStatus(kanban board.Board) func(t *testing.T) {
 		}
 	}
 }
+
+func testDeleteEmptyStatus(kanban board.Board, statusID int, wantPositions map[int]string) func(t *testing.T) {
+	return func(t *testing.T) {
+		t.Log("When deleting an empty status.")
+
+		err := kanban.DeleteStatus(statusID)
+		if err != nil {
+			t.Fatalf("ERROR: an error was received when attempting to delete the status from the database; %v", err)
+		}
+
+		statuses, err := kanban.StatusList()
+		if err != nil {
+			t.Fatalf("ERROR: an error was received when attempting to get the list of statuses from the database; %v", err)
+		}
+
+		gotPositions := make(map[int]string)
+		for _, status := range statuses {
+			gotPositions[status.Position] = status.Name
+		}
+
+		if !reflect.DeepEqual(wantPositions, gotPositions) {
+			t.Errorf("%s\tUnexpected positions received from the database; want: %v, got %v", failure, wantPositions, gotPositions)
+		} else {
+			t.Logf("%s\tExpected positions received from the database; got %v", success, gotPositions)
+		}
+	}
+}
+
+func testDeleteNonEmptyStatus(kanban board.Board, statusID int) func(t *testing.T) {
+	return func(t *testing.T) {
+		t.Log("When deleting a non-empty status.")
+
+		err := kanban.DeleteStatus(statusID)
+
+		switch {
+		case err == nil:
+			t.Errorf("%s\tExpected an error for deleting a non-empty status but received 'nil'", failure)
+		case errors.As(err, &board.StatusNotEmptyError{}):
+			t.Logf("%s\tExpected error received after attempting to delete a non-empty status; got: '%v'", success, err)
+		default:
+			t.Errorf("%s\tUnexpected error received after attempting to delete a non-empty status; got: '%v'", failure, err)
+		}
+	}
+}

internal/ui/init.go

@@ -24,6 +24,7 @@ func (a *App) initColumns() error {
 	}
 
 	a.columns = columns
+	a.focusedColumn = 0
 
 	return nil
 }
@@ -47,23 +48,28 @@ func (a *App) initCardForm() {
 	a.cardForm.setDoneFunc(doneFunc)
 }
 
-// initDeleteCardModal initialises the modal for deleting cards.
-func (a *App) initDeleteCardModal() {
+// initDeleteModal initialises the modal for deleting cards or statuses.
+func (a *App) initDeleteModal() {
 	doneFunc := func(_ int, buttonLabel string) {
 		if buttonLabel == "Confirm" {
-			a.deleteFocusedCard()
+			switch a.mode {
+			case normal:
+				a.deleteFocusedCard()
+			case boardEdit:
+				a.deleteFocusedStatusColumn()
+			}
 		}
 
-		a.pages.HidePage(deleteCardModalPage)
+		a.pages.HidePage(deleteModalPage)
 		a.setColumnFocus()
 	}
 
-	a.deleteCardModal.AddButtons([]string{"Confirm", "Cancel"}).SetDoneFunc(doneFunc)
+	a.deleteModal.AddButtons([]string{"Cancel", "Confirm"}).SetDoneFunc(doneFunc)
 
-	a.deleteCardModal.SetBorder(true).SetBorderColor(tcell.ColorOrangeRed)
-	a.deleteCardModal.SetBackgroundColor(tcell.ColorBlack.TrueColor())
-	a.deleteCardModal.SetButtonBackgroundColor(tcell.ColorBlueViolet.TrueColor())
-	a.deleteCardModal.SetTextColor(tcell.ColorWhite.TrueColor())
+	a.deleteModal.SetBorder(true).SetBorderColor(tcell.ColorOrangeRed)
+	a.deleteModal.SetBackgroundColor(tcell.ColorBlack.TrueColor())
+	a.deleteModal.SetButtonBackgroundColor(tcell.ColorBlueViolet.TrueColor())
+	a.deleteModal.SetTextColor(tcell.ColorWhite.TrueColor())
 }
 
