Add config, prompting for server connect on first run

backend/config.go

@@ -0,0 +1,85 @@
+package backend
+
+import (
+	"os"
+
+	"github.com/google/uuid"
+	"github.com/pelletier/go-toml"
+)
+
+type ServerConfig struct {
+	ID       uuid.UUID
+	Nickname string
+	Hostname string
+	Username string
+	Default  bool
+}
+
+type Config struct {
+	Servers []*ServerConfig
+}
+
+func DefaultConfig() *Config {
+	return &Config{}
+}
+
+func ReadConfigFile(filepath string) (*Config, error) {
+	f, err := os.Open(filepath)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	c := &Config{}
+	if err := toml.NewDecoder(f).Decode(c); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func (c *Config) GetDefaultServer() *ServerConfig {
+	for _, s := range c.Servers {
+		if s.Default {
+			return s
+		}
+	}
+	if len(c.Servers) > 0 {
+		return c.Servers[0]
+	}
+	return nil
+}
+
+func (c *Config) SetDefaultServer(serverID uuid.UUID) {
+	var found bool
+	for _, s := range c.Servers {
+		f := s.ID == serverID
+		if f {
+			found = true
+		}
+		s.Default = f
+	}
+	if !found && len(c.Servers) > 0 {
+		c.Servers[0].Default = true
+	}
+}
+
+func (c *Config) AddServer(nickname, hostname, username string) *ServerConfig {
+	s := &ServerConfig{
+		ID:       uuid.New(),
+		Nickname: nickname,
+		Hostname: hostname,
+		Username: username,
+	}
+	c.Servers = append(c.Servers, s)
+	return s
+}
+
+func (c *Config) WriteConfigFile(filepath string) error {
+	b, err := toml.Marshal(c)
+	if err != nil {
+		return err
+	}
+	os.WriteFile(filepath, b, 0644)
+
+	return nil
+}