package main

import (
	"errors"
	"fmt"
	_ "strconv"
	"strings"
)

// Configuration errors
var ErrUndefined = errors.New("value not defined")

type ConfigError struct {
	Key	string
	Value	interface{}
	Err	error
}

func (e *ConfigError) Error() string {
	return fmt.Sprintf("Error in configuration for %s: %s",
		e.Key, e.Err.Error())
}

func (e *ConfigError) Unwrap() error { return e.Err }

func undefinedError(key string) *ConfigError {
	return &ConfigError{key, nil, ErrUndefined}
}

// Get the first host port from a service
func (s ServiceConfig) GetHostPort() (string, error) {
	if s.Ports == nil {
		return "", undefinedError("ports")
	}

	ports := strings.Split(s.Ports[0], ":")
	if len(ports) == 0 {
		return "", undefinedError("ports")
	}

	return ports[0], nil
}