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|
package repl
import (
"bufio"
"fmt"
"os"
"os/signal"
"path/filepath"
"strings"
"syscall"
"codeberg.org/snonux/perc/internal/calculator"
"github.com/mattn/go-isatty"
"github.com/c-bata/go-prompt"
)
const historyFile = ".perc_history"
// executor runs a calculation command and returns the result
func executor(input string) {
input = strings.TrimSpace(input)
if input == "" {
return
}
// Check if it's a built-in command
if cmd, ok := isBuiltinCommand(input); ok {
output, err := ExecuteCommand(cmd)
if err != nil {
fmt.Printf("Error: %v\n", err)
}
if output != "" {
fmt.Println(output)
}
// Don't add built-in commands to history
return
}
// Run the calculation
result, err := calculator.Parse(input)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
fmt.Println(result)
}
// isBuiltinCommand checks if input starts with a built-in command
func isBuiltinCommand(input string) (string, bool) {
args := strings.Fields(input)
if len(args) == 0 {
return "", false
}
cmd := strings.ToLower(args[0])
for _, builtin := range builtinCommands {
if cmd == builtin {
return input, true
}
}
return "", false
}
// getHistoryPath returns the path to the history file
func getHistoryPath() string {
home, err := os.UserHomeDir()
if err != nil {
return ""
}
return filepath.Join(home, historyFile)
}
// loadHistory loads history from file
func loadHistory() []string {
historyPath := getHistoryPath()
if historyPath == "" {
return nil
}
file, err := os.Open(historyPath)
if err != nil {
return nil
}
defer file.Close()
var history []string
scanner := bufio.NewScanner(file)
for scanner.Scan() {
history = append(history, scanner.Text())
}
return history
}
// saveHistory saves history to file
func saveHistory(history []string) error {
historyPath := getHistoryPath()
if historyPath == "" {
return nil
}
// Keep only last 1000 entries to prevent unlimited growth
if len(history) > 1000 {
history = history[len(history)-1000:]
}
file, err := os.Create(historyPath)
if err != nil {
return err
}
defer file.Close()
writer := bufio.NewWriter(file)
for _, entry := range history {
if _, err := writer.WriteString(entry + "\n"); err != nil {
return err
}
}
return writer.Flush()
}
// RunREPL starts the interactive REPL
func RunREPL() error {
// Check if stdin is a TTY
if !isatty.IsTerminal(os.Stdin.Fd()) {
fmt.Fprintln(os.Stderr, "REPL mode requires a TTY. Use 'perc <calculation>' for non-interactive mode.")
return fmt.Errorf("stdin is not a TTY")
}
history := loadHistory()
p := prompt.New(
executor,
completer,
prompt.OptionTitle("perc - Percentage Calculator"),
prompt.OptionPrefix("perc> "),
prompt.OptionLivePrefix(func() (string, bool) {
return "perc> ", true
}),
prompt.OptionHistory(history),
)
// Handle SIGINT gracefully
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, syscall.SIGINT)
go func() {
<-sigChan
fmt.Println("\nUse 'quit' or 'exit' to exit, or Ctrl+D")
}()
// Run the prompt
p.Run()
// Note: History is not saved automatically in this version
// The prompt library stores it in memory but doesn't expose a getter
return nil
}
// completer provides auto-completion for built-in commands
func completer(d prompt.Document) []prompt.Suggest {
text := d.GetWordBeforeCursor()
if text == "" {
return nil
}
var suggestions []prompt.Suggest
for _, cmd := range builtinCommands {
if strings.HasPrefix(strings.ToLower(cmd), strings.ToLower(text)) {
suggestions = append(suggestions, prompt.Suggest{Text: cmd, Description: getCommandDescription(cmd)})
}
}
return suggestions
}
func getCommandDescription(cmd string) string {
descriptions := map[string]string{
"help": "Show help information",
"clear": "Clear the screen",
"quit": "Exit the REPL",
"exit": "Exit the REPL",
}
return descriptions[cmd]
}
|
