package config

import (
	"fmt"
	"os"
)

var ERR_DUP_API error = fmt.Errorf(
	"api key and api key file cannot both be defined",
)
var ERR_NO_API error = fmt.Errorf(
	"no api key or api key file defined",
)
var ERR_NO_GROUPHOST error = fmt.Errorf(
	"no groups or hosts configured",
)
var ERR_MISSING_KEYFILE error = fmt.Errorf(
	"api key file not found",
)

func (cfg *Config) Validate() error {
	if cfg.APIKey != "" && cfg.APIKeyFile != "" {
		return ERR_DUP_API
	}

	if cfg.APIKey == "" && cfg.APIKeyFile == "" {
		return ERR_NO_API
	}

	if cfg.APIKeyFile != "" {
		if _, err := os.Stat(cfg.APIKeyFile); err != nil {
			return ERR_MISSING_KEYFILE
		}
	}

	if len(cfg.Groups) == 0 && len(cfg.Hosts) == 0 {
		return ERR_NO_GROUPHOST
	}

	set := make(map[string]bool)
	for _, host := range cfg.Hosts {
		name := host.NameOrAddress()
		if _, exists := set[name]; exists {
			return fmt.Errorf("duplicate host \"%s\"", name)
		}
		set[name] = true
	}

	for group, hosts := range cfg.Groups {
		set = make(map[string]bool)
		for _, host := range hosts {
			name := host.NameOrAddress()
			if _, exists := set[name]; exists {
				return fmt.Errorf(
					"duplicate host \"%s\" in group \"%s\"", group, name,
				)
			}
			set[name] = true
		}
	}

	return nil
}