 // initQuitModal initialises the quit modal.

internal/ui/keymappings.go

@@ -87,16 +87,22 @@ func (a *App) edit() {
 }
 
 func (a *App) delete() {
-	if a.mode == normal {
+	switch a.mode {
+	case normal:
 		card, ok := a.getFocusedCard()
 		if !ok {
 			return
 		}
 
-		text := fmt.Sprintf("Do you want to delete '%s'?", card.Title)
-		a.deleteCardModal.SetText(text)
-		a.pages.ShowPage(deleteCardModalPage)
-		a.SetFocus(a.deleteCardModal)
+		text := fmt.Sprintf("Do you want to delete the CARD %q?", card.Title)
+		a.deleteModal.SetText(text)
+		a.pages.ShowPage(deleteModalPage)
+		a.SetFocus(a.deleteModal)
+	case boardEdit:
+		text := fmt.Sprintf("Do you want to delete the STATUS %q?", a.focusedStatusName())
+		a.deleteModal.SetText(text)
+		a.pages.ShowPage(deleteModalPage)
+		a.SetFocus(a.deleteModal)
 	}
 }
 

internal/ui/ui.go

@@ -19,12 +19,12 @@ const (
 )
 
 const (
-	mainPage            string = "main"
-	quitPage            string = "quit"
-	cardFormPage        string = "card form"
-	deleteCardModalPage string = "delete card modal"
-	viewPage            string = "view"
-	statusFormPage      string = "status form"
+	mainPage        string = "main"
+	quitPage        string = "quit"
+	cardFormPage    string = "card form"
+	deleteModalPage string = "delete modal"
+	viewPage        string = "view"
+	statusFormPage  string = "status form"
 )
 
 const (
@@ -51,7 +51,7 @@ type App struct {
 	modeView        *modeView
 	quitModal       *tview.Modal
 	cardForm        *cardForm
-	deleteCardModal *tview.Modal
+	deleteModal     *tview.Modal
 	statusSelection statusSelection
 	cardView        *cardView
 	statusbar       *statusbar
@@ -75,7 +75,7 @@ func NewApp(path string) (App, error) {
 		focusedColumn:   0,
 		columns:         nil,
 		board:           kanban,
-		deleteCardModal: tview.NewModal(),
+		deleteModal:     tview.NewModal(),
 		mode:            normal,
 		modeView:        newModeView(),
 		statusSelection: statusSelection{0, 0, 0},
@@ -108,8 +108,8 @@ func (a *App) Init() error {
 	a.initCardForm()
 	a.pages.AddPage(cardFormPage, a.cardForm, false, false)
 
-	a.initDeleteCardModal()
-	a.pages.AddPage(deleteCardModalPage, a.deleteCardModal, false, false)
+	a.initDeleteModal()
+	a.pages.AddPage(deleteModalPage, a.deleteModal, false, false)
 
 	a.initCardView()
 	a.pages.AddPage(viewPage, a.cardView, false, false)
@@ -366,3 +366,20 @@ func (a *App) saveNewStatus(name string) {
 
 	a.refresh(refreshArgs{updateFocusedColumnOnly: false, reinitialiseColumns: true})
 }
+
+// deleteFocusedStatusColumn deletes the focused status column from the database.
+// If the column is not empty, the column will not be deleted and an error will
+// be shown in the status bar.
+func (a *App) deleteFocusedStatusColumn() {
+	statusID := a.focusedStatusID()
+
+	if err := a.board.DeleteStatus(statusID); err != nil {
+		a.statusbar.displayMessage(errorLevel, fmt.Sprintf("Failed to delete the status column: %v.", err))
+
+		return
+	}
+
+	a.statusbar.displayMessage(infoLevel, "Status deleted successfully.")
+
+	a.refresh(refreshArgs{updateFocusedColumnOnly: false, reinitialiseColumns: true})
+}