wip refactoring: better logging and error systems

internal/pkg/config/config.go

@@ -0,0 +1,122 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	defaultWaitTimeoutEnvVar  = "DEFAULT_WAIT_TIMEOUT"
+	defaultListenPortEnvVar   = "DEFAULT_LISTEN_PORT"
+	disableGoogleChromeEnvVar = "DISABLE_GOOGLE_CHROME"
+	disableUnoconvEnvVar      = "DISABLE_UNOCONV"
+	logLevelEnvVar            = "LOG_LEVEL"
+)
+
+type Config struct {
+	defaultWaitTimeout     float64
+	defaultListenPort      string
+	enableChromeEndpoints  bool
+	enableUnoconvEndpoints bool
+	logLevel               log.Level
+}
+
+func defaultConfig() *Config {
+	return &Config{
+		defaultWaitTimeout:     10,
+		defaultListenPort:      "3000",
+		enableChromeEndpoints:  true,
+		enableUnoconvEndpoints: true,
+		logLevel:               log.InfoLevel,
+	}
+}
+
+func FromEnv() (*Config, error) {
+	c := defaultConfig()
+	defaultWaitTimeout, err := defaultWaitTimeoutFromEnv(defaultWaitTimeoutEnvVar, c.DefaultWaitTimeout())
+	c.defaultWaitTimeout = defaultWaitTimeout
+	if err != nil {
+		return c, err
+	}
+	defaultListenPort, err := defaultListenPortFromEnv(defaultListenPortEnvVar, c.DefaultListenPort())
+	c.defaultListenPort = defaultListenPort
+	if err != nil {
+		return c, err
+	}
+	disableChromeEndpoints, err := boolFromEnv(disableGoogleChromeEnvVar, c.EnableChromeEndpoints())
+	c.enableChromeEndpoints = !disableChromeEndpoints
+	if err != nil {
+		return c, err
+	}
+	disableUnoconvEndpoints, err := boolFromEnv(disableUnoconvEnvVar, c.EnableUnoconvEndpoints())
+	c.enableUnoconvEndpoints = !disableUnoconvEndpoints
+	if err != nil {
+		return c, err
+	}
+	logLevel, err := logLevelFromEnv(logLevelEnvVar, c.LogLevel())
+	c.logLevel = logLevel
+	if err != nil {
+		return c, err
+	}
+	return c, nil
+}
+
+func (c *Config) DefaultWaitTimeout() float64  { return c.defaultWaitTimeout }
+func (c *Config) DefaultListenPort() string    { return c.defaultListenPort }
+func (c *Config) EnableChromeEndpoints() bool  { return c.enableChromeEndpoints }
+func (c *Config) EnableUnoconvEndpoints() bool { return c.enableUnoconvEndpoints }
+func (c *Config) LogLevel() log.Level          { return c.logLevel }
+
+func defaultWaitTimeoutFromEnv(envVar string, defaultValue float64) (float64, error) {
+	if v, ok := os.LookupEnv(envVar); ok {
+		waitTimeout, err := strconv.ParseFloat(v, 64)
+		if err != nil {
+			return defaultValue, fmt.Errorf("%s: wrong value: want float got %v", envVar, err)
+		}
+		return waitTimeout, nil
+	}
+	return defaultValue, nil
+}
+
+func defaultListenPortFromEnv(envVar string, defaultValue string) (string, error) {
+	if v, ok := os.LookupEnv(envVar); ok {
+		portAsUint, err := strconv.ParseUint(v, 10, 64)
+		if err != nil {
+			return defaultValue, fmt.Errorf("%s: wrong value: want uint got %v", envVar, err)
+		}
+		if portAsUint > 65535 {
+			return defaultValue, fmt.Errorf("%s: wrong value: want uint < 65535 got %d", envVar, portAsUint)
+		}
+		return v, nil
+	}
+	return defaultValue, nil
+}
+
+func boolFromEnv(envVar string, defaultValue bool) (bool, error) {
+	if v, ok := os.LookupEnv(envVar); ok {
+		if v != "1" && v != "0" {
+			return defaultValue, fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %s", envVar, v)
+		}
+		return v == "1", nil
+	}
+	return defaultValue, nil
+}
+
+func logLevelFromEnv(envVar string, defaultValue log.Level) (log.Level, error) {
+	if v, ok := os.LookupEnv(envVar); ok {
+		switch v {
+		case "DEBUG":
+			return log.DebugLevel, nil
+		case "INFO":
+			return log.InfoLevel, nil
+		case "ERROR":
+			return log.ErrorLevel, nil
+		default:
+			return defaultValue, fmt.Errorf("%s: wrong value: want \"DEBUG\",\"INFO\" or \"ERROR\" got %s", envVar, v)
+		}
+	}
+	return defaultValue, nil
+}

internal/pkg/config/doc.go

@@ -0,0 +1 @@
+package config