up3

server/player/scoreboard/scoreboard.go

@@ -0,0 +1,105 @@
+package scoreboard
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+)
+
+// Scoreboard represents a scoreboard that may be sent to a player. The scoreboard is shown on the right side
+// of the player's screen.
+// Scoreboard implements the io.Writer and io.StringWriter interfaces. fmt.Fprintf and fmt.Fprint may be used
+// to write formatted text to the scoreboard.
+type Scoreboard struct {
+	name       string
+	lines      []string
+	padding    bool
+	descending bool
+}
+
+// New returns a new scoreboard with the display name passed. Once returned, lines may be added to the
+// scoreboard to add text to it. The name is formatted according to the rules of fmt.Sprintln.
+// Changing the scoreboard after sending it to a player will not update the scoreboard of the player
+// automatically: Player.SendScoreboard() must be called again to update it.
+func New(name ...any) *Scoreboard {
+	return &Scoreboard{name: strings.TrimSuffix(fmt.Sprintln(name...), "\n"), padding: true}
+}
+
+// Name returns the display name of the scoreboard, as passed during the construction of the scoreboard.
+func (board *Scoreboard) Name() string {
+	return board.name
+}
+
+// Write writes a slice of data as text to the scoreboard. Newlines may be written to create a new line on
+// the scoreboard.
+func (board *Scoreboard) Write(p []byte) (n int, err error) {
+	return board.WriteString(string(p))
+}
+
+// WriteString writes a string of text to the scoreboard. Newlines may be written to create a new line on
+// the scoreboard.
+func (board *Scoreboard) WriteString(s string) (n int, err error) {
+	lines := strings.Split(s, "\n")
+	board.lines = append(board.lines, lines...)
+
+	// Scoreboards can have up to 15 lines. (16 including the title.)
+	if len(board.lines) >= 15 {
+		return len(lines), fmt.Errorf("write scoreboard: maximum of 15 lines of text exceeded")
+	}
+	return len(lines), nil
+}
+
+// Set changes a specific line in the scoreboard and adds empty lines until this index is reached. Set panics if the
+// index passed is negative or 15+.
+func (board *Scoreboard) Set(index int, s string) {
+	if index < 0 || index >= 15 {
+		panic(fmt.Sprintf("index out of range %v", index))
+	}
+	if diff := index - (len(board.lines) - 1); diff > 0 {
+		board.lines = append(board.lines, make([]string, diff)...)
+	}
+	// Remove new lines from the string
+	board.lines[index] = strings.TrimSuffix(strings.TrimSuffix(s, "\n"), "\n")
+}
+
+// Remove removes a specific line from the scoreboard. Remove panics if the index passed is negative or 15+.
+func (board *Scoreboard) Remove(index int) {
+	if index < 0 || index >= 15 {
+		panic(fmt.Sprintf("index out of range %v", index))
+	}
+	board.lines = append(board.lines[:index], board.lines[index+1:]...)
+}
+
+// RemovePadding removes the padding of one space that is added to the start of every line.
+func (board *Scoreboard) RemovePadding() {
+	board.padding = false
+}
+
+// Lines returns the data of the Scoreboard as a slice of strings.
+func (board *Scoreboard) Lines() []string {
+	lines := slices.Clone(board.lines)
+	if board.padding {
+		for i, line := range lines {
+			if len(board.name)-len(line)-2 <= 0 {
+				lines[i] = " " + line + " "
+				continue
+			}
+			lines[i] = " " + line + strings.Repeat(" ", len(board.name)-len(line)-2)
+		}
+	}
+	if board.descending {
+		slices.Reverse(lines)
+	}
+	return lines
+}
+
+// Descending returns whether the scoreboard is sorted in descending order.
+func (board *Scoreboard) Descending() bool {
+	return board.descending
+}
+
+// SetDescending sets the scoreboard sort order to descending.
+// When sending the scoreboard to the player, it will reverse the order of the lines to match when it's ascending.
+func (board *Scoreboard) SetDescending() {
+	board.descending = true
+}