✨ feat: rewrite in Go

src/config.go

@@ -0,0 +1,142 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type PlaybackMode string
+
+const (
+	PlaybackLoop   PlaybackMode = "loop"
+	PlaybackRandom PlaybackMode = "random"
+)
+
+type Config struct {
+	Host                string
+	Port                int
+	MaxLoop             int
+	PlaybackMode        PlaybackMode
+	AllowUserControl    bool
+	SwitchDebounce      time.Duration
+	LoginDelay          time.Duration
+	MaxConnections      int
+	MaxTotalConnections int
+	MaxAuthAttempts     int
+	HandshakeTimeout    time.Duration
+	MaxDimension        int
+	FrameResolution     int
+	BrightnessThreshold int
+	Charset             string
+	Invert              bool
+	LogCredentials      bool
+}
+
+func warnInvalid(name, value string, fallback any) {
+	logWarn(fmt.Sprintf("Invalid %s=%q, using default %v", name, sanitize(value), fallback))
+}
+
+func envString(name, fallback string) string {
+	value := strings.TrimSpace(os.Getenv(name))
+	if value == "" {
+		return fallback
+	}
+	return value
+}
+
+func envInt(name string, fallback, min, max int) int {
+	raw := strings.TrimSpace(os.Getenv(name))
+	if raw == "" {
+		return fallback
+	}
+	parsed, err := strconv.Atoi(raw)
+	if err != nil {
+		warnInvalid(name, raw, fallback)
+		return fallback
+	}
+	if parsed < min {
+		return min
+	}
+	if parsed > max {
+		return max
+	}
+	return parsed
+}
+
+func envBool(name string, fallback bool) bool {
+	raw := strings.TrimSpace(os.Getenv(name))
+	if raw == "" {
+		return fallback
+	}
+	parsed, err := strconv.ParseBool(strings.ToLower(raw))
+	if err != nil {
+		warnInvalid(name, raw, fallback)
+		return fallback
+	}
+	return parsed
+}
+
+func envDurationMs(name string, fallback time.Duration) time.Duration {
+	raw := strings.TrimSpace(os.Getenv(name))
+	if raw == "" {
+		return fallback
+	}
+	ms, err := strconv.Atoi(raw)
+	if err != nil {
+		warnInvalid(name, raw, fallback)
+		return fallback
+	}
+	if ms < 0 {
+		ms = 0
+	}
+	return time.Duration(ms) * time.Millisecond
+}
+
+func envPlaybackMode(name string, fallback PlaybackMode) PlaybackMode {
+	raw := strings.TrimSpace(os.Getenv(name))
+	if raw == "" {
+		return fallback
+	}
+	switch PlaybackMode(strings.ToLower(raw)) {
+	case PlaybackLoop:
+		return PlaybackLoop
+	case PlaybackRandom:
+		return PlaybackRandom
+	}
+	warnInvalid(name, raw, fallback)
+	return fallback
+}
+
+func loadConfig() Config {
+	const maxInt = int(^uint(0) >> 1)
+	return Config{
+		Host:                envString("HOST", "0.0.0.0"),
+		Port:                envInt("PORT", 22, 1, 65535),
+		MaxLoop:             envInt("MAX_LOOP", 5, 0, maxInt),
+		PlaybackMode:        envPlaybackMode("PLAYBACK_MODE", PlaybackLoop),
+		AllowUserControl:    envBool("ALLOW_USER_CONTROL", true),
+		SwitchDebounce:      envDurationMs("SWITCH_DEBOUNCE_MS", 120*time.Millisecond),
+		LoginDelay:          envDurationMs("LOGIN_DELAY", 1500*time.Millisecond),
+		MaxConnections:      envInt("MAX_CONNECTIONS", 10, 1, maxInt),
+		MaxTotalConnections: envInt("MAX_TOTAL_CONNECTIONS", 1000, 1, maxInt),
+		MaxAuthAttempts:     envInt("MAX_AUTH_ATTEMPTS", 6, 1, maxInt),
+		HandshakeTimeout:    envDurationMs("HANDSHAKE_TIMEOUT", 10*time.Second),
+		MaxDimension:        envInt("MAX_DIMENSION", 512, 1, 4096),
+		FrameResolution:     envInt("FRAME_RESOLUTION", 360, 16, 1080),
+		BrightnessThreshold: envInt("BRIGHTNESS_THRESHOLD", 40, 0, 100),
+		Charset:             envString("CHARSET", "detailed"),
+		Invert:              envBool("INVERT", false),
+		LogCredentials:      envBool("LOG_CREDENTIALS", false),
+	}
+}
+
+func loadOptionalTextFile(filePath string) (string, bool) {
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return "", false
+	}
+	return string(data), true
+}