Initial commit: email-openclaw bridge v1

Full pipeline: IMAP ingress -> OpenClaw dispatch -> callback -> SMTP reply.
SQLite stateful storage with idempotency, threading, and retry logic.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/config/config.go

@@ -0,0 +1,111 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/joho/godotenv"
+)
+
+// Config holds all application configuration loaded from environment variables.
+type Config struct {
+	// IMAP settings
+	IMAPHost string
+	IMAPPort string
+	IMAPUser string
+	IMAPPass string
+
+	// SMTP settings
+	SMTPHost string
+	SMTPPort string
+	SMTPUser string
+	SMTPPass string
+
+	// OpenClaw settings
+	OpenClawURL    string
+	OpenClawAPIKey string
+
+	// Bridge settings
+	BridgeCallbackToken string
+	SystemEmail         string
+	WhitelistEmails     []string
+
+	// Optional
+	IMAPProxyURL string
+
+	// Server
+	ListenAddr string
+}
+
+// Load reads .env (if present) and populates Config from environment variables.
+// Returns an error if any required variable is missing.
+func Load() (*Config, error) {
+	// Best-effort load .env — ignore error if file doesn't exist.
+	_ = godotenv.Load()
+
+	cfg := &Config{
+		IMAPHost:            os.Getenv("IMAP_HOST"),
+		IMAPPort:            os.Getenv("IMAP_PORT"),
+		IMAPUser:            os.Getenv("IMAP_USER"),
+		IMAPPass:            os.Getenv("IMAP_PASS"),
+		SMTPHost:            os.Getenv("SMTP_HOST"),
+		SMTPPort:            os.Getenv("SMTP_PORT"),
+		SMTPUser:            os.Getenv("SMTP_USER"),
+		SMTPPass:            os.Getenv("SMTP_PASS"),
+		OpenClawURL:         os.Getenv("OPENCLAW_URL"),
+		OpenClawAPIKey:      os.Getenv("OPENCLAW_API_KEY"),
+		BridgeCallbackToken: os.Getenv("BRIDGE_CALLBACK_TOKEN"),
+		SystemEmail:         os.Getenv("SYSTEM_EMAIL"),
+		IMAPProxyURL:        os.Getenv("IMAP_PROXY_URL"),
+		ListenAddr:          os.Getenv("LISTEN_ADDR"),
+	}
+
+	if raw := os.Getenv("WHITELIST_EMAILS"); raw != "" {
+		for _, email := range strings.Split(raw, ",") {
+			if trimmed := strings.TrimSpace(email); trimmed != "" {
+				cfg.WhitelistEmails = append(cfg.WhitelistEmails, trimmed)
+			}
+		}
+	}
+
+	if cfg.ListenAddr == "" {
+		cfg.ListenAddr = ":8080"
+	}
+
+	if err := cfg.validate(); err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+// validate checks that all required configuration values are present.
+func (c *Config) validate() error {
+	required := map[string]string{
+		"IMAP_HOST":              c.IMAPHost,
+		"IMAP_PORT":              c.IMAPPort,
+		"IMAP_USER":              c.IMAPUser,
+		"IMAP_PASS":              c.IMAPPass,
+		"SMTP_HOST":              c.SMTPHost,
+		"SMTP_PORT":              c.SMTPPort,
+		"SMTP_USER":              c.SMTPUser,
+		"SMTP_PASS":              c.SMTPPass,
+		"OPENCLAW_URL":           c.OpenClawURL,
+		"BRIDGE_CALLBACK_TOKEN":  c.BridgeCallbackToken,
+		"SYSTEM_EMAIL":           c.SystemEmail,
+	}
+
+	var missing []string
+	for name, val := range required {
+		if val == "" {
+			missing = append(missing, name)
+		}
+	}
+
+	if len(missing) > 0 {
+		return fmt.Errorf("missing required config: %s", strings.Join(missing, ", "))
+	}
+
+	return nil
+